Update liblmdb, unify 32/64 sources

58 files changed, 2464 insertions, 16992 deletions

diff --git a/external/db_drivers/CMakeLists.txt b/external/db_drivers/CMakeLists.txt
index 4d1b95c94..98c451ad1 100644
--- a/external/db_drivers/CMakeLists.txt
+++ b/external/db_drivers/CMakeLists.txt
@@ -29,6 +29,6 @@
 # We aren't even going to check the system for an installed LMDB driver, as it is too
 # critical a consensus component to rely on dynamically linked libraries
 message(STATUS "Using ${ARCH_WIDTH}-bit LMDB from source tree")
-add_subdirectory(liblmdb${ARCH_WIDTH})
-set(LMDB_INCLUDE "${CMAKE_CURRENT_SOURCE_DIR}/liblmdb${ARCH_WIDTH}" CACHE STRING "LMDB Include path")
+add_subdirectory(liblmdb)
+set(LMDB_INCLUDE "${CMAKE_CURRENT_SOURCE_DIR}/liblmdb" CACHE STRING "LMDB Include path")
 set(LMDB_LIBRARY "lmdb" CACHE STRING "LMDB Library name")
diff --git a/external/db_drivers/liblmdb64/.gitignore b/external/db_drivers/liblmdb/.gitignore
index d5102a87c..d5102a87c 100644
--- a/external/db_drivers/liblmdb64/.gitignore
+++ b/external/db_drivers/liblmdb/.gitignore
diff --git a/external/db_drivers/liblmdb64/CHANGES b/external/db_drivers/liblmdb/CHANGES
index 957742e75..aabb1adfd 100644
--- a/external/db_drivers/liblmdb64/CHANGES
+++ b/external/db_drivers/liblmdb/CHANGES
@@ -1,5 +1,57 @@
 LMDB 0.9 Change Log
 
+LMDB 0.9.18 Release Engineering
+	Fix robust mutex detection on glibc 2.10-11 (ITS#8330)
+	Check for utf8_to_utf16 failures (ITS#7992)
+	Catch strdup failure in mdb_dbi_open
+	Build
+		Additional makefile var tweaks (ITS#8169)
+	Documentation
+		Add Getting Started page
+
+
+LMDB 0.9.17 Release (2015/11/30)
+	Fix ITS#7377 catch calloc failure
+	Fix ITS#8237 regression from ITS#7589
+	Fix ITS#8238 page_split for DUPFIXED pages
+	Fix ITS#8221 MDB_PAGE_FULL on delete/rebalance
+	Fix ITS#8258 rebalance/split assert
+	Fix ITS#8263 cursor_put cursor tracking
+	Fix ITS#8264 cursor_del cursor tracking
+	Fix ITS#8310 cursor_del cursor tracking
+	Fix ITS#8299 mdb_del cursor tracking
+	Fix ITS#8300 mdb_del cursor tracking
+	Fix ITS#8304 mdb_del cursor tracking
+	Fix ITS#7771 fakepage cursor tracking
+	Fix ITS#7789 ensure mapsize >= pages in use
+	Fix ITS#7971 mdb_txn_renew0() new reader slots
+	Fix ITS#7969 use __sync_synchronize on non-x86
+	Fix ITS#8311 page_split from update_key
+	Fix ITS#8312 loose pages in nested txn
+	Fix ITS#8313 mdb_rebalance dummy cursor
+	Fix ITS#8315 dirty_room in nested txn
+	Fix ITS#8323 dirty_list in nested txn
+	Fix ITS#8316 page_merge cursor tracking
+	Fix ITS#8321 cursor tracking
+	Fix ITS#8319 mdb_load error messages
+	Fix ITS#8320 mdb_load plaintext input
+	Added mdb_txn_id() (ITS#7994)
+	Added robust mutex support
+	Miscellaneous cleanup/simplification
+	Build
+		Create install dirs if needed (ITS#8256)
+		Fix ThreadProc decl on Win32/MSVC (ITS#8270)
+		Added ssize_t typedef for MSVC (ITS#8067)
+		Use ANSI apis on Windows (ITS#8069)
+		Use O_SYNC if O_DSYNC,MDB_DSYNC are not defined (ITS#7209)
+		Allow passing AR to make (ITS#8168)
+		Allow passing mandir to make install (ITS#8169)
+
+LMDB 0.9.16 Release (2015/08/14)
+	Fix cursor EOF bug (ITS#8190)
+	Fix handling of subDB records (ITS#8181)
+	Fix mdb_midl_shrink() usage (ITS#8200)
+
 LMDB 0.9.15 Release (2015/06/19)
 	Fix txn init (ITS#7961,#7987)
 	Fix MDB_PREV_DUP (ITS#7955,#7671)
diff --git a/external/db_drivers/liblmdb32/CMakeLists.txt b/external/db_drivers/liblmdb/CMakeLists.txt
index 293da1039..d951c83c5 100644
--- a/external/db_drivers/liblmdb32/CMakeLists.txt
+++ b/external/db_drivers/liblmdb/CMakeLists.txt
@@ -27,12 +27,9 @@
 # THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 if(FREEBSD)
-  set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -DMDB_DSYNC=O_SYNC")
+  add_definitions(-DMDB_DSYNC=O_SYNC)
 endif()
 
-# pass the VL32 flag so that we actually invoke the VL32 extensions
-set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -DVL32")
-
 set (lmdb_sources
 mdb.c
 midl.c)
@@ -44,3 +41,11 @@ add_library(lmdb
 target_link_libraries(lmdb
   LINK_PRIVATE
     ${CMAKE_THREAD_LIBS_INIT})
+if(WIN32)
+  target_link_libraries(lmdb
+    -lntdll)
+endif()
+if(${ARCH_WIDTH} EQUAL 32)
+  target_compile_definitions(lmdb
+    PUBLIC -DMDB_VL32)
+endif()
diff --git a/external/db_drivers/liblmdb32/COPYRIGHT b/external/db_drivers/liblmdb/COPYRIGHT
index 722d1a515..722d1a515 100644
--- a/external/db_drivers/liblmdb32/COPYRIGHT
+++ b/external/db_drivers/liblmdb/COPYRIGHT
diff --git a/external/db_drivers/liblmdb32/Doxyfile b/external/db_drivers/liblmdb/Doxyfile
index 92d17b09e..5047c0bb1 100644
--- a/external/db_drivers/liblmdb32/Doxyfile
+++ b/external/db_drivers/liblmdb/Doxyfile
@@ -582,7 +582,7 @@ WARN_LOGFILE           =
 # directories like "/usr/src/myproject". Separate the files or directories
 # with spaces.
 
-INPUT                  = lmdb.h midl.h mdb.c midl.c
+INPUT                  = lmdb.h midl.h mdb.c midl.c intro.doc
 
 # This tag can be used to specify the character encoding of the source files
 # that doxygen parses. Internally doxygen uses the UTF-8 encoding, which is
diff --git a/external/db_drivers/liblmdb32/LICENSE b/external/db_drivers/liblmdb/LICENSE
index 05ad7571e..05ad7571e 100644
--- a/external/db_drivers/liblmdb32/LICENSE
+++ b/external/db_drivers/liblmdb/LICENSE
diff --git a/external/db_drivers/liblmdb64/Makefile b/external/db_drivers/liblmdb/Makefile
index 2d0983eff..f3c93a2ff 100644
--- a/external/db_drivers/liblmdb64/Makefile
+++ b/external/db_drivers/liblmdb/Makefile
@@ -8,23 +8,31 @@
 # platforms; you should not need to change any of these.
 # Read their descriptions in mdb.c if you do:
 #
-# - MDB_USE_POSIX_SEM
+# - MDB_USE_POSIX_MUTEX, MDB_USE_POSIX_SEM, MDB_USE_SYSV_SEM
 # - MDB_DSYNC
 # - MDB_FDATASYNC
 # - MDB_FDATASYNC_WORKS
 # - MDB_USE_PWRITEV
+# - MDB_USE_ROBUST
 #
 # There may be other macros in mdb.c of interest. You should
 # read mdb.c before changing any of them.
 #
 CC	= gcc
+AR	= ar
 W	= -W -Wall -Wno-unused-parameter -Wbad-function-cast -Wuninitialized
 THREADS = -pthread
 OPT = -O2 -g
 CFLAGS	= $(THREADS) $(OPT) $(W) $(XCFLAGS)
-LDLIBS	=
-SOLIBS	=
+LDLIBS	= # -lntdll # Windows needs ntdll
+SOLIBS	= # -lntdll
 prefix	= /usr/local
+exec_prefix = $(prefix)
+bindir = $(exec_prefix)/bin
+libdir = $(exec_prefix)/lib
+includedir = $(prefix)/include
+datarootdir = $(prefix)/share
+mandir = $(datarootdir)/man
 
 ########################################################################
 
@@ -36,10 +44,14 @@ PROGS	= $(IPROGS) mtest mtest2 mtest3 mtest4 mtest5
 all:	$(ILIBS) $(PROGS)
 
 install: $(ILIBS) $(IPROGS) $(IHDRS)
-	for f in $(IPROGS); do cp $$f $(DESTDIR)$(prefix)/bin; done
-	for f in $(ILIBS); do cp $$f $(DESTDIR)$(prefix)/lib; done
-	for f in $(IHDRS); do cp $$f $(DESTDIR)$(prefix)/include; done
-	for f in $(IDOCS); do cp $$f $(DESTDIR)$(prefix)/man/man1; done
+	mkdir -p $(DESTDIR)$(bindir)
+	mkdir -p $(DESTDIR)$(libdir)
+	mkdir -p $(DESTDIR)$(includedir)
+	mkdir -p $(DESTDIR)$(mandir)/man1
+	for f in $(IPROGS); do cp $$f $(DESTDIR)$(bindir); done
+	for f in $(ILIBS); do cp $$f $(DESTDIR)$(libdir); done
+	for f in $(IHDRS); do cp $$f $(DESTDIR)$(includedir); done
+	for f in $(IDOCS); do cp $$f $(DESTDIR)$(mandir)/man1; done
 
 clean:
 	rm -rf $(PROGS) *.[ao] *.[ls]o *~ testdb
@@ -49,7 +61,7 @@ test:	all
 	./mtest && ./mdb_stat testdb
 
 liblmdb.a:	mdb.o midl.o
-	ar rs $@ mdb.o midl.o
+	$(AR) rs $@ mdb.o midl.o
 
 liblmdb.so:	mdb.lo midl.lo
 #	$(CC) $(LDFLAGS) -pthread -shared -Wl,-Bsymbolic -o $@ mdb.o midl.o $(SOLIBS)
diff --git a/external/db_drivers/liblmdb/intro.doc b/external/db_drivers/liblmdb/intro.doc
new file mode 100644
index 000000000..870c7bb8e
--- /dev/null
+++ b/external/db_drivers/liblmdb/intro.doc
@@ -0,0 +1,192 @@
+/*
+ * Copyright 2015 Howard Chu, Symas Corp.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted only as authorized by the OpenLDAP
+ * Public License.
+ *
+ * A copy of this license is available in the file LICENSE in the
+ * top-level directory of the distribution or, alternatively, at
+ * <http://www.OpenLDAP.org/license.html>.
+ */
+/** @page starting Getting Started
+
+LMDB is compact, fast, powerful, and robust and implements a simplified
+variant of the BerkeleyDB (BDB) API. (BDB is also very powerful, and verbosely
+documented in its own right.) After reading this page, the main
+\ref mdb documentation should make sense. Thanks to Bert Hubert
+for creating the
+<a href="https://github.com/ahupowerdns/ahutils/blob/master/lmdb-semantics.md">
+initial version</a> of this writeup.
+
+Everything starts with an environment, created by #mdb_env_create().
+Once created, this environment must also be opened with #mdb_env_open().
+
+#mdb_env_open() gets passed a name which is interpreted as a directory
+path. Note that this directory must exist already, it is not created
+for you. Within that directory, a lock file and a storage file will be
+generated. If you don't want to use a directory, you can pass the
+#MDB_NOSUBDIR option, in which case the path you provided is used
+directly as the data file, and another file with a "-lock" suffix
+added will be used for the lock file.
+
+Once the environment is open, a transaction can be created within it
+using #mdb_txn_begin(). Transactions may be read-write or read-only,
+and read-write transactions may be nested. A transaction must only
+be used by one thread at a time. Transactions are always required,
+even for read-only access. The transaction provides a consistent
+view of the data.
+
+Once a transaction has been created, a database can be opened within it
+using #mdb_dbi_open(). If only one database will ever be used in the
+environment, a NULL can be passed as the database name. For named
+databases, the #MDB_CREATE flag must be used to create the database
+if it doesn't already exist. Also, #mdb_env_set_maxdbs() must be
+called after #mdb_env_create() and before #mdb_env_open() to set the
+maximum number of named databases you want to support.
+
+Note: a single transaction can open multiple databases. Generally
+databases should only be opened once, by the first transaction in
+the process. After the first transaction completes, the database
+handles can freely be used by all subsequent transactions.
+
+Within a transaction, #mdb_get() and #mdb_put() can store single
+key/value pairs if that is all you need to do (but see \ref Cursors
+below if you want to do more).
+
+A key/value pair is expressed as two #MDB_val structures. This struct
+has two fields, \c mv_size and \c mv_data. The data is a \c void pointer to
+an array of \c mv_size bytes.
+
+Because LMDB is very efficient (and usually zero-copy), the data returned
+in an #MDB_val structure may be memory-mapped straight from disk. In
+other words <b>look but do not touch</b> (or free() for that matter).
+Once a transaction is closed, the values can no longer be used, so
+make a copy if you need to keep them after that.
+
+@section Cursors Cursors
+
+To do more powerful things, we must use a cursor.
+
+Within the transaction, a cursor can be created with #mdb_cursor_open().
+With this cursor we can store/retrieve/delete (multiple) values using
+#mdb_cursor_get(), #mdb_cursor_put(), and #mdb_cursor_del().
+
+#mdb_cursor_get() positions itself depending on the cursor operation
+requested, and for some operations, on the supplied key. For example,
+to list all key/value pairs in a database, use operation #MDB_FIRST for
+the first call to #mdb_cursor_get(), and #MDB_NEXT on subsequent calls,
+until the end is hit.
+
+To retrieve all keys starting from a specified key value, use #MDB_SET.
+For more cursor operations, see the \ref mdb docs.
+
+When using #mdb_cursor_put(), either the function will position the
+cursor for you based on the \b key, or you can use operation
+#MDB_CURRENT to use the current position of the cursor. Note that
+\b key must then match the current position's key.
+
+@subsection summary Summarizing the Opening
+
+So we have a cursor in a transaction which opened a database in an
+environment which is opened from a filesystem after it was
+separately created.
+
+Or, we create an environment, open it from a filesystem, create a
+transaction within it, open a database within that transaction,
+and create a cursor within all of the above.
+
+Got it?
+
+@section thrproc Threads and Processes
+
+LMDB uses POSIX locks on files, and these locks have issues if one
+process opens a file multiple times. Because of this, do not
+#mdb_env_open() a file multiple times from a single process. Instead,
+share the LMDB environment that has opened the file across all threads.
+Otherwise, if a single process opens the same environment multiple times,
+closing it once will remove all the locks held on it, and the other
+instances will be vulnerable to corruption from other processes.
+
+Also note that a transaction is tied to one thread by default using
+Thread Local Storage. If you want to pass read-only transactions across
+threads, you can use the #MDB_NOTLS option on the environment.
+
+@section txns Transactions, Rollbacks, etc.
+
+To actually get anything done, a transaction must be committed using
+#mdb_txn_commit(). Alternatively, all of a transaction's operations
+can be discarded using #mdb_txn_abort(). In a read-only transaction,
+any cursors will \b not automatically be freed. In a read-write
+transaction, all cursors will be freed and must not be used again.
+
+For read-only transactions, obviously there is nothing to commit to
+storage. The transaction still must eventually be aborted to close
+any database handle(s) opened in it, or committed to keep the
+database handles around for reuse in new transactions.
+
+In addition, as long as a transaction is open, a consistent view of
+the database is kept alive, which requires storage. A read-only
+transaction that no longer requires this consistent view should
+be terminated (committed or aborted) when the view is no longer
+needed (but see below for an optimization).
+
+There can be multiple simultaneously active read-only transactions
+but only one that can write. Once a single read-write transaction
+is opened, all further attempts to begin one will block until the
+first one is committed or aborted. This has no effect on read-only
+transactions, however, and they may continue to be opened at any time.
+
+@section dupkeys Duplicate Keys
+
+#mdb_get() and #mdb_put() respectively have no and only some support
+for multiple key/value pairs with identical keys. If there are multiple
+values for a key, #mdb_get() will only return the first value.
+
+When multiple values for one key are required, pass the #MDB_DUPSORT
+flag to #mdb_dbi_open(). In an #MDB_DUPSORT database, by default
+#mdb_put() will not replace the value for a key if the key existed
+already. Instead it will add the new value to the key. In addition,
+#mdb_del() will pay attention to the value field too, allowing for
+specific values of a key to be deleted.
+
+Finally, additional cursor operations become available for
+traversing through and retrieving duplicate values.
+
+@section optim Some Optimization
+
+If you frequently begin and abort read-only transactions, as an
+optimization, it is possible to only reset and renew a transaction.
+
+#mdb_txn_reset() releases any old copies of data kept around for
+a read-only transaction. To reuse this reset transaction, call
+#mdb_txn_renew() on it. Any cursors in this transaction must also
+be renewed using #mdb_cursor_renew().
+
+Note that #mdb_txn_reset() is similar to #mdb_txn_abort() and will
+close any databases you opened within the transaction.
+
+To permanently free a transaction, reset or not, use #mdb_txn_abort().
+
+@section cleanup Cleaning Up
+
+For read-only transactions, any cursors created within it must
+be closed using #mdb_cursor_close().
+
+It is very rarely necessary to close a database handle, and in
+general they should just be left open.
+
+@section onward The Full API
+
+The full \ref mdb documentation lists further details, like how to:
+
+  \li size a database (the default limits are intentionally small)
+  \li drop and clean a database
+  \li detect and report errors
+  \li optimize (bulk) loading speed
+  \li (temporarily) reduce robustness to gain even more speed
+  \li gather statistics about the database
+  \li define custom sort orders
+
+*/
diff --git a/external/db_drivers/liblmdb32/lmdb.h b/external/db_drivers/liblmdb/lmdb.h
index 2f523579c..587a44eaf 100644
--- a/external/db_drivers/liblmdb32/lmdb.h
+++ b/external/db_drivers/liblmdb/lmdb.h
@@ -40,6 +40,9 @@
  *	corrupt the database. Of course if your application code is known to
  *	be bug-free (...) then this is not an issue.
  *
+ *	If this is your first time using a transactional embedded key/value
+ *	store, you may find the \ref starting page to be helpful.
+ *
  *	@section caveats_sec Caveats
  *	Troubleshooting the lock file, plus semaphores on BSD systems:
  *
@@ -49,11 +52,16 @@
  *	  stale locks can block further operation.
  *
  *	  Fix: Check for stale readers periodically, using the
- *	  #mdb_reader_check function or the \ref mdb_stat_1 "mdb_stat" tool. Or just
- *	  make all programs using the database close it; the lockfile
- *	  is always reset on first open of the environment.
+ *	  #mdb_reader_check function or the \ref mdb_stat_1 "mdb_stat" tool.
+ *	  Stale writers will be cleared automatically on most systems:
+ *	  - Windows - automatic
+ *	  - BSD, systems using SysV semaphores - automatic
+ *	  - Linux, systems using POSIX mutexes with Robust option - automatic
+ *	  Otherwise just make all programs using the database close it;
+ *	  the lockfile is always reset on first open of the environment.
  *
- *	- On BSD systems or others configured with MDB_USE_POSIX_SEM,
+ *	- On BSD systems or others configured with MDB_USE_SYSV_SEM or
+ *	  MDB_USE_POSIX_SEM,
  *	  startup can fail due to semaphores owned by another userid.
  *
  *	  Fix: Open and close the database as the user which owns the
@@ -106,6 +114,9 @@
  *	  for stale readers is performed or the lockfile is reset,
  *	  since the process may not remove it from the lockfile.
  *
+ *	  This does not apply to write transactions if the system clears
+ *	  stale writers, see above.
+ *
  *	- If you do that anyway, do a periodic check for stale readers. Or
  *	  close the environment once in a while, so the lockfile can get reset.
  *
@@ -150,6 +161,7 @@
 #define _LMDB_H_
 
 #include <sys/types.h>
+#include <inttypes.h>
 
 #ifdef __cplusplus
 extern "C" {
@@ -162,6 +174,13 @@ typedef	int	mdb_mode_t;
 typedef	mode_t	mdb_mode_t;
 #endif
 
+#ifdef MDB_VL32
+typedef uint64_t	mdb_size_t;
+#define mdb_env_create(env)	mdb_env_create_vl32(env)	/**< Prevent mixing with non-VL32 builds */
+#else
+typedef size_t	mdb_size_t;
+#endif
+
 /** An abstraction for a file handle.
  *	On POSIX systems file handles are small integers. On Windows
  *	they're opaque pointers.
@@ -184,7 +203,7 @@ typedef int mdb_filehandle_t;
 /** Library minor version */
 #define MDB_VERSION_MINOR	9
 /** Library patch version */
-#define MDB_VERSION_PATCH	15
+#define MDB_VERSION_PATCH	70
 
 /** Combine args a,b,c into a single integer for easy version comparisons */
 #define MDB_VERINT(a,b,c)	(((a) << 24) | ((b) << 16) | (c))
@@ -194,7 +213,7 @@ typedef int mdb_filehandle_t;
 	MDB_VERINT(MDB_VERSION_MAJOR,MDB_VERSION_MINOR,MDB_VERSION_PATCH)
 
 /** The release date of this library version */
-#define MDB_VERSION_DATE	"June 19, 2015"
+#define MDB_VERSION_DATE	"December 19, 2015"
 
 /** A stringifier for the version info */
 #define MDB_VERSTR(a,b,c,d)	"LMDB " #a "." #b "." #c ": (" d ")"
@@ -391,7 +410,7 @@ typedef enum MDB_cursor_op {
 #define MDB_PAGE_NOTFOUND	(-30797)
 	/** Located page was wrong type */
 #define MDB_CORRUPTED	(-30796)
-	/** Update of meta page failed, probably I/O error */
+	/** Update of meta page failed or environment had fatal error */
 #define MDB_PANIC		(-30795)
 	/** Environment version mismatch */
 #define MDB_VERSION_MISMATCH	(-30794)
@@ -413,11 +432,18 @@ typedef enum MDB_cursor_op {
 #define MDB_PAGE_FULL	(-30786)
 	/** Database contents grew beyond environment mapsize */
 #define MDB_MAP_RESIZED	(-30785)
-	/** MDB_INCOMPATIBLE: Operation and DB incompatible, or DB flags changed */
+	/** Operation and DB incompatible, or DB type changed. This can mean:
+	 *	<ul>
+	 *	<li>The operation expects an #MDB_DUPSORT / #MDB_DUPFIXED database.
+	 *	<li>Opening a named DB when the unnamed DB has #MDB_DUPSORT / #MDB_INTEGERKEY.
+	 *	<li>Accessing a data record as a database, or vice versa.
+	 *	<li>The database was dropped and recreated with different flags.
+	 *	</ul>
+	 */
 #define MDB_INCOMPATIBLE	(-30784)
 	/** Invalid reuse of reader locktable slot */
 #define MDB_BAD_RSLOT		(-30783)
-	/** Transaction cannot recover - it must be aborted */
+	/** Transaction must abort, has a child, or is invalid */
 #define MDB_BAD_TXN			(-30782)
 	/** Unsupported size of key/DB name/data, or wrong DUPFIXED size */
 #define MDB_BAD_VALSIZE		(-30781)
@@ -432,18 +458,18 @@ typedef struct MDB_stat {
 	unsigned int	ms_psize;			/**< Size of a database page.
 											This is currently the same for all databases. */
 	unsigned int	ms_depth;			/**< Depth (height) of the B-tree */
-	size_t		ms_branch_pages;	/**< Number of internal (non-leaf) pages */
-	size_t		ms_leaf_pages;		/**< Number of leaf pages */
-	size_t		ms_overflow_pages;	/**< Number of overflow pages */
-	size_t		ms_entries;			/**< Number of data items */
+	mdb_size_t		ms_branch_pages;	/**< Number of internal (non-leaf) pages */
+	mdb_size_t		ms_leaf_pages;		/**< Number of leaf pages */
+	mdb_size_t		ms_overflow_pages;	/**< Number of overflow pages */
+	mdb_size_t		ms_entries;			/**< Number of data items */
 } MDB_stat;
 
 /** @brief Information about the environment */
 typedef struct MDB_envinfo {
 	void	*me_mapaddr;			/**< Address of map, if fixed */
-	size_t	me_mapsize;				/**< Size of the data memory map */
-	size_t	me_last_pgno;			/**< ID of the last used page */
-	size_t	me_last_txnid;			/**< ID of the last committed transaction */
+	mdb_size_t	me_mapsize;				/**< Size of the data memory map */
+	mdb_size_t	me_last_pgno;			/**< ID of the last used page */
+	mdb_size_t	me_last_txnid;			/**< ID of the last committed transaction */
 	unsigned int me_maxreaders;		/**< max reader slots in the environment */
 	unsigned int me_numreaders;		/**< max reader slots used in the environment */
 } MDB_envinfo;
@@ -810,7 +836,7 @@ int  mdb_env_get_fd(MDB_env *env, mdb_filehandle_t *fd);
 	 *   	an active write transaction.
 	 * </ul>
 	 */
-int  mdb_env_set_mapsize(MDB_env *env, size_t size);
+int  mdb_env_set_mapsize(MDB_env *env, mdb_size_t size);
 
 	/** @brief Set the maximum number of threads/reader slots for the environment.
 	 *
@@ -923,6 +949,10 @@ int  mdb_env_set_assert(MDB_env *env, MDB_assert_func *func);
 	 * <ul>
 	 *	<li>#MDB_RDONLY
 	 *		This transaction will not perform any write operations.
+	 *	<li>#MDB_NOSYNC
+	 *		Don't flush system buffers to disk when committing this transaction.
+	 *	<li>#MDB_NOMETASYNC
+	 *		Flush system buffers but omit metadata flush when committing this transaction.
 	 * </ul>
 	 * @param[out] txn Address where the new #MDB_txn handle will be stored
 	 * @return A non-zero error value on failure and 0 on success. Some possible
@@ -946,6 +976,17 @@ int  mdb_txn_begin(MDB_env *env, MDB_txn *parent, unsigned int flags, MDB_txn **
 	 */
 MDB_env *mdb_txn_env(MDB_txn *txn);
 
+	/** @brief Return the transaction's ID.
+	 *
+	 * This returns the identifier associated with this transaction. For a
+	 * read-only transaction, this corresponds to the snapshot being read;
+	 * concurrent readers will frequently have the same transaction ID.
+	 *
+	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()
+	 * @return A transaction ID, valid if input is an active transaction.
+	 */
+mdb_size_t mdb_txn_id(MDB_txn *txn);
+
 	/** @brief Commit all the operations of a transaction into the database.
 	 *
 	 * The transaction handle is freed. It and its cursors must not be used
@@ -1034,8 +1075,9 @@ int  mdb_txn_renew(MDB_txn *txn);
 	 * any other transaction in the process may use this function.
 	 *
 	 * To use named databases (with name != NULL), #mdb_env_set_maxdbs()
-	 * must be called before opening the environment.  Database names
-	 * are kept as keys in the unnamed database.
+	 * must be called before opening the environment.  Database names are
+	 * keys in the unnamed database, and may be read but not written.
+	 *
 	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()
 	 * @param[in] name The name of the database to open. If only a single
 	 * 	database is needed in the environment, this value may be NULL.
@@ -1272,7 +1314,8 @@ int  mdb_get(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data);
 	 *		the next update operation or the transaction ends. This saves
 	 *		an extra memcpy if the data is being generated later.
 	 *		LMDB does nothing else with this memory, the caller is expected
-	 *		to modify all of the space requested.
+	 *		to modify all of the space requested. This flag must not be
+	 *		specified if the database was opened with #MDB_DUPSORT.
 	 *	<li>#MDB_APPEND - append the given key/data pair to the end of the
 	 *		database. This option allows fast bulk loading when keys are
 	 *		already known to be in the correct order. Loading unsorted keys
@@ -1428,13 +1471,15 @@ int  mdb_cursor_get(MDB_cursor *cursor, MDB_val *key, MDB_val *data,
 	 *		the database supports duplicates (#MDB_DUPSORT).
 	 *	<li>#MDB_RESERVE - reserve space for data of the given size, but
 	 *		don't copy the given data. Instead, return a pointer to the
-	 *		reserved space, which the caller can fill in later. This saves
-	 *		an extra memcpy if the data is being generated later.
+	 *		reserved space, which the caller can fill in later - before
+	 *		the next update operation or the transaction ends. This saves
+	 *		an extra memcpy if the data is being generated later. This flag
+	 *		must not be specified if the database was opened with #MDB_DUPSORT.
 	 *	<li>#MDB_APPEND - append the given key/data pair to the end of the
 	 *		database. No key comparisons are performed. This option allows
 	 *		fast bulk loading when keys are already known to be in the
 	 *		correct order. Loading unsorted keys with this flag will cause
-	 *		data corruption.
+	 *		a #MDB_KEYEXIST error.
 	 *	<li>#MDB_APPENDDUP - as above, but for sorted dup data.
 	 *	<li>#MDB_MULTIPLE - store multiple contiguous data elements in a
 	 *		single request. This flag may only be specified if the database
diff --git a/external/db_drivers/liblmdb32/mdb.c b/external/db_drivers/liblmdb/mdb.c
index dd3d5848f..e42c34498 100644
--- a/external/db_drivers/liblmdb32/mdb.c
+++ b/external/db_drivers/liblmdb/mdb.c
@@ -35,9 +35,42 @@
 #ifndef _GNU_SOURCE
 #define _GNU_SOURCE 1
 #endif
+#ifdef MDB_VL32
+#define _FILE_OFFSET_BITS	64
+#endif
 #ifdef _WIN32
 #include <malloc.h>
 #include <windows.h>
+
+/* We use native NT APIs to setup the memory map, so that we can
+ * let the DB file grow incrementally instead of always preallocating
+ * the full size. These APIs are defined in <wdm.h> and <ntifs.h>
+ * but those headers are meant for driver-level development and
+ * conflict with the regular user-level headers, so we explicitly
+ * declare them here. Using these APIs also means we must link to
+ * ntdll.dll, which is not linked by default in user code.
+ */
+NTSTATUS WINAPI
+NtCreateSection(OUT PHANDLE sh, IN ACCESS_MASK acc,
+  IN void * oa OPTIONAL,
+  IN PLARGE_INTEGER ms OPTIONAL,
+  IN ULONG pp, IN ULONG aa, IN HANDLE fh OPTIONAL);
+
+typedef enum _SECTION_INHERIT {
+	ViewShare = 1,
+	ViewUnmap = 2
+} SECTION_INHERIT;
+
+NTSTATUS WINAPI
+NtMapViewOfSection(IN PHANDLE sh, IN HANDLE ph,
+  IN OUT PVOID *addr, IN ULONG_PTR zbits,
+  IN SIZE_T cs, IN OUT PLARGE_INTEGER off OPTIONAL,
+  IN OUT PSIZE_T vs, IN SECTION_INHERIT ih,
+  IN ULONG at, IN ULONG pp);
+
+NTSTATUS WINAPI
+NtClose(HANDLE h);
+
 /** getpid() returns int; MinGW defines pid_t but MinGW64 typedefs it
  *  as int64 which is wrong. MSVC doesn't define it at all, so just
  *  don't use it.
@@ -96,7 +129,13 @@ extern int cacheflush(char *addr, int nbytes, int cache);
 #include <stdlib.h>
 #include <string.h>
 #include <time.h>
+
+#ifdef _MSC_VER
+#include <io.h>
+typedef SSIZE_T	ssize_t;
+#else
 #include <unistd.h>
+#endif
 
 #if defined(__sun) || defined(ANDROID)
 /* Most platforms have posix_memalign, older may only have memalign */
@@ -110,7 +149,9 @@ extern int cacheflush(char *addr, int nbytes, int cache);
 #endif
 
 #if defined(__APPLE__) || defined (BSD)
-# define MDB_USE_POSIX_SEM	1
+# if !(defined(MDB_USE_POSIX_MUTEX) || defined(MDB_USE_POSIX_SEM))
+# define MDB_USE_SYSV_SEM	1
+# endif
 # define MDB_FDATASYNC		fsync
 #elif defined(ANDROID)
 # define MDB_FDATASYNC		fsync
@@ -121,7 +162,24 @@ extern int cacheflush(char *addr, int nbytes, int cache);
 #ifdef MDB_USE_POSIX_SEM
 # define MDB_USE_HASH		1
 #include <semaphore.h>
-#endif
+#elif defined(MDB_USE_SYSV_SEM)
+#include <sys/ipc.h>
+#include <sys/sem.h>
+#ifdef _SEM_SEMUN_UNDEFINED
+union semun {
+	int val;
+	struct semid_ds *buf;
+	unsigned short *array;
+};
+#endif /* _SEM_SEMUN_UNDEFINED */
+#else
+#define MDB_USE_POSIX_MUTEX	1
+#endif /* MDB_USE_POSIX_SEM */
+#endif /* !_WIN32 */
+
+#if defined(_WIN32) + defined(MDB_USE_POSIX_SEM) + defined(MDB_USE_SYSV_SEM) \
+	+ defined(MDB_USE_POSIX_MUTEX) != 1
+# error "Ambiguous shared-lock implementation"
 #endif
 
 #ifdef USE_VALGRIND
@@ -185,6 +243,12 @@ extern int cacheflush(char *addr, int nbytes, int cache);
 #define ESECT
 #endif
 
+#ifdef _WIN32
+#define CALL_CONV WINAPI
+#else
+#define CALL_CONV
+#endif
+
 /** @defgroup internal	LMDB Internals
  *	@{
  */
@@ -211,6 +275,47 @@ extern int cacheflush(char *addr, int nbytes, int cache);
 # define mdb_func_	"<mdb_unknown>"
 #endif
 
+/* Internal error codes, not exposed outside liblmdb */
+#define	MDB_NO_ROOT		(MDB_LAST_ERRCODE + 10)
+#ifdef _WIN32
+#define MDB_OWNERDEAD	((int) WAIT_ABANDONED)
+#elif defined MDB_USE_SYSV_SEM
+#define MDB_OWNERDEAD	(MDB_LAST_ERRCODE + 11)
+#elif defined(MDB_USE_POSIX_MUTEX) && defined(EOWNERDEAD)
+#define MDB_OWNERDEAD	EOWNERDEAD	/**< #LOCK_MUTEX0() result if dead owner */
+#endif
+
+#ifdef __GLIBC__
+#define	GLIBC_VER	((__GLIBC__ << 16 )| __GLIBC_MINOR__)
+#endif
+/** Some platforms define the EOWNERDEAD error code
+ * even though they don't support Robust Mutexes.
+ * Compile with -DMDB_USE_ROBUST=0, or use some other
+ * mechanism like -DMDB_USE_SYSV_SEM instead of
+ * -DMDB_USE_POSIX_MUTEX. (SysV semaphores are
+ * also Robust, but some systems don't support them
+ * either.)
+ */
+#ifndef MDB_USE_ROBUST
+/* Android currently lacks Robust Mutex support. So does glibc < 2.4. */
+# if defined(MDB_USE_POSIX_MUTEX) && (defined(ANDROID) || \
+	(defined(__GLIBC__) && GLIBC_VER < 0x020004))
+#  define MDB_USE_ROBUST	0
+# else
+#  define MDB_USE_ROBUST	1
+/* glibc < 2.12 only provided _np API */
+#  if defined(__GLIBC__) && GLIBC_VER < 0x02000c
+#   define PTHREAD_MUTEX_ROBUST	PTHREAD_MUTEX_ROBUST_NP
+#   define pthread_mutexattr_setrobust(attr, flag)	pthread_mutexattr_setrobust_np(attr, flag)
+#   define pthread_mutex_consistent(mutex)	pthread_mutex_consistent_np(mutex)
+#  endif
+# endif
+#endif /* MDB_USE_ROBUST */
+
+#if defined(MDB_OWNERDEAD) && MDB_USE_ROBUST
+#define MDB_ROBUST_SUPPORTED	1
+#endif
+
 #ifdef _WIN32
 #define MDB_USE_HASH	1
 #define MDB_PIDLOCK	0
@@ -218,6 +323,7 @@ extern int cacheflush(char *addr, int nbytes, int cache);
 #define pthread_t	HANDLE
 #define pthread_mutex_t	HANDLE
 #define pthread_cond_t	HANDLE
+typedef HANDLE mdb_mutex_t, mdb_mutexref_t;
 #define pthread_key_t	DWORD
 #define pthread_self()	GetCurrentThreadId()
 #define pthread_key_create(x,y)	\
@@ -231,10 +337,9 @@ extern int cacheflush(char *addr, int nbytes, int cache);
 #define pthread_cond_wait(cond,mutex)	do{SignalObjectAndWait(*mutex, *cond, INFINITE, FALSE); WaitForSingleObject(*mutex, INFINITE);}while(0)
 #define THREAD_CREATE(thr,start,arg)	thr=CreateThread(NULL,0,start,arg,0,NULL)
 #define THREAD_FINISH(thr)	WaitForSingleObject(thr, INFINITE)
-#define LOCK_MUTEX_R(env)	pthread_mutex_lock(&(env)->me_rmutex)
-#define UNLOCK_MUTEX_R(env)	pthread_mutex_unlock(&(env)->me_rmutex)
-#define LOCK_MUTEX_W(env)	pthread_mutex_lock(&(env)->me_wmutex)
-#define UNLOCK_MUTEX_W(env)	pthread_mutex_unlock(&(env)->me_wmutex)
+#define LOCK_MUTEX0(mutex)		WaitForSingleObject(mutex, INFINITE)
+#define UNLOCK_MUTEX(mutex)		ReleaseMutex(mutex)
+#define mdb_mutex_consistent(mutex)	0
 #define getpid()	GetCurrentProcessId()
 #define	MDB_FDATASYNC(fd)	(!FlushFileBuffers(fd))
 #define	MDB_MSYNC(addr,len,flags)	(!FlushViewOfFile(addr,len))
@@ -259,10 +364,9 @@ extern int cacheflush(char *addr, int nbytes, int cache);
 
 #ifdef MDB_USE_POSIX_SEM
 
-#define LOCK_MUTEX_R(env)	mdb_sem_wait((env)->me_rmutex)
-#define UNLOCK_MUTEX_R(env)	sem_post((env)->me_rmutex)
-#define LOCK_MUTEX_W(env)	mdb_sem_wait((env)->me_wmutex)
-#define UNLOCK_MUTEX_W(env)	sem_post((env)->me_wmutex)
+typedef sem_t *mdb_mutex_t, *mdb_mutexref_t;
+#define LOCK_MUTEX0(mutex)		mdb_sem_wait(mutex)
+#define UNLOCK_MUTEX(mutex)		sem_post(mutex)
 
 static int
 mdb_sem_wait(sem_t *sem)
@@ -272,23 +376,61 @@ mdb_sem_wait(sem_t *sem)
    return rc;
 }
 
-#else
-	/** Lock the reader mutex.
+#elif defined MDB_USE_SYSV_SEM
+
+typedef struct mdb_mutex {
+	int semid;
+	int semnum;
+	int *locked;
+} mdb_mutex_t[1], *mdb_mutexref_t;
+
+#define LOCK_MUTEX0(mutex)		mdb_sem_wait(mutex)
+#define UNLOCK_MUTEX(mutex)		do { \
+	struct sembuf sb = { 0, 1, SEM_UNDO }; \
+	sb.sem_num = (mutex)->semnum; \
+	*(mutex)->locked = 0; \
+	semop((mutex)->semid, &sb, 1); \
+} while(0)
+
+static int
+mdb_sem_wait(mdb_mutexref_t sem)
+{
+	int rc, *locked = sem->locked;
+	struct sembuf sb = { 0, -1, SEM_UNDO };
+	sb.sem_num = sem->semnum;
+	do {
+		if (!semop(sem->semid, &sb, 1)) {
+			rc = *locked ? MDB_OWNERDEAD : MDB_SUCCESS;
+			*locked = 1;
+			break;
+		}
+	} while ((rc = errno) == EINTR);
+	return rc;
+}
+
+#define mdb_mutex_consistent(mutex)	0
+
+#else	/* MDB_USE_POSIX_MUTEX: */
+	/** Shared mutex/semaphore as it is stored (mdb_mutex_t), and as
+	 *	local variables keep it (mdb_mutexref_t).
+	 *
+	 *	An mdb_mutex_t can be assigned to an mdb_mutexref_t.  They can
+	 *	be the same, or an array[size 1] and a pointer.
+	 *	@{
 	 */
-#define LOCK_MUTEX_R(env)	pthread_mutex_lock(&(env)->me_txns->mti_mutex)
-	/** Unlock the reader mutex.
+typedef pthread_mutex_t mdb_mutex_t[1], *mdb_mutexref_t;
+	/*	@} */
+	/** Lock the reader or writer mutex.
+	 *	Returns 0 or a code to give #mdb_mutex_failed(), as in #LOCK_MUTEX().
 	 */
-#define UNLOCK_MUTEX_R(env)	pthread_mutex_unlock(&(env)->me_txns->mti_mutex)
-
-	/** Lock the writer mutex.
-	 *	Only a single write transaction is allowed at a time. Other writers
-	 *	will block waiting for this mutex.
+#define LOCK_MUTEX0(mutex)	pthread_mutex_lock(mutex)
+	/** Unlock the reader or writer mutex.
 	 */
-#define LOCK_MUTEX_W(env)	pthread_mutex_lock(&(env)->me_txns->mti_wmutex)
-	/** Unlock the writer mutex.
+#define UNLOCK_MUTEX(mutex)	pthread_mutex_unlock(mutex)
+	/** Mark mutex-protected data as repaired, after death of previous owner.
 	 */
-#define UNLOCK_MUTEX_W(env)	pthread_mutex_unlock(&(env)->me_txns->mti_wmutex)
-#endif	/* MDB_USE_POSIX_SEM */
+#define mdb_mutex_consistent(mutex)	pthread_mutex_consistent(mutex)
+#endif	/* MDB_USE_POSIX_SEM || MDB_USE_SYSV_SEM */
 
 	/** Get the error code for the last failed system function.
 	 */
@@ -313,14 +455,46 @@ mdb_sem_wait(sem_t *sem)
 #define	GET_PAGESIZE(x)	((x) = sysconf(_SC_PAGE_SIZE))
 #endif
 
+#ifndef MDB_VL32
+#define Yd	Z"d"
+#define Yu	Z"u"
+#elif defined _WIN32
+#define	Yd	"I64d"
+#define	Yu	"I64u"
+#else
+#define	Yd	PRId64
+#define	Yu	PRIu64
+#endif
+
 #if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
 #define MNAME_LEN	32
+#elif defined(MDB_USE_SYSV_SEM)
+#define MNAME_LEN	(sizeof(int))
 #else
 #define MNAME_LEN	(sizeof(pthread_mutex_t))
 #endif
 
+#ifdef MDB_USE_SYSV_SEM
+#define SYSV_SEM_FLAG	1		/**< SysV sems in lockfile format */
+#else
+#define SYSV_SEM_FLAG	0
+#endif
+
 /** @} */
 
+#ifdef MDB_ROBUST_SUPPORTED
+	/** Lock mutex, handle any error, set rc = result.
+	 *	Return 0 on success, nonzero (not rc) on error.
+	 */
+#define LOCK_MUTEX(rc, env, mutex) \
+	(((rc) = LOCK_MUTEX0(mutex)) && \
+	 ((rc) = mdb_mutex_failed(env, mutex, rc)))
+static int mdb_mutex_failed(MDB_env *env, mdb_mutexref_t mutex, int rc);
+#else
+#define LOCK_MUTEX(rc, env, mutex) ((rc) = LOCK_MUTEX0(mutex))
+#define mdb_mutex_failed(env, mutex, rc) (rc)
+#endif
+
 #ifndef _WIN32
 /**	A flag for opening a file and requesting synchronous data writes.
  *	This is only used when writing a meta page. It's not strictly needed;
@@ -329,10 +503,13 @@ mdb_sem_wait(sem_t *sem)
  *
  *	@note If O_DSYNC is undefined but exists in /usr/include,
  * preferably set some compiler flag to get the definition.
- * Otherwise compile with the less efficient -DMDB_DSYNC=O_SYNC.
  */
 #ifndef MDB_DSYNC
+# ifdef O_DSYNC
 # define MDB_DSYNC	O_DSYNC
+# else
+# define MDB_DSYNC	O_SYNC
+# endif
 #endif
 #endif
 
@@ -444,7 +621,7 @@ static txnid_t mdb_debug_start;
 	/**	The version number for a database's datafile format. */
 #define MDB_DATA_VERSION	 ((MDB_DEVEL) ? 999 : 1)
 	/**	The version number for a database's lockfile format. */
-#define MDB_LOCK_VERSION	 1
+#define MDB_LOCK_VERSION	 ((MDB_DEVEL) ? 999 : 1)
 
 	/**	@brief The max size of a key we can write, or 0 for computed max.
 	 *
@@ -635,11 +812,14 @@ typedef struct MDB_txbody {
 	uint32_t	mtb_format;
 #if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
 	char	mtb_rmname[MNAME_LEN];
+#elif defined(MDB_USE_SYSV_SEM)
+	int 	mtb_semid;
+	int		mtb_rlocked;
 #else
 		/** Mutex protecting access to this table.
-		 *	This is the reader lock that #LOCK_MUTEX_R acquires.
+		 *	This is the reader table lock used with LOCK_MUTEX().
 		 */
-	pthread_mutex_t	mtb_mutex;
+	mdb_mutex_t	mtb_rmutex;
 #endif
 		/**	The ID of the last transaction committed to the database.
 		 *	This is recorded here only for convenience; the value can always
@@ -659,18 +839,25 @@ typedef struct MDB_txninfo {
 		MDB_txbody mtb;
 #define mti_magic	mt1.mtb.mtb_magic
 #define mti_format	mt1.mtb.mtb_format
-#define mti_mutex	mt1.mtb.mtb_mutex
+#define mti_rmutex	mt1.mtb.mtb_rmutex
 #define mti_rmname	mt1.mtb.mtb_rmname
 #define mti_txnid	mt1.mtb.mtb_txnid
 #define mti_numreaders	mt1.mtb.mtb_numreaders
+#ifdef MDB_USE_SYSV_SEM
+#define	mti_semid	mt1.mtb.mtb_semid
+#define	mti_rlocked	mt1.mtb.mtb_rlocked
+#endif
 		char pad[(sizeof(MDB_txbody)+CACHELINE-1) & ~(CACHELINE-1)];
 	} mt1;
 	union {
 #if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
 		char mt2_wmname[MNAME_LEN];
 #define	mti_wmname	mt2.mt2_wmname
+#elif defined MDB_USE_SYSV_SEM
+		int mt2_wlocked;
+#define mti_wlocked	mt2.mt2_wlocked
 #else
-		pthread_mutex_t	mt2_wmutex;
+		mdb_mutex_t	mt2_wmutex;
 #define mti_wmutex	mt2.mt2_wmutex
 #endif
 		char pad[(MNAME_LEN+CACHELINE-1) & ~(CACHELINE-1)];
@@ -683,6 +870,7 @@ typedef struct MDB_txninfo {
 	((uint32_t) \
 	 ((MDB_LOCK_VERSION) \
 	  /* Flags which describe functionality */ \
+	  + (SYSV_SEM_FLAG << 18) \
 	  + (((MDB_PIDLOCK) != 0) << 16)))
 /** @} */
 
@@ -888,7 +1076,7 @@ typedef struct MDB_db {
 	pgno_t		md_branch_pages;	/**< number of internal pages */
 	pgno_t		md_leaf_pages;		/**< number of leaf pages */
 	pgno_t		md_overflow_pages;	/**< number of overflow pages */
-	size_t		md_entries;		/**< number of data items */
+	pgno_t		md_entries;		/**< number of data items */
 	pgno_t		md_root;		/**< the root page of this tree */
 } MDB_db;
 
@@ -902,6 +1090,11 @@ typedef struct MDB_db {
 #define	FREE_DBI	0
 	/** Handle for the default DB. */
 #define	MAIN_DBI	1
+	/** Number of DBs in metapage (free and main) - also hardcoded elsewhere */
+#define CORE_DBS	2
+
+	/** Number of meta pages - also hardcoded elsewhere */
+#define NUM_METAS	2
 
 	/** Meta page content.
 	 *	A meta page is the start point for accessing a database snapshot.
@@ -913,13 +1106,21 @@ typedef struct MDB_meta {
 	uint32_t	mm_magic;
 		/** Version number of this file. Must be set to #MDB_DATA_VERSION. */
 	uint32_t	mm_version;
+#ifdef MDB_VL32
+	union {		/* always zero since we don't support fixed mapping in MDB_VL32 */
+		MDB_ID	mmun_ull;
+		void *mmun_address;
+	} mm_un;
+#define	mm_address mm_un.mmun_address
+#else
 	void		*mm_address;		/**< address for fixed mapping */
-	size_t		mm_mapsize;			/**< size of mmap region */
-	MDB_db		mm_dbs[2];			/**< first is free space, 2nd is main db */
+#endif
+	pgno_t		mm_mapsize;			/**< size of mmap region */
+	MDB_db		mm_dbs[CORE_DBS];	/**< first is free space, 2nd is main db */
 	/** The size of pages used in this DB */
-#define	mm_psize	mm_dbs[0].md_pad
+#define	mm_psize	mm_dbs[FREE_DBI].md_pad
 	/** Any persistent environment flags. @ref mdb_env */
-#define	mm_flags	mm_dbs[0].md_flags
+#define	mm_flags	mm_dbs[FREE_DBI].md_flags
 	pgno_t		mm_last_pg;			/**< last used page in file */
 	volatile txnid_t	mm_txnid;	/**< txnid that committed this page */
 } MDB_meta;
@@ -954,8 +1155,12 @@ typedef struct MDB_dbx {
 	 */
 struct MDB_txn {
 	MDB_txn		*mt_parent;		/**< parent of a nested txn */
-	MDB_txn		*mt_child;		/**< nested txn under this txn */
+	/** Nested txn under this txn, set together with flag #MDB_TXN_HAS_CHILD */
+	MDB_txn		*mt_child;
 	pgno_t		mt_next_pgno;	/**< next unallocated page */
+#ifdef MDB_VL32
+	pgno_t		mt_last_pgno;	/**< last written page */
+#endif
 	/** The ID of this transaction. IDs are integers incrementing from 1.
 	 *	Only committed write transactions increment the ID. If a transaction
 	 *	aborts, the ID may be re-used by the next writer.
@@ -996,17 +1201,28 @@ struct MDB_txn {
 #define DB_STALE	0x02		/**< Named-DB record is older than txnID */
 #define DB_NEW		0x04		/**< Named-DB handle opened in this txn */
 #define DB_VALID	0x08		/**< DB handle is valid, see also #MDB_VALID */
+#define DB_USRVALID	0x10		/**< As #DB_VALID, but not set for #FREE_DBI */
 /** @} */
 	/** In write txns, array of cursors for each DB */
 	MDB_cursor	**mt_cursors;
 	/** Array of flags for each DB */
 	unsigned char	*mt_dbflags;
-#ifdef VL32
-	/** List of read-only pages */
-	MDB_ID2L	mt_rpages;
-#endif	
-	/**	Number of DB records in use. This number only ever increments;
-	 *	we don't decrement it when individual DB handles are closed.
+#ifdef MDB_VL32
+	/** List of read-only pages (actually chunks) */
+	MDB_ID3L	mt_rpages;
+	/** We map chunks of 16 pages. Even though Windows uses 4KB pages, all
+	 * mappings must begin on 64KB boundaries. So we round off all pgnos to
+	 * a chunk boundary. We do the same on Linux for symmetry, and also to
+	 * reduce the frequency of mmap/munmap calls.
+	 */
+#define MDB_RPAGE_CHUNK	16
+#define MDB_TRPAGE_SIZE	4096	/**< size of #mt_rpages array of chunks */
+#define MDB_TRPAGE_MAX	(MDB_TRPAGE_SIZE-1)	/**< maximum chunk index */
+	unsigned int mt_rpcheck;	/**< threshold for reclaiming unref'd chunks */
+#endif
+	/**	Number of DB records in use, or 0 when the txn is finished.
+	 *	This number only ever increments until the txn finishes; we
+	 *	don't decrement it when individual DB handles are closed.
 	 */
 	MDB_dbi		mt_numdbs;
 
@@ -1014,10 +1230,20 @@ struct MDB_txn {
  *	@ingroup internal
  *	@{
  */
-#define MDB_TXN_RDONLY		0x01		/**< read-only transaction */
+	/** #mdb_txn_begin() flags */
+#define MDB_TXN_BEGIN_FLAGS	(MDB_NOMETASYNC|MDB_NOSYNC|MDB_RDONLY)
+#define MDB_TXN_NOMETASYNC	MDB_NOMETASYNC	/**< don't sync meta for this txn on commit */
+#define MDB_TXN_NOSYNC		MDB_NOSYNC	/**< don't sync this txn on commit */
+#define MDB_TXN_RDONLY		MDB_RDONLY	/**< read-only transaction */
+	/* internal txn flags */
+#define MDB_TXN_WRITEMAP	MDB_WRITEMAP	/**< copy of #MDB_env flag in writers */
+#define MDB_TXN_FINISHED	0x01		/**< txn is finished or never began */
 #define MDB_TXN_ERROR		0x02		/**< txn is unusable after an error */
 #define MDB_TXN_DIRTY		0x04		/**< must write, even if dirty list is empty */
 #define MDB_TXN_SPILLS		0x08		/**< txn or a parent has spilled pages */
+#define MDB_TXN_HAS_CHILD	0x10		/**< txn has an #MDB_txn.%mt_child */
+	/** most operations on the txn are currently illegal */
+#define MDB_TXN_BLOCKED		(MDB_TXN_FINISHED|MDB_TXN_ERROR|MDB_TXN_HAS_CHILD)
 /** @} */
 	unsigned int	mt_flags;		/**< @ref mdb_txn */
 	/** #dirty_list room: Array size - \#dirty pages visible to this txn.
@@ -1072,12 +1298,20 @@ struct MDB_cursor {
 #define C_EOF	0x02			/**< No more data */
 #define C_SUB	0x04			/**< Cursor is a sub-cursor */
 #define C_DEL	0x08			/**< last op was a cursor_del */
-#define C_SPLITTING	0x20		/**< Cursor is in page_split */
 #define C_UNTRACK	0x40		/**< Un-track cursor when closing */
+#define C_WRITEMAP	MDB_TXN_WRITEMAP /**< Copy of txn flag */
+/** Read-only cursor into the txn's original snapshot in the map.
+ *	Set for read-only txns, and in #mdb_page_alloc() for #FREE_DBI when
+ *	#MDB_DEVEL & 2. Only implements code which is necessary for this.
+ */
+#define C_ORIG_RDONLY	MDB_TXN_RDONLY
 /** @} */
 	unsigned int	mc_flags;	/**< @ref mdb_cursor */
 	MDB_page	*mc_pg[CURSOR_STACK];	/**< stack of pushed pages */
 	indx_t		mc_ki[CURSOR_STACK];	/**< stack of page indices */
+#ifdef MDB_VL32
+	MDB_page	*mc_ovpg;		/**< a referenced overflow page */
+#endif
 };
 
 	/** Context for sorted-dup records.
@@ -1107,7 +1341,7 @@ struct MDB_env {
 	HANDLE		me_fd;		/**< The main data file */
 	HANDLE		me_lfd;		/**< The lock file */
 	HANDLE		me_mfd;			/**< just for writing the meta pages */
-#if defined(VL32) && defined(_WIN32)
+#if defined(MDB_VL32) && defined(_WIN32)
 	HANDLE		me_fmh;		/**< File Mapping handle */
 #endif
 	/** Failed to update the meta page. Probably an I/O error. */
@@ -1122,18 +1356,19 @@ struct MDB_env {
 	unsigned int	me_psize;	/**< DB page size, inited from me_os_psize */
 	unsigned int	me_os_psize;	/**< OS page size, from #GET_PAGESIZE */
 	unsigned int	me_maxreaders;	/**< size of the reader table */
-	unsigned int	me_numreaders;	/**< max numreaders set by this env */
+	/** Max #MDB_txninfo.%mti_numreaders of interest to #mdb_env_close() */
+	volatile int	me_close_readers;
 	MDB_dbi		me_numdbs;		/**< number of DBs opened */
 	MDB_dbi		me_maxdbs;		/**< size of the DB table */
 	MDB_PID_T	me_pid;		/**< process ID of this env */
 	char		*me_path;		/**< path to the DB files */
 	char		*me_map;		/**< the memory map of the data file */
 	MDB_txninfo	*me_txns;		/**< the memory map of the lock file or NULL */
-	MDB_meta	*me_metas[2];	/**< pointers to the two meta pages */
+	MDB_meta	*me_metas[NUM_METAS];	/**< pointers to the two meta pages */
 	void		*me_pbuf;		/**< scratch area for DUPSORT put() */
 	MDB_txn		*me_txn;		/**< current write transaction */
 	MDB_txn		*me_txn0;		/**< prealloc'd write transaction */
-	size_t		me_mapsize;		/**< size of the data memory map */
+	mdb_size_t	me_mapsize;		/**< size of the data memory map */
 	off_t		me_size;		/**< current file size */
 	pgno_t		me_maxpg;		/**< me_mapsize / me_psize */
 	MDB_dbx		*me_dbxs;		/**< array of static DB info */
@@ -1159,11 +1394,20 @@ struct MDB_env {
 	int		me_live_reader;		/**< have liveness lock in reader table */
 #ifdef _WIN32
 	int		me_pidquery;		/**< Used in OpenProcess */
-	HANDLE		me_rmutex;		/* Windows mutexes don't reside in shared mem */
-	HANDLE		me_wmutex;
-#elif defined(MDB_USE_POSIX_SEM)
-	sem_t		*me_rmutex;		/* Shared mutexes are not supported */
-	sem_t		*me_wmutex;
+#endif
+#ifdef MDB_USE_POSIX_MUTEX	/* Posix mutexes reside in shared mem */
+#	define		me_rmutex	me_txns->mti_rmutex /**< Shared reader lock */
+#	define		me_wmutex	me_txns->mti_wmutex /**< Shared writer lock */
+#else
+	mdb_mutex_t	me_rmutex;
+	mdb_mutex_t	me_wmutex;
+#endif
+#ifdef MDB_VL32
+	MDB_ID3L	me_rpages;	/**< like #mt_rpages, but global to env */
+	pthread_mutex_t	me_rpmutex;	/**< control access to #me_rpages */
+#define MDB_ERPAGE_SIZE	16384
+#define MDB_ERPAGE_MAX	(MDB_ERPAGE_SIZE-1)
+	unsigned int me_rpcheck;
 #endif
 	void		*me_userctx;	 /**< User-settable context */
 	MDB_assert_func *me_assert_func; /**< Callback for assertion failures */
@@ -1186,8 +1430,8 @@ typedef struct MDB_ntxn {
 #define MAX_WRITE		(0x80000000U >> (sizeof(ssize_t) == 4))
 
 	/** Check \b txn and \b dbi arguments to a function */
-#define TXN_DBI_EXIST(txn, dbi) \
-	((txn) && (dbi) < (txn)->mt_numdbs && ((txn)->mt_dbflags[dbi] & DB_VALID))
+#define TXN_DBI_EXIST(txn, dbi, validity) \
+	((txn) && (dbi)<(txn)->mt_numdbs && ((txn)->mt_dbflags[dbi] & (validity)))
 
 	/** Check for misused \b dbi handles */
 #define TXN_DBI_CHANGED(txn, dbi) \
@@ -1197,7 +1441,20 @@ static int  mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp);
 static int  mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp);
 static int  mdb_page_touch(MDB_cursor *mc);
 
-static int  mdb_page_get(MDB_txn *txn, pgno_t pgno, MDB_page **mp, int *lvl);
+#define MDB_END_NAMES {"committed", "empty-commit", "abort", "reset", \
+	"reset-tmp", "fail-begin", "fail-beginchild"}
+enum {
+	/* mdb_txn_end operation number, for logging */
+	MDB_END_COMMITTED, MDB_END_EMPTY_COMMIT, MDB_END_ABORT, MDB_END_RESET,
+	MDB_END_RESET_TMP, MDB_END_FAIL_BEGIN, MDB_END_FAIL_BEGINCHILD
+};
+#define MDB_END_OPMASK	0x0F	/**< mask for #mdb_txn_end() operation number */
+#define MDB_END_UPDATE	0x10	/**< update env state (DBIs) */
+#define MDB_END_FREE	0x20	/**< free txn unless it is #MDB_env.%me_txn0 */
+#define MDB_END_SLOT MDB_NOTLS	/**< release any reader slot if #MDB_NOTLS */
+static void mdb_txn_end(MDB_txn *txn, unsigned mode);
+
+static int  mdb_page_get(MDB_cursor *mc, pgno_t pgno, MDB_page **mp, int *lvl);
 static int  mdb_page_search_root(MDB_cursor *mc,
 			    MDB_val *key, int modify);
 #define MDB_PS_MODIFY	1
@@ -1213,9 +1470,9 @@ static int	mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata,
 				pgno_t newpgno, unsigned int nflags);
 
 static int  mdb_env_read_header(MDB_env *env, MDB_meta *meta);
-static int  mdb_env_pick_meta(const MDB_env *env);
+static MDB_meta *mdb_env_pick_meta(const MDB_env *env);
 static int  mdb_env_write_meta(MDB_txn *txn);
-#if !(defined(_WIN32) || defined(MDB_USE_POSIX_SEM)) /* Drop unused excl arg */
+#ifdef MDB_USE_POSIX_MUTEX /* Drop unused excl arg */
 # define mdb_env_close0(env, excl) mdb_env_close1(env)
 #endif
 static void mdb_env_close0(MDB_env *env, int excl);
@@ -1225,8 +1482,8 @@ static int  mdb_node_add(MDB_cursor *mc, indx_t indx,
 			    MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags);
 static void mdb_node_del(MDB_cursor *mc, int ksize);
 static void mdb_node_shrink(MDB_page *mp, indx_t indx);
-static int	mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst);
-static int  mdb_node_read(MDB_txn *txn, MDB_node *leaf, MDB_val *data);
+static int	mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst, int fromleft);
+static int  mdb_node_read(MDB_cursor *mc, MDB_node *leaf, MDB_val *data);
 static size_t	mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data);
 static size_t	mdb_branch_size(MDB_env *env, MDB_val *key);
 
@@ -1249,9 +1506,11 @@ static int	mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data);
 static void	mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx);
 static void	mdb_xcursor_init0(MDB_cursor *mc);
 static void	mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node);
+static void	mdb_xcursor_init2(MDB_cursor *mc, MDB_xcursor *src_mx, int force);
 
 static int	mdb_drop0(MDB_cursor *mc, int subs);
 static void mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi);
+static int mdb_reader_check0(MDB_env *env, int rlocked, int *dead);
 
 /** @cond */
 static MDB_cmp_func	mdb_cmp_memn, mdb_cmp_memnr, mdb_cmp_int, mdb_cmp_cint, mdb_cmp_long;
@@ -1268,10 +1527,12 @@ static MDB_cmp_func	mdb_cmp_memn, mdb_cmp_memnr, mdb_cmp_int, mdb_cmp_cint, mdb_
 static SECURITY_DESCRIPTOR mdb_null_sd;
 static SECURITY_ATTRIBUTES mdb_all_sa;
 static int mdb_sec_inited;
+
+static int utf8_to_utf16(const char *src, int srcsize, wchar_t **dst, int *dstsize);
 #endif
 
 /** Return the library version info. */
-char *
+char * ESECT
 mdb_version(int *major, int *minor, int *patch)
 {
 	if (major) *major = MDB_VERSION_MAJOR;
@@ -1286,7 +1547,7 @@ static char *const mdb_errstr[] = {
 	"MDB_NOTFOUND: No matching key/data pair found",
 	"MDB_PAGE_NOTFOUND: Requested page not found",
 	"MDB_CORRUPTED: Located page was wrong type",
-	"MDB_PANIC: Update of meta page failed",
+	"MDB_PANIC: Update of meta page failed or environment had fatal error",
 	"MDB_VERSION_MISMATCH: Database environment version mismatch",
 	"MDB_INVALID: File is not an LMDB file",
 	"MDB_MAP_FULL: Environment mapsize limit reached",
@@ -1299,7 +1560,7 @@ static char *const mdb_errstr[] = {
 	"MDB_MAP_RESIZED: Database contents grew beyond environment mapsize",
 	"MDB_INCOMPATIBLE: Operation and DB incompatible, or DB flags changed",
 	"MDB_BAD_RSLOT: Invalid reuse of reader locktable slot",
-	"MDB_BAD_TXN: Transaction cannot recover - it must be aborted",
+	"MDB_BAD_TXN: Transaction must abort, has a child, or is invalid",
 	"MDB_BAD_VALSIZE: Unsupported size of key/DB name/data, or wrong DUPFIXED size",
 	"MDB_BAD_DBI: The specified DBI handle was closed/changed unexpectedly",
 };
@@ -1343,7 +1604,7 @@ mdb_strerror(int err)
 		;
 	}
 	buf[0] = 0;
-	FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM |
+	FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM |
 		FORMAT_MESSAGE_IGNORE_INSERTS,
 		NULL, err, 0, ptr, sizeof(buf), (va_list *)pad);
 	return ptr;
@@ -1355,7 +1616,7 @@ mdb_strerror(int err)
 /** assert(3) variant in cursor context */
 #define mdb_cassert(mc, expr)	mdb_assert0((mc)->mc_txn->mt_env, expr, #expr)
 /** assert(3) variant in transaction context */
-#define mdb_tassert(mc, expr)	mdb_assert0((txn)->mt_env, expr, #expr)
+#define mdb_tassert(txn, expr)	mdb_assert0((txn)->mt_env, expr, #expr)
 /** assert(3) variant in environment context */
 #define mdb_eassert(env, expr)	mdb_assert0(env, expr, #expr)
 
@@ -1363,7 +1624,7 @@ mdb_strerror(int err)
 # define mdb_assert0(env, expr, expr_txt) ((expr) ? (void)0 : \
 		mdb_assert_fail(env, expr_txt, mdb_func_, __FILE__, __LINE__))
 
-static void
+static void ESECT
 mdb_assert_fail(MDB_env *env, const char *expr_txt,
 	const char *func, const char *file, int line)
 {
@@ -1445,20 +1706,20 @@ mdb_page_list(MDB_page *mp)
 	case P_LEAF|P_LEAF2:        type = "LEAF2 page";		break;
 	case P_LEAF|P_LEAF2|P_SUBP: type = "LEAF2 sub-page";	break;
 	case P_OVERFLOW:
-		fprintf(stderr, "Overflow page %"Z"u pages %u%s\n",
+		fprintf(stderr, "Overflow page %"Yu" pages %u%s\n",
 			pgno, mp->mp_pages, state);
 		return;
 	case P_META:
-		fprintf(stderr, "Meta-page %"Z"u txnid %"Z"u\n",
+		fprintf(stderr, "Meta-page %"Yu" txnid %"Yu"\n",
 			pgno, ((MDB_meta *)METADATA(mp))->mm_txnid);
 		return;
 	default:
-		fprintf(stderr, "Bad page %"Z"u flags 0x%u\n", pgno, mp->mp_flags);
+		fprintf(stderr, "Bad page %"Yu" flags 0x%u\n", pgno, mp->mp_flags);
 		return;
 	}
 
 	nkeys = NUMKEYS(mp);
-	fprintf(stderr, "%s %"Z"u numkeys %d%s\n", type, pgno, nkeys, state);
+	fprintf(stderr, "%s %"Yu" numkeys %d%s\n", type, pgno, nkeys, state);
 
 	for (i=0; i<nkeys; i++) {
 		if (IS_LEAF2(mp)) {	/* LEAF2 pages have no mp_ptrs[] or node headers */
@@ -1473,7 +1734,7 @@ mdb_page_list(MDB_page *mp)
 		key.mv_data = node->mn_data;
 		nsize = NODESIZE + key.mv_size;
 		if (IS_BRANCH(mp)) {
-			fprintf(stderr, "key %d: page %"Z"u, %s\n", i, NODEPGNO(node),
+			fprintf(stderr, "key %d: page %"Yu", %s\n", i, NODEPGNO(node),
 				DKEY(&key));
 			total += nsize;
 		} else {
@@ -1499,7 +1760,7 @@ mdb_cursor_chk(MDB_cursor *mc)
 	MDB_node *node;
 	MDB_page *mp;
 
-	if (!mc->mc_snum && !(mc->mc_flags & C_INITIALIZED)) return;
+	if (!mc->mc_snum || !(mc->mc_flags & C_INITIALIZED)) return;
 	for (i=0; i<mc->mc_top; i++) {
 		mp = mc->mc_pg[i];
 		node = NODEPTR(mp, mc->mc_ki[i]);
@@ -1508,6 +1769,13 @@ mdb_cursor_chk(MDB_cursor *mc)
 	}
 	if (mc->mc_ki[i] >= NUMKEYS(mc->mc_pg[i]))
 		printf("ack!\n");
+	if (mc->mc_xcursor && (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {
+		node = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
+		if (((node->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA) &&
+			mc->mc_xcursor->mx_cursor.mc_pg[0] != NODEDATA(node)) {
+			printf("blah!\n");
+		}
+	}
 }
 #endif
 
@@ -1561,9 +1829,10 @@ static void mdb_audit(MDB_txn *txn)
 			mdb_tassert(txn, rc == MDB_NOTFOUND);
 		}
 	}
-	if (freecount + count + 2 /* metapages */ != txn->mt_next_pgno) {
-		fprintf(stderr, "audit: %lu freecount: %lu count: %lu total: %lu next_pgno: %lu\n",
-			txn->mt_txnid, freecount, count+2, freecount+count+2, txn->mt_next_pgno);
+	if (freecount + count + NUM_METAS != txn->mt_next_pgno) {
+		fprintf(stderr, "audit: %"Yu" freecount: %"Yu" count: %"Yu" total: %"Yu" next_pgno: %"Yu"\n",
+			txn->mt_txnid, freecount, count+NUM_METAS,
+			freecount+count+NUM_METAS, txn->mt_next_pgno);
 	}
 }
 #endif
@@ -1578,8 +1847,8 @@ int
 mdb_dcmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
 {
 	MDB_cmp_func *dcmp = txn->mt_dbxs[dbi].md_dcmp;
-#if UINT_MAX < SIZE_MAX
-	if (dcmp == mdb_cmp_int && a->mv_size == sizeof(size_t))
+#if UINT_MAX < SIZE_MAX || defined(MDB_VL32)
+	if (dcmp == mdb_cmp_int && a->mv_size == sizeof(mdb_size_t))
 		dcmp = mdb_cmp_clong;
 #endif
 	return dcmp(a, b);
@@ -1661,6 +1930,45 @@ mdb_dlist_free(MDB_txn *txn)
 	dl[0].mid = 0;
 }
 
+#ifdef MDB_VL32
+static void
+mdb_page_unref(MDB_txn *txn, MDB_page *mp)
+{
+	pgno_t pgno;
+	MDB_ID3L tl = txn->mt_rpages;
+	unsigned x, rem;
+	if (mp->mp_flags & (P_SUBP|P_DIRTY))
+		return;
+	rem = mp->mp_pgno & (MDB_RPAGE_CHUNK-1);
+	pgno = mp->mp_pgno ^ rem;
+	x = mdb_mid3l_search(tl, pgno);
+	if (x != tl[0].mid && tl[x+1].mid == mp->mp_pgno)
+		x++;
+	if (tl[x].mref)
+		tl[x].mref--;
+}
+#define MDB_PAGE_UNREF(txn, mp)	mdb_page_unref(txn, mp)
+
+static void
+mdb_cursor_unref(MDB_cursor *mc)
+{
+	int i;
+	if (!mc->mc_pg[0] || IS_SUBP(mc->mc_pg[0]))
+		return;
+	for (i=0; i<mc->mc_snum; i++)
+		mdb_page_unref(mc->mc_txn, mc->mc_pg[i]);
+	if (mc->mc_ovpg) {
+		mdb_page_unref(mc->mc_txn, mc->mc_ovpg);
+		mc->mc_ovpg = 0;
+	}
+	mc->mc_snum = mc->mc_top = 0;
+	mc->mc_pg[0] = NULL;
+	mc->mc_flags &= ~C_INITIALIZED;
+}
+#else
+#define MDB_PAGE_UNREF(txn, mp)
+#endif /* MDB_VL32 */
+
 /** Loosen or free a single page.
  * Saves single pages to a list for future reuse
  * in this same txn. It has been pulled from the freeDB
@@ -1702,7 +2010,7 @@ mdb_page_loose(MDB_cursor *mc, MDB_page *mp)
 		}
 	}
 	if (loose) {
-		DPRINTF(("loosen db %d page %"Z"u", DDBI(mc),
+		DPRINTF(("loosen db %d page %"Yu"", DDBI(mc),
 			mp->mp_pgno));
 		NEXT_LOOSE_PAGE(mp) = txn->mt_loose_pgs;
 		txn->mt_loose_pgs = mp;
@@ -1729,7 +2037,7 @@ mdb_pages_xkeep(MDB_cursor *mc, unsigned pflags, int all)
 {
 	enum { Mask = P_SUBP|P_DIRTY|P_LOOSE|P_KEEP };
 	MDB_txn *txn = mc->mc_txn;
-	MDB_cursor *m3;
+	MDB_cursor *m3, *m0 = mc;
 	MDB_xcursor *mx;
 	MDB_page *dp, *mp;
 	MDB_node *leaf;
@@ -1772,7 +2080,7 @@ mdb_pages_xkeep(MDB_cursor *mc, unsigned pflags, int all)
 				pgno_t pgno = txn->mt_dbs[i].md_root;
 				if (pgno == P_INVALID)
 					continue;
-				if ((rc = mdb_page_get(txn, pgno, &dp, &level)) != MDB_SUCCESS)
+				if ((rc = mdb_page_get(m0, pgno, &dp, &level)) != MDB_SUCCESS)
 					break;
 				if ((dp->mp_flags & Mask) == pflags && level <= 1)
 					dp->mp_flags ^= P_KEEP;
@@ -1832,7 +2140,7 @@ mdb_page_spill(MDB_cursor *m0, MDB_val *key, MDB_val *data)
 	/* Estimate how much space this op will take */
 	i = m0->mc_db->md_depth;
 	/* Named DBs also dirty the main DB */
-	if (m0->mc_dbi > MAIN_DBI)
+	if (m0->mc_dbi >= CORE_DBS)
 		i += txn->mt_dbs[MAIN_DBI].md_depth;
 	/* For puts, roughly factor in the key+data size */
 	if (key)
@@ -1941,7 +2249,7 @@ mdb_page_dirty(MDB_txn *txn, MDB_page *mp)
 	MDB_ID2 mid;
 	int rc, (*insert)(MDB_ID2L, MDB_ID2 *);
 
-	if (txn->mt_env->me_flags & MDB_WRITEMAP) {
+	if (txn->mt_flags & MDB_TXN_WRITEMAP) {
 		insert = mdb_mid2l_append;
 	} else {
 		insert = mdb_mid2l_insert;
@@ -1961,6 +2269,8 @@ mdb_page_dirty(MDB_txn *txn, MDB_page *mp)
  * Do not modify the freedB, just merge freeDB records into me_pghead[]
  * and move me_pglast to say which records were consumed.  Only this
  * function can create me_pghead and move me_pglast/mt_next_pgno.
+ * When #MDB_DEVEL & 2, it is not affected by #mdb_freelist_save(): it
+ * then uses the transaction's original snapshot of the freeDB.
  * @param[in] mc cursor A cursor handle identifying the transaction and
  *	database for which we are allocating.
  * @param[in] num the number of pages to allocate.
@@ -1998,7 +2308,7 @@ mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp)
 		np = txn->mt_loose_pgs;
 		txn->mt_loose_pgs = NEXT_LOOSE_PAGE(np);
 		txn->mt_loose_count--;
-		DPRINTF(("db %d use loose page %"Z"u", DDBI(mc),
+		DPRINTF(("db %d use loose page %"Yu"", DDBI(mc),
 				np->mp_pgno));
 		*mp = np;
 		return MDB_SUCCESS;
@@ -2036,6 +2346,14 @@ mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp)
 			last = env->me_pglast;
 			oldest = env->me_pgoldest;
 			mdb_cursor_init(&m2, txn, FREE_DBI, NULL);
+#if (MDB_DEVEL) & 2	/* "& 2" so MDB_DEVEL=1 won't hide bugs breaking freeDB */
+			/* Use original snapshot. TODO: Should need less care in code
+			 * which modifies the database. Maybe we can delete some code?
+			 */
+			m2.mc_flags |= C_ORIG_RDONLY;
+			m2.mc_db = &env->me_metas[(txn->mt_txnid-1) & 1]->mm_dbs[FREE_DBI];
+			m2.mc_dbflag = (unsigned char *)""; /* probably unnecessary */
+#endif
 			if (last) {
 				op = MDB_SET_RANGE;
 				key.mv_data = &last; /* will look up last+1 */
@@ -2076,7 +2394,7 @@ mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp)
 		}
 		np = m2.mc_pg[m2.mc_top];
 		leaf = NODEPTR(np, m2.mc_ki[m2.mc_top]);
-		if ((rc = mdb_node_read(txn, leaf, &data)) != MDB_SUCCESS)
+		if ((rc = mdb_node_read(&m2, leaf, &data)) != MDB_SUCCESS)
 			return rc;
 
 		idl = (MDB_ID *) data.mv_data;
@@ -2093,10 +2411,10 @@ mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp)
 		}
 		env->me_pglast = last;
 #if (MDB_DEBUG) > 1
-		DPRINTF(("IDL read txn %"Z"u root %"Z"u num %u",
+		DPRINTF(("IDL read txn %"Yu" root %"Yu" num %u",
 			last, txn->mt_dbs[FREE_DBI].md_root, i));
 		for (j = i; j; j--)
-			DPRINTF(("IDL %"Z"u", idl[j]));
+			DPRINTF(("IDL %"Yu"", idl[j]));
 #endif
 		/* Merge in descending sorted order */
 		mdb_midl_xmerge(mop, idl);
@@ -2111,6 +2429,20 @@ mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp)
 			rc = MDB_MAP_FULL;
 			goto fail;
 	}
+#ifdef _WIN32
+	if (env->me_flags & MDB_WRITEMAP) {
+		void *p;
+		p = (MDB_page *)(env->me_map + env->me_psize * pgno);
+		p = VirtualAlloc(p, env->me_psize * num, MEM_COMMIT,
+			(env->me_flags & MDB_WRITEMAP) ? PAGE_READWRITE:
+			PAGE_READONLY);
+		if (!p) {
+			DPUTS("VirtualAlloc failed");
+			rc = ErrCode();
+			goto fail;
+		}
+	}
+#endif
 
 search_done:
 	if (env->me_flags & MDB_WRITEMAP) {
@@ -2252,7 +2584,7 @@ mdb_page_touch(MDB_cursor *mc)
 			(rc = mdb_page_alloc(mc, 1, &np)))
 			goto fail;
 		pgno = np->mp_pgno;
-		DPRINTF(("touched db %d page %"Z"u -> %"Z"u", DDBI(mc),
+		DPRINTF(("touched db %d page %"Yu" -> %"Yu"", DDBI(mc),
 			mp->mp_pgno, pgno));
 		mdb_cassert(mc, mp->mp_pgno != pgno);
 		mdb_midl_xappend(txn->mt_free_pgs, mp->mp_pgno);
@@ -2312,33 +2644,21 @@ done:
 	} else {
 		for (; m2; m2=m2->mc_next) {
 			if (m2->mc_snum < mc->mc_snum) continue;
+			if (m2 == mc) continue;
 			if (m2->mc_pg[mc->mc_top] == mp) {
 				m2->mc_pg[mc->mc_top] = np;
 				if ((mc->mc_db->md_flags & MDB_DUPSORT) &&
 					IS_LEAF(np) &&
-					m2->mc_ki[mc->mc_top] == mc->mc_ki[mc->mc_top])
+					(m2->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED))
 				{
-					MDB_node *leaf = NODEPTR(np, mc->mc_ki[mc->mc_top]);
-					if (!(leaf->mn_flags & F_SUBDATA))
+					MDB_node *leaf = NODEPTR(np, m2->mc_ki[mc->mc_top]);
+					if ((leaf->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA)
 						m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
 				}
 			}
 		}
 	}
-#ifdef VL32
-	{
-		MDB_ID2L rl = mc->mc_txn->mt_rpages;
-		unsigned x = mdb_mid2l_search(rl, mp->mp_pgno);
-		if (x <= rl[0].mid && rl[x].mid == mp->mp_pgno) {
-			munmap(mp, mc->mc_txn->mt_env->me_psize);
-			while (x < rl[0].mid) {
-				rl[x] = rl[x+1];
-				x++;
-			}
-			rl[0].mid--;
-		}
-	}
-#endif
+	MDB_PAGE_UNREF(mc->mc_txn, mp);
 	return 0;
 
 fail:
@@ -2347,7 +2667,7 @@ fail:
 }
 
 int
-mdb_env_sync(MDB_env *env, int force)
+mdb_env_sync0(MDB_env *env, int force, pgno_t numpgs)
 {
 	int rc = 0;
 	if (env->me_flags & MDB_RDONLY)
@@ -2356,7 +2676,7 @@ mdb_env_sync(MDB_env *env, int force)
 		if (env->me_flags & MDB_WRITEMAP) {
 			int flags = ((env->me_flags & MDB_MAPASYNC) && !force)
 				? MS_ASYNC : MS_SYNC;
-			if (MDB_MSYNC(env->me_map, env->me_mapsize, flags))
+			if (MDB_MSYNC(env->me_map, env->me_psize * numpgs, flags))
 				rc = ErrCode();
 #ifdef _WIN32
 			else if (flags == MS_SYNC && MDB_FDATASYNC(env->me_fd))
@@ -2376,6 +2696,13 @@ mdb_env_sync(MDB_env *env, int force)
 	return rc;
 }
 
+int
+mdb_env_sync(MDB_env *env, int force)
+{
+	MDB_meta *m = mdb_env_pick_meta(env);
+	return mdb_env_sync0(env, force, m->mm_last_pg+1);
+}
+
 /** Back up parent txn's cursors, then grab the originals for tracking */
 static int
 mdb_cursor_shadow(MDB_txn *src, MDB_txn *dst)
@@ -2397,14 +2724,15 @@ mdb_cursor_shadow(MDB_txn *src, MDB_txn *dst)
 				*bk = *mc;
 				mc->mc_backup = bk;
 				mc->mc_db = &dst->mt_dbs[i];
-				/* Kill pointers into src - and dst to reduce abuse: The
-				 * user may not use mc until dst ends. Otherwise we'd...
+				/* Kill pointers into src to reduce abuse: The
+				 * user may not use mc until dst ends. But we need a valid
+				 * txn pointer here for cursor fixups to keep working.
 				 */
-				mc->mc_txn    = NULL;	/* ...set this to dst */
-				mc->mc_dbflag = NULL;	/* ...and &dst->mt_dbflags[i] */
+				mc->mc_txn    = dst;
+				mc->mc_dbflag = &dst->mt_dbflags[i];
 				if ((mx = mc->mc_xcursor) != NULL) {
 					*(MDB_xcursor *)(bk+1) = *mx;
-					mx->mx_cursor.mc_txn = NULL; /* ...and dst. */
+					mx->mx_cursor.mc_txn = dst;
 				}
 				mc->mc_next = dst->mt_cursors[i];
 				dst->mt_cursors[i] = mc;
@@ -2454,12 +2782,6 @@ mdb_cursors_close(MDB_txn *txn, unsigned merge)
 	}
 }
 
-#if !(MDB_DEBUG)
-#define mdb_txn_reset0(txn, act) mdb_txn_reset0(txn)
-#endif
-static void
-mdb_txn_reset0(MDB_txn *txn, const char *act);
-
 #if !(MDB_PIDLOCK)		/* Currently the same as defined(_WIN32) */
 enum Pidlock_op {
 	Pidset, Pidcheck
@@ -2530,7 +2852,7 @@ mdb_txn_renew0(MDB_txn *txn)
 
 	if ((flags &= MDB_TXN_RDONLY) != 0) {
 		if (!ti) {
-			meta = env->me_metas[ mdb_env_pick_meta(env) ];
+			meta = mdb_env_pick_meta(env);
 			txn->mt_txnid = meta->mm_txnid;
 			txn->mt_u.reader = NULL;
 		} else {
@@ -2542,6 +2864,7 @@ mdb_txn_renew0(MDB_txn *txn)
 			} else {
 				MDB_PID_T pid = env->me_pid;
 				MDB_THR_T tid = pthread_self();
+				mdb_mutexref_t rmutex = env->me_rmutex;
 
 				if (!env->me_live_reader) {
 					rc = mdb_reader_pid(env, Pidset, pid);
@@ -2550,24 +2873,32 @@ mdb_txn_renew0(MDB_txn *txn)
 					env->me_live_reader = 1;
 				}
 
-				LOCK_MUTEX_R(env);
+				if (LOCK_MUTEX(rc, env, rmutex))
+					return rc;
 				nr = ti->mti_numreaders;
 				for (i=0; i<nr; i++)
 					if (ti->mti_readers[i].mr_pid == 0)
 						break;
 				if (i == env->me_maxreaders) {
-					UNLOCK_MUTEX_R(env);
+					UNLOCK_MUTEX(rmutex);
 					return MDB_READERS_FULL;
 				}
-				ti->mti_readers[i].mr_pid = pid;
-				ti->mti_readers[i].mr_tid = tid;
+				r = &ti->mti_readers[i];
+				/* Claim the reader slot, carefully since other code
+				 * uses the reader table un-mutexed: First reset the
+				 * slot, next publish it in mti_numreaders.  After
+				 * that, it is safe for mdb_env_close() to touch it.
+				 * When it will be closed, we can finally claim it.
+				 */
+				r->mr_pid = 0;
+				r->mr_txnid = (txnid_t)-1;
+				r->mr_tid = tid;
 				if (i == nr)
 					ti->mti_numreaders = ++nr;
-				/* Save numreaders for un-mutexed mdb_env_close() */
-				env->me_numreaders = nr;
-				UNLOCK_MUTEX_R(env);
+				env->me_close_readers = nr;
+				r->mr_pid = pid;
+				UNLOCK_MUTEX(rmutex);
 
-				r = &ti->mti_readers[i];
 				new_notls = (env->me_flags & MDB_NOTLS);
 				if (!new_notls && (rc=pthread_setspecific(env->me_txkey, r))) {
 					r->mr_pid = 0;
@@ -2581,15 +2912,16 @@ mdb_txn_renew0(MDB_txn *txn)
 			txn->mt_u.reader = r;
 			meta = env->me_metas[txn->mt_txnid & 1];
 		}
-		txn->mt_dbxs = env->me_dbxs;	/* mostly static anyway */
+
 	} else {
+		/* Not yet touching txn == env->me_txn0, it may be active */
 		if (ti) {
-			LOCK_MUTEX_W(env);
-
+			if (LOCK_MUTEX(rc, env, env->me_wmutex))
+				return rc;
 			txn->mt_txnid = ti->mti_txnid;
 			meta = env->me_metas[txn->mt_txnid & 1];
 		} else {
-			meta = env->me_metas[ mdb_env_pick_meta(env) ];
+			meta = mdb_env_pick_meta(env);
 			txn->mt_txnid = meta->mm_txnid;
 		}
 		txn->mt_txnid++;
@@ -2611,32 +2943,36 @@ mdb_txn_renew0(MDB_txn *txn)
 	}
 
 	/* Copy the DB info and flags */
-	memcpy(txn->mt_dbs, meta->mm_dbs, 2 * sizeof(MDB_db));
+	memcpy(txn->mt_dbs, meta->mm_dbs, CORE_DBS * sizeof(MDB_db));
 
 	/* Moved to here to avoid a data race in read TXNs */
 	txn->mt_next_pgno = meta->mm_last_pg+1;
+#ifdef MDB_VL32
+	txn->mt_last_pgno = txn->mt_next_pgno - 1;
+#endif
 
 	txn->mt_flags = flags;
 
 	/* Setup db info */
 	txn->mt_numdbs = env->me_numdbs;
-	for (i=2; i<txn->mt_numdbs; i++) {
+	for (i=CORE_DBS; i<txn->mt_numdbs; i++) {
 		x = env->me_dbflags[i];
 		txn->mt_dbs[i].md_flags = x & PERSISTENT_FLAGS;
-		txn->mt_dbflags[i] = (x & MDB_VALID) ? DB_VALID|DB_STALE : 0;
+		txn->mt_dbflags[i] = (x & MDB_VALID) ? DB_VALID|DB_USRVALID|DB_STALE : 0;
 	}
-	txn->mt_dbflags[0] = txn->mt_dbflags[1] = DB_VALID;
+	txn->mt_dbflags[MAIN_DBI] = DB_VALID|DB_USRVALID;
+	txn->mt_dbflags[FREE_DBI] = DB_VALID;
 
-	if (env->me_maxpg < txn->mt_next_pgno) {
-		mdb_txn_reset0(txn, "renew0-mapfail");
-		if (new_notls) {
-			txn->mt_u.reader->mr_pid = 0;
-			txn->mt_u.reader = NULL;
-		}
-		return MDB_MAP_RESIZED;
+	if (env->me_flags & MDB_FATAL_ERROR) {
+		DPUTS("environment had fatal error, must shutdown!");
+		rc = MDB_PANIC;
+	} else if (env->me_maxpg < txn->mt_next_pgno) {
+		rc = MDB_MAP_RESIZED;
+	} else {
+		return MDB_SUCCESS;
 	}
-
-	return MDB_SUCCESS;
+	mdb_txn_end(txn, new_notls /*0 or MDB_END_SLOT*/ | MDB_END_FAIL_BEGIN);
+	return rc;
 }
 
 int
@@ -2644,17 +2980,12 @@ mdb_txn_renew(MDB_txn *txn)
 {
 	int rc;
 
-	if (!txn || txn->mt_dbxs)	/* A reset txn has mt_dbxs==NULL */
+	if (!txn || !F_ISSET(txn->mt_flags, MDB_TXN_RDONLY|MDB_TXN_FINISHED))
 		return EINVAL;
 
-	if (txn->mt_env->me_flags & MDB_FATAL_ERROR) {
-		DPUTS("environment had fatal error, must shutdown!");
-		return MDB_PANIC;
-	}
-
 	rc = mdb_txn_renew0(txn);
 	if (rc == MDB_SUCCESS) {
-		DPRINTF(("renew txn %"Z"u%c %p on mdbenv %p, root page %"Z"u",
+		DPRINTF(("renew txn %"Yu"%c %p on mdbenv %p, root page %"Yu"",
 			txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
 			(void *)txn, (void *)txn->mt_env, txn->mt_dbs[MAIN_DBI].md_root));
 	}
@@ -2666,69 +2997,58 @@ mdb_txn_begin(MDB_env *env, MDB_txn *parent, unsigned int flags, MDB_txn **ret)
 {
 	MDB_txn *txn;
 	MDB_ntxn *ntxn;
-	int rc, size, tsize = sizeof(MDB_txn);
+	int rc, size, tsize;
 
-	if (env->me_flags & MDB_FATAL_ERROR) {
-		DPUTS("environment had fatal error, must shutdown!");
-		return MDB_PANIC;
-	}
-	if ((env->me_flags & MDB_RDONLY) && !(flags & MDB_RDONLY))
+	flags &= MDB_TXN_BEGIN_FLAGS;
+	flags |= env->me_flags & MDB_WRITEMAP;
+
+	if (env->me_flags & MDB_RDONLY & ~flags) /* write txn in RDONLY env */
 		return EACCES;
+
 	if (parent) {
 		/* Nested transactions: Max 1 child, write txns only, no writemap */
-		if (parent->mt_child ||
-			(flags & MDB_RDONLY) ||
-			(parent->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_ERROR)) ||
-			(env->me_flags & MDB_WRITEMAP))
-		{
+		flags |= parent->mt_flags;
+		if (flags & (MDB_RDONLY|MDB_WRITEMAP|MDB_TXN_BLOCKED)) {
 			return (parent->mt_flags & MDB_TXN_RDONLY) ? EINVAL : MDB_BAD_TXN;
 		}
-		tsize = sizeof(MDB_ntxn);
-	}
-	size = tsize;
-	if (!(flags & MDB_RDONLY)) {
-		if (!parent) {
-			txn = env->me_txn0;	/* just reuse preallocated write txn */
-			goto ok;
-		}
-		/* child txns use own copy of cursors */
-		size += env->me_maxdbs * sizeof(MDB_cursor *);
+		/* Child txns save MDB_pgstate and use own copy of cursors */
+		size = env->me_maxdbs * (sizeof(MDB_db)+sizeof(MDB_cursor *)+1);
+		size += tsize = sizeof(MDB_ntxn);
+	} else if (flags & MDB_RDONLY) {
+		size = env->me_maxdbs * (sizeof(MDB_db)+1);
+		size += tsize = sizeof(MDB_txn);
+	} else {
+		/* Reuse preallocated write txn. However, do not touch it until
+		 * mdb_txn_renew0() succeeds, since it currently may be active.
+		 */
+		txn = env->me_txn0;
+		goto renew;
 	}
-	size += env->me_maxdbs * (sizeof(MDB_db)+1);
-
 	if ((txn = calloc(1, size)) == NULL) {
 		DPRINTF(("calloc: %s", strerror(errno)));
 		return ENOMEM;
 	}
-#ifdef VL32
+#ifdef MDB_VL32
 	if (!parent) {
-		txn->mt_rpages = calloc(MDB_IDL_UM_SIZE, sizeof(MDB_ID2));
+		txn->mt_rpages = malloc(MDB_TRPAGE_SIZE * sizeof(MDB_ID3));
 		if (!txn->mt_rpages) {
 			free(txn);
 			return ENOMEM;
 		}
+		txn->mt_rpages[0].mid = 0;
+		txn->mt_rpcheck = MDB_TRPAGE_SIZE/2;
 	}
 #endif
+	txn->mt_dbxs = env->me_dbxs;	/* static */
 	txn->mt_dbs = (MDB_db *) ((char *)txn + tsize);
-	if (flags & MDB_RDONLY) {
-		txn->mt_flags |= MDB_TXN_RDONLY;
-		txn->mt_dbflags = (unsigned char *)(txn->mt_dbs + env->me_maxdbs);
-		txn->mt_dbiseqs = env->me_dbiseqs;
-	} else {
-		txn->mt_cursors = (MDB_cursor **)(txn->mt_dbs + env->me_maxdbs);
-		if (parent) {
-			txn->mt_dbiseqs = parent->mt_dbiseqs;
-			txn->mt_dbflags = (unsigned char *)(txn->mt_cursors + env->me_maxdbs);
-		} else {
-			txn->mt_dbiseqs = (unsigned int *)(txn->mt_cursors + env->me_maxdbs);
-			txn->mt_dbflags = (unsigned char *)(txn->mt_dbiseqs + env->me_maxdbs);
-		}
-	}
+	txn->mt_dbflags = (unsigned char *)txn + size - env->me_maxdbs;
+	txn->mt_flags = flags;
 	txn->mt_env = env;
 
-ok:
 	if (parent) {
 		unsigned int i;
+		txn->mt_cursors = (MDB_cursor **)(txn->mt_dbs + env->me_maxdbs);
+		txn->mt_dbiseqs = parent->mt_dbiseqs;
 		txn->mt_u.dirty_list = malloc(sizeof(MDB_ID2)*MDB_IDL_UM_SIZE);
 		if (!txn->mt_u.dirty_list ||
 			!(txn->mt_free_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX)))
@@ -2742,12 +3062,11 @@ ok:
 		txn->mt_u.dirty_list[0].mid = 0;
 		txn->mt_spill_pgs = NULL;
 		txn->mt_next_pgno = parent->mt_next_pgno;
+		parent->mt_flags |= MDB_TXN_HAS_CHILD;
 		parent->mt_child = txn;
 		txn->mt_parent = parent;
 		txn->mt_numdbs = parent->mt_numdbs;
-		txn->mt_flags = parent->mt_flags;
-		txn->mt_dbxs = parent->mt_dbxs;
-#ifdef VL32
+#ifdef MDB_VL32
 		txn->mt_rpages = parent->mt_rpages;
 #endif
 		memcpy(txn->mt_dbs, parent->mt_dbs, txn->mt_numdbs * sizeof(MDB_db));
@@ -2768,17 +3087,24 @@ ok:
 		if (!rc)
 			rc = mdb_cursor_shadow(parent, txn);
 		if (rc)
-			mdb_txn_reset0(txn, "beginchild-fail");
-	} else {
+			mdb_txn_end(txn, MDB_END_FAIL_BEGINCHILD);
+	} else { /* MDB_RDONLY */
+		txn->mt_dbiseqs = env->me_dbiseqs;
+renew:
 		rc = mdb_txn_renew0(txn);
 	}
 	if (rc) {
-		if (txn != env->me_txn0)
+		if (txn != env->me_txn0) {
+#ifdef MDB_VL32
+			free(txn->mt_rpages);
+#endif
 			free(txn);
+		}
 	} else {
+		txn->mt_flags |= flags;	/* could not change txn=me_txn0 earlier */
 		*ret = txn;
-		DPRINTF(("begin txn %"Z"u%c %p on mdbenv %p, root page %"Z"u",
-			txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
+		DPRINTF(("begin txn %"Yu"%c %p on mdbenv %p, root page %"Yu"",
+			txn->mt_txnid, (flags & MDB_RDONLY) ? 'r' : 'w',
 			(void *) txn, (void *) env, txn->mt_dbs[MAIN_DBI].md_root));
 	}
 
@@ -2792,6 +3118,13 @@ mdb_txn_env(MDB_txn *txn)
 	return txn->mt_env;
 }
 
+mdb_size_t
+mdb_txn_id(MDB_txn *txn)
+{
+    if(!txn) return 0;
+    return txn->mt_txnid;
+}
+
 /** Export or close DBI handles opened in this txn. */
 static void
 mdb_dbis_update(MDB_txn *txn, int keep)
@@ -2801,7 +3134,7 @@ mdb_dbis_update(MDB_txn *txn, int keep)
 	MDB_env *env = txn->mt_env;
 	unsigned char *tdbflags = txn->mt_dbflags;
 
-	for (i = n; --i >= 2;) {
+	for (i = n; --i >= CORE_DBS;) {
 		if (tdbflags[i] & DB_NEW) {
 			if (keep) {
 				env->me_dbflags[i] = txn->mt_dbs[i].md_flags | MDB_VALID;
@@ -2821,52 +3154,68 @@ mdb_dbis_update(MDB_txn *txn, int keep)
 		env->me_numdbs = n;
 }
 
-/** Common code for #mdb_txn_reset() and #mdb_txn_abort().
+/** End a transaction, except successful commit of a nested transaction.
  * May be called twice for readonly txns: First reset it, then abort.
- * @param[in] txn the transaction handle to reset
- * @param[in] act why the transaction is being reset
+ * @param[in] txn the transaction handle to end
+ * @param[in] mode why and how to end the transaction
  */
 static void
-mdb_txn_reset0(MDB_txn *txn, const char *act)
+mdb_txn_end(MDB_txn *txn, unsigned mode)
 {
 	MDB_env	*env = txn->mt_env;
+#if MDB_DEBUG
+	static const char *const names[] = MDB_END_NAMES;
+#endif
 
-	/* Close any DBI handles opened in this txn */
-	mdb_dbis_update(txn, 0);
+	/* Export or close DBI handles opened in this txn */
+	mdb_dbis_update(txn, mode & MDB_END_UPDATE);
 
-	DPRINTF(("%s txn %"Z"u%c %p on mdbenv %p, root page %"Z"u",
-		act, txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
+	DPRINTF(("%s txn %"Yu"%c %p on mdbenv %p, root page %"Yu"",
+		names[mode & MDB_END_OPMASK],
+		txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
 		(void *) txn, (void *)env, txn->mt_dbs[MAIN_DBI].md_root));
 
 	if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
 		if (txn->mt_u.reader) {
 			txn->mt_u.reader->mr_txnid = (txnid_t)-1;
-			if (!(env->me_flags & MDB_NOTLS))
+			if (!(env->me_flags & MDB_NOTLS)) {
 				txn->mt_u.reader = NULL; /* txn does not own reader */
+			} else if (mode & MDB_END_SLOT) {
+				txn->mt_u.reader->mr_pid = 0;
+				txn->mt_u.reader = NULL;
+			} /* else txn owns the slot until it does MDB_END_SLOT */
 		}
-		txn->mt_numdbs = 0;		/* close nothing if called again */
-		txn->mt_dbxs = NULL;	/* mark txn as reset */
-	} else {
+		txn->mt_numdbs = 0;		/* prevent further DBI activity */
+		txn->mt_flags |= MDB_TXN_FINISHED;
+
+	} else if (!F_ISSET(txn->mt_flags, MDB_TXN_FINISHED)) {
 		pgno_t *pghead = env->me_pghead;
 
-		mdb_cursors_close(txn, 0);
+		if (!(mode & MDB_END_UPDATE)) /* !(already closed cursors) */
+			mdb_cursors_close(txn, 0);
 		if (!(env->me_flags & MDB_WRITEMAP)) {
 			mdb_dlist_free(txn);
 		}
 
+		txn->mt_numdbs = 0;
+		txn->mt_flags = MDB_TXN_FINISHED;
+
 		if (!txn->mt_parent) {
-			if (mdb_midl_shrink(&txn->mt_free_pgs))
-				env->me_free_pgs = txn->mt_free_pgs;
+			mdb_midl_shrink(&txn->mt_free_pgs);
+			env->me_free_pgs = txn->mt_free_pgs;
 			/* me_pgstate: */
 			env->me_pghead = NULL;
 			env->me_pglast = 0;
 
 			env->me_txn = NULL;
+			mode = 0;	/* txn == env->me_txn0, do not free() it */
+
 			/* The writer mutex was locked in mdb_txn_begin. */
 			if (env->me_txns)
-				UNLOCK_MUTEX_W(env);
+				UNLOCK_MUTEX(env->me_wmutex);
 		} else {
 			txn->mt_parent->mt_child = NULL;
+			txn->mt_parent->mt_flags &= ~MDB_TXN_HAS_CHILD;
 			env->me_pgstate = ((MDB_ntxn *)txn)->mnt_pgstate;
 			mdb_midl_free(txn->mt_free_pgs);
 			mdb_midl_free(txn->mt_spill_pgs);
@@ -2875,22 +3224,33 @@ mdb_txn_reset0(MDB_txn *txn, const char *act)
 
 		mdb_midl_free(pghead);
 	}
-#ifdef VL32
-	{
-		unsigned i, n = txn->mt_rpages[0].mid;
+#ifdef MDB_VL32
+	if (!txn->mt_parent) {
+		MDB_ID3L el = env->me_rpages, tl = txn->mt_rpages;
+		unsigned i, x, n = tl[0].mid;
+		pthread_mutex_lock(&env->me_rpmutex);
 		for (i = 1; i <= n; i++) {
-#ifdef _WIN32
-			UnmapViewOfFile(txn->mt_rpages[i].mptr);
-#else
-			MDB_page *mp = txn->mt_rpages[i].mptr;
-			int size = txn->mt_env->me_psize;
-			if (IS_OVERFLOW(mp)) size *= mp->mp_pages;
-			munmap(mp, size);
-#endif
+			if (tl[i].mid & (MDB_RPAGE_CHUNK-1)) {
+				/* tmp overflow pages that we didn't share in env */
+				munmap(tl[i].mptr, tl[i].mcnt * env->me_psize);
+			} else {
+				x = mdb_mid3l_search(el, tl[i].mid);
+				if (tl[i].mptr == el[x].mptr) {
+					el[x].mref--;
+				} else {
+					/* another tmp overflow page */
+					munmap(tl[i].mptr, tl[i].mcnt * env->me_psize);
+				}
+			}
 		}
+		pthread_mutex_unlock(&env->me_rpmutex);
+		tl[0].mid = 0;
+		if (mode & MDB_END_FREE)
+			free(tl);
 	}
-	txn->mt_rpages[0].mid = 0;
 #endif
+	if (mode & MDB_END_FREE)
+		free(txn);
 }
 
 void
@@ -2903,7 +3263,7 @@ mdb_txn_reset(MDB_txn *txn)
 	if (!(txn->mt_flags & MDB_TXN_RDONLY))
 		return;
 
-	mdb_txn_reset0(txn, "reset");
+	mdb_txn_end(txn, MDB_END_RESET);
 }
 
 void
@@ -2915,21 +3275,14 @@ mdb_txn_abort(MDB_txn *txn)
 	if (txn->mt_child)
 		mdb_txn_abort(txn->mt_child);
 
-	mdb_txn_reset0(txn, "abort");
-	/* Free reader slot tied to this txn (if MDB_NOTLS && writable FS) */
-	if ((txn->mt_flags & MDB_TXN_RDONLY) && txn->mt_u.reader)
-		txn->mt_u.reader->mr_pid = 0;
-
-	if (txn != txn->mt_env->me_txn0) {
-#ifdef VL32
-		free(txn->mt_rpages);
-#endif
-		free(txn);
-	}
+	mdb_txn_end(txn, MDB_END_ABORT|MDB_END_SLOT|MDB_END_FREE);
 }
 
 /** Save the freelist as of this transaction to the freeDB.
  * This changes the freelist. Keep trying until it stabilizes.
+ *
+ * When (MDB_DEVEL) & 2, the changes do not affect #mdb_page_alloc(),
+ * it then uses the transaction's original snapshot of the freeDB.
  */
 static int
 mdb_freelist_save(MDB_txn *txn)
@@ -3018,10 +3371,10 @@ mdb_freelist_save(MDB_txn *txn)
 #if (MDB_DEBUG) > 1
 			{
 				unsigned int i = free_pgs[0];
-				DPRINTF(("IDL write txn %"Z"u root %"Z"u num %u",
+				DPRINTF(("IDL write txn %"Yu" root %"Yu" num %u",
 					txn->mt_txnid, txn->mt_dbs[FREE_DBI].md_root, i));
 				for (; i; i--)
-					DPRINTF(("IDL %"Z"u", free_pgs[i]));
+					DPRINTF(("IDL %"Yu"", free_pgs[i]));
 			}
 #endif
 			continue;
@@ -3132,15 +3485,16 @@ mdb_page_flush(MDB_txn *txn, int keep)
 	MDB_ID2L	dl = txn->mt_u.dirty_list;
 	unsigned	psize = env->me_psize, j;
 	int			i, pagecount = dl[0].mid, rc;
-	size_t		size = 0, pos = 0;
+	size_t		size = 0;
+	off_t		pos = 0;
 	pgno_t		pgno = 0;
 	MDB_page	*dp = NULL;
 #ifdef _WIN32
 	OVERLAPPED	ov;
 #else
 	struct iovec iov[MDB_COMMIT_PAGES];
-	ssize_t		wpos = 0, wsize = 0, wres;
-	size_t		next_pos = 1; /* impossible pos, so pos != next_pos */
+	ssize_t		wsize = 0, wres;
+	off_t		wpos = 0, next_pos = 1; /* impossible pos, so pos != next_pos */
 	int			n = 0;
 #endif
 
@@ -3239,7 +3593,7 @@ retry_seek:
 			wpos = pos;
 			wsize = 0;
 		}
-		DPRINTF(("committing page %"Z"u", pgno));
+		DPRINTF(("committing page %"Yu"", pgno));
 		next_pos = pos + size;
 		iov[n].iov_len = size;
 		iov[n].iov_base = (char *)dp;
@@ -3247,6 +3601,10 @@ retry_seek:
 		n++;
 #endif	/* _WIN32 */
 	}
+#ifdef MDB_VL32
+	if (pgno > txn->mt_last_pgno)
+		txn->mt_last_pgno = pgno;
+#endif
 
 	/* MIPS has cache coherency issues, this is a no-op everywhere else
 	 * Note: for any size >= on-chip cache size, entire on-chip cache is
@@ -3276,15 +3634,17 @@ int
 mdb_txn_commit(MDB_txn *txn)
 {
 	int		rc;
-	unsigned int i;
+	unsigned int i, end_mode;
 	MDB_env	*env;
 
-	if (txn == NULL || txn->mt_env == NULL)
+	if (txn == NULL)
 		return EINVAL;
 
+	/* mdb_txn_end() mode for a commit which writes nothing */
+	end_mode = MDB_END_EMPTY_COMMIT|MDB_END_UPDATE|MDB_END_SLOT|MDB_END_FREE;
+
 	if (txn->mt_child) {
 		rc = mdb_txn_commit(txn->mt_child);
-		txn->mt_child = NULL;
 		if (rc)
 			goto fail;
 	}
@@ -3292,14 +3652,11 @@ mdb_txn_commit(MDB_txn *txn)
 	env = txn->mt_env;
 
 	if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
-		mdb_dbis_update(txn, 1);
-		txn->mt_numdbs = 2; /* so txn_abort() doesn't close any new handles */
-		mdb_txn_abort(txn);
-		return MDB_SUCCESS;
+		goto done;
 	}
 
-	if (F_ISSET(txn->mt_flags, MDB_TXN_ERROR)) {
-		DPUTS("error flag is set, can't commit");
+	if (txn->mt_flags & (MDB_TXN_FINISHED|MDB_TXN_ERROR)) {
+		DPUTS("txn has failed/finished, can't commit");
 		if (txn->mt_parent)
 			txn->mt_parent->mt_flags |= MDB_TXN_ERROR;
 		rc = MDB_BAD_TXN;
@@ -3331,9 +3688,9 @@ mdb_txn_commit(MDB_txn *txn)
 		/* Update parent's DB table. */
 		memcpy(parent->mt_dbs, txn->mt_dbs, txn->mt_numdbs * sizeof(MDB_db));
 		parent->mt_numdbs = txn->mt_numdbs;
-		parent->mt_dbflags[0] = txn->mt_dbflags[0];
-		parent->mt_dbflags[1] = txn->mt_dbflags[1];
-		for (i=2; i<txn->mt_numdbs; i++) {
+		parent->mt_dbflags[FREE_DBI] = txn->mt_dbflags[FREE_DBI];
+		parent->mt_dbflags[MAIN_DBI] = txn->mt_dbflags[MAIN_DBI];
+		for (i=CORE_DBS; i<txn->mt_numdbs; i++) {
 			/* preserve parent's DB_NEW status */
 			x = parent->mt_dbflags[i] & DB_NEW;
 			parent->mt_dbflags[i] = txn->mt_dbflags[i] | x;
@@ -3362,6 +3719,25 @@ mdb_txn_commit(MDB_txn *txn)
 			pspill[0] = y;
 		}
 
+		/* Remove anything in our spill list from parent's dirty list */
+		if (txn->mt_spill_pgs && txn->mt_spill_pgs[0]) {
+			for (i=1; i<=txn->mt_spill_pgs[0]; i++) {
+				MDB_ID pn = txn->mt_spill_pgs[i];
+				if (pn & 1)
+					continue;	/* deleted spillpg */
+				pn >>= 1;
+				y = mdb_mid2l_search(dst, pn);
+				if (y <= dst[0].mid && dst[y].mid == pn) {
+					free(dst[y].mptr);
+					while (y < dst[0].mid) {
+						dst[y] = dst[y+1];
+						y++;
+					}
+					dst[0].mid--;
+				}
+			}
+		}
+
 		/* Find len = length of merging our dirty list with parent's */
 		x = dst[0].mid;
 		dst[0].mid = 0;		/* simplify loops */
@@ -3407,7 +3783,7 @@ mdb_txn_commit(MDB_txn *txn)
 		}
 
 		/* Append our loose page list to parent's */
-		for (lp = &parent->mt_loose_pgs; *lp; lp = &NEXT_LOOSE_PAGE(lp))
+		for (lp = &parent->mt_loose_pgs; *lp; lp = &NEXT_LOOSE_PAGE(*lp))
 			;
 		*lp = txn->mt_loose_pgs;
 		parent->mt_loose_count += txn->mt_loose_count;
@@ -3430,25 +3806,26 @@ mdb_txn_commit(MDB_txn *txn)
 		!(txn->mt_flags & (MDB_TXN_DIRTY|MDB_TXN_SPILLS)))
 		goto done;
 
-	DPRINTF(("committing txn %"Z"u %p on mdbenv %p, root page %"Z"u",
+	DPRINTF(("committing txn %"Yu" %p on mdbenv %p, root page %"Yu"",
 	    txn->mt_txnid, (void*)txn, (void*)env, txn->mt_dbs[MAIN_DBI].md_root));
 
 	/* Update DB root pointers */
-	if (txn->mt_numdbs > 2) {
+	if (txn->mt_numdbs > CORE_DBS) {
 		MDB_cursor mc;
 		MDB_dbi i;
 		MDB_val data;
 		data.mv_size = sizeof(MDB_db);
 
 		mdb_cursor_init(&mc, txn, MAIN_DBI, NULL);
-		for (i = 2; i < txn->mt_numdbs; i++) {
+		for (i = CORE_DBS; i < txn->mt_numdbs; i++) {
 			if (txn->mt_dbflags[i] & DB_DIRTY) {
 				if (TXN_DBI_CHANGED(txn, i)) {
 					rc = MDB_BAD_DBI;
 					goto fail;
 				}
 				data.mv_data = &txn->mt_dbs[i];
-				rc = mdb_cursor_put(&mc, &txn->mt_dbxs[i].md_name, &data, 0);
+				rc = mdb_cursor_put(&mc, &txn->mt_dbxs[i].md_name, &data,
+					F_SUBDATA);
 				if (rc)
 					goto fail;
 			}
@@ -3461,32 +3838,23 @@ mdb_txn_commit(MDB_txn *txn)
 
 	mdb_midl_free(env->me_pghead);
 	env->me_pghead = NULL;
-	if (mdb_midl_shrink(&txn->mt_free_pgs))
-		env->me_free_pgs = txn->mt_free_pgs;
+	mdb_midl_shrink(&txn->mt_free_pgs);
 
 #if (MDB_DEBUG) > 2
 	mdb_audit(txn);
 #endif
 
-	if ((rc = mdb_page_flush(txn, 0)) ||
-		(rc = mdb_env_sync(env, 0)) ||
-		(rc = mdb_env_write_meta(txn)))
+	if ((rc = mdb_page_flush(txn, 0)))
 		goto fail;
-
-	/* Free P_LOOSE pages left behind in dirty_list */
-	if (!(env->me_flags & MDB_WRITEMAP))
-		mdb_dlist_free(txn);
+	if (!F_ISSET(txn->mt_flags, MDB_TXN_NOSYNC) &&
+		(rc = mdb_env_sync0(env, 0, txn->mt_next_pgno)))
+		goto fail;
+	if ((rc = mdb_env_write_meta(txn)))
+		goto fail;
+	end_mode = MDB_END_COMMITTED|MDB_END_UPDATE;
 
 done:
-	env->me_pglast = 0;
-	env->me_txn = NULL;
-	mdb_dbis_update(txn, 1);
-
-	if (env->me_txns)
-		UNLOCK_MUTEX_W(env);
-	if (txn != env->me_txn0)
-		free(txn);
-
+	mdb_txn_end(txn, end_mode);
 	return MDB_SUCCESS;
 
 fail:
@@ -3513,7 +3881,7 @@ mdb_env_read_header(MDB_env *env, MDB_meta *meta)
 	 * Read both meta pages so we can use the latest one.
 	 */
 
-	for (i=off=0; i<2; i++, off = meta->mm_psize) {
+	for (i=off=0; i<NUM_METAS; i++, off += meta->mm_psize) {
 #ifdef _WIN32
 		DWORD len;
 		OVERLAPPED ov;
@@ -3536,7 +3904,7 @@ mdb_env_read_header(MDB_env *env, MDB_meta *meta)
 		p = (MDB_page *)&pbuf;
 
 		if (!F_ISSET(p->mp_flags, P_META)) {
-			DPRINTF(("page %"Z"u not a meta page", p->mp_pgno));
+			DPRINTF(("page %"Yu" not a meta page", p->mp_pgno));
 			return MDB_INVALID;
 		}
 
@@ -3558,6 +3926,7 @@ mdb_env_read_header(MDB_env *env, MDB_meta *meta)
 	return 0;
 }
 
+/** Fill in most of the zeroed #MDB_meta for an empty database environment */
 static void ESECT
 mdb_env_init_meta0(MDB_env *env, MDB_meta *meta)
 {
@@ -3565,16 +3934,16 @@ mdb_env_init_meta0(MDB_env *env, MDB_meta *meta)
 	meta->mm_version = MDB_DATA_VERSION;
 	meta->mm_mapsize = env->me_mapsize;
 	meta->mm_psize = env->me_psize;
-	meta->mm_last_pg = 1;
+	meta->mm_last_pg = NUM_METAS-1;
 	meta->mm_flags = env->me_flags & 0xffff;
-	meta->mm_flags |= MDB_INTEGERKEY;
-	meta->mm_dbs[0].md_root = P_INVALID;
-	meta->mm_dbs[1].md_root = P_INVALID;
+	meta->mm_flags |= MDB_INTEGERKEY; /* this is mm_dbs[FREE_DBI].md_flags */
+	meta->mm_dbs[FREE_DBI].md_root = P_INVALID;
+	meta->mm_dbs[MAIN_DBI].md_root = P_INVALID;
 }
 
 /** Write the environment parameters of a freshly created DB environment.
  * @param[in] env the environment handle
- * @param[out] meta address of where to store the meta information
+ * @param[in] meta the #MDB_meta to write
  * @return 0 on success, non-zero on failure.
  */
 static int ESECT
@@ -3602,9 +3971,9 @@ mdb_env_init_meta(MDB_env *env, MDB_meta *meta)
 
 	psize = env->me_psize;
 
-	mdb_env_init_meta0(env, meta);
-
-	p = calloc(2, psize);
+	p = calloc(NUM_METAS, psize);
+	if (!p)
+		return ENOMEM;
 	p->mp_pgno = 0;
 	p->mp_flags = P_META;
 	*(MDB_meta *)METADATA(p) = *meta;
@@ -3614,10 +3983,10 @@ mdb_env_init_meta(MDB_env *env, MDB_meta *meta)
 	q->mp_flags = P_META;
 	*(MDB_meta *)METADATA(q) = *meta;
 
-	DO_PWRITE(rc, env->me_fd, p, psize * 2, len, 0);
+	DO_PWRITE(rc, env->me_fd, p, psize * NUM_METAS, len, 0);
 	if (!rc)
 		rc = ErrCode();
-	else if ((unsigned) len == psize * 2)
+	else if ((unsigned) len == psize * NUM_METAS)
 		rc = MDB_SUCCESS;
 	else
 		rc = ENOSPC;
@@ -3634,7 +4003,8 @@ mdb_env_write_meta(MDB_txn *txn)
 {
 	MDB_env *env;
 	MDB_meta	meta, metab, *mp;
-	size_t mapsize;
+	unsigned flags;
+	mdb_size_t mapsize;
 	off_t off;
 	int rc, len, toggle;
 	char *ptr;
@@ -3646,34 +4016,37 @@ mdb_env_write_meta(MDB_txn *txn)
 #endif
 
 	toggle = txn->mt_txnid & 1;
-	DPRINTF(("writing meta page %d for root page %"Z"u",
+	DPRINTF(("writing meta page %d for root page %"Yu"",
 		toggle, txn->mt_dbs[MAIN_DBI].md_root));
 
 	env = txn->mt_env;
+	flags = txn->mt_flags | env->me_flags;
 	mp = env->me_metas[toggle];
 	mapsize = env->me_metas[toggle ^ 1]->mm_mapsize;
 	/* Persist any increases of mapsize config */
 	if (mapsize < env->me_mapsize)
 		mapsize = env->me_mapsize;
 
-	if (env->me_flags & MDB_WRITEMAP) {
+	if (flags & MDB_WRITEMAP) {
 		mp->mm_mapsize = mapsize;
-		mp->mm_dbs[0] = txn->mt_dbs[0];
-		mp->mm_dbs[1] = txn->mt_dbs[1];
+		mp->mm_dbs[FREE_DBI] = txn->mt_dbs[FREE_DBI];
+		mp->mm_dbs[MAIN_DBI] = txn->mt_dbs[MAIN_DBI];
 		mp->mm_last_pg = txn->mt_next_pgno - 1;
+#if (__GNUC__ * 100 + __GNUC_MINOR__ >= 404) && /* TODO: portability */	\
+	!(defined(__i386__) || defined(__x86_64__))
+		/* LY: issue a memory barrier, if not x86. ITS#7969 */
+		__sync_synchronize();
+#endif
 		mp->mm_txnid = txn->mt_txnid;
-		if (!(env->me_flags & (MDB_NOMETASYNC|MDB_NOSYNC))) {
+		if (!(flags & (MDB_NOMETASYNC|MDB_NOSYNC))) {
 			unsigned meta_size = env->me_psize;
 			rc = (env->me_flags & MDB_MAPASYNC) ? MS_ASYNC : MS_SYNC;
-			ptr = env->me_map;
-			if (toggle) {
+			ptr = (char *)mp - PAGEHDRSZ;
 #ifndef _WIN32	/* POSIX msync() requires ptr = start of OS page */
-				if (meta_size < env->me_os_psize)
-					meta_size += meta_size;
-				else
+			r2 = (ptr - env->me_map) & (env->me_os_psize - 1);
+			ptr -= r2;
+			meta_size += r2;
 #endif
-					ptr += meta_size;
-			}
 			if (MDB_MSYNC(ptr, meta_size, rc)) {
 				rc = ErrCode();
 				goto fail;
@@ -3681,26 +4054,22 @@ mdb_env_write_meta(MDB_txn *txn)
 		}
 		goto done;
 	}
-	metab.mm_txnid = env->me_metas[toggle]->mm_txnid;
-	metab.mm_last_pg = env->me_metas[toggle]->mm_last_pg;
+	metab.mm_txnid = mp->mm_txnid;
+	metab.mm_last_pg = mp->mm_last_pg;
 
 	meta.mm_mapsize = mapsize;
-	meta.mm_dbs[0] = txn->mt_dbs[0];
-	meta.mm_dbs[1] = txn->mt_dbs[1];
+	meta.mm_dbs[FREE_DBI] = txn->mt_dbs[FREE_DBI];
+	meta.mm_dbs[MAIN_DBI] = txn->mt_dbs[MAIN_DBI];
 	meta.mm_last_pg = txn->mt_next_pgno - 1;
 	meta.mm_txnid = txn->mt_txnid;
 
 	off = offsetof(MDB_meta, mm_mapsize);
 	ptr = (char *)&meta + off;
 	len = sizeof(MDB_meta) - off;
-	if (toggle)
-		off += env->me_psize;
-	off += PAGEHDRSZ;
+	off += (char *)mp - env->me_map;
 
 	/* Write to the SYNC fd */
-	mfd = env->me_flags & (MDB_NOSYNC|MDB_NOMETASYNC) ?
-		env->me_fd : env->me_mfd;
-retry_write:
+	mfd = (flags & (MDB_NOSYNC|MDB_NOMETASYNC)) ? env->me_fd : env->me_mfd;
 #ifdef _WIN32
 	{
 		memset(&ov, 0, sizeof(ov));
@@ -3709,12 +4078,15 @@ retry_write:
 			rc = -1;
 	}
 #else
+retry_write:
 	rc = pwrite(mfd, ptr, len, off);
 #endif
 	if (rc != len) {
 		rc = rc < 0 ? ErrCode() : EIO;
+#ifndef _WIN32
 		if (rc == EINTR)
 			goto retry_write;
+#endif
 		DPUTS("write failed, disk error?");
 		/* On a failure, the pagecache still contains the new data.
 		 * Write some old data back, to prevent it from being used.
@@ -3751,12 +4123,13 @@ done:
 
 /** Check both meta pages to see which one is newer.
  * @param[in] env the environment handle
- * @return meta toggle (0 or 1).
+ * @return newest #MDB_meta.
  */
-static int
+static MDB_meta *
 mdb_env_pick_meta(const MDB_env *env)
 {
-	return (env->me_metas[0]->mm_txnid < env->me_metas[1]->mm_txnid);
+	MDB_meta *const *metas = env->me_metas;
+	return metas[ metas[0]->mm_txnid < metas[1]->mm_txnid ];
 }
 
 int ESECT
@@ -3769,13 +4142,16 @@ mdb_env_create(MDB_env **env)
 		return ENOMEM;
 
 	e->me_maxreaders = DEFAULT_READERS;
-	e->me_maxdbs = e->me_numdbs = 2;
+	e->me_maxdbs = e->me_numdbs = CORE_DBS;
 	e->me_fd = INVALID_HANDLE_VALUE;
 	e->me_lfd = INVALID_HANDLE_VALUE;
 	e->me_mfd = INVALID_HANDLE_VALUE;
 #ifdef MDB_USE_POSIX_SEM
 	e->me_rmutex = SEM_FAILED;
 	e->me_wmutex = SEM_FAILED;
+#elif defined MDB_USE_SYSV_SEM
+	e->me_rmutex->semid = -1;
+	e->me_wmutex->semid = -1;
 #endif
 	e->me_pid = getpid();
 	GET_PAGESIZE(e->me_os_psize);
@@ -3791,53 +4167,46 @@ mdb_env_map(MDB_env *env, void *addr)
 	unsigned int flags = env->me_flags;
 #ifdef _WIN32
 	int rc;
+	int access = SECTION_MAP_READ;
 	HANDLE mh;
-	LONG sizelo, sizehi;
-	size_t msize;
+	void *map;
+	SIZE_T msize;
+	ULONG pageprot = PAGE_READONLY, secprot, alloctype;
 
+	if (flags & MDB_WRITEMAP) {
+		access |= SECTION_MAP_WRITE;
+		pageprot = PAGE_READWRITE;
+	}
 	if (flags & MDB_RDONLY) {
-		/* Don't set explicit map size, use whatever exists */
+		secprot = PAGE_READONLY;
 		msize = 0;
-		sizelo = 0;
-		sizehi = 0;
+		alloctype = 0;
 	} else {
+		secprot = PAGE_READWRITE;
 		msize = env->me_mapsize;
-		sizelo = msize & 0xffffffff;
-		sizehi = msize >> 16 >> 16; /* only needed on Win64 */
-
-		/* Windows won't create mappings for zero length files.
-		 * and won't map more than the file size.
-		 * Just set the maxsize right now.
-		 */
-		if (SetFilePointer(env->me_fd, sizelo, &sizehi, 0) != (DWORD)sizelo
-			|| !SetEndOfFile(env->me_fd)
-			|| SetFilePointer(env->me_fd, 0, NULL, 0) != 0)
-			return ErrCode();
+		alloctype = MEM_RESERVE;
 	}
 
-	mh = CreateFileMapping(env->me_fd, NULL, flags & MDB_WRITEMAP ?
-		PAGE_READWRITE : PAGE_READONLY,
-		sizehi, sizelo, NULL);
-	if (!mh)
-		return ErrCode();
-#ifdef VL32
-	msize = 2 * env->me_psize;
-#endif
-	env->me_map = MapViewOfFileEx(mh, flags & MDB_WRITEMAP ?
-		FILE_MAP_WRITE : FILE_MAP_READ,
-		0, 0, msize, addr);
-	rc = env->me_map ? 0 : ErrCode();
-#ifdef VL32
+	rc = NtCreateSection(&mh, access, NULL, NULL, secprot, SEC_RESERVE, env->me_fd);
+	if (rc)
+		return rc;
+	map = addr;
+#ifdef MDB_VL32
+	msize = NUM_METAS * env->me_psize;
+#endif
+	rc = NtMapViewOfSection(mh, GetCurrentProcess(), &map, 0, 0, NULL, &msize, ViewUnmap, alloctype, pageprot);
+#ifdef MDB_VL32
 	env->me_fmh = mh;
 #else
-	CloseHandle(mh);
+	NtClose(mh);
 #endif
 	if (rc)
 		return rc;
+	env->me_map = map;
 #else
-#ifdef VL32
+#ifdef MDB_VL32
 	(void) flags;
-	env->me_map = mmap(addr, 2 * env->me_psize, PROT_READ, MAP_SHARED,
+	env->me_map = mmap(addr, NUM_METAS * env->me_psize, PROT_READ, MAP_SHARED,
 		env->me_fd, 0);
 	if (env->me_map == MAP_FAILED) {
 		env->me_map = NULL;
@@ -3886,32 +4255,39 @@ mdb_env_map(MDB_env *env, void *addr)
 }
 
 int ESECT
-mdb_env_set_mapsize(MDB_env *env, size_t size)
+mdb_env_set_mapsize(MDB_env *env, mdb_size_t size)
 {
 	/* If env is already open, caller is responsible for making
 	 * sure there are no active txns.
 	 */
 	if (env->me_map) {
-		int rc;
+		MDB_meta *meta;
+#ifndef MDB_VL32
 		void *old;
+		int rc;
+#endif
 		if (env->me_txn)
 			return EINVAL;
+		meta = mdb_env_pick_meta(env);
 		if (!size)
-			size = env->me_metas[mdb_env_pick_meta(env)]->mm_mapsize;
-		else if (size < env->me_mapsize) {
-			/* If the configured size is smaller, make sure it's
-			 * still big enough. Silently round up to minimum if not.
-			 */
-			size_t minsize = (env->me_metas[mdb_env_pick_meta(env)]->mm_last_pg + 1) * env->me_psize;
+			size = meta->mm_mapsize;
+		{
+			/* Silently round up to minimum if the size is too small */
+			size_t minsize = (meta->mm_last_pg + 1) * env->me_psize;
 			if (size < minsize)
 				size = minsize;
 		}
+#ifndef MDB_VL32
+		/* For MDB_VL32 this bit is a noop since we dynamically remap
+		 * chunks of the DB anyway.
+		 */
 		munmap(env->me_map, env->me_mapsize);
 		env->me_mapsize = size;
 		old = (env->me_flags & MDB_FIXEDMAP) ? env->me_map : NULL;
 		rc = mdb_env_map(env, old);
 		if (rc)
 			return rc;
+#endif /* !MDB_VL32 */
 	}
 	env->me_mapsize = size;
 	if (env->me_psize)
@@ -3924,7 +4300,7 @@ mdb_env_set_maxdbs(MDB_env *env, MDB_dbi dbs)
 {
 	if (env->me_map)
 		return EINVAL;
-	env->me_maxdbs = dbs + 2; /* Named databases + main and free DB */
+	env->me_maxdbs = dbs + CORE_DBS;
 	return MDB_SUCCESS;
 }
 
@@ -3947,7 +4323,7 @@ mdb_env_get_maxreaders(MDB_env *env, unsigned int *readers)
 }
 
 static int ESECT
-mdb_fsize(HANDLE fd, size_t *size)
+mdb_fsize(HANDLE fd, mdb_size_t *size)
 {
 #ifdef _WIN32
 	LARGE_INTEGER fsize;
@@ -3989,6 +4365,7 @@ mdb_env_open2(MDB_env *env)
 	else
 		env->me_pidquery = PROCESS_QUERY_INFORMATION;
 #endif /* _WIN32 */
+
 #ifdef BROKEN_FDATASYNC
 	/* ext3/ext4 fdatasync is broken on some older Linux kernels.
 	 * https://lkml.org/lkml/2012/9/3/83
@@ -4037,8 +4414,6 @@ mdb_env_open2(MDB_env *env)
 	}
 #endif
 
-	memset(&meta, 0, sizeof(meta));
-
 	if ((i = mdb_env_read_header(env, &meta)) != 0) {
 		if (i != ENOENT)
 			return i;
@@ -4047,24 +4422,52 @@ mdb_env_open2(MDB_env *env)
 		env->me_psize = env->me_os_psize;
 		if (env->me_psize > MAX_PAGESIZE)
 			env->me_psize = MAX_PAGESIZE;
+		memset(&meta, 0, sizeof(meta));
+		mdb_env_init_meta0(env, &meta);
+		meta.mm_mapsize = DEFAULT_MAPSIZE;
 	} else {
 		env->me_psize = meta.mm_psize;
 	}
 
 	/* Was a mapsize configured? */
 	if (!env->me_mapsize) {
-		/* If this is a new environment, take the default,
-		 * else use the size recorded in the existing env.
-		 */
-		env->me_mapsize = newenv ? DEFAULT_MAPSIZE : meta.mm_mapsize;
-	} else if (env->me_mapsize < meta.mm_mapsize) {
-		/* If the configured size is smaller, make sure it's
-		 * still big enough. Silently round up to minimum if not.
+		env->me_mapsize = meta.mm_mapsize;
+	}
+	{
+		/* Make sure mapsize >= committed data size.  Even when using
+		 * mm_mapsize, which could be broken in old files (ITS#7789).
 		 */
-		size_t minsize = (meta.mm_last_pg + 1) * meta.mm_psize;
+		mdb_size_t minsize = (meta.mm_last_pg + 1) * meta.mm_psize;
 		if (env->me_mapsize < minsize)
 			env->me_mapsize = minsize;
 	}
+	meta.mm_mapsize = env->me_mapsize;
+
+	if (newenv && !(flags & MDB_FIXEDMAP)) {
+		/* mdb_env_map() may grow the datafile.  Write the metapages
+		 * first, so the file will be valid if initialization fails.
+		 * Except with FIXEDMAP, since we do not yet know mm_address.
+		 * We could fill in mm_address later, but then a different
+		 * program might end up doing that - one with a memory layout
+		 * and map address which does not suit the main program.
+		 */
+		rc = mdb_env_init_meta(env, &meta);
+		if (rc)
+			return rc;
+		newenv = 0;
+	}
+#ifdef _WIN32
+	/* For FIXEDMAP, make sure the file is non-empty before we attempt to map it */
+	if (newenv) {
+		char dummy = 0;
+		DWORD len;
+		rc = WriteFile(env->me_fd, &dummy, 1, &len, NULL);
+		if (!rc) {
+			rc = ErrCode();
+			return rc;
+		}
+	}
+#endif
 
 	rc = mdb_env_map(env, (flags & MDB_FIXEDMAP) ? meta.mm_address : NULL);
 	if (rc)
@@ -4089,18 +4492,18 @@ mdb_env_open2(MDB_env *env)
 
 #if MDB_DEBUG
 	{
-		int toggle = mdb_env_pick_meta(env);
-		MDB_db *db = &env->me_metas[toggle]->mm_dbs[MAIN_DBI];
+		MDB_meta *meta = mdb_env_pick_meta(env);
+		MDB_db *db = &meta->mm_dbs[MAIN_DBI];
 
 		DPRINTF(("opened database version %u, pagesize %u",
-			env->me_metas[0]->mm_version, env->me_psize));
-		DPRINTF(("using meta page %d",    toggle));
+			meta->mm_version, env->me_psize));
+		DPRINTF(("using meta page %d",    (int) (meta->mm_txnid & 1)));
 		DPRINTF(("depth: %u",             db->md_depth));
-		DPRINTF(("entries: %"Z"u",        db->md_entries));
-		DPRINTF(("branch pages: %"Z"u",   db->md_branch_pages));
-		DPRINTF(("leaf pages: %"Z"u",     db->md_leaf_pages));
-		DPRINTF(("overflow pages: %"Z"u", db->md_overflow_pages));
-		DPRINTF(("root: %"Z"u",           db->md_root));
+		DPRINTF(("entries: %"Yu"",        db->md_entries));
+		DPRINTF(("branch pages: %"Yu"",   db->md_branch_pages));
+		DPRINTF(("leaf pages: %"Yu"",     db->md_leaf_pages));
+		DPRINTF(("overflow pages: %"Yu"", db->md_overflow_pages));
+		DPRINTF(("root: %"Yu"",           db->md_root));
 	}
 #endif
 
@@ -4181,9 +4584,10 @@ PIMAGE_TLS_CALLBACK mdb_tls_cbp = mdb_tls_callback;
 static int ESECT
 mdb_env_share_locks(MDB_env *env, int *excl)
 {
-	int rc = 0, toggle = mdb_env_pick_meta(env);
+	int rc = 0;
+	MDB_meta *meta = mdb_env_pick_meta(env);
 
-	env->me_txns->mti_txnid = env->me_metas[toggle]->mm_txnid;
+	env->me_txns->mti_txnid = meta->mm_txnid;
 
 #ifdef _WIN32
 	{
@@ -4248,8 +4652,8 @@ mdb_env_excl_lock(MDB_env *env, int *excl)
 	if (!rc) {
 		*excl = 1;
 	} else
-# ifdef MDB_USE_POSIX_SEM
-	if (*excl < 0) /* always true when !MDB_USE_POSIX_SEM */
+# ifndef MDB_USE_POSIX_MUTEX
+	if (*excl < 0) /* always true when MDB_USE_POSIX_MUTEX */
 # endif
 	{
 		lock_info.l_type = F_RDLCK;
@@ -4332,7 +4736,7 @@ mdb_hash_val(MDB_val *val, mdb_hash_t hval)
  */
 static const char mdb_a85[]= "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz!#$%&()*+-;<=>?@^_`{|}~";
 
-static void
+static void ESECT
 mdb_pack85(unsigned long l, char *out)
 {
 	int i;
@@ -4343,7 +4747,7 @@ mdb_pack85(unsigned long l, char *out)
 	}
 }
 
-static void
+static void ESECT
 mdb_hash_enc(MDB_val *val, char *encbuf)
 {
 	mdb_hash_t h = mdb_hash_val(val, MDB_HASH_INIT);
@@ -4375,13 +4779,22 @@ mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
 #	define MDB_CLOEXEC		0
 #endif
 #endif
+#ifdef MDB_USE_SYSV_SEM
+	int semid;
+	union semun semu;
+#endif
 	int rc;
 	off_t size, rsize;
 
 #ifdef _WIN32
-	env->me_lfd = CreateFile(lpath, GENERIC_READ|GENERIC_WRITE,
+	wchar_t *wlpath;
+	rc = utf8_to_utf16(lpath, -1, &wlpath, NULL);
+	if (rc)
+		return rc;
+	env->me_lfd = CreateFileW(wlpath, GENERIC_READ|GENERIC_WRITE,
 		FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_ALWAYS,
 		FILE_ATTRIBUTE_NORMAL, NULL);
+	free(wlpath);
 #else
 	env->me_lfd = open(lpath, O_RDWR|O_CREAT|MDB_CLOEXEC, mode);
 #endif
@@ -4483,9 +4896,9 @@ mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
 		mdb_hash_enc(&val, encbuf);
 		sprintf(env->me_txns->mti_rmname, "Global\\MDBr%s", encbuf);
 		sprintf(env->me_txns->mti_wmname, "Global\\MDBw%s", encbuf);
-		env->me_rmutex = CreateMutex(&mdb_all_sa, FALSE, env->me_txns->mti_rmname);
+		env->me_rmutex = CreateMutexA(&mdb_all_sa, FALSE, env->me_txns->mti_rmname);
 		if (!env->me_rmutex) goto fail_errno;
-		env->me_wmutex = CreateMutex(&mdb_all_sa, FALSE, env->me_txns->mti_wmname);
+		env->me_wmutex = CreateMutexA(&mdb_all_sa, FALSE, env->me_txns->mti_wmname);
 		if (!env->me_wmutex) goto fail_errno;
 #elif defined(MDB_USE_POSIX_SEM)
 		struct stat stbuf;
@@ -4521,16 +4934,31 @@ mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
 		env->me_wmutex = sem_open(env->me_txns->mti_wmname,
 			O_CREAT|O_EXCL, mode, 1);
 		if (env->me_wmutex == SEM_FAILED) goto fail_errno;
-#else	/* MDB_USE_POSIX_SEM */
+#elif defined(MDB_USE_SYSV_SEM)
+		unsigned short vals[2] = {1, 1};
+		key_t key = ftok(lpath, 'M');
+		if (key == -1)
+			goto fail_errno;
+		semid = semget(key, 2, (mode & 0777) | IPC_CREAT);
+		if (semid < 0)
+			goto fail_errno;
+		semu.array = vals;
+		if (semctl(semid, 0, SETALL, semu) < 0)
+			goto fail_errno;
+		env->me_txns->mti_semid = semid;
+#else	/* MDB_USE_POSIX_MUTEX: */
 		pthread_mutexattr_t mattr;
 
 		if ((rc = pthread_mutexattr_init(&mattr))
 			|| (rc = pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED))
-			|| (rc = pthread_mutex_init(&env->me_txns->mti_mutex, &mattr))
-			|| (rc = pthread_mutex_init(&env->me_txns->mti_wmutex, &mattr)))
+#ifdef MDB_ROBUST_SUPPORTED
+			|| (rc = pthread_mutexattr_setrobust(&mattr, PTHREAD_MUTEX_ROBUST))
+#endif
+			|| (rc = pthread_mutex_init(env->me_txns->mti_rmutex, &mattr))
+			|| (rc = pthread_mutex_init(env->me_txns->mti_wmutex, &mattr)))
 			goto fail;
 		pthread_mutexattr_destroy(&mattr);
-#endif	/* _WIN32 || MDB_USE_POSIX_SEM */
+#endif	/* _WIN32 || ... */
 
 		env->me_txns->mti_magic = MDB_MAGIC;
 		env->me_txns->mti_format = MDB_LOCK_FORMAT;
@@ -4538,6 +4966,9 @@ mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
 		env->me_txns->mti_numreaders = 0;
 
 	} else {
+#ifdef MDB_USE_SYSV_SEM
+		struct semid_ds buf;
+#endif
 		if (env->me_txns->mti_magic != MDB_MAGIC) {
 			DPUTS("lock region has invalid magic");
 			rc = MDB_INVALID;
@@ -4554,17 +4985,42 @@ mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
 			goto fail;
 		}
 #ifdef _WIN32
-		env->me_rmutex = OpenMutex(SYNCHRONIZE, FALSE, env->me_txns->mti_rmname);
+		env->me_rmutex = OpenMutexA(SYNCHRONIZE, FALSE, env->me_txns->mti_rmname);
 		if (!env->me_rmutex) goto fail_errno;
-		env->me_wmutex = OpenMutex(SYNCHRONIZE, FALSE, env->me_txns->mti_wmname);
+		env->me_wmutex = OpenMutexA(SYNCHRONIZE, FALSE, env->me_txns->mti_wmname);
 		if (!env->me_wmutex) goto fail_errno;
 #elif defined(MDB_USE_POSIX_SEM)
 		env->me_rmutex = sem_open(env->me_txns->mti_rmname, 0);
 		if (env->me_rmutex == SEM_FAILED) goto fail_errno;
 		env->me_wmutex = sem_open(env->me_txns->mti_wmname, 0);
 		if (env->me_wmutex == SEM_FAILED) goto fail_errno;
+#elif defined(MDB_USE_SYSV_SEM)
+		semid = env->me_txns->mti_semid;
+		semu.buf = &buf;
+		/* check for read access */
+		if (semctl(semid, 0, IPC_STAT, semu) < 0)
+			goto fail_errno;
+		/* check for write access */
+		if (semctl(semid, 0, IPC_SET, semu) < 0)
+			goto fail_errno;
 #endif
 	}
+#ifdef MDB_USE_SYSV_SEM
+	env->me_rmutex->semid = semid;
+	env->me_wmutex->semid = semid;
+	env->me_rmutex->semnum = 0;
+	env->me_wmutex->semnum = 1;
+	env->me_rmutex->locked = &env->me_txns->mti_rlocked;
+	env->me_wmutex->locked = &env->me_txns->mti_wlocked;
+#endif
+#ifdef MDB_VL32
+#ifdef _WIN32
+	env->me_rpmutex = CreateMutex(NULL, FALSE, NULL);
+#else
+	pthread_mutex_init(&env->me_rpmutex, NULL);
+#endif
+#endif
+
 	return MDB_SUCCESS;
 
 fail_errno:
@@ -4584,8 +5040,8 @@ fail:
 	 *	environment and re-opening it with the new flags.
 	 */
 #define	CHANGEABLE	(MDB_NOSYNC|MDB_NOMETASYNC|MDB_MAPASYNC|MDB_NOMEMINIT)
-#define	CHANGELESS	(MDB_FIXEDMAP|MDB_NOSUBDIR|MDB_RDONLY|MDB_WRITEMAP| \
-	MDB_NOTLS|MDB_NOLOCK|MDB_NORDAHEAD)
+#define	CHANGELESS	(MDB_FIXEDMAP|MDB_NOSUBDIR|MDB_RDONLY| \
+	MDB_WRITEMAP|MDB_NOTLS|MDB_NOLOCK|MDB_NORDAHEAD)
 
 #if VALID_FLAGS & PERSISTENT_FLAGS & (CHANGEABLE|CHANGELESS)
 # error "Persistent DB flags & env flags overlap, but both go in mm_flags"
@@ -4596,11 +5052,14 @@ mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mdb_mode_t mode
 {
 	int		oflags, rc, len, excl = -1;
 	char *lpath, *dpath;
+#ifdef _WIN32
+	wchar_t *wpath;
+#endif
 
 	if (env->me_fd!=INVALID_HANDLE_VALUE || (flags & ~(CHANGEABLE|CHANGELESS)))
 		return EINVAL;
 
-#ifdef VL32
+#ifdef MDB_VL32
 	if (flags & MDB_WRITEMAP) {
 		/* silently ignore WRITEMAP in 32 bit mode */
 		flags ^= MDB_WRITEMAP;
@@ -4640,6 +5099,17 @@ mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mdb_mode_t mode
 			  (env->me_dirty_list = calloc(MDB_IDL_UM_SIZE, sizeof(MDB_ID2)))))
 			rc = ENOMEM;
 	}
+#ifdef MDB_VL32
+	if (!rc) {
+		env->me_rpages = malloc(MDB_ERPAGE_SIZE * sizeof(MDB_ID3));
+		if (!env->me_rpages) {
+			rc = ENOMEM;
+			goto leave;
+		}
+		env->me_rpages[0].mid = 0;
+		env->me_rpcheck = MDB_ERPAGE_SIZE/2;
+	}
+#endif
 	env->me_flags = flags |= MDB_ENV_ACTIVE;
 	if (rc)
 		goto leave;
@@ -4652,6 +5122,7 @@ mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mdb_mode_t mode
 		rc = ENOMEM;
 		goto leave;
 	}
+	env->me_dbxs[FREE_DBI].md_cmp = mdb_cmp_long; /* aligned MDB_INTEGERKEY */
 
 	/* For RDONLY, get lockfile after we know datafile exists */
 	if (!(flags & (MDB_RDONLY|MDB_NOLOCK))) {
@@ -4669,8 +5140,12 @@ mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mdb_mode_t mode
 		len = OPEN_ALWAYS;
 	}
 	mode = FILE_ATTRIBUTE_NORMAL;
-	env->me_fd = CreateFile(dpath, oflags, FILE_SHARE_READ|FILE_SHARE_WRITE,
+	rc = utf8_to_utf16(dpath, -1, &wpath, NULL);
+	if (rc)
+		goto leave;
+	env->me_fd = CreateFileW(wpath, oflags, FILE_SHARE_READ|FILE_SHARE_WRITE,
 		NULL, len, mode, NULL);
+	free(wpath);
 #else
 	if (F_ISSET(flags, MDB_RDONLY))
 		oflags = O_RDONLY;
@@ -4699,9 +5174,13 @@ mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mdb_mode_t mode
 			 */
 #ifdef _WIN32
 			len = OPEN_EXISTING;
-			env->me_mfd = CreateFile(dpath, oflags,
+			rc = utf8_to_utf16(dpath, -1, &wpath, NULL);
+			if (rc)
+				goto leave;
+			env->me_mfd = CreateFileW(wpath, oflags,
 				FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, len,
 				mode | FILE_FLAG_WRITE_THROUGH, NULL);
+			free(wpath);
 #else
 			oflags &= ~O_CREAT;
 			env->me_mfd = open(dpath, oflags | MDB_DSYNC, mode);
@@ -4717,28 +5196,30 @@ mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mdb_mode_t mode
 			if (rc)
 				goto leave;
 		}
-		if (!((flags & MDB_RDONLY) ||
-			  (env->me_pbuf = calloc(1, env->me_psize))))
-			rc = ENOMEM;
 		if (!(flags & MDB_RDONLY)) {
 			MDB_txn *txn;
 			int tsize = sizeof(MDB_txn), size = tsize + env->me_maxdbs *
 				(sizeof(MDB_db)+sizeof(MDB_cursor *)+sizeof(unsigned int)+1);
-			txn = calloc(1, size);
-			if (txn) {
+			if ((env->me_pbuf = calloc(1, env->me_psize)) &&
+				(txn = calloc(1, size)))
+			{
 				txn->mt_dbs = (MDB_db *)((char *)txn + tsize);
 				txn->mt_cursors = (MDB_cursor **)(txn->mt_dbs + env->me_maxdbs);
 				txn->mt_dbiseqs = (unsigned int *)(txn->mt_cursors + env->me_maxdbs);
 				txn->mt_dbflags = (unsigned char *)(txn->mt_dbiseqs + env->me_maxdbs);
 				txn->mt_env = env;
-				txn->mt_dbxs = env->me_dbxs;
-#ifdef VL32
-				txn->mt_rpages = calloc(MDB_IDL_UM_SIZE, sizeof(MDB_ID2));
+#ifdef MDB_VL32
+				txn->mt_rpages = malloc(MDB_TRPAGE_SIZE * sizeof(MDB_ID3));
 				if (!txn->mt_rpages) {
 					free(txn);
 					rc = ENOMEM;
+					goto leave;
 				}
+				txn->mt_rpages[0].mid = 0;
+				txn->mt_rpcheck = MDB_TRPAGE_SIZE/2;
 #endif
+				txn->mt_dbxs = env->me_dbxs;
+				txn->mt_flags = MDB_TXN_FINISHED;
 				env->me_txn0 = txn;
 			} else {
 				rc = ENOMEM;
@@ -4765,7 +5246,7 @@ mdb_env_close0(MDB_env *env, int excl)
 
 	/* Doing this here since me_dbxs may not exist during mdb_env_close */
 	if (env->me_dbxs) {
-		for (i = env->me_maxdbs; --i > MAIN_DBI; )
+		for (i = env->me_maxdbs; --i >= CORE_DBS; )
 			free(env->me_dbxs[i].md_name.mv_data);
 		free(env->me_dbxs);
 	}
@@ -4776,6 +5257,13 @@ mdb_env_close0(MDB_env *env, int excl)
 	free(env->me_path);
 	free(env->me_dirty_list);
 	free(env->me_txn0);
+#ifdef MDB_VL32
+	{ unsigned int x;
+		for (x=1; x<=env->me_rpages[0].mid; x++)
+		munmap(env->me_rpages[x].mptr, env->me_rpages[x].mcnt * env->me_psize);
+	}
+	free(env->me_rpages);
+#endif
 	mdb_midl_free(env->me_free_pgs);
 
 	if (env->me_flags & MDB_ENV_TXKEY) {
@@ -4792,8 +5280,8 @@ mdb_env_close0(MDB_env *env, int excl)
 	}
 
 	if (env->me_map) {
-#ifdef VL32
-		munmap(env->me_map, 2*env->me_psize);
+#ifdef MDB_VL32
+		munmap(env->me_map, NUM_METAS*env->me_psize);
 #else
 		munmap(env->me_map, env->me_mapsize);
 #endif
@@ -4806,8 +5294,12 @@ mdb_env_close0(MDB_env *env, int excl)
 		MDB_PID_T pid = env->me_pid;
 		/* Clearing readers is done in this function because
 		 * me_txkey with its destructor must be disabled first.
+		 *
+		 * We skip the the reader mutex, so we touch only
+		 * data owned by this process (me_close_readers and
+		 * our readers), and clear each reader atomically.
 		 */
-		for (i = env->me_numreaders; --i >= 0; )
+		for (i = env->me_close_readers; --i >= 0; )
 			if (env->me_txns->mti_readers[i].mr_pid == pid)
 				env->me_txns->mti_readers[i].mr_pid = 0;
 #ifdef _WIN32
@@ -4833,6 +5325,16 @@ mdb_env_close0(MDB_env *env, int excl)
 				sem_unlink(env->me_txns->mti_wmname);
 			}
 		}
+#elif defined(MDB_USE_SYSV_SEM)
+		if (env->me_rmutex->semid != -1) {
+			/* If we have the filelock:  If we are the
+			 * only remaining user, clean up semaphores.
+			 */
+			if (excl == 0)
+				mdb_env_excl_lock(env, &excl);
+			if (excl > 0)
+				semctl(env->me_rmutex->semid, 0, IPC_RMID);
+		}
 #endif
 		munmap((void *)env->me_txns, (env->me_maxreaders-1)*sizeof(MDB_reader)+sizeof(MDB_txninfo));
 	}
@@ -4847,11 +5349,17 @@ mdb_env_close0(MDB_env *env, int excl)
 #endif
 		(void) close(env->me_lfd);
 	}
+#ifdef MDB_VL32
+#ifdef _WIN32
+	if (env->me_rpmutex) CloseHandle(env->me_rpmutex);
+#else
+	pthread_mutex_destroy(&env->me_rpmutex);
+#endif
+#endif
 
 	env->me_flags &= ~(MDB_ENV_ACTIVE|MDB_ENV_TXKEY);
 }
 
-
 void ESECT
 mdb_env_close(MDB_env *env)
 {
@@ -4871,18 +5379,18 @@ mdb_env_close(MDB_env *env)
 	free(env);
 }
 
-/** Compare two items pointing at aligned size_t's */
+/** Compare two items pointing at aligned mdb_size_t's */
 static int
 mdb_cmp_long(const MDB_val *a, const MDB_val *b)
 {
-	return (*(size_t *)a->mv_data < *(size_t *)b->mv_data) ? -1 :
-		*(size_t *)a->mv_data > *(size_t *)b->mv_data;
+	return (*(mdb_size_t *)a->mv_data < *(mdb_size_t *)b->mv_data) ? -1 :
+		*(mdb_size_t *)a->mv_data > *(mdb_size_t *)b->mv_data;
 }
 
 /** Compare two items pointing at aligned unsigned int's.
  *
  *	This is also set as #MDB_INTEGERDUP|#MDB_DUPFIXED's #MDB_dbx.%md_dcmp,
- *	but #mdb_cmp_clong() is called instead if the data type is size_t.
+ *	but #mdb_cmp_clong() is called instead if the data type is mdb_size_t.
  */
 static int
 mdb_cmp_int(const MDB_val *a, const MDB_val *b)
@@ -4987,7 +5495,7 @@ mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp)
 
 	nkeys = NUMKEYS(mp);
 
-	DPRINTF(("searching %u keys in %s %spage %"Z"u",
+	DPRINTF(("searching %u keys in %s %spage %"Yu"",
 	    nkeys, IS_LEAF(mp) ? "leaf" : "branch", IS_SUBP(mp) ? "sub-" : "",
 	    mdb_dbg_pgno(mp)));
 
@@ -4999,7 +5507,7 @@ mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp)
 	 * alignment is guaranteed. Use faster mdb_cmp_int.
 	 */
 	if (cmp == mdb_cmp_cint && IS_BRANCH(mp)) {
-		if (NODEPTR(mp, 1)->mn_ksize == sizeof(size_t))
+		if (NODEPTR(mp, 1)->mn_ksize == sizeof(mdb_size_t))
 			cmp = mdb_cmp_long;
 		else
 			cmp = mdb_cmp_int;
@@ -5035,7 +5543,7 @@ mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp)
 				DPRINTF(("found leaf index %u [%s], rc = %i",
 				    i, DKEY(&nodekey), rc));
 			else
-				DPRINTF(("found branch index %u [%s -> %"Z"u], rc = %i",
+				DPRINTF(("found branch index %u [%s -> %"Yu"], rc = %i",
 				    i, DKEY(&nodekey), NODEPGNO(node), rc));
 #endif
 			if (rc == 0)
@@ -5083,15 +5591,15 @@ static void
 mdb_cursor_pop(MDB_cursor *mc)
 {
 	if (mc->mc_snum) {
-#if MDB_DEBUG
-		MDB_page	*top = mc->mc_pg[mc->mc_top];
-#endif
+		DPRINTF(("popping page %"Yu" off db %d cursor %p",
+			mc->mc_pg[mc->mc_top]->mp_pgno, DDBI(mc), (void *) mc));
+
 		mc->mc_snum--;
-		if (mc->mc_snum)
+		if (mc->mc_snum) {
 			mc->mc_top--;
-
-		DPRINTF(("popped page %"Z"u off db %d cursor %p", top->mp_pgno,
-			DDBI(mc), (void *) mc));
+		} else {
+			mc->mc_flags &= ~C_INITIALIZED;
+		}
 	}
 }
 
@@ -5099,7 +5607,7 @@ mdb_cursor_pop(MDB_cursor *mc)
 static int
 mdb_cursor_push(MDB_cursor *mc, MDB_page *mp)
 {
-	DPRINTF(("pushing page %"Z"u on db %d cursor %p", mp->mp_pgno,
+	DPRINTF(("pushing page %"Yu" on db %d cursor %p", mp->mp_pgno,
 		DDBI(mc), (void *) mc));
 
 	if (mc->mc_snum >= CURSOR_STACK) {
@@ -5114,21 +5622,332 @@ mdb_cursor_push(MDB_cursor *mc, MDB_page *mp)
 	return MDB_SUCCESS;
 }
 
-/** Find the address of the page corresponding to a given page number.
+#ifdef MDB_VL32
+/** Map a read-only page.
+ * There are two levels of tracking in use, a per-txn list and a per-env list.
+ * ref'ing and unref'ing the per-txn list is faster since it requires no
+ * locking. Pages are cached in the per-env list for global reuse, and a lock
+ * is required. Pages are not immediately unmapped when their refcnt goes to
+ * zero; they hang around in case they will be reused again soon.
+ *
+ * When the per-txn list gets full, all pages with refcnt=0 are purged from the
+ * list and their refcnts in the per-env list are decremented.
+ *
+ * When the per-env list gets full, all pages with refcnt=0 are purged from the
+ * list and their pages are unmapped.
+ *
+ * @note "full" means the list has reached its respective rpcheck threshold.
+ * This threshold slowly raises if no pages could be purged on a given check,
+ * and returns to its original value when enough pages were purged.
+ *
+ * If purging doesn't free any slots, filling the per-txn list will return
+ * MDB_TXN_FULL, and filling the per-env list returns MDB_MAP_FULL.
+ *
+ * Reference tracking in a txn is imperfect, pages can linger with non-zero
+ * refcnt even without active references. It was deemed to be too invasive
+ * to add unrefs in every required location. However, all pages are unref'd
+ * at the end of the transaction. This guarantees that no stale references
+ * linger in the per-env list.
+ *
+ * Usually we map chunks of 16 pages at a time, but if an overflow page begins
+ * at the tail of the chunk we extend the chunk to include the entire overflow
+ * page. Unfortunately, pages can be turned into overflow pages after their
+ * chunk was already mapped. In that case we must remap the chunk if the
+ * overflow page is referenced. If the chunk's refcnt is 0 we can just remap
+ * it, otherwise we temporarily map a new chunk just for the overflow page.
+ *
+ * @note this chunk handling means we cannot guarantee that a data item
+ * returned from the DB will stay alive for the duration of the transaction:
+ *   We unref pages as soon as a cursor moves away from the page
+ *   A subsequent op may cause a purge, which may unmap any unref'd chunks
+ * The caller must copy the data if it must be used later in the same txn.
+ *
+ * Also - our reference counting revolves around cursors, but overflow pages
+ * aren't pointed to by a cursor's page stack. We have to remember them
+ * explicitly, in the added mc_ovpg field. A single cursor can only hold a
+ * reference to one overflow page at a time.
+ *
  * @param[in] txn the transaction for this access.
  * @param[in] pgno the page number for the page to retrieve.
  * @param[out] ret address of a pointer where the page's address will be stored.
+ * @return 0 on success, non-zero on failure.
+ */
+static int
+mdb_rpage_get(MDB_txn *txn, pgno_t pg0, MDB_page **ret)
+{
+	MDB_env *env = txn->mt_env;
+	MDB_page *p;
+	MDB_ID3L tl = txn->mt_rpages;
+	MDB_ID3L el = env->me_rpages;
+	MDB_ID3 id3;
+	unsigned x, rem;
+	pgno_t pgno;
+	int rc, retries = 1;
+#ifdef _WIN32
+	LARGE_INTEGER off;
+	SIZE_T len;
+#define SET_OFF(off,val)	off.QuadPart = val
+#define MAP(rc,env,addr,len,off)	\
+	addr = NULL; \
+	rc = NtMapViewOfSection(env->me_fmh, GetCurrentProcess(), &addr, 0, \
+		len, &off, &len, ViewUnmap, (env->me_flags & MDB_RDONLY) ? 0 : MEM_RESERVE, PAGE_READONLY)
+#else
+	off_t off;
+	size_t len;
+#define SET_OFF(off,val)	off = val
+#define MAP(rc,env,addr,len,off)	\
+	addr = mmap(NULL, len, PROT_READ, MAP_SHARED, env->me_fd, off); \
+	rc = (addr == MAP_FAILED) ? errno : 0
+#endif
+
+	/* remember the offset of the actual page number, so we can
+	 * return the correct pointer at the end.
+	 */
+	rem = pg0 & (MDB_RPAGE_CHUNK-1);
+	pgno = pg0 ^ rem;
+
+	id3.mid = 0;
+	x = mdb_mid3l_search(tl, pgno);
+	if (x <= tl[0].mid && tl[x].mid == pgno) {
+		if (x != tl[0].mid && tl[x+1].mid == pg0)
+			x++;
+		/* check for overflow size */
+		p = (MDB_page *)((char *)tl[x].mptr + rem * env->me_psize);
+		if (IS_OVERFLOW(p) && p->mp_pages + rem > tl[x].mcnt) {
+			id3.mcnt = p->mp_pages + rem;
+			len = id3.mcnt * env->me_psize;
+			SET_OFF(off, pgno * env->me_psize);
+			MAP(rc, env, id3.mptr, len, off);
+			if (rc)
+				return rc;
+			/* check for local-only page */
+			if (rem) {
+				mdb_tassert(txn, tl[x].mid != pg0);
+				/* hope there's room to insert this locally.
+				 * setting mid here tells later code to just insert
+				 * this id3 instead of searching for a match.
+				 */
+				id3.mid = pg0;
+				goto notlocal;
+			} else {
+				/* ignore the mapping we got from env, use new one */
+				tl[x].mptr = id3.mptr;
+				tl[x].mcnt = id3.mcnt;
+				/* if no active ref, see if we can replace in env */
+				if (!tl[x].mref) {
+					unsigned i;
+					pthread_mutex_lock(&env->me_rpmutex);
+					i = mdb_mid3l_search(el, tl[x].mid);
+					if (el[i].mref == 1) {
+						/* just us, replace it */
+						munmap(el[i].mptr, el[i].mcnt * env->me_psize);
+						el[i].mptr = tl[x].mptr;
+						el[i].mcnt = tl[x].mcnt;
+					} else {
+						/* there are others, remove ourself */
+						el[i].mref--;
+					}
+					pthread_mutex_unlock(&env->me_rpmutex);
+				}
+			}
+		}
+		id3.mptr = tl[x].mptr;
+		id3.mcnt = tl[x].mcnt;
+		tl[x].mref++;
+		goto ok;
+	}
+
+notlocal:
+	if (tl[0].mid >= MDB_TRPAGE_MAX - txn->mt_rpcheck) {
+		unsigned i, y;
+		/* purge unref'd pages from our list and unref in env */
+		pthread_mutex_lock(&env->me_rpmutex);
+retry:
+		y = 0;
+		for (i=1; i<tl[0].mid; i++) {
+			if (!tl[i].mref) {
+				if (!y) y = i;
+				/* tmp overflow pages don't go to env */
+				if (tl[i].mid & (MDB_RPAGE_CHUNK-1)) {
+					munmap(tl[i].mptr, tl[i].mcnt * env->me_psize);
+					continue;
+				}
+				x = mdb_mid3l_search(el, tl[i].mid);
+				el[x].mref--;
+			}
+		}
+		pthread_mutex_unlock(&env->me_rpmutex);
+		if (!y) {
+			/* we didn't find any unref'd chunks.
+			 * if we're out of room, fail.
+			 */
+			if (tl[0].mid >= MDB_TRPAGE_MAX)
+				return MDB_TXN_FULL;
+			/* otherwise, raise threshold for next time around
+			 * and let this go.
+			 */
+			txn->mt_rpcheck /= 2;
+		} else {
+			/* we found some unused; consolidate the list */
+			for (i=y+1; i<= tl[0].mid; i++)
+				if (tl[i].mref)
+					tl[y++] = tl[i];
+			tl[0].mid = y-1;
+			/* decrease the check threshold toward its original value */
+			if (!txn->mt_rpcheck)
+				txn->mt_rpcheck = 1;
+			while (txn->mt_rpcheck < tl[0].mid && txn->mt_rpcheck < MDB_TRPAGE_SIZE/2)
+				txn->mt_rpcheck *= 2;
+		}
+	}
+	if (tl[0].mid < MDB_TRPAGE_SIZE) {
+		id3.mref = 1;
+		if (id3.mid)
+			goto found;
+		/* don't map past last written page in read-only envs */
+		if ((env->me_flags & MDB_RDONLY) && pgno + MDB_RPAGE_CHUNK-1 > txn->mt_last_pgno)
+			id3.mcnt = txn->mt_last_pgno + 1 - pgno;
+		else
+			id3.mcnt = MDB_RPAGE_CHUNK;
+		len = id3.mcnt * env->me_psize;
+		id3.mid = pgno;
+
+		/* search for page in env */
+		pthread_mutex_lock(&env->me_rpmutex);
+		x = mdb_mid3l_search(el, pgno);
+		if (x <= el[0].mid && el[x].mid == pgno) {
+			id3.mptr = el[x].mptr;
+			id3.mcnt = el[x].mcnt;
+			/* check for overflow size */
+			p = (MDB_page *)((char *)id3.mptr + rem * env->me_psize);
+			if (IS_OVERFLOW(p) && p->mp_pages + rem > id3.mcnt) {
+				id3.mcnt = p->mp_pages + rem;
+				len = id3.mcnt * env->me_psize;
+				SET_OFF(off, pgno * env->me_psize);
+				MAP(rc, env, id3.mptr, len, off);
+				if (rc)
+					goto fail;
+				if (!el[x].mref) {
+					munmap(el[x].mptr, el[x].mcnt);
+					el[x].mptr = id3.mptr;
+					el[x].mcnt = id3.mcnt;
+				} else {
+					id3.mid = pg0;
+					pthread_mutex_unlock(&env->me_rpmutex);
+					goto found;
+				}
+			}
+			el[x].mref++;
+			pthread_mutex_unlock(&env->me_rpmutex);
+			goto found;
+		}
+		if (el[0].mid >= MDB_ERPAGE_MAX - env->me_rpcheck) {
+			/* purge unref'd pages */
+			unsigned i, y = 0;
+			for (i=1; i<el[0].mid; i++) {
+				if (!el[i].mref) {
+					if (!y) y = i;
+					munmap(el[i].mptr, env->me_psize * el[i].mcnt);
+				}
+			}
+			if (!y) {
+				if (retries) {
+					/* see if we can unref some local pages */
+					retries--;
+					id3.mid = 0;
+					goto retry;
+				}
+				if (el[0].mid >= MDB_ERPAGE_MAX) {
+					pthread_mutex_unlock(&env->me_rpmutex);
+					return MDB_MAP_FULL;
+				}
+				env->me_rpcheck /= 2;
+			} else {
+				for (i=y+1; i<= el[0].mid; i++)
+					if (el[i].mref)
+						el[y++] = el[i];
+				el[0].mid = y-1;
+				if (!env->me_rpcheck)
+					env->me_rpcheck = 1;
+				while (env->me_rpcheck < el[0].mid && env->me_rpcheck < MDB_ERPAGE_SIZE/2)
+					env->me_rpcheck *= 2;
+			}
+		}
+		SET_OFF(off, pgno * env->me_psize);
+		MAP(rc, env, id3.mptr, len, off);
+		if (rc) {
+fail:
+			pthread_mutex_unlock(&env->me_rpmutex);
+			return rc;
+		}
+		/* If this page is far enough from the end of the env, scan for
+		 * any overflow pages that would spill onto another block.
+		 * Note we must compare against mt_last_pgno, the last written
+		 * page in the environment. Not mt_next_pgno, which increases
+		 * for every newly allocated (but not yet written) page. If
+		 * we scanned beyond the last written page we'd get a bus error.
+		 */
+		if (pgno + MDB_RPAGE_CHUNK <= txn->mt_last_pgno) {
+			int i;
+			char *cp = (char *)id3.mptr + rem * env->me_psize;
+			for (i=rem; i<MDB_RPAGE_CHUNK;) {
+				p = (MDB_page *)cp;
+				if (IS_OVERFLOW(p)) {
+					int nop = p->mp_pages;
+					if (nop + i > MDB_RPAGE_CHUNK) {
+						munmap(id3.mptr, len);
+						id3.mcnt = nop + i;
+						len = id3.mcnt * env->me_psize;
+						MAP(rc, env, id3.mptr, len, off);
+						if (rc)
+							goto fail;
+						break;
+					}
+					i += nop;
+					cp += nop * env->me_psize;
+				} else {
+					i++;
+					cp += env->me_psize;
+				}
+			}
+		}
+		mdb_mid3l_insert(el, &id3);
+		pthread_mutex_unlock(&env->me_rpmutex);
+found:
+		mdb_mid3l_insert(tl, &id3);
+	} else {
+		return MDB_TXN_FULL;
+	}
+ok:
+	p = (MDB_page *)((char *)id3.mptr + rem * env->me_psize);
+#if MDB_DEBUG	/* we don't need this check any more */
+	if (IS_OVERFLOW(p)) {
+		mdb_tassert(txn, p->mp_pages + rem <= id3.mcnt);
+	}
+#endif
+	*ret = p;
+	return MDB_SUCCESS;
+}
+#endif
+
+/** Find the address of the page corresponding to a given page number.
+ * @param[in] mc the cursor accessing the page.
+ * @param[in] pgno the page number for the page to retrieve.
+ * @param[out] ret address of a pointer where the page's address will be stored.
  * @param[out] lvl dirty_list inheritance level of found page. 1=current txn, 0=mapped page.
  * @return 0 on success, non-zero on failure.
  */
 static int
-mdb_page_get(MDB_txn *txn, pgno_t pgno, MDB_page **ret, int *lvl)
+mdb_page_get(MDB_cursor *mc, pgno_t pgno, MDB_page **ret, int *lvl)
 {
+	MDB_txn *txn = mc->mc_txn;
+#ifndef MDB_VL32
 	MDB_env *env = txn->mt_env;
+#endif
 	MDB_page *p = NULL;
 	int level;
 
-	if (!((txn->mt_flags & MDB_TXN_RDONLY) | (env->me_flags & MDB_WRITEMAP))) {
+	if (! (mc->mc_flags & (C_ORIG_RDONLY|C_WRITEMAP))) {
 		MDB_txn *tx2 = txn;
 		level = 1;
 		do {
@@ -5143,7 +5962,13 @@ mdb_page_get(MDB_txn *txn, pgno_t pgno, MDB_page **ret, int *lvl)
 				MDB_ID pn = pgno << 1;
 				x = mdb_midl_search(tx2->mt_spill_pgs, pn);
 				if (x <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[x] == pn) {
+#ifdef MDB_VL32
+					int rc = mdb_rpage_get(txn, pgno, &p);
+					if (rc)
+						return rc;
+#else
 					p = (MDB_page *)(env->me_map + env->me_psize * pgno);
+#endif
 					goto done;
 				}
 			}
@@ -5160,62 +5985,17 @@ mdb_page_get(MDB_txn *txn, pgno_t pgno, MDB_page **ret, int *lvl)
 
 	if (pgno < txn->mt_next_pgno) {
 		level = 0;
-#ifdef VL32
+#ifdef MDB_VL32
 		{
-			unsigned x = mdb_mid2l_search(txn->mt_rpages, pgno);
-			if (x <= txn->mt_rpages[0].mid && txn->mt_rpages[x].mid == pgno) {
-				p = txn->mt_rpages[x].mptr;
-				goto done;
-			}
-			if (txn->mt_rpages[0].mid >= MDB_IDL_UM_MAX) {
-				/* unmap some other page */
-				mdb_tassert(txn, 0);
-			}
-			if (txn->mt_rpages[0].mid < MDB_IDL_UM_SIZE) {
-				MDB_ID2 id2;
-				size_t len = env->me_psize;
-				int np;
-#ifdef _WIN32
-				size_t off = pgno * env->me_psize;
-				DWORD lo, hi;
-				lo = off & 0xffffffff;
-				hi = off >> 16 >> 16;
-				p = MapViewOfFile(env->me_fmh, FILE_MAP_READ, hi, lo, len);
-				if (p == NULL)
-					return ErrCode();
-				if (IS_OVERFLOW(p)) {
-					np = p->mp_pages;
-					UnmapViewOfFile(p);
-					len *= np;
-					p = MapViewOfFile(env->me_fmh, FILE_MAP_READ, hi, lo, len);
-					if (p == NULL)
-						return ErrCode();
-				}
-#else
-				off_t off = pgno * env->me_psize;
-				p = mmap(NULL, len, PROT_READ, MAP_SHARED, env->me_fd, off);
-				if (p == MAP_FAILED)
-					return errno;
-				if (IS_OVERFLOW(p)) {
-					np = p->mp_pages;
-					munmap(p, len);
-					len *= np;
-					p = mmap(NULL, len, PROT_READ, MAP_SHARED, env->me_fd, off);
-					if (p == MAP_FAILED)
-						return errno;
-				}
-#endif
-				id2.mid = pgno;
-				id2.mptr = p;
-				mdb_mid2l_insert(txn->mt_rpages, &id2);
-				goto done;
-			}
+			int rc = mdb_rpage_get(txn, pgno, &p);
+			if (rc)
+				return rc;
 		}
 #else
 		p = (MDB_page *)(env->me_map + env->me_psize * pgno);
 #endif
 	} else {
-		DPRINTF(("page %"Z"u not found", pgno));
+		DPRINTF(("page %"Yu" not found", pgno));
 		txn->mt_flags |= MDB_TXN_ERROR;
 		return MDB_PAGE_NOTFOUND;
 	}
@@ -5241,9 +6021,13 @@ mdb_page_search_root(MDB_cursor *mc, MDB_val *key, int flags)
 		MDB_node	*node;
 		indx_t		i;
 
-		DPRINTF(("branch page %"Z"u has %u keys", mp->mp_pgno, NUMKEYS(mp)));
-		mdb_cassert(mc, NUMKEYS(mp) > 1);
-		DPRINTF(("found index 0 to page %"Z"u", NODEPGNO(NODEPTR(mp, 0))));
+		DPRINTF(("branch page %"Yu" has %u keys", mp->mp_pgno, NUMKEYS(mp)));
+		/* Don't assert on branch pages in the FreeDB. We can get here
+		 * while in the process of rebalancing a FreeDB branch page; we must
+		 * let that proceed. ITS#8336
+		 */
+		mdb_cassert(mc, !mc->mc_dbi || NUMKEYS(mp) > 1);
+		DPRINTF(("found index 0 to page %"Yu"", NODEPGNO(NODEPTR(mp, 0))));
 
 		if (flags & (MDB_PS_FIRST|MDB_PS_LAST)) {
 			i = 0;
@@ -5267,7 +6051,7 @@ mdb_page_search_root(MDB_cursor *mc, MDB_val *key, int flags)
 		mdb_cassert(mc, i < NUMKEYS(mp));
 		node = NODEPTR(mp, i);
 
-		if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mp, NULL)) != 0)
+		if ((rc = mdb_page_get(mc, NODEPGNO(node), &mp, NULL)) != 0)
 			return rc;
 
 		mc->mc_ki[mc->mc_top] = i;
@@ -5288,7 +6072,7 @@ mdb_page_search_root(MDB_cursor *mc, MDB_val *key, int flags)
 		return MDB_CORRUPTED;
 	}
 
-	DPRINTF(("found leaf page %"Z"u for key [%s]", mp->mp_pgno,
+	DPRINTF(("found leaf page %"Yu" for key [%s]", mp->mp_pgno,
 	    key ? DKEY(key) : "null"));
 	mc->mc_flags |= C_INITIALIZED;
 	mc->mc_flags &= ~C_EOF;
@@ -5309,7 +6093,7 @@ mdb_page_search_lowest(MDB_cursor *mc)
 	MDB_node	*node = NODEPTR(mp, 0);
 	int rc;
 
-	if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mp, NULL)) != 0)
+	if ((rc = mdb_page_get(mc, NODEPGNO(node), &mp, NULL)) != 0)
 		return rc;
 
 	mc->mc_ki[mc->mc_top] = 0;
@@ -5338,8 +6122,8 @@ mdb_page_search(MDB_cursor *mc, MDB_val *key, int flags)
 	/* Make sure the txn is still viable, then find the root from
 	 * the txn's db table and set it as the root of the cursor's stack.
 	 */
-	if (F_ISSET(mc->mc_txn->mt_flags, MDB_TXN_ERROR)) {
-		DPUTS("transaction has failed, must abort");
+	if (mc->mc_txn->mt_flags & MDB_TXN_BLOCKED) {
+		DPUTS("transaction may not be used now");
 		return MDB_BAD_TXN;
 	} else {
 		/* Make sure we're using an up-to-date root */
@@ -5359,7 +6143,9 @@ mdb_page_search(MDB_cursor *mc, MDB_val *key, int flags)
 						&mc->mc_dbx->md_name, &exact);
 					if (!exact)
 						return MDB_NOTFOUND;
-					rc = mdb_node_read(mc->mc_txn, leaf, &data);
+					if ((leaf->mn_flags & (F_DUPDATA|F_SUBDATA)) != F_SUBDATA)
+						return MDB_INCOMPATIBLE; /* not a named DB */
+					rc = mdb_node_read(&mc2, leaf, &data);
 					if (rc)
 						return rc;
 					memcpy(&flags, ((char *) data.mv_data + offsetof(MDB_db, md_flags)),
@@ -5382,14 +6168,26 @@ mdb_page_search(MDB_cursor *mc, MDB_val *key, int flags)
 	}
 
 	mdb_cassert(mc, root > 1);
-	if (!mc->mc_pg[0] || mc->mc_pg[0]->mp_pgno != root)
-		if ((rc = mdb_page_get(mc->mc_txn, root, &mc->mc_pg[0], NULL)) != 0)
+	if (!mc->mc_pg[0] || mc->mc_pg[0]->mp_pgno != root) {
+#ifdef MDB_VL32
+		if (mc->mc_pg[0])
+			MDB_PAGE_UNREF(mc->mc_txn, mc->mc_pg[0]);
+#endif
+		if ((rc = mdb_page_get(mc, root, &mc->mc_pg[0], NULL)) != 0)
 			return rc;
+	}
 
+#ifdef MDB_VL32
+	{
+		int i;
+		for (i=1; i<mc->mc_snum; i++)
+			MDB_PAGE_UNREF(mc->mc_txn, mc->mc_pg[i]);
+	}
+#endif
 	mc->mc_snum = 1;
 	mc->mc_top = 0;
 
-	DPRINTF(("db %d root page %"Z"u has flags 0x%X",
+	DPRINTF(("db %d root page %"Yu" has flags 0x%X",
 		DDBI(mc), root, mc->mc_pg[0]->mp_flags));
 
 	if (flags & MDB_PS_MODIFY) {
@@ -5414,7 +6212,7 @@ mdb_ovpage_free(MDB_cursor *mc, MDB_page *mp)
 	MDB_ID pn = pg << 1;
 	int rc;
 
-	DPRINTF(("free ov page %"Z"u (%d)", pg, ovpages));
+	DPRINTF(("free ov page %"Yu" (%d)", pg, ovpages));
 	/* If the page is dirty or on the spill list we just acquired it,
 	 * so we should give it back to our current free list, if any.
 	 * Otherwise put it onto the list of pages we freed in this txn.
@@ -5458,6 +6256,7 @@ mdb_ovpage_free(MDB_cursor *mc, MDB_page *mp)
 				return MDB_CORRUPTED;
 			}
 		}
+		txn->mt_dirty_room++;
 		if (!(env->me_flags & MDB_WRITEMAP))
 			mdb_dpage_free(env, mp);
 release:
@@ -5479,18 +6278,24 @@ release:
 }
 
 /** Return the data associated with a given node.
- * @param[in] txn The transaction for this operation.
+ * @param[in] mc The cursor for this operation.
  * @param[in] leaf The node being read.
  * @param[out] data Updated to point to the node's data.
  * @return 0 on success, non-zero on failure.
  */
 static int
-mdb_node_read(MDB_txn *txn, MDB_node *leaf, MDB_val *data)
+mdb_node_read(MDB_cursor *mc, MDB_node *leaf, MDB_val *data)
 {
 	MDB_page	*omp;		/* overflow page */
 	pgno_t		 pgno;
 	int rc;
 
+#ifdef MDB_VL32
+	if (mc->mc_ovpg) {
+		MDB_PAGE_UNREF(mc->mc_txn, mc->mc_ovpg);
+		mc->mc_ovpg = 0;
+	}
+#endif
 	if (!F_ISSET(leaf->mn_flags, F_BIGDATA)) {
 		data->mv_size = NODEDSZ(leaf);
 		data->mv_data = NODEDATA(leaf);
@@ -5501,11 +6306,14 @@ mdb_node_read(MDB_txn *txn, MDB_node *leaf, MDB_val *data)
 	 */
 	data->mv_size = NODEDSZ(leaf);
 	memcpy(&pgno, NODEDATA(leaf), sizeof(pgno));
-	if ((rc = mdb_page_get(txn, pgno, &omp, NULL)) != 0) {
-		DPRINTF(("read overflow page %"Z"u failed", pgno));
+	if ((rc = mdb_page_get(mc, pgno, &omp, NULL)) != 0) {
+		DPRINTF(("read overflow page %"Yu" failed", pgno));
 		return rc;
 	}
 	data->mv_data = METADATA(omp);
+#ifdef MDB_VL32
+	mc->mc_ovpg = omp;
+#endif
 
 	return MDB_SUCCESS;
 }
@@ -5516,19 +6324,28 @@ mdb_get(MDB_txn *txn, MDB_dbi dbi,
 {
 	MDB_cursor	mc;
 	MDB_xcursor	mx;
-	int exact = 0;
+	int exact = 0, rc;
 	DKBUF;
 
 	DPRINTF(("===> get db %u key [%s]", dbi, DKEY(key)));
 
-	if (!key || !data || dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
+	if (!key || !data || !TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
 		return EINVAL;
 
-	if (txn->mt_flags & MDB_TXN_ERROR)
+	if (txn->mt_flags & MDB_TXN_BLOCKED)
 		return MDB_BAD_TXN;
 
 	mdb_cursor_init(&mc, txn, dbi, &mx);
-	return mdb_cursor_set(&mc, key, data, MDB_SET, &exact);
+	rc = mdb_cursor_set(&mc, key, data, MDB_SET, &exact);
+#ifdef MDB_VL32
+	{
+		/* unref all the pages - caller must copy the data
+		 * before doing anything else
+		 */
+		mdb_cursor_unref(&mc);
+	}
+#endif
+	return rc;
 }
 
 /** Find a sibling for a page.
@@ -5545,7 +6362,7 @@ mdb_cursor_sibling(MDB_cursor *mc, int move_right)
 	int		 rc;
 	MDB_node	*indx;
 	MDB_page	*mp;
-#ifdef VL32
+#ifdef MDB_VL32
 	MDB_page	*op;
 #endif
 
@@ -5553,12 +6370,11 @@ mdb_cursor_sibling(MDB_cursor *mc, int move_right)
 		return MDB_NOTFOUND;		/* root has no siblings */
 	}
 
-#ifdef VL32
+#ifdef MDB_VL32
 	op = mc->mc_pg[mc->mc_top];
 #endif
-
 	mdb_cursor_pop(mc);
-	DPRINTF(("parent page is page %"Z"u, index %u",
+	DPRINTF(("parent page is page %"Yu", index %u",
 		mc->mc_pg[mc->mc_top]->mp_pgno, mc->mc_ki[mc->mc_top]));
 
 	if (move_right ? (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mc->mc_pg[mc->mc_top]))
@@ -5581,23 +6397,10 @@ mdb_cursor_sibling(MDB_cursor *mc, int move_right)
 	}
 	mdb_cassert(mc, IS_BRANCH(mc->mc_pg[mc->mc_top]));
 
-#ifdef VL32
-	{
-		MDB_ID2L rl = mc->mc_txn->mt_rpages;
-		unsigned x = mdb_mid2l_search(rl, op->mp_pgno);
-		if (x <= rl[0].mid && rl[x].mid == op->mp_pgno) {
-			munmap(op, mc->mc_txn->mt_env->me_psize);
-			while (x < rl[0].mid) {
-				rl[x] = rl[x+1];
-				x++;
-			}
-			rl[0].mid--;
-		}
-	}
-#endif
+	MDB_PAGE_UNREF(mc->mc_txn, op);
 
 	indx = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
-	if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(indx), &mp, NULL)) != 0) {
+	if ((rc = mdb_page_get(mc, NODEPGNO(indx), &mp, NULL)) != 0) {
 		/* mc will be inconsistent if caller does mc_snum++ as above */
 		mc->mc_flags &= ~(C_INITIALIZED|C_EOF);
 		return rc;
@@ -5637,6 +6440,13 @@ mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
 					return rc;
 				}
 			}
+#ifdef MDB_VL32
+			else {
+				if (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) {
+					mdb_cursor_unref(&mc->mc_xcursor->mx_cursor);
+				}
+			}
+#endif
 		} else {
 			mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
 			if (op == MDB_NEXT_DUP)
@@ -5644,7 +6454,7 @@ mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
 		}
 	}
 
-	DPRINTF(("cursor_next: top page is %"Z"u in cursor %p",
+	DPRINTF(("cursor_next: top page is %"Yu" in cursor %p",
 		mdb_dbg_pgno(mp), (void *) mc));
 	if (mc->mc_flags & C_DEL)
 		goto skip;
@@ -5656,12 +6466,12 @@ mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
 			return rc;
 		}
 		mp = mc->mc_pg[mc->mc_top];
-		DPRINTF(("next page is %"Z"u, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]));
+		DPRINTF(("next page is %"Yu", key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]));
 	} else
 		mc->mc_ki[mc->mc_top]++;
 
 skip:
-	DPRINTF(("==> cursor points to page %"Z"u with %u keys, key index %u",
+	DPRINTF(("==> cursor points to page %"Yu" with %u keys, key index %u",
 	    mdb_dbg_pgno(mp), NUMKEYS(mp), mc->mc_ki[mc->mc_top]));
 
 	if (IS_LEAF2(mp)) {
@@ -5677,7 +6487,7 @@ skip:
 		mdb_xcursor_init1(mc, leaf);
 	}
 	if (data) {
-		if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
+		if ((rc = mdb_node_read(mc, leaf, data)) != MDB_SUCCESS)
 			return rc;
 
 		if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
@@ -5716,6 +6526,13 @@ mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
 					return rc;
 				}
 			}
+#ifdef MDB_VL32
+			else {
+				if (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) {
+					mdb_cursor_unref(&mc->mc_xcursor->mx_cursor);
+				}
+			}
+#endif
 		} else {
 			mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
 			if (op == MDB_PREV_DUP)
@@ -5723,7 +6540,7 @@ mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
 		}
 	}
 
-	DPRINTF(("cursor_prev: top page is %"Z"u in cursor %p",
+	DPRINTF(("cursor_prev: top page is %"Yu" in cursor %p",
 		mdb_dbg_pgno(mp), (void *) mc));
 
 	if (mc->mc_ki[mc->mc_top] == 0)  {
@@ -5733,13 +6550,13 @@ mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
 		}
 		mp = mc->mc_pg[mc->mc_top];
 		mc->mc_ki[mc->mc_top] = NUMKEYS(mp) - 1;
-		DPRINTF(("prev page is %"Z"u, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]));
+		DPRINTF(("prev page is %"Yu", key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]));
 	} else
 		mc->mc_ki[mc->mc_top]--;
 
 	mc->mc_flags &= ~C_EOF;
 
-	DPRINTF(("==> cursor points to page %"Z"u with %u keys, key index %u",
+	DPRINTF(("==> cursor points to page %"Yu" with %u keys, key index %u",
 	    mdb_dbg_pgno(mp), NUMKEYS(mp), mc->mc_ki[mc->mc_top]));
 
 	if (IS_LEAF2(mp)) {
@@ -5755,7 +6572,7 @@ mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
 		mdb_xcursor_init1(mc, leaf);
 	}
 	if (data) {
-		if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
+		if ((rc = mdb_node_read(mc, leaf, data)) != MDB_SUCCESS)
 			return rc;
 
 		if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
@@ -5874,6 +6691,8 @@ mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data,
 			} else
 				return MDB_NOTFOUND;
 		}
+	} else {
+		mc->mc_pg[0] = 0;
 	}
 
 	rc = mdb_page_search(mc, key, 0);
@@ -5892,8 +6711,10 @@ set2:
 
 	if (leaf == NULL) {
 		DPUTS("===> inexact leaf not found, goto sibling");
-		if ((rc = mdb_cursor_sibling(mc, 1)) != MDB_SUCCESS)
+		if ((rc = mdb_cursor_sibling(mc, 1)) != MDB_SUCCESS) {
+			mc->mc_flags |= C_EOF;
 			return rc;		/* no entries matched */
+		}
 		mp = mc->mc_pg[mc->mc_top];
 		mdb_cassert(mc, IS_LEAF(mp));
 		leaf = NODEPTR(mp, 0);
@@ -5911,6 +6732,11 @@ set1:
 		return MDB_SUCCESS;
 	}
 
+#ifdef MDB_VL32
+	if (mc->mc_xcursor && mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) {
+		mdb_cursor_unref(&mc->mc_xcursor->mx_cursor);
+	}
+#endif
 	if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
 		mdb_xcursor_init1(mc, leaf);
 	}
@@ -5933,11 +6759,11 @@ set1:
 		} else if (op == MDB_GET_BOTH || op == MDB_GET_BOTH_RANGE) {
 			MDB_val olddata;
 			MDB_cmp_func *dcmp;
-			if ((rc = mdb_node_read(mc->mc_txn, leaf, &olddata)) != MDB_SUCCESS)
+			if ((rc = mdb_node_read(mc, leaf, &olddata)) != MDB_SUCCESS)
 				return rc;
 			dcmp = mc->mc_dbx->md_dcmp;
-#if UINT_MAX < SIZE_MAX
-			if (dcmp == mdb_cmp_int && olddata.mv_size == sizeof(size_t))
+#if UINT_MAX < SIZE_MAX || defined(MDB_VL32)
+			if (dcmp == mdb_cmp_int && olddata.mv_size == sizeof(mdb_size_t))
 				dcmp = mdb_cmp_clong;
 #endif
 			rc = dcmp(data, &olddata);
@@ -5951,7 +6777,7 @@ set1:
 		} else {
 			if (mc->mc_xcursor)
 				mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
-			if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
+			if ((rc = mdb_node_read(mc, leaf, data)) != MDB_SUCCESS)
 				return rc;
 		}
 	}
@@ -5971,8 +6797,14 @@ mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data)
 	int		 rc;
 	MDB_node	*leaf;
 
-	if (mc->mc_xcursor)
+	if (mc->mc_xcursor) {
+#ifdef MDB_VL32
+		if (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) {
+			mdb_cursor_unref(&mc->mc_xcursor->mx_cursor);
+		}
+#endif
 		mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
+	}
 
 	if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) {
 		rc = mdb_page_search(mc, NULL, MDB_PS_FIRST);
@@ -6000,7 +6832,7 @@ mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data)
 			if (rc)
 				return rc;
 		} else {
-			if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
+			if ((rc = mdb_node_read(mc, leaf, data)) != MDB_SUCCESS)
 				return rc;
 		}
 	}
@@ -6015,8 +6847,14 @@ mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data)
 	int		 rc;
 	MDB_node	*leaf;
 
-	if (mc->mc_xcursor)
+	if (mc->mc_xcursor) {
+#ifdef MDB_VL32
+		if (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) {
+			mdb_cursor_unref(&mc->mc_xcursor->mx_cursor);
+		}
+#endif
 		mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
+	}
 
 	if (!(mc->mc_flags & C_EOF)) {
 
@@ -6045,7 +6883,7 @@ mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data)
 			if (rc)
 				return rc;
 		} else {
-			if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
+			if ((rc = mdb_node_read(mc, leaf, data)) != MDB_SUCCESS)
 				return rc;
 		}
 	}
@@ -6065,7 +6903,7 @@ mdb_cursor_get(MDB_cursor *mc, MDB_val *key, MDB_val *data,
 	if (mc == NULL)
 		return EINVAL;
 
-	if (mc->mc_txn->mt_flags & MDB_TXN_ERROR)
+	if (mc->mc_txn->mt_flags & MDB_TXN_BLOCKED)
 		return MDB_BAD_TXN;
 
 	switch (op) {
@@ -6089,11 +6927,9 @@ mdb_cursor_get(MDB_cursor *mc, MDB_val *key, MDB_val *data,
 				MDB_GET_KEY(leaf, key);
 				if (data) {
 					if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
-						if (mc->mc_flags & C_DEL)
-							mdb_xcursor_init1(mc, leaf);
 						rc = mdb_cursor_get(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_GET_CURRENT);
 					} else {
-						rc = mdb_node_read(mc->mc_txn, leaf, data);
+						rc = mdb_node_read(mc, leaf, data);
 					}
 				}
 			}
@@ -6199,7 +7035,7 @@ fetchm:
 			MDB_node *leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
 			if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
 				MDB_GET_KEY(leaf, key);
-				rc = mdb_node_read(mc->mc_txn, leaf, data);
+				rc = mdb_node_read(mc, leaf, data);
 				break;
 			}
 		}
@@ -6236,7 +7072,7 @@ mdb_cursor_touch(MDB_cursor *mc)
 {
 	int rc = MDB_SUCCESS;
 
-	if (mc->mc_dbi > MAIN_DBI && !(*mc->mc_dbflag & DB_DIRTY)) {
+	if (mc->mc_dbi >= CORE_DBS && !(*mc->mc_dbflag & DB_DIRTY)) {
 		MDB_cursor mc2;
 		MDB_xcursor mcx;
 		if (TXN_DBI_CHANGED(mc->mc_txn, mc->mc_dbi))
@@ -6264,10 +7100,9 @@ int
 mdb_cursor_put(MDB_cursor *mc, MDB_val *key, MDB_val *data,
     unsigned int flags)
 {
-	enum { MDB_NO_ROOT = MDB_LAST_ERRCODE+10 }; /* internal code */
 	MDB_env		*env;
 	MDB_node	*leaf = NULL;
-	MDB_page	*fp, *mp;
+	MDB_page	*fp, *mp, *sub_root = NULL;
 	uint16_t	fp_flags;
 	MDB_val		xdata, *rdata, dkey, olddata;
 	MDB_db dummy;
@@ -6296,7 +7131,7 @@ mdb_cursor_put(MDB_cursor *mc, MDB_val *key, MDB_val *data,
 	nospill = flags & MDB_NOSPILL;
 	flags &= ~MDB_NOSPILL;
 
-	if (mc->mc_txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_ERROR))
+	if (mc->mc_txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED))
 		return (mc->mc_txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
 
 	if (key->mv_size-1 >= ENV_MAXKEY(env))
@@ -6421,16 +7256,18 @@ fix_parent:
 			 * update branch key if there is a parent page
 			 */
 			if (mc->mc_top && !mc->mc_ki[mc->mc_top]) {
-				unsigned short top = mc->mc_top;
+				unsigned short dtop = 1;
 				mc->mc_top--;
 				/* slot 0 is always an empty key, find real slot */
-				while (mc->mc_top && !mc->mc_ki[mc->mc_top])
+				while (mc->mc_top && !mc->mc_ki[mc->mc_top]) {
 					mc->mc_top--;
+					dtop++;
+				}
 				if (mc->mc_ki[mc->mc_top])
 					rc2 = mdb_update_key(mc, key);
 				else
 					rc2 = MDB_SUCCESS;
-				mc->mc_top = top;
+				mc->mc_top += dtop;
 				if (rc2)
 					return rc2;
 			}
@@ -6460,13 +7297,13 @@ more:
 				if (flags == MDB_CURRENT)
 					goto current;
 				dcmp = mc->mc_dbx->md_dcmp;
-#if UINT_MAX < SIZE_MAX
-				if (dcmp == mdb_cmp_int && olddata.mv_size == sizeof(size_t))
+#if UINT_MAX < SIZE_MAX || defined(MDB_VL32)
+				if (dcmp == mdb_cmp_int && olddata.mv_size == sizeof(mdb_size_t))
 					dcmp = mdb_cmp_clong;
 #endif
 				/* does data match? */
 				if (!dcmp(data, &olddata)) {
-					if (flags & MDB_NODUPDATA)
+					if (flags & (MDB_NODUPDATA|MDB_APPENDDUP))
 						return MDB_KEYEXIST;
 					/* overwrite it */
 					goto current;
@@ -6547,6 +7384,7 @@ prep_subDB:
 					offset = env->me_psize - olddata.mv_size;
 					flags |= F_DUPDATA|F_SUBDATA;
 					dummy.md_root = mp->mp_pgno;
+					sub_root = mp;
 			}
 			if (mp != fp) {
 				mp->mp_flags = fp_flags | P_DIRTY;
@@ -6571,6 +7409,9 @@ prep_subDB:
 			goto new_sub;
 		}
 current:
+		/* LMDB passes F_SUBDATA in 'flags' to write a DB record */
+		if ((leaf->mn_flags ^ flags) & F_SUBDATA)
+			return MDB_INCOMPATIBLE;
 		/* overflow page overwrites need special handling */
 		if (F_ISSET(leaf->mn_flags, F_BIGDATA)) {
 			MDB_page *omp;
@@ -6578,7 +7419,7 @@ current:
 			int level, ovpages, dpages = OVPAGES(data->mv_size, env->me_psize);
 
 			memcpy(&pg, olddata.mv_data, sizeof(pg));
-			if ((rc2 = mdb_page_get(mc->mc_txn, pg, &omp, &level)) != 0)
+			if ((rc2 = mdb_page_get(mc, pg, &omp, &level)) != 0)
 				return rc2;
 			ovpages = omp->mp_pages;
 
@@ -6607,6 +7448,7 @@ current:
 						return ENOMEM;
 					id2.mid = pg;
 					id2.mptr = np;
+					/* Note - this page is already counted in parent's dirty_room */
 					rc2 = mdb_mid2l_insert(mc->mc_txn->mt_u.dirty_list, &id2);
 					mdb_cassert(mc, rc2 == 0);
 					if (!(flags & MDB_RESERVE)) {
@@ -6663,7 +7505,7 @@ new_sub:
 	} else {
 		/* There is room already in this leaf page. */
 		rc = mdb_node_add(mc, mc->mc_ki[mc->mc_top], key, rdata, 0, nflags);
-		if (rc == 0 && insert_key) {
+		if (rc == 0) {
 			/* Adjust other cursors pointing to mp */
 			MDB_cursor *m2, *m3;
 			MDB_dbi dbi = mc->mc_dbi;
@@ -6675,10 +7517,15 @@ new_sub:
 					m3 = &m2->mc_xcursor->mx_cursor;
 				else
 					m3 = m2;
-				if (m3 == mc || m3->mc_snum < mc->mc_snum) continue;
-				if (m3->mc_pg[i] == mp && m3->mc_ki[i] >= mc->mc_ki[i]) {
+				if (m3 == mc || m3->mc_snum < mc->mc_snum || m3->mc_pg[i] != mp) continue;
+				if (m3->mc_ki[i] >= mc->mc_ki[i] && insert_key) {
 					m3->mc_ki[i]++;
 				}
+				if (m3->mc_xcursor && (m3->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {
+					MDB_node *n2 = NODEPTR(mp, m3->mc_ki[i]);
+					if ((n2->mn_flags & (F_SUBDATA|F_DUPDATA)) == F_DUPDATA)
+						m3->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(n2);
+				}
 			}
 		}
 	}
@@ -6690,7 +7537,7 @@ new_sub:
 		 * DB are all zero size.
 		 */
 		if (do_sub) {
-			int xflags;
+			int xflags, new_dupdata;
 			size_t ecount;
 put_sub:
 			xdata.mv_size = 0;
@@ -6703,27 +7550,38 @@ put_sub:
 				xflags = (flags & MDB_NODUPDATA) ?
 					MDB_NOOVERWRITE|MDB_NOSPILL : MDB_NOSPILL;
 			}
+			if (sub_root)
+				mc->mc_xcursor->mx_cursor.mc_pg[0] = sub_root;
+			new_dupdata = (int)dkey.mv_size;
 			/* converted, write the original data first */
 			if (dkey.mv_size) {
 				rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, &dkey, &xdata, xflags);
 				if (rc)
 					goto bad_sub;
-				{
-					/* Adjust other cursors pointing to mp */
-					MDB_cursor *m2;
-					unsigned i = mc->mc_top;
-					MDB_page *mp = mc->mc_pg[i];
-
-					for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
-						if (m2 == mc || m2->mc_snum < mc->mc_snum) continue;
-						if (!(m2->mc_flags & C_INITIALIZED)) continue;
-						if (m2->mc_pg[i] == mp && m2->mc_ki[i] == mc->mc_ki[i]) {
-							mdb_xcursor_init1(m2, leaf);
+				/* we've done our job */
+				dkey.mv_size = 0;
+			}
+			if (!(leaf->mn_flags & F_SUBDATA) || sub_root) {
+				/* Adjust other cursors pointing to mp */
+				MDB_cursor *m2;
+				MDB_xcursor *mx = mc->mc_xcursor;
+				unsigned i = mc->mc_top;
+				MDB_page *mp = mc->mc_pg[i];
+				int nkeys = NUMKEYS(mp);
+
+				for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
+					if (m2 == mc || m2->mc_snum < mc->mc_snum) continue;
+					if (!(m2->mc_flags & C_INITIALIZED)) continue;
+					if (m2->mc_pg[i] == mp) {
+						if (m2->mc_ki[i] == mc->mc_ki[i]) {
+							mdb_xcursor_init2(m2, mx, new_dupdata);
+						} else if (!insert_key && m2->mc_ki[i] < nkeys) {
+							MDB_node *n2 = NODEPTR(mp, m2->mc_ki[i]);
+							if ((n2->mn_flags & (F_SUBDATA|F_DUPDATA)) == F_DUPDATA)
+								m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(n2);
 						}
 					}
 				}
-				/* we've done our job */
-				dkey.mv_size = 0;
 			}
 			ecount = mc->mc_xcursor->mx_db.md_entries;
 			if (flags & MDB_APPENDDUP)
@@ -6775,7 +7633,7 @@ mdb_cursor_del(MDB_cursor *mc, unsigned int flags)
 	MDB_page	*mp;
 	int rc;
 
-	if (mc->mc_txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_ERROR))
+	if (mc->mc_txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED))
 		return (mc->mc_txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
 
 	if (!(mc->mc_flags & C_INITIALIZED))
@@ -6800,6 +7658,7 @@ mdb_cursor_del(MDB_cursor *mc, unsigned int flags)
 		if (flags & MDB_NODUPDATA) {
 			/* mdb_cursor_del0() will subtract the final entry */
 			mc->mc_db->md_entries -= mc->mc_xcursor->mx_db.md_entries - 1;
+			mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED;
 		} else {
 			if (!F_ISSET(leaf->mn_flags, F_SUBDATA)) {
 				mc->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
@@ -6819,17 +7678,25 @@ mdb_cursor_del(MDB_cursor *mc, unsigned int flags)
 					mdb_node_shrink(mp, mc->mc_ki[mc->mc_top]);
 					leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
 					mc->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
-					/* fix other sub-DB cursors pointed at this fake page */
+					/* fix other sub-DB cursors pointed at fake pages on this page */
 					for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
 						if (m2 == mc || m2->mc_snum < mc->mc_snum) continue;
-						if (m2->mc_pg[mc->mc_top] == mp &&
-							m2->mc_ki[mc->mc_top] == mc->mc_ki[mc->mc_top])
-							m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
+						if (!(m2->mc_flags & C_INITIALIZED)) continue;
+						if (m2->mc_pg[mc->mc_top] == mp) {
+							if (m2->mc_ki[mc->mc_top] == mc->mc_ki[mc->mc_top]) {
+								m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
+							} else {
+								MDB_node *n2 = NODEPTR(mp, m2->mc_ki[mc->mc_top]);
+								if (!(n2->mn_flags & F_SUBDATA))
+									m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(n2);
+							}
+						}
 					}
 				}
 				mc->mc_db->md_entries--;
-				mc->mc_flags |= C_DEL;
 				return rc;
+			} else {
+				mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED;
 			}
 			/* otherwise fall thru and delete the sub-DB */
 		}
@@ -6841,6 +7708,11 @@ mdb_cursor_del(MDB_cursor *mc, unsigned int flags)
 				goto fail;
 		}
 	}
+	/* LMDB passes F_SUBDATA in 'flags' to delete a DB record */
+	else if ((leaf->mn_flags ^ flags) & F_SUBDATA) {
+		rc = MDB_INCOMPATIBLE;
+		goto fail;
+	}
 
 	/* add overflow pages to free list */
 	if (F_ISSET(leaf->mn_flags, F_BIGDATA)) {
@@ -6848,7 +7720,7 @@ mdb_cursor_del(MDB_cursor *mc, unsigned int flags)
 		pgno_t pg;
 
 		memcpy(&pg, NODEDATA(leaf), sizeof(pg));
-		if ((rc = mdb_page_get(mc->mc_txn, pg, &omp, NULL)) ||
+		if ((rc = mdb_page_get(mc, pg, &omp, NULL)) ||
 			(rc = mdb_ovpage_free(mc, omp)))
 			goto fail;
 	}
@@ -6877,7 +7749,7 @@ mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp)
 
 	if ((rc = mdb_page_alloc(mc, num, &np)))
 		return rc;
-	DPRINTF(("allocated new mpage %"Z"u, page size %u",
+	DPRINTF(("allocated new mpage %"Yu", page size %u",
 	    np->mp_pgno, mc->mc_txn->mt_env->me_psize));
 	np->mp_flags = flags | P_DIRTY;
 	np->mp_lower = (PAGEHDRSZ-PAGEBASE);
@@ -6972,11 +7844,12 @@ mdb_node_add(MDB_cursor *mc, indx_t indx,
 	MDB_node	*node;
 	MDB_page	*mp = mc->mc_pg[mc->mc_top];
 	MDB_page	*ofp = NULL;		/* overflow page */
+	void		*ndata;
 	DKBUF;
 
 	mdb_cassert(mc, mp->mp_upper >= mp->mp_lower);
 
-	DPRINTF(("add to %s %spage %"Z"u index %i, data size %"Z"u key size %"Z"u [%s]",
+	DPRINTF(("add to %s %spage %"Yu" index %i, data size %"Z"u key size %"Z"u [%s]",
 	    IS_LEAF(mp) ? "leaf" : "branch",
 		IS_SUBP(mp) ? "sub-" : "",
 		mdb_dbg_pgno(mp), indx, data ? data->mv_size : 0,
@@ -7002,7 +7875,7 @@ mdb_node_add(MDB_cursor *mc, indx_t indx,
 	if (key != NULL)
 		node_size += key->mv_size;
 	if (IS_LEAF(mp)) {
-		mdb_cassert(mc, data);
+		mdb_cassert(mc, key && data);
 		if (F_ISSET(flags, F_BIGDATA)) {
 			/* Data already on overflow page. */
 			node_size += sizeof(pgno_t);
@@ -7017,7 +7890,7 @@ mdb_node_add(MDB_cursor *mc, indx_t indx,
 				goto full;
 			if ((rc = mdb_page_new(mc, P_OVERFLOW, ovpages, &ofp)))
 				return rc;
-			DPRINTF(("allocated overflow page %"Z"u", ofp->mp_pgno));
+			DPRINTF(("allocated overflow page %"Yu"", ofp->mp_pgno));
 			flags |= F_BIGDATA;
 			goto update;
 		} else {
@@ -7053,30 +7926,28 @@ update:
 		memcpy(NODEKEY(node), key->mv_data, key->mv_size);
 
 	if (IS_LEAF(mp)) {
-		mdb_cassert(mc, key);
+		ndata = NODEDATA(node);
 		if (ofp == NULL) {
 			if (F_ISSET(flags, F_BIGDATA))
-				memcpy(node->mn_data + key->mv_size, data->mv_data,
-				    sizeof(pgno_t));
+				memcpy(ndata, data->mv_data, sizeof(pgno_t));
 			else if (F_ISSET(flags, MDB_RESERVE))
-				data->mv_data = node->mn_data + key->mv_size;
+				data->mv_data = ndata;
 			else
-				memcpy(node->mn_data + key->mv_size, data->mv_data,
-				    data->mv_size);
+				memcpy(ndata, data->mv_data, data->mv_size);
 		} else {
-			memcpy(node->mn_data + key->mv_size, &ofp->mp_pgno,
-			    sizeof(pgno_t));
+			memcpy(ndata, &ofp->mp_pgno, sizeof(pgno_t));
+			ndata = METADATA(ofp);
 			if (F_ISSET(flags, MDB_RESERVE))
-				data->mv_data = METADATA(ofp);
+				data->mv_data = ndata;
 			else
-				memcpy(METADATA(ofp), data->mv_data, data->mv_size);
+				memcpy(ndata, data->mv_data, data->mv_size);
 		}
 	}
 
 	return MDB_SUCCESS;
 
 full:
-	DPRINTF(("not enough room in page %"Z"u, got %u ptrs",
+	DPRINTF(("not enough room in page %"Yu", got %u ptrs",
 		mdb_dbg_pgno(mp), NUMKEYS(mp)));
 	DPRINTF(("upper-lower = %u - %u = %"Z"d", mp->mp_upper,mp->mp_lower,room));
 	DPRINTF(("node size = %"Z"u", node_size));
@@ -7099,7 +7970,7 @@ mdb_node_del(MDB_cursor *mc, int ksize)
 	MDB_node	*node;
 	char		*base;
 
-	DPRINTF(("delete node %u on %s page %"Z"u", indx,
+	DPRINTF(("delete node %u on %s page %"Yu"", indx,
 	    IS_LEAF(mp) ? "leaf" : "branch", mdb_dbg_pgno(mp)));
 	numkeys = NUMKEYS(mp);
 	mdb_cassert(mc, indx < numkeys);
@@ -7151,45 +8022,38 @@ mdb_node_shrink(MDB_page *mp, indx_t indx)
 	MDB_node *node;
 	MDB_page *sp, *xp;
 	char *base;
-	int nsize, delta;
-	indx_t		 i, numkeys, ptr;
+	indx_t delta, nsize, len, ptr;
+	int i;
 
 	node = NODEPTR(mp, indx);
 	sp = (MDB_page *)NODEDATA(node);
 	delta = SIZELEFT(sp);
-	xp = (MDB_page *)((char *)sp + delta);
+	nsize = NODEDSZ(node) - delta;
 
-	/* shift subpage upward */
+	/* Prepare to shift upward, set len = length(subpage part to shift) */
 	if (IS_LEAF2(sp)) {
-		nsize = NUMKEYS(sp) * sp->mp_pad;
+		len = nsize;
 		if (nsize & 1)
 			return;		/* do not make the node uneven-sized */
-		memmove(METADATA(xp), METADATA(sp), nsize);
 	} else {
-		int i;
-		numkeys = NUMKEYS(sp);
-		for (i=numkeys-1; i>=0; i--)
+		xp = (MDB_page *)((char *)sp + delta); /* destination subpage */
+		for (i = NUMKEYS(sp); --i >= 0; )
 			xp->mp_ptrs[i] = sp->mp_ptrs[i] - delta;
+		len = PAGEHDRSZ;
 	}
-	xp->mp_upper = sp->mp_lower;
-	xp->mp_lower = sp->mp_lower;
-	xp->mp_flags = sp->mp_flags;
-	xp->mp_pad = sp->mp_pad;
-	COPY_PGNO(xp->mp_pgno, mp->mp_pgno);
-
-	nsize = NODEDSZ(node) - delta;
+	sp->mp_upper = sp->mp_lower;
+	COPY_PGNO(sp->mp_pgno, mp->mp_pgno);
 	SETDSZ(node, nsize);
 
-	/* shift lower nodes upward */
+	/* Shift <lower nodes...initial part of subpage> upward */
+	base = (char *)mp + mp->mp_upper + PAGEBASE;
+	memmove(base + delta, base, (char *)sp + len - base);
+
 	ptr = mp->mp_ptrs[indx];
-	numkeys = NUMKEYS(mp);
-	for (i = 0; i < numkeys; i++) {
+	for (i = NUMKEYS(mp); --i >= 0; ) {
 		if (mp->mp_ptrs[i] <= ptr)
 			mp->mp_ptrs[i] += delta;
 	}
-
-	base = (char *)mp + mp->mp_upper + PAGEBASE;
-	memmove(base + delta, base, ptr - mp->mp_upper + NODESIZE + NODEKSZ(node));
 	mp->mp_upper += delta;
 }
 
@@ -7215,7 +8079,10 @@ mdb_xcursor_init0(MDB_cursor *mc)
 	mx->mx_cursor.mc_dbflag = &mx->mx_dbflag;
 	mx->mx_cursor.mc_snum = 0;
 	mx->mx_cursor.mc_top = 0;
-	mx->mx_cursor.mc_flags = C_SUB;
+#ifdef MDB_VL32
+	mx->mx_cursor.mc_ovpg = 0;
+#endif
+	mx->mx_cursor.mc_flags = C_SUB | (mc->mc_flags & (C_ORIG_RDONLY|C_WRITEMAP));
 	mx->mx_dbx.md_name.mv_size = 0;
 	mx->mx_dbx.md_name.mv_data = NULL;
 	mx->mx_dbx.md_cmp = mc->mc_dbx->md_dcmp;
@@ -7234,15 +8101,15 @@ mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node)
 {
 	MDB_xcursor *mx = mc->mc_xcursor;
 
+	mx->mx_cursor.mc_flags &= C_SUB|C_ORIG_RDONLY|C_WRITEMAP;
 	if (node->mn_flags & F_SUBDATA) {
 		memcpy(&mx->mx_db, NODEDATA(node), sizeof(MDB_db));
 		mx->mx_cursor.mc_pg[0] = 0;
 		mx->mx_cursor.mc_snum = 0;
 		mx->mx_cursor.mc_top = 0;
-		mx->mx_cursor.mc_flags = C_SUB;
 	} else {
 		MDB_page *fp = NODEDATA(node);
-		mx->mx_db.md_pad = mc->mc_pg[mc->mc_top]->mp_pad;
+		mx->mx_db.md_pad = 0;
 		mx->mx_db.md_flags = 0;
 		mx->mx_db.md_depth = 1;
 		mx->mx_db.md_branch_pages = 0;
@@ -7252,7 +8119,7 @@ mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node)
 		COPY_PGNO(mx->mx_db.md_root, fp->mp_pgno);
 		mx->mx_cursor.mc_snum = 1;
 		mx->mx_cursor.mc_top = 0;
-		mx->mx_cursor.mc_flags = C_INITIALIZED|C_SUB;
+		mx->mx_cursor.mc_flags |= C_INITIALIZED;
 		mx->mx_cursor.mc_pg[0] = fp;
 		mx->mx_cursor.mc_ki[0] = 0;
 		if (mc->mc_db->md_flags & MDB_DUPFIXED) {
@@ -7262,15 +8129,47 @@ mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node)
 				mx->mx_db.md_flags |= MDB_INTEGERKEY;
 		}
 	}
-	DPRINTF(("Sub-db -%u root page %"Z"u", mx->mx_cursor.mc_dbi,
+	DPRINTF(("Sub-db -%u root page %"Yu"", mx->mx_cursor.mc_dbi,
 		mx->mx_db.md_root));
-	mx->mx_dbflag = DB_VALID|DB_DIRTY; /* DB_DIRTY guides mdb_cursor_touch */
-#if UINT_MAX < SIZE_MAX
-	if (mx->mx_dbx.md_cmp == mdb_cmp_int && mx->mx_db.md_pad == sizeof(size_t))
+	mx->mx_dbflag = DB_VALID|DB_USRVALID|DB_DIRTY; /* DB_DIRTY guides mdb_cursor_touch */
+#if UINT_MAX < SIZE_MAX || defined(MDB_VL32)
+	if (mx->mx_dbx.md_cmp == mdb_cmp_int && mx->mx_db.md_pad == sizeof(mdb_size_t))
 		mx->mx_dbx.md_cmp = mdb_cmp_clong;
 #endif
 }
 
+
+/** Fixup a sorted-dups cursor due to underlying update.
+ *	Sets up some fields that depend on the data from the main cursor.
+ *	Almost the same as init1, but skips initialization steps if the
+ *	xcursor had already been used.
+ * @param[in] mc The main cursor whose sorted-dups cursor is to be fixed up.
+ * @param[in] src_mx The xcursor of an up-to-date cursor.
+ * @param[in] new_dupdata True if converting from a non-#F_DUPDATA item.
+ */
+static void
+mdb_xcursor_init2(MDB_cursor *mc, MDB_xcursor *src_mx, int new_dupdata)
+{
+	MDB_xcursor *mx = mc->mc_xcursor;
+
+	if (new_dupdata) {
+		mx->mx_cursor.mc_snum = 1;
+		mx->mx_cursor.mc_top = 0;
+		mx->mx_cursor.mc_flags |= C_INITIALIZED;
+		mx->mx_cursor.mc_ki[0] = 0;
+		mx->mx_dbflag = DB_VALID|DB_USRVALID|DB_DIRTY; /* DB_DIRTY guides mdb_cursor_touch */
+#if UINT_MAX < SIZE_MAX
+		mx->mx_dbx.md_cmp = src_mx->mx_dbx.md_cmp;
+#endif
+	} else if (!(mx->mx_cursor.mc_flags & C_INITIALIZED)) {
+		return;
+	}
+	mx->mx_db = src_mx->mx_db;
+	mx->mx_cursor.mc_pg[0] = src_mx->mx_cursor.mc_pg[0];
+	DPRINTF(("Sub-db -%u root page %"Yu"", mx->mx_cursor.mc_dbi,
+		mx->mx_db.md_root));
+}
+
 /** Initialize a cursor for a given transaction and database. */
 static void
 mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx)
@@ -7286,7 +8185,10 @@ mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx)
 	mc->mc_top = 0;
 	mc->mc_pg[0] = 0;
 	mc->mc_ki[0] = 0;
-	mc->mc_flags = 0;
+#ifdef MDB_VL32
+	mc->mc_ovpg = 0;
+#endif
+	mc->mc_flags = txn->mt_flags & (C_ORIG_RDONLY|C_WRITEMAP);
 	if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) {
 		mdb_tassert(txn, mx != NULL);
 		mc->mc_xcursor = mx;
@@ -7305,14 +8207,13 @@ mdb_cursor_open(MDB_txn *txn, MDB_dbi dbi, MDB_cursor **ret)
 	MDB_cursor	*mc;
 	size_t size = sizeof(MDB_cursor);
 
-	if (!ret || !TXN_DBI_EXIST(txn, dbi))
+	if (!ret || !TXN_DBI_EXIST(txn, dbi, DB_VALID))
 		return EINVAL;
 
-	if (txn->mt_flags & MDB_TXN_ERROR)
+	if (txn->mt_flags & MDB_TXN_BLOCKED)
 		return MDB_BAD_TXN;
 
-	/* Allow read access to the freelist */
-	if (!dbi && !F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))
+	if (dbi == FREE_DBI && !F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))
 		return EINVAL;
 
 	if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT)
@@ -7337,13 +8238,13 @@ mdb_cursor_open(MDB_txn *txn, MDB_dbi dbi, MDB_cursor **ret)
 int
 mdb_cursor_renew(MDB_txn *txn, MDB_cursor *mc)
 {
-	if (!mc || !TXN_DBI_EXIST(txn, mc->mc_dbi))
+	if (!mc || !TXN_DBI_EXIST(txn, mc->mc_dbi, DB_VALID))
 		return EINVAL;
 
 	if ((mc->mc_flags & C_UNTRACK) || txn->mt_cursors)
 		return EINVAL;
 
-	if (txn->mt_flags & MDB_TXN_ERROR)
+	if (txn->mt_flags & MDB_TXN_BLOCKED)
 		return MDB_BAD_TXN;
 
 	mdb_cursor_init(mc, txn, mc->mc_dbi, mc->mc_xcursor);
@@ -7362,7 +8263,7 @@ mdb_cursor_count(MDB_cursor *mc, size_t *countp)
 	if (mc->mc_xcursor == NULL)
 		return MDB_INCOMPATIBLE;
 
-	if (mc->mc_txn->mt_flags & MDB_TXN_ERROR)
+	if (mc->mc_txn->mt_flags & MDB_TXN_BLOCKED)
 		return MDB_BAD_TXN;
 
 	if (!(mc->mc_flags & C_INITIALIZED))
@@ -7437,7 +8338,7 @@ mdb_update_key(MDB_cursor *mc, MDB_val *key)
 		char kbuf2[DKBUF_MAXKEYSIZE*2+1];
 		k2.mv_data = NODEKEY(node);
 		k2.mv_size = node->mn_ksize;
-		DPRINTF(("update key %u (ofs %u) [%s] to [%s] on page %"Z"u",
+		DPRINTF(("update key %u (ofs %u) [%s] to [%s] on page %"Yu"",
 			indx, ptr,
 			mdb_dkey(&k2, kbuf2),
 			DKEY(key),
@@ -7488,10 +8389,26 @@ mdb_update_key(MDB_cursor *mc, MDB_val *key)
 static void
 mdb_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst);
 
+/** Perform \b act while tracking temporary cursor \b mn */
+#define WITH_CURSOR_TRACKING(mn, act) do { \
+	MDB_cursor dummy, *tracked, **tp = &(mn).mc_txn->mt_cursors[mn.mc_dbi]; \
+	if ((mn).mc_flags & C_SUB) { \
+		dummy.mc_flags =  C_INITIALIZED; \
+		dummy.mc_xcursor = (MDB_xcursor *)&(mn);	\
+		tracked = &dummy; \
+	} else { \
+		tracked = &(mn); \
+	} \
+	tracked->mc_next = *tp; \
+	*tp = tracked; \
+	{ act; } \
+	*tp = tracked->mc_next; \
+} while (0)
+
 /** Move a node from csrc to cdst.
  */
 static int
-mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst)
+mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst, int fromleft)
 {
 	MDB_node		*srcnode;
 	MDB_val		 key, data;
@@ -7543,6 +8460,7 @@ mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst)
 		data.mv_size = NODEDSZ(srcnode);
 		data.mv_data = NODEDATA(srcnode);
 	}
+	mn.mc_xcursor = NULL;
 	if (IS_BRANCH(cdst->mc_pg[cdst->mc_top]) && cdst->mc_ki[cdst->mc_top] == 0) {
 		unsigned int snum = cdst->mc_snum;
 		MDB_node *s2;
@@ -7568,7 +8486,7 @@ mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst)
 			return rc;
 	}
 
-	DPRINTF(("moving %s node %u [%s] on page %"Z"u to node %u on page %"Z"u",
+	DPRINTF(("moving %s node %u [%s] on page %"Yu" to node %u on page %"Yu"",
 	    IS_LEAF(csrc->mc_pg[csrc->mc_top]) ? "leaf" : "branch",
 	    csrc->mc_ki[csrc->mc_top],
 		DKEY(&key),
@@ -7589,18 +8507,64 @@ mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst)
 		/* Adjust other cursors pointing to mp */
 		MDB_cursor *m2, *m3;
 		MDB_dbi dbi = csrc->mc_dbi;
-		MDB_page *mp = csrc->mc_pg[csrc->mc_top];
-
-		for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
-			if (csrc->mc_flags & C_SUB)
-				m3 = &m2->mc_xcursor->mx_cursor;
-			else
-				m3 = m2;
-			if (m3 == csrc) continue;
-			if (m3->mc_pg[csrc->mc_top] == mp && m3->mc_ki[csrc->mc_top] ==
-				csrc->mc_ki[csrc->mc_top]) {
-				m3->mc_pg[csrc->mc_top] = cdst->mc_pg[cdst->mc_top];
-				m3->mc_ki[csrc->mc_top] = cdst->mc_ki[cdst->mc_top];
+		MDB_page *mpd, *mps;
+
+		mps = csrc->mc_pg[csrc->mc_top];
+		/* If we're adding on the left, bump others up */
+		if (fromleft) {
+			mpd = cdst->mc_pg[csrc->mc_top];
+			for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
+				if (csrc->mc_flags & C_SUB)
+					m3 = &m2->mc_xcursor->mx_cursor;
+				else
+					m3 = m2;
+				if (!(m3->mc_flags & C_INITIALIZED) || m3->mc_top < csrc->mc_top)
+					continue;
+				if (m3 != cdst &&
+					m3->mc_pg[csrc->mc_top] == mpd &&
+					m3->mc_ki[csrc->mc_top] >= cdst->mc_ki[csrc->mc_top]) {
+					m3->mc_ki[csrc->mc_top]++;
+				}
+				if (m3 !=csrc &&
+					m3->mc_pg[csrc->mc_top] == mps &&
+					m3->mc_ki[csrc->mc_top] == csrc->mc_ki[csrc->mc_top]) {
+					m3->mc_pg[csrc->mc_top] = cdst->mc_pg[cdst->mc_top];
+					m3->mc_ki[csrc->mc_top] = cdst->mc_ki[cdst->mc_top];
+					m3->mc_ki[csrc->mc_top-1]++;
+				}
+				if (m3->mc_xcursor && (m3->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) &&
+					IS_LEAF(mps)) {
+					MDB_node *node = NODEPTR(m3->mc_pg[csrc->mc_top], m3->mc_ki[csrc->mc_top]);
+					if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA)
+						m3->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(node);
+				}
+			}
+		} else
+		/* Adding on the right, bump others down */
+		{
+			for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
+				if (csrc->mc_flags & C_SUB)
+					m3 = &m2->mc_xcursor->mx_cursor;
+				else
+					m3 = m2;
+				if (m3 == csrc) continue;
+				if (!(m3->mc_flags & C_INITIALIZED) || m3->mc_top < csrc->mc_top)
+					continue;
+				if (m3->mc_pg[csrc->mc_top] == mps) {
+					if (!m3->mc_ki[csrc->mc_top]) {
+						m3->mc_pg[csrc->mc_top] = cdst->mc_pg[cdst->mc_top];
+						m3->mc_ki[csrc->mc_top] = cdst->mc_ki[cdst->mc_top];
+						m3->mc_ki[csrc->mc_top-1]--;
+					} else {
+						m3->mc_ki[csrc->mc_top]--;
+					}
+					if (m3->mc_xcursor && (m3->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) &&
+						IS_LEAF(mps)) {
+						MDB_node *node = NODEPTR(m3->mc_pg[csrc->mc_top], m3->mc_ki[csrc->mc_top]);
+						if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA)
+							m3->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(node);
+					}
+				}
 			}
 		}
 	}
@@ -7616,12 +8580,15 @@ mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst)
 				key.mv_size = NODEKSZ(srcnode);
 				key.mv_data = NODEKEY(srcnode);
 			}
-			DPRINTF(("update separator for source page %"Z"u to [%s]",
+			DPRINTF(("update separator for source page %"Yu" to [%s]",
 				csrc->mc_pg[csrc->mc_top]->mp_pgno, DKEY(&key)));
 			mdb_cursor_copy(csrc, &mn);
 			mn.mc_snum--;
 			mn.mc_top--;
-			if ((rc = mdb_update_key(&mn, &key)) != MDB_SUCCESS)
+			/* We want mdb_rebalance to find mn when doing fixups */
+			WITH_CURSOR_TRACKING(mn,
+				rc = mdb_update_key(&mn, &key));
+			if (rc)
 				return rc;
 		}
 		if (IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {
@@ -7644,12 +8611,15 @@ mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst)
 				key.mv_size = NODEKSZ(srcnode);
 				key.mv_data = NODEKEY(srcnode);
 			}
-			DPRINTF(("update separator for destination page %"Z"u to [%s]",
+			DPRINTF(("update separator for destination page %"Yu" to [%s]",
 				cdst->mc_pg[cdst->mc_top]->mp_pgno, DKEY(&key)));
 			mdb_cursor_copy(cdst, &mn);
 			mn.mc_snum--;
 			mn.mc_top--;
-			if ((rc = mdb_update_key(&mn, &key)) != MDB_SUCCESS)
+			/* We want mdb_rebalance to find mn when doing fixups */
+			WITH_CURSOR_TRACKING(mn,
+				rc = mdb_update_key(&mn, &key));
+			if (rc)
 				return rc;
 		}
 		if (IS_BRANCH(cdst->mc_pg[cdst->mc_top])) {
@@ -7687,7 +8657,7 @@ mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst)
 	psrc = csrc->mc_pg[csrc->mc_top];
 	pdst = cdst->mc_pg[cdst->mc_top];
 
-	DPRINTF(("merging page %"Z"u into %"Z"u", psrc->mp_pgno, pdst->mp_pgno));
+	DPRINTF(("merging page %"Yu" into %"Yu"", psrc->mp_pgno, pdst->mp_pgno));
 
 	mdb_cassert(csrc, csrc->mc_snum > 1);	/* can't merge root page */
 	mdb_cassert(csrc, cdst->mc_snum > 1);
@@ -7696,6 +8666,9 @@ mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst)
 	if ((rc = mdb_page_touch(cdst)))
 		return rc;
 
+	/* get dst page again now that we've touched it. */
+	pdst = cdst->mc_pg[cdst->mc_top];
+
 	/* Move all nodes from src to dst.
 	 */
 	j = nkeys = NUMKEYS(pdst);
@@ -7715,6 +8688,7 @@ mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst)
 				MDB_cursor mn;
 				MDB_node *s2;
 				mdb_cursor_copy(csrc, &mn);
+				mn.mc_xcursor = NULL;
 				/* must find the lowest key below src */
 				rc = mdb_page_search_lowest(&mn);
 				if (rc)
@@ -7740,7 +8714,7 @@ mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst)
 		}
 	}
 
-	DPRINTF(("dst page %"Z"u now has %u keys (%.1f%% filled)",
+	DPRINTF(("dst page %"Yu" now has %u keys (%.1f%% filled)",
 	    pdst->mp_pgno, NUMKEYS(pdst),
 		(float)PAGEFILL(cdst->mc_txn->mt_env, pdst) / 10));
 
@@ -7773,6 +8747,7 @@ mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst)
 		/* Adjust other cursors pointing to mp */
 		MDB_cursor *m2, *m3;
 		MDB_dbi dbi = csrc->mc_dbi;
+		unsigned int top = csrc->mc_top;
 
 		for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
 			if (csrc->mc_flags & C_SUB)
@@ -7781,9 +8756,19 @@ mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst)
 				m3 = m2;
 			if (m3 == csrc) continue;
 			if (m3->mc_snum < csrc->mc_snum) continue;
-			if (m3->mc_pg[csrc->mc_top] == psrc) {
-				m3->mc_pg[csrc->mc_top] = pdst;
-				m3->mc_ki[csrc->mc_top] += nkeys;
+			if (m3->mc_pg[top] == psrc) {
+				m3->mc_pg[top] = pdst;
+				m3->mc_ki[top] += nkeys;
+				m3->mc_ki[top-1] = cdst->mc_ki[top-1];
+			} else if (m3->mc_pg[top-1] == csrc->mc_pg[top-1] &&
+				m3->mc_ki[top-1] > csrc->mc_ki[top-1]) {
+				m3->mc_ki[top-1]--;
+			}
+			if (m3->mc_xcursor && (m3->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) &&
+				IS_LEAF(psrc)) {
+				MDB_node *node = NODEPTR(m3->mc_pg[top], m3->mc_ki[top]);
+				if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA)
+					m3->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(node);
 			}
 		}
 	}
@@ -7792,9 +8777,9 @@ mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst)
 		uint16_t depth = cdst->mc_db->md_depth;
 		mdb_cursor_pop(cdst);
 		rc = mdb_rebalance(cdst);
-		/* Did the tree shrink? */
-		if (depth > cdst->mc_db->md_depth)
-			snum--;
+		/* Did the tree height change? */
+		if (depth != cdst->mc_db->md_depth)
+			snum += cdst->mc_db->md_depth - depth;
 		cdst->mc_snum = snum;
 		cdst->mc_top = snum-1;
 	}
@@ -7817,6 +8802,9 @@ mdb_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst)
 	cdst->mc_snum = csrc->mc_snum;
 	cdst->mc_top = csrc->mc_top;
 	cdst->mc_flags = csrc->mc_flags;
+#ifdef MDB_VL32
+	cdst->mc_ovpg = csrc->mc_ovpg;
+#endif
 
 	for (i=0; i<csrc->mc_snum; i++) {
 		cdst->mc_pg[i] = csrc->mc_pg[i];
@@ -7833,20 +8821,26 @@ static int
 mdb_rebalance(MDB_cursor *mc)
 {
 	MDB_node	*node;
-	int rc;
-	unsigned int ptop, minkeys;
+	int rc, fromleft;
+	unsigned int ptop, minkeys, thresh;
 	MDB_cursor	mn;
 	indx_t oldki;
 
-	minkeys = 1 + (IS_BRANCH(mc->mc_pg[mc->mc_top]));
-	DPRINTF(("rebalancing %s page %"Z"u (has %u keys, %.1f%% full)",
+	if (IS_BRANCH(mc->mc_pg[mc->mc_top])) {
+		minkeys = 2;
+		thresh = 1;
+	} else {
+		minkeys = 1;
+		thresh = FILL_THRESHOLD;
+	}
+	DPRINTF(("rebalancing %s page %"Yu" (has %u keys, %.1f%% full)",
 	    IS_LEAF(mc->mc_pg[mc->mc_top]) ? "leaf" : "branch",
 	    mdb_dbg_pgno(mc->mc_pg[mc->mc_top]), NUMKEYS(mc->mc_pg[mc->mc_top]),
 		(float)PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) / 10));
 
-	if (PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) >= FILL_THRESHOLD &&
+	if (PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) >= thresh &&
 		NUMKEYS(mc->mc_pg[mc->mc_top]) >= minkeys) {
-		DPRINTF(("no need to rebalance page %"Z"u, above fill threshold",
+		DPRINTF(("no need to rebalance page %"Yu", above fill threshold",
 		    mdb_dbg_pgno(mc->mc_pg[mc->mc_top])));
 		return MDB_SUCCESS;
 	}
@@ -7878,7 +8872,8 @@ mdb_rebalance(MDB_cursor *mc)
 						m3 = &m2->mc_xcursor->mx_cursor;
 					else
 						m3 = m2;
-					if (m3->mc_snum < mc->mc_snum) continue;
+					if (!(m3->mc_flags & C_INITIALIZED) || (m3->mc_snum < mc->mc_snum))
+						continue;
 					if (m3->mc_pg[0] == mp) {
 						m3->mc_snum = 0;
 						m3->mc_top = 0;
@@ -7893,7 +8888,7 @@ mdb_rebalance(MDB_cursor *mc)
 			if (rc)
 				return rc;
 			mc->mc_db->md_root = NODEPGNO(NODEPTR(mp, 0));
-			rc = mdb_page_get(mc->mc_txn,mc->mc_db->md_root,&mc->mc_pg[0],NULL);
+			rc = mdb_page_get(mc, mc->mc_db->md_root, &mc->mc_pg[0], NULL);
 			if (rc)
 				return rc;
 			mc->mc_db->md_depth--;
@@ -7913,9 +8908,11 @@ mdb_rebalance(MDB_cursor *mc)
 						m3 = &m2->mc_xcursor->mx_cursor;
 					else
 						m3 = m2;
-					if (m3 == mc || m3->mc_snum < mc->mc_snum) continue;
+					if (m3 == mc) continue;
+					if (!(m3->mc_flags & C_INITIALIZED))
+						continue;
 					if (m3->mc_pg[0] == mp) {
-						for (i=0; i<m3->mc_snum; i++) {
+						for (i=0; i<mc->mc_db->md_depth; i++) {
 							m3->mc_pg[i] = m3->mc_pg[i+1];
 							m3->mc_ki[i] = m3->mc_ki[i+1];
 						}
@@ -7952,25 +8949,27 @@ mdb_rebalance(MDB_cursor *mc)
 		DPUTS("reading right neighbor");
 		mn.mc_ki[ptop]++;
 		node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]);
-		rc = mdb_page_get(mc->mc_txn,NODEPGNO(node),&mn.mc_pg[mn.mc_top],NULL);
+		rc = mdb_page_get(mc, NODEPGNO(node), &mn.mc_pg[mn.mc_top], NULL);
 		if (rc)
 			return rc;
 		mn.mc_ki[mn.mc_top] = 0;
 		mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]);
+		fromleft = 0;
 	} else {
 		/* There is at least one neighbor to the left.
 		 */
 		DPUTS("reading left neighbor");
 		mn.mc_ki[ptop]--;
 		node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]);
-		rc = mdb_page_get(mc->mc_txn,NODEPGNO(node),&mn.mc_pg[mn.mc_top],NULL);
+		rc = mdb_page_get(mc, NODEPGNO(node), &mn.mc_pg[mn.mc_top], NULL);
 		if (rc)
 			return rc;
 		mn.mc_ki[mn.mc_top] = NUMKEYS(mn.mc_pg[mn.mc_top]) - 1;
 		mc->mc_ki[mc->mc_top] = 0;
+		fromleft = 1;
 	}
 
-	DPRINTF(("found neighbor page %"Z"u (%u keys, %.1f%% full)",
+	DPRINTF(("found neighbor page %"Yu" (%u keys, %.1f%% full)",
 	    mn.mc_pg[mn.mc_top]->mp_pgno, NUMKEYS(mn.mc_pg[mn.mc_top]),
 		(float)PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) / 10));
 
@@ -7978,33 +8977,21 @@ mdb_rebalance(MDB_cursor *mc)
 	 * move one key from it. Otherwise we should try to merge them.
 	 * (A branch page must never have less than 2 keys.)
 	 */
-	minkeys = 1 + (IS_BRANCH(mn.mc_pg[mn.mc_top]));
-	if (PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) >= FILL_THRESHOLD && NUMKEYS(mn.mc_pg[mn.mc_top]) > minkeys) {
-		rc = mdb_node_move(&mn, mc);
-		if (mc->mc_ki[ptop]) {
+	if (PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) >= thresh && NUMKEYS(mn.mc_pg[mn.mc_top]) > minkeys) {
+		rc = mdb_node_move(&mn, mc, fromleft);
+		if (fromleft) {
+			/* if we inserted on left, bump position up */
 			oldki++;
 		}
 	} else {
-		if (mc->mc_ki[ptop] == 0) {
+		if (!fromleft) {
 			rc = mdb_page_merge(&mn, mc);
 		} else {
-			MDB_cursor dummy;
 			oldki += NUMKEYS(mn.mc_pg[mn.mc_top]);
 			mn.mc_ki[mn.mc_top] += mc->mc_ki[mn.mc_top] + 1;
 			/* We want mdb_rebalance to find mn when doing fixups */
-			if (mc->mc_flags & C_SUB) {
-				dummy.mc_next = mc->mc_txn->mt_cursors[mc->mc_dbi];
-				mc->mc_txn->mt_cursors[mc->mc_dbi] = &dummy;
-				dummy.mc_xcursor = (MDB_xcursor *)&mn;
-			} else {
-				mn.mc_next = mc->mc_txn->mt_cursors[mc->mc_dbi];
-				mc->mc_txn->mt_cursors[mc->mc_dbi] = &mn;
-			}
-			rc = mdb_page_merge(mc, &mn);
-			if (mc->mc_flags & C_SUB)
-				mc->mc_txn->mt_cursors[mc->mc_dbi] = dummy.mc_next;
-			else
-				mc->mc_txn->mt_cursors[mc->mc_dbi] = mn.mc_next;
+			WITH_CURSOR_TRACKING(mn,
+				rc = mdb_page_merge(mc, &mn));
 			mdb_cursor_copy(&mn, mc);
 		}
 		mc->mc_flags &= ~C_EOF;
@@ -8021,16 +9008,40 @@ mdb_cursor_del0(MDB_cursor *mc)
 	MDB_page *mp;
 	indx_t ki;
 	unsigned int nkeys;
+	MDB_cursor *m2, *m3;
+	MDB_dbi dbi = mc->mc_dbi;
 
 	ki = mc->mc_ki[mc->mc_top];
+	mp = mc->mc_pg[mc->mc_top];
 	mdb_node_del(mc, mc->mc_db->md_pad);
 	mc->mc_db->md_entries--;
+	{
+		/* Adjust other cursors pointing to mp */
+		for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
+			m3 = (mc->mc_flags & C_SUB) ? &m2->mc_xcursor->mx_cursor : m2;
+			if (! (m2->mc_flags & m3->mc_flags & C_INITIALIZED))
+				continue;
+			if (m3 == mc || m3->mc_snum < mc->mc_snum)
+				continue;
+			if (m3->mc_pg[mc->mc_top] == mp) {
+				if (m3->mc_ki[mc->mc_top] == ki) {
+					m3->mc_flags |= C_DEL;
+					if (mc->mc_db->md_flags & MDB_DUPSORT)
+						m3->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED;
+				} else if (m3->mc_ki[mc->mc_top] > ki) {
+					m3->mc_ki[mc->mc_top]--;
+				}
+				if (m3->mc_xcursor && (m3->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {
+					MDB_node *node = NODEPTR(m3->mc_pg[mc->mc_top], m3->mc_ki[mc->mc_top]);
+					if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA)
+						m3->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(node);
+				}
+			}
+		}
+	}
 	rc = mdb_rebalance(mc);
 
 	if (rc == MDB_SUCCESS) {
-		MDB_cursor *m2, *m3;
-		MDB_dbi dbi = mc->mc_dbi;
-
 		/* DB is totally empty now, just bail out.
 		 * Other cursors adjustments were already done
 		 * by mdb_rebalance and aren't needed here.
@@ -8041,30 +9052,15 @@ mdb_cursor_del0(MDB_cursor *mc)
 		mp = mc->mc_pg[mc->mc_top];
 		nkeys = NUMKEYS(mp);
 
-		/* if mc points past last node in page, find next sibling */
-		if (mc->mc_ki[mc->mc_top] >= nkeys) {
-			rc = mdb_cursor_sibling(mc, 1);
-			if (rc == MDB_NOTFOUND) {
-				mc->mc_flags |= C_EOF;
-				rc = MDB_SUCCESS;
-			}
-		}
-
 		/* Adjust other cursors pointing to mp */
 		for (m2 = mc->mc_txn->mt_cursors[dbi]; !rc && m2; m2=m2->mc_next) {
 			m3 = (mc->mc_flags & C_SUB) ? &m2->mc_xcursor->mx_cursor : m2;
 			if (! (m2->mc_flags & m3->mc_flags & C_INITIALIZED))
 				continue;
-			if (m3 == mc || m3->mc_snum < mc->mc_snum)
+			if (m3->mc_snum < mc->mc_snum)
 				continue;
 			if (m3->mc_pg[mc->mc_top] == mp) {
-				if (m3->mc_ki[mc->mc_top] >= ki) {
-					m3->mc_flags |= C_DEL;
-					if (m3->mc_ki[mc->mc_top] > ki)
-						m3->mc_ki[mc->mc_top]--;
-					else if (mc->mc_db->md_flags & MDB_DUPSORT)
-						m3->mc_xcursor->mx_cursor.mc_flags |= C_EOF;
-				}
+				/* if m3 points past last node in page, find next sibling */
 				if (m3->mc_ki[mc->mc_top] >= nkeys) {
 					rc = mdb_cursor_sibling(m3, 1);
 					if (rc == MDB_NOTFOUND) {
@@ -8086,10 +9082,10 @@ int
 mdb_del(MDB_txn *txn, MDB_dbi dbi,
     MDB_val *key, MDB_val *data)
 {
-	if (!key || dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
+	if (!key || !TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
 		return EINVAL;
 
-	if (txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_ERROR))
+	if (txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED))
 		return (txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
 
 	if (!F_ISSET(txn->mt_dbs[dbi].md_flags, MDB_DUPSORT)) {
@@ -8175,27 +9171,34 @@ mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno
 	newindx = mc->mc_ki[mc->mc_top];
 	nkeys = NUMKEYS(mp);
 
-	DPRINTF(("-----> splitting %s page %"Z"u and adding [%s] at index %i/%i",
+	DPRINTF(("-----> splitting %s page %"Yu" and adding [%s] at index %i/%i",
 	    IS_LEAF(mp) ? "leaf" : "branch", mp->mp_pgno,
 	    DKEY(newkey), mc->mc_ki[mc->mc_top], nkeys));
 
 	/* Create a right sibling. */
 	if ((rc = mdb_page_new(mc, mp->mp_flags, 1, &rp)))
 		return rc;
-	DPRINTF(("new right sibling: page %"Z"u", rp->mp_pgno));
+	rp->mp_pad = mp->mp_pad;
+	DPRINTF(("new right sibling: page %"Yu"", rp->mp_pgno));
 
-	if (mc->mc_snum < 2) {
+	/* Usually when splitting the root page, the cursor
+	 * height is 1. But when called from mdb_update_key,
+	 * the cursor height may be greater because it walks
+	 * up the stack while finding the branch slot to update.
+	 */
+	if (mc->mc_top < 1) {
 		if ((rc = mdb_page_new(mc, P_BRANCH, 1, &pp)))
 			goto done;
 		/* shift current top to make room for new parent */
-		mc->mc_pg[1] = mc->mc_pg[0];
-		mc->mc_ki[1] = mc->mc_ki[0];
+		for (i=mc->mc_snum; i>0; i--) {
+			mc->mc_pg[i] = mc->mc_pg[i-1];
+			mc->mc_ki[i] = mc->mc_ki[i-1];
+		}
 		mc->mc_pg[0] = pp;
 		mc->mc_ki[0] = 0;
 		mc->mc_db->md_root = pp->mp_pgno;
-		DPRINTF(("root split! new root = %"Z"u", pp->mp_pgno));
-		mc->mc_db->md_depth++;
-		new_root = 1;
+		DPRINTF(("root split! new root = %"Yu"", pp->mp_pgno));
+		new_root = mc->mc_db->md_depth++;
 
 		/* Add left (implicit) pointer. */
 		if ((rc = mdb_node_add(mc, 0, NULL, NULL, mp->mp_pgno, 0)) != MDB_SUCCESS) {
@@ -8206,16 +9209,16 @@ mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno
 			mc->mc_db->md_depth--;
 			goto done;
 		}
-		mc->mc_snum = 2;
-		mc->mc_top = 1;
+		mc->mc_snum++;
+		mc->mc_top++;
 		ptop = 0;
 	} else {
 		ptop = mc->mc_top-1;
-		DPRINTF(("parent branch page is %"Z"u", mc->mc_pg[ptop]->mp_pgno));
+		DPRINTF(("parent branch page is %"Yu"", mc->mc_pg[ptop]->mp_pgno));
 	}
 
-	mc->mc_flags |= C_SPLITTING;
 	mdb_cursor_copy(mc, &mn);
+	mn.mc_xcursor = NULL;
 	mn.mc_pg[mn.mc_top] = rp;
 	mn.mc_ki[ptop] = mc->mc_ki[ptop]+1;
 
@@ -8265,7 +9268,6 @@ mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno
 				rp->mp_lower += sizeof(indx_t);
 				rp->mp_upper -= ksize - sizeof(indx_t);
 				mc->mc_ki[mc->mc_top] = x;
-				mc->mc_pg[mc->mc_top] = rp;
 			}
 		} else {
 			int psize, nsize, k;
@@ -8316,7 +9318,7 @@ mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno
 				psize = 0;
 				if (newindx <= split_indx || newindx >= nkeys) {
 					i = 0; j = 1;
-					k = newindx >= nkeys ? nkeys : split_indx+2;
+					k = newindx >= nkeys ? nkeys : split_indx+1+IS_LEAF(mp);
 				} else {
 					i = nkeys; j = -1;
 					k = split_indx-1;
@@ -8358,21 +9360,18 @@ mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno
 	/* Copy separator key to the parent.
 	 */
 	if (SIZELEFT(mn.mc_pg[ptop]) < mdb_branch_size(env, &sepkey)) {
+		int snum = mc->mc_snum;
 		mn.mc_snum--;
 		mn.mc_top--;
 		did_split = 1;
-		rc = mdb_page_split(&mn, &sepkey, NULL, rp->mp_pgno, 0);
+		/* We want other splits to find mn when doing fixups */
+		WITH_CURSOR_TRACKING(mn,
+			rc = mdb_page_split(&mn, &sepkey, NULL, rp->mp_pgno, 0));
 		if (rc)
 			goto done;
 
 		/* root split? */
-		if (mn.mc_snum == mc->mc_snum) {
-			mc->mc_pg[mc->mc_snum] = mc->mc_pg[mc->mc_top];
-			mc->mc_ki[mc->mc_snum] = mc->mc_ki[mc->mc_top];
-			mc->mc_pg[mc->mc_top] = mc->mc_pg[ptop];
-			mc->mc_ki[mc->mc_top] = mc->mc_ki[ptop];
-			mc->mc_snum++;
-			mc->mc_top++;
+		if (mc->mc_snum > snum) {
 			ptop++;
 		}
 		/* Right page might now have changed parent.
@@ -8398,7 +9397,6 @@ mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno
 		rc = mdb_node_add(&mn, mn.mc_ki[ptop], &sepkey, NULL, rp->mp_pgno, 0);
 		mn.mc_top++;
 	}
-	mc->mc_flags ^= C_SPLITTING;
 	if (rc != MDB_SUCCESS) {
 		goto done;
 	}
@@ -8468,11 +9466,6 @@ mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno
 		/* reset back to original page */
 		if (newindx < split_indx) {
 			mc->mc_pg[mc->mc_top] = mp;
-			if (nflags & MDB_RESERVE) {
-				node = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
-				if (!(node->mn_flags & F_BIGDATA))
-					newdata->mv_data = NODEDATA(node);
-			}
 		} else {
 			mc->mc_pg[mc->mc_top] = rp;
 			mc->mc_ki[ptop]++;
@@ -8486,13 +9479,32 @@ mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno
 				}
 			}
 		}
+		if (nflags & MDB_RESERVE) {
+			node = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
+			if (!(node->mn_flags & F_BIGDATA))
+				newdata->mv_data = NODEDATA(node);
+		}
+	} else {
+		if (newindx >= split_indx) {
+			mc->mc_pg[mc->mc_top] = rp;
+			mc->mc_ki[ptop]++;
+			/* Make sure mc_ki is still valid.
+			 */
+			if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&
+				mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) {
+				for (i=0; i<=ptop; i++) {
+					mc->mc_pg[i] = mn.mc_pg[i];
+					mc->mc_ki[i] = mn.mc_ki[i];
+				}
+			}
+		}
 	}
 
 	{
 		/* Adjust other cursors pointing to mp */
 		MDB_cursor *m2, *m3;
 		MDB_dbi dbi = mc->mc_dbi;
-		int fixup = NUMKEYS(mp);
+		nkeys = NUMKEYS(mp);
 
 		for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
 			if (mc->mc_flags & C_SUB)
@@ -8503,16 +9515,17 @@ mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno
 				continue;
 			if (!(m2->mc_flags & m3->mc_flags & C_INITIALIZED))
 				continue;
-			if (m3->mc_flags & C_SPLITTING)
-				continue;
 			if (new_root) {
 				int k;
+				/* sub cursors may be on different DB */
+				if (m3->mc_pg[0] != mp)
+					continue;
 				/* root split */
-				for (k=m3->mc_top; k>=0; k--) {
+				for (k=new_root; k>=0; k--) {
 					m3->mc_ki[k+1] = m3->mc_ki[k];
 					m3->mc_pg[k+1] = m3->mc_pg[k];
 				}
-				if (m3->mc_ki[0] >= split_indx) {
+				if (m3->mc_ki[0] >= nkeys) {
 					m3->mc_ki[0] = 1;
 				} else {
 					m3->mc_ki[0] = 0;
@@ -8524,15 +9537,24 @@ mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno
 			if (m3->mc_top >= mc->mc_top && m3->mc_pg[mc->mc_top] == mp) {
 				if (m3->mc_ki[mc->mc_top] >= newindx && !(nflags & MDB_SPLIT_REPLACE))
 					m3->mc_ki[mc->mc_top]++;
-				if (m3->mc_ki[mc->mc_top] >= fixup) {
+				if (m3->mc_ki[mc->mc_top] >= nkeys) {
 					m3->mc_pg[mc->mc_top] = rp;
-					m3->mc_ki[mc->mc_top] -= fixup;
-					m3->mc_ki[ptop] = mn.mc_ki[ptop];
+					m3->mc_ki[mc->mc_top] -= nkeys;
+					for (i=0; i<mc->mc_top; i++) {
+						m3->mc_ki[i] = mn.mc_ki[i];
+						m3->mc_pg[i] = mn.mc_pg[i];
+					}
 				}
 			} else if (!did_split && m3->mc_top >= ptop && m3->mc_pg[ptop] == mc->mc_pg[ptop] &&
 				m3->mc_ki[ptop] >= mc->mc_ki[ptop]) {
 				m3->mc_ki[ptop]++;
 			}
+			if (m3->mc_xcursor && (m3->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) &&
+				IS_LEAF(mp)) {
+				MDB_node *node = NODEPTR(m3->mc_pg[mc->mc_top], m3->mc_ki[mc->mc_top]);
+				if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA)
+					m3->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(node);
+			}
 		}
 	}
 	DPRINTF(("mp left: %d, rp left: %d", SIZELEFT(mp), SIZELEFT(rp)));
@@ -8551,15 +9573,23 @@ mdb_put(MDB_txn *txn, MDB_dbi dbi,
 {
 	MDB_cursor mc;
 	MDB_xcursor mx;
+	int rc;
 
-	if (!key || !data || dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
+	if (!key || !data || !TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
 		return EINVAL;
 
-	if ((flags & (MDB_NOOVERWRITE|MDB_NODUPDATA|MDB_RESERVE|MDB_APPEND|MDB_APPENDDUP)) != flags)
+	if (flags & ~(MDB_NOOVERWRITE|MDB_NODUPDATA|MDB_RESERVE|MDB_APPEND|MDB_APPENDDUP))
 		return EINVAL;
 
+	if (txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED))
+		return (txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
+
 	mdb_cursor_init(&mc, txn, dbi, &mx);
-	return mdb_cursor_put(&mc, key, data, flags);
+	mc.mc_next = txn->mt_cursors[dbi];
+	txn->mt_cursors[dbi] = &mc;
+	rc = mdb_cursor_put(&mc, key, data, flags);
+	txn->mt_cursors[dbi] = mc.mc_next;
+	return rc;
 }
 
 #ifndef MDB_WBUF
@@ -8585,7 +9615,7 @@ typedef struct mdb_copy {
 } mdb_copy;
 
 	/** Dedicated writer thread for compacting copy. */
-static THREAD_RET ESECT
+static THREAD_RET ESECT CALL_CONV
 mdb_env_copythr(void *arg)
 {
 	mdb_copy *my = arg;
@@ -8673,7 +9703,6 @@ static int ESECT
 mdb_env_cwalk(mdb_copy *my, pgno_t *pg, int flags)
 {
 	MDB_cursor mc;
-	MDB_txn *txn = my->mc_txn;
 	MDB_node *ni;
 	MDB_page *mo, *mp, *leaf;
 	char *buf, *ptr;
@@ -8686,9 +9715,9 @@ mdb_env_cwalk(mdb_copy *my, pgno_t *pg, int flags)
 
 	mc.mc_snum = 1;
 	mc.mc_top = 0;
-	mc.mc_txn = txn;
+	mc.mc_txn = my->mc_txn;
 
-	rc = mdb_page_get(my->mc_txn, *pg, &mc.mc_pg[0], NULL);
+	rc = mdb_page_get(&mc, *pg, &mc.mc_pg[0], NULL);
 	if (rc)
 		return rc;
 	rc = mdb_page_search_root(&mc, NULL, MDB_PS_FIRST);
@@ -8732,7 +9761,7 @@ mdb_env_cwalk(mdb_copy *my, pgno_t *pg, int flags)
 						}
 
 						memcpy(&pg, NODEDATA(ni), sizeof(pg));
-						rc = mdb_page_get(txn, pg, &omp, NULL);
+						rc = mdb_page_get(&mc, pg, &omp, NULL);
 						if (rc)
 							goto done;
 						if (my->mc_wlen[toggle] >= MDB_WBUF) {
@@ -8783,7 +9812,7 @@ mdb_env_cwalk(mdb_copy *my, pgno_t *pg, int flags)
 again:
 				ni = NODEPTR(mp, mc.mc_ki[mc.mc_top]);
 				pg = NODEPGNO(ni);
-				rc = mdb_page_get(txn, pg, &mp, NULL);
+				rc = mdb_page_get(&mc, pg, &mp, NULL);
 				if (rc)
 					goto done;
 				mc.mc_top++;
@@ -8862,7 +9891,7 @@ mdb_env_copyfd1(MDB_env *env, HANDLE fd)
 	my.mc_wlen[1] = 0;
 	my.mc_olen[0] = 0;
 	my.mc_olen[1] = 0;
-	my.mc_next_pgno = 2;
+	my.mc_next_pgno = NUM_METAS;
 	my.mc_status = 0;
 	my.mc_new = 1;
 	my.mc_toggle = 0;
@@ -8875,7 +9904,7 @@ mdb_env_copyfd1(MDB_env *env, HANDLE fd)
 		return rc;
 
 	mp = (MDB_page *)my.mc_wbuf[0];
-	memset(mp, 0, 2*env->me_psize);
+	memset(mp, 0, NUM_METAS * env->me_psize);
 	mp->mp_pgno = 0;
 	mp->mp_flags = P_META;
 	mm = (MDB_meta *)METADATA(mp);
@@ -8898,27 +9927,27 @@ mdb_env_copyfd1(MDB_env *env, HANDLE fd)
 		mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
 		while ((rc = mdb_cursor_get(&mc, &key, &data, MDB_NEXT)) == 0)
 			freecount += *(MDB_ID *)data.mv_data;
-		freecount += txn->mt_dbs[0].md_branch_pages +
-			txn->mt_dbs[0].md_leaf_pages +
-			txn->mt_dbs[0].md_overflow_pages;
+		freecount += txn->mt_dbs[FREE_DBI].md_branch_pages +
+			txn->mt_dbs[FREE_DBI].md_leaf_pages +
+			txn->mt_dbs[FREE_DBI].md_overflow_pages;
 
 		/* Set metapage 1 */
 		mm->mm_last_pg = txn->mt_next_pgno - freecount - 1;
-		mm->mm_dbs[1] = txn->mt_dbs[1];
-		if (mm->mm_last_pg > 1) {
-			mm->mm_dbs[1].md_root = mm->mm_last_pg;
+		mm->mm_dbs[MAIN_DBI] = txn->mt_dbs[MAIN_DBI];
+		if (mm->mm_last_pg > NUM_METAS-1) {
+			mm->mm_dbs[MAIN_DBI].md_root = mm->mm_last_pg;
 			mm->mm_txnid = 1;
 		} else {
-			mm->mm_dbs[1].md_root = P_INVALID;
+			mm->mm_dbs[MAIN_DBI].md_root = P_INVALID;
 		}
 	}
-	my.mc_wlen[0] = env->me_psize * 2;
+	my.mc_wlen[0] = env->me_psize * NUM_METAS;
 	my.mc_txn = txn;
 	pthread_mutex_lock(&my.mc_mutex);
 	while(my.mc_new)
 		pthread_cond_wait(&my.mc_cond, &my.mc_mutex);
 	pthread_mutex_unlock(&my.mc_mutex);
-	rc = mdb_env_cwalk(&my, &txn->mt_dbs[1].md_root, 0);
+	rc = mdb_env_cwalk(&my, &txn->mt_dbs[MAIN_DBI].md_root, 0);
 	if (rc == MDB_SUCCESS && my.mc_wlen[my.mc_toggle])
 		rc = mdb_env_cthr_toggle(&my, 1);
 	mdb_env_cthr_toggle(&my, -1);
@@ -8946,6 +9975,7 @@ static int ESECT
 mdb_env_copyfd0(MDB_env *env, HANDLE fd)
 {
 	MDB_txn *txn = NULL;
+	mdb_mutexref_t wmutex = NULL;
 	int rc;
 	size_t wsize;
 	char *ptr;
@@ -8967,19 +9997,21 @@ mdb_env_copyfd0(MDB_env *env, HANDLE fd)
 
 	if (env->me_txns) {
 		/* We must start the actual read txn after blocking writers */
-		mdb_txn_reset0(txn, "reset-stage1");
+		mdb_txn_end(txn, MDB_END_RESET_TMP);
 
 		/* Temporarily block writers until we snapshot the meta pages */
-		LOCK_MUTEX_W(env);
+		wmutex = env->me_wmutex;
+		if (LOCK_MUTEX(rc, env, wmutex))
+			goto leave;
 
 		rc = mdb_txn_renew0(txn);
 		if (rc) {
-			UNLOCK_MUTEX_W(env);
+			UNLOCK_MUTEX(wmutex);
 			goto leave;
 		}
 	}
 
-	wsize = env->me_psize * 2;
+	wsize = env->me_psize * NUM_METAS;
 	ptr = env->me_map;
 	w2 = wsize;
 	while (w2 > 0) {
@@ -8998,15 +10030,15 @@ mdb_env_copyfd0(MDB_env *env, HANDLE fd)
 			break;
 		}
 	}
-	if (env->me_txns)
-		UNLOCK_MUTEX_W(env);
+	if (wmutex)
+		UNLOCK_MUTEX(wmutex);
 
 	if (rc)
 		goto leave;
 
 	w2 = txn->mt_next_pgno * env->me_psize;
 	{
-		size_t fsize = 0;
+		mdb_size_t fsize = 0;
 		if ((rc = mdb_fsize(env->me_fd, &fsize)))
 			goto leave;
 		if (w2 > fsize)
@@ -9059,6 +10091,9 @@ mdb_env_copy2(MDB_env *env, const char *path, unsigned int flags)
 	int rc, len;
 	char *lpath;
 	HANDLE newfd = INVALID_HANDLE_VALUE;
+#ifdef _WIN32
+	wchar_t *wpath;
+#endif
 
 	if (env->me_flags & MDB_NOSUBDIR) {
 		lpath = (char *)path;
@@ -9076,8 +10111,12 @@ mdb_env_copy2(MDB_env *env, const char *path, unsigned int flags)
 	 * already in the OS cache.
 	 */
 #ifdef _WIN32
-	newfd = CreateFile(lpath, GENERIC_WRITE, 0, NULL, CREATE_NEW,
+	rc = utf8_to_utf16(lpath, -1, &wpath, NULL);
+	if (rc)
+		return rc;
+	newfd = CreateFileW(wpath, GENERIC_WRITE, 0, NULL, CREATE_NEW,
 				FILE_FLAG_NO_BUFFERING|FILE_FLAG_WRITE_THROUGH, NULL);
+	free(wpath);
 #else
 	newfd = open(lpath, O_WRONLY|O_CREAT|O_EXCL, 0666);
 #endif
@@ -9122,7 +10161,7 @@ mdb_env_copy(MDB_env *env, const char *path)
 int ESECT
 mdb_env_set_flags(MDB_env *env, unsigned int flag, int onoff)
 {
-	if ((flag & CHANGEABLE) != flag)
+	if (flag & ~CHANGEABLE)
 		return EINVAL;
 	if (onoff)
 		env->me_flags |= flag;
@@ -9137,7 +10176,7 @@ mdb_env_get_flags(MDB_env *env, unsigned int *arg)
 	if (!env || !arg)
 		return EINVAL;
 
-	*arg = env->me_flags;
+	*arg = env->me_flags & (CHANGEABLE|CHANGELESS);
 	return MDB_SUCCESS;
 }
 
@@ -9209,36 +10248,32 @@ mdb_stat0(MDB_env *env, MDB_db *db, MDB_stat *arg)
 int ESECT
 mdb_env_stat(MDB_env *env, MDB_stat *arg)
 {
-	int toggle;
+	MDB_meta *meta;
 
 	if (env == NULL || arg == NULL)
 		return EINVAL;
 
-	toggle = mdb_env_pick_meta(env);
+	meta = mdb_env_pick_meta(env);
 
-	return mdb_stat0(env, &env->me_metas[toggle]->mm_dbs[MAIN_DBI], arg);
+	return mdb_stat0(env, &meta->mm_dbs[MAIN_DBI], arg);
 }
 
 int ESECT
 mdb_env_info(MDB_env *env, MDB_envinfo *arg)
 {
-	int toggle;
+	MDB_meta *meta;
 
 	if (env == NULL || arg == NULL)
 		return EINVAL;
 
-	toggle = mdb_env_pick_meta(env);
-	arg->me_mapaddr = env->me_metas[toggle]->mm_address;
+	meta = mdb_env_pick_meta(env);
+	arg->me_mapaddr = meta->mm_address;
+	arg->me_last_pgno = meta->mm_last_pg;
+	arg->me_last_txnid = meta->mm_txnid;
+
 	arg->me_mapsize = env->me_mapsize;
 	arg->me_maxreaders = env->me_maxreaders;
-
-	/* me_numreaders may be zero if this process never used any readers. Use
-	 * the shared numreader count if it exists.
-	 */
-	arg->me_numreaders = env->me_txns ? env->me_txns->mti_numreaders : env->me_numreaders;
-
-	arg->me_last_pgno = env->me_metas[toggle]->mm_last_pg;
-	arg->me_last_txnid = env->me_metas[toggle]->mm_txnid;
+	arg->me_numreaders = env->me_txns ? env->me_txns->mti_numreaders : 0;
 	return MDB_SUCCESS;
 }
 
@@ -9273,15 +10308,12 @@ int mdb_dbi_open(MDB_txn *txn, const char *name, unsigned int flags, MDB_dbi *db
 	MDB_db dummy;
 	int rc, dbflag, exact;
 	unsigned int unused = 0, seq;
+	char *namedup;
 	size_t len;
 
-	if (txn->mt_dbxs[FREE_DBI].md_cmp == NULL) {
-		mdb_default_cmp(txn, FREE_DBI);
-	}
-
-	if ((flags & VALID_FLAGS) != flags)
+	if (flags & ~VALID_FLAGS)
 		return EINVAL;
-	if (txn->mt_flags & MDB_TXN_ERROR)
+	if (txn->mt_flags & MDB_TXN_BLOCKED)
 		return MDB_BAD_TXN;
 
 	/* main DB? */
@@ -9305,7 +10337,7 @@ int mdb_dbi_open(MDB_txn *txn, const char *name, unsigned int flags, MDB_dbi *db
 
 	/* Is the DB already open? */
 	len = strlen(name);
-	for (i=2; i<txn->mt_numdbs; i++) {
+	for (i=CORE_DBS; i<txn->mt_numdbs; i++) {
 		if (!txn->mt_dbxs[i].md_name.mv_size) {
 			/* Remember this free slot */
 			if (!unused) unused = i;
@@ -9327,7 +10359,7 @@ int mdb_dbi_open(MDB_txn *txn, const char *name, unsigned int flags, MDB_dbi *db
 		return (flags & MDB_CREATE) ? MDB_INCOMPATIBLE : MDB_NOTFOUND;
 
 	/* Find the DB info */
-	dbflag = DB_NEW|DB_VALID;
+	dbflag = DB_NEW|DB_VALID|DB_USRVALID;
 	exact = 0;
 	key.mv_size = len;
 	key.mv_data = (void *)name;
@@ -9336,10 +10368,18 @@ int mdb_dbi_open(MDB_txn *txn, const char *name, unsigned int flags, MDB_dbi *db
 	if (rc == MDB_SUCCESS) {
 		/* make sure this is actually a DB */
 		MDB_node *node = NODEPTR(mc.mc_pg[mc.mc_top], mc.mc_ki[mc.mc_top]);
-		if (!(node->mn_flags & F_SUBDATA))
+		if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) != F_SUBDATA)
 			return MDB_INCOMPATIBLE;
-	} else if (rc == MDB_NOTFOUND && (flags & MDB_CREATE)) {
-		/* Create if requested */
+	} else if (! (rc == MDB_NOTFOUND && (flags & MDB_CREATE))) {
+		return rc;
+	}
+
+	/* Done here so we cannot fail after creating a new DB */
+	if ((namedup = strdup(name)) == NULL)
+		return ENOMEM;
+
+	if (rc) {
+		/* MDB_NOTFOUND and MDB_CREATE: Create new DB */
 		data.mv_size = sizeof(MDB_db);
 		data.mv_data = &dummy;
 		memset(&dummy, 0, sizeof(dummy));
@@ -9349,10 +10389,12 @@ int mdb_dbi_open(MDB_txn *txn, const char *name, unsigned int flags, MDB_dbi *db
 		dbflag |= DB_DIRTY;
 	}
 
-	/* OK, got info, add to table */
-	if (rc == MDB_SUCCESS) {
+	if (rc) {
+		free(namedup);
+	} else {
+		/* Got info, register DBI in this txn */
 		unsigned int slot = unused ? unused : txn->mt_numdbs;
-		txn->mt_dbxs[slot].md_name.mv_data = strdup(name);
+		txn->mt_dbxs[slot].md_name.mv_data = namedup;
 		txn->mt_dbxs[slot].md_name.mv_size = len;
 		txn->mt_dbxs[slot].md_rel = NULL;
 		txn->mt_dbflags[slot] = dbflag;
@@ -9373,12 +10415,13 @@ int mdb_dbi_open(MDB_txn *txn, const char *name, unsigned int flags, MDB_dbi *db
 	return rc;
 }
 
-int mdb_stat(MDB_txn *txn, MDB_dbi dbi, MDB_stat *arg)
+int ESECT
+mdb_stat(MDB_txn *txn, MDB_dbi dbi, MDB_stat *arg)
 {
-	if (!arg || !TXN_DBI_EXIST(txn, dbi))
+	if (!arg || !TXN_DBI_EXIST(txn, dbi, DB_VALID))
 		return EINVAL;
 
-	if (txn->mt_flags & MDB_TXN_ERROR)
+	if (txn->mt_flags & MDB_TXN_BLOCKED)
 		return MDB_BAD_TXN;
 
 	if (txn->mt_dbflags[dbi] & DB_STALE) {
@@ -9393,7 +10436,7 @@ int mdb_stat(MDB_txn *txn, MDB_dbi dbi, MDB_stat *arg)
 void mdb_dbi_close(MDB_env *env, MDB_dbi dbi)
 {
 	char *ptr;
-	if (dbi <= MAIN_DBI || dbi >= env->me_maxdbs)
+	if (dbi < CORE_DBS || dbi >= env->me_maxdbs)
 		return;
 	ptr = env->me_dbxs[dbi].md_name.mv_data;
 	/* If there was no name, this was already closed */
@@ -9409,7 +10452,7 @@ void mdb_dbi_close(MDB_env *env, MDB_dbi dbi)
 int mdb_dbi_flags(MDB_txn *txn, MDB_dbi dbi, unsigned int *flags)
 {
 	/* We could return the flags for the FREE_DBI too but what's the point? */
-	if (dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
+	if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
 		return EINVAL;
 	*flags = txn->mt_dbs[dbi].md_flags & PERSISTENT_FLAGS;
 	return MDB_SUCCESS;
@@ -9432,11 +10475,18 @@ mdb_drop0(MDB_cursor *mc, int subs)
 		MDB_cursor mx;
 		unsigned int i;
 
-		/* LEAF2 pages have no nodes, cannot have sub-DBs */
-		if (IS_LEAF2(mc->mc_pg[mc->mc_top]))
+		/* DUPSORT sub-DBs have no ovpages/DBs. Omit scanning leaves.
+		 * This also avoids any P_LEAF2 pages, which have no nodes.
+		 */
+		if (mc->mc_flags & C_SUB)
 			mdb_cursor_pop(mc);
 
 		mdb_cursor_copy(mc, &mx);
+#ifdef MDB_VL32
+		/* bump refcount for mx's pages */
+		for (i=0; i<mc->mc_snum; i++)
+			mdb_page_get(&mx, mc->mc_pg[i]->mp_pgno, &mx.mc_pg[i], NULL);
+#endif
 		while (mc->mc_snum > 0) {
 			MDB_page *mp = mc->mc_pg[mc->mc_top];
 			unsigned n = NUMKEYS(mp);
@@ -9447,7 +10497,7 @@ mdb_drop0(MDB_cursor *mc, int subs)
 						MDB_page *omp;
 						pgno_t pg;
 						memcpy(&pg, NODEDATA(ni), sizeof(pg));
-						rc = mdb_page_get(txn, pg, &omp, NULL);
+						rc = mdb_page_get(mc, pg, &omp, NULL);
 						if (rc != 0)
 							goto done;
 						mdb_cassert(mc, IS_OVERFLOW(omp));
@@ -9496,9 +10546,14 @@ mdb_drop0(MDB_cursor *mc, int subs)
 done:
 		if (rc)
 			txn->mt_flags |= MDB_TXN_ERROR;
+#ifdef MDB_VL32
+		/* drop refcount for mx's pages */
+		mdb_cursor_unref(&mx);
+#endif
 	} else if (rc == MDB_NOTFOUND) {
 		rc = MDB_SUCCESS;
 	}
+	mc->mc_flags &= ~C_INITIALIZED;
 	return rc;
 }
 
@@ -9507,13 +10562,13 @@ int mdb_drop(MDB_txn *txn, MDB_dbi dbi, int del)
 	MDB_cursor *mc, *m2;
 	int rc;
 
-	if ((unsigned)del > 1 || dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
+	if ((unsigned)del > 1 || !TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
 		return EINVAL;
 
 	if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))
 		return EACCES;
 
-	if (dbi > MAIN_DBI && TXN_DBI_CHANGED(txn, dbi))
+	if (TXN_DBI_CHANGED(txn, dbi))
 		return MDB_BAD_DBI;
 
 	rc = mdb_cursor_open(txn, dbi, &mc);
@@ -9528,8 +10583,8 @@ int mdb_drop(MDB_txn *txn, MDB_dbi dbi, int del)
 		goto leave;
 
 	/* Can't delete the main DB */
-	if (del && dbi > MAIN_DBI) {
-		rc = mdb_del0(txn, MAIN_DBI, &mc->mc_dbx->md_name, NULL, 0);
+	if (del && dbi >= CORE_DBS) {
+		rc = mdb_del0(txn, MAIN_DBI, &mc->mc_dbx->md_name, NULL, F_SUBDATA);
 		if (!rc) {
 			txn->mt_dbflags[dbi] = DB_STALE;
 			mdb_dbi_close(txn->mt_env, dbi);
@@ -9555,7 +10610,7 @@ leave:
 
 int mdb_set_compare(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)
 {
-	if (dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
+	if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
 		return EINVAL;
 
 	txn->mt_dbxs[dbi].md_cmp = cmp;
@@ -9564,7 +10619,7 @@ int mdb_set_compare(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)
 
 int mdb_set_dupsort(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)
 {
-	if (dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
+	if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
 		return EINVAL;
 
 	txn->mt_dbxs[dbi].md_dcmp = cmp;
@@ -9573,7 +10628,7 @@ int mdb_set_dupsort(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)
 
 int mdb_set_relfunc(MDB_txn *txn, MDB_dbi dbi, MDB_rel_func *rel)
 {
-	if (dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
+	if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
 		return EINVAL;
 
 	txn->mt_dbxs[dbi].md_rel = rel;
@@ -9582,7 +10637,7 @@ int mdb_set_relfunc(MDB_txn *txn, MDB_dbi dbi, MDB_rel_func *rel)
 
 int mdb_set_relctx(MDB_txn *txn, MDB_dbi dbi, void *ctx)
 {
-	if (dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
+	if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
 		return EINVAL;
 
 	txn->mt_dbxs[dbi].md_relctx = ctx;
@@ -9614,7 +10669,7 @@ mdb_reader_list(MDB_env *env, MDB_msg_func *func, void *ctx)
 		if (mr[i].mr_pid) {
 			txnid_t	txnid = mr[i].mr_txnid;
 			sprintf(buf, txnid == (txnid_t)-1 ?
-				"%10d %"Z"x -\n" : "%10d %"Z"x %"Z"u\n",
+				"%10d %"Z"x -\n" : "%10d %"Z"x %"Yu"\n",
 				(int)mr[i].mr_pid, (size_t)mr[i].mr_tid, txnid);
 			if (first) {
 				first = 0;
@@ -9676,17 +10731,23 @@ mdb_pid_insert(MDB_PID_T *ids, MDB_PID_T pid)
 int ESECT
 mdb_reader_check(MDB_env *env, int *dead)
 {
-	unsigned int i, j, rdrs;
-	MDB_reader *mr;
-	MDB_PID_T *pids, pid;
-	int count = 0;
-
 	if (!env)
 		return EINVAL;
 	if (dead)
 		*dead = 0;
-	if (!env->me_txns)
-		return MDB_SUCCESS;
+	return env->me_txns ? mdb_reader_check0(env, 0, dead) : MDB_SUCCESS;
+}
+
+/** As #mdb_reader_check(). rlocked = <caller locked the reader mutex>. */
+static int ESECT
+mdb_reader_check0(MDB_env *env, int rlocked, int *dead)
+{
+	mdb_mutexref_t rmutex = rlocked ? NULL : env->me_rmutex;
+	unsigned int i, j, rdrs;
+	MDB_reader *mr;
+	MDB_PID_T *pids, pid;
+	int rc = MDB_SUCCESS, count = 0;
+
 	rdrs = env->me_txns->mti_numreaders;
 	pids = malloc((rdrs+1) * sizeof(MDB_PID_T));
 	if (!pids)
@@ -9694,22 +10755,32 @@ mdb_reader_check(MDB_env *env, int *dead)
 	pids[0] = 0;
 	mr = env->me_txns->mti_readers;
 	for (i=0; i<rdrs; i++) {
-		if (mr[i].mr_pid && mr[i].mr_pid != env->me_pid) {
-			pid = mr[i].mr_pid;
+		pid = mr[i].mr_pid;
+		if (pid && pid != env->me_pid) {
 			if (mdb_pid_insert(pids, pid) == 0) {
 				if (!mdb_reader_pid(env, Pidcheck, pid)) {
-					LOCK_MUTEX_R(env);
-					/* Recheck, a new process may have reused pid */
-					if (!mdb_reader_pid(env, Pidcheck, pid)) {
-						for (j=i; j<rdrs; j++)
+					/* Stale reader found */
+					j = i;
+					if (rmutex) {
+						if ((rc = LOCK_MUTEX0(rmutex)) != 0) {
+							if ((rc = mdb_mutex_failed(env, rmutex, rc)))
+								break;
+							rdrs = 0; /* the above checked all readers */
+						} else {
+							/* Recheck, a new process may have reused pid */
+							if (mdb_reader_pid(env, Pidcheck, pid))
+								j = rdrs;
+						}
+					}
+					for (; j<rdrs; j++)
 							if (mr[j].mr_pid == pid) {
-								DPRINTF(("clear stale reader pid %u txn %"Z"d",
+								DPRINTF(("clear stale reader pid %u txn %"Yd,
 									(unsigned) pid, mr[j].mr_txnid));
 								mr[j].mr_pid = 0;
 								count++;
 							}
-					}
-					UNLOCK_MUTEX_R(env);
+					if (rmutex)
+						UNLOCK_MUTEX(rmutex);
 				}
 			}
 		}
@@ -9717,6 +10788,78 @@ mdb_reader_check(MDB_env *env, int *dead)
 	free(pids);
 	if (dead)
 		*dead = count;
-	return MDB_SUCCESS;
+	return rc;
+}
+
+#ifdef MDB_ROBUST_SUPPORTED
+/** Handle #LOCK_MUTEX0() failure.
+ * Try to repair the lock file if the mutex owner died.
+ * @param[in] env	the environment handle
+ * @param[in] mutex	LOCK_MUTEX0() mutex
+ * @param[in] rc	LOCK_MUTEX0() error (nonzero)
+ * @return 0 on success with the mutex locked, or an error code on failure.
+ */
+static int ESECT
+mdb_mutex_failed(MDB_env *env, mdb_mutexref_t mutex, int rc)
+{
+	int rlocked, rc2;
+	MDB_meta *meta;
+
+	if (rc == MDB_OWNERDEAD) {
+		/* We own the mutex. Clean up after dead previous owner. */
+		rc = MDB_SUCCESS;
+		rlocked = (mutex == env->me_rmutex);
+		if (!rlocked) {
+			/* Keep mti_txnid updated, otherwise next writer can
+			 * overwrite data which latest meta page refers to.
+			 */
+			meta = mdb_env_pick_meta(env);
+			env->me_txns->mti_txnid = meta->mm_txnid;
+			/* env is hosed if the dead thread was ours */
+			if (env->me_txn) {
+				env->me_flags |= MDB_FATAL_ERROR;
+				env->me_txn = NULL;
+				rc = MDB_PANIC;
+			}
+		}
+		DPRINTF(("%cmutex owner died, %s", (rlocked ? 'r' : 'w'),
+			(rc ? "this process' env is hosed" : "recovering")));
+		rc2 = mdb_reader_check0(env, rlocked, NULL);
+		if (rc2 == 0)
+			rc2 = mdb_mutex_consistent(mutex);
+		if (rc || (rc = rc2)) {
+			DPRINTF(("LOCK_MUTEX recovery failed, %s", mdb_strerror(rc)));
+			UNLOCK_MUTEX(mutex);
+		}
+	} else {
+#ifdef _WIN32
+		rc = ErrCode();
+#endif
+		DPRINTF(("LOCK_MUTEX failed, %s", mdb_strerror(rc)));
+	}
+
+	return rc;
 }
+#endif	/* MDB_ROBUST_SUPPORTED */
 /** @} */
+
+#if defined(_WIN32)
+static int utf8_to_utf16(const char *src, int srcsize, wchar_t **dst, int *dstsize)
+{
+	int need;
+	wchar_t *result;
+	need = MultiByteToWideChar(CP_UTF8, 0, src, srcsize, NULL, 0);
+	if (need == 0xFFFD)
+		return EILSEQ;
+	if (need == 0)
+		return EINVAL;
+	result = malloc(sizeof(wchar_t) * need);
+	if (!result)
+		return ENOMEM;
+	MultiByteToWideChar(CP_UTF8, 0, src, srcsize, result, need);
+	if (dstsize)
+		*dstsize = need;
+	*dst = result;
+	return 0;
+}
+#endif /* defined(_WIN32) */
diff --git a/external/db_drivers/liblmdb32/mdb_copy.1 b/external/db_drivers/liblmdb/mdb_copy.1
index 1e2a97694..1e2a97694 100644
--- a/external/db_drivers/liblmdb32/mdb_copy.1
+++ b/external/db_drivers/liblmdb/mdb_copy.1
diff --git a/external/db_drivers/liblmdb32/mdb_copy.c b/external/db_drivers/liblmdb/mdb_copy.c
index f37ccbcc2..f37ccbcc2 100644
--- a/external/db_drivers/liblmdb32/mdb_copy.c
+++ b/external/db_drivers/liblmdb/mdb_copy.c
diff --git a/external/db_drivers/liblmdb32/mdb_dump.1 b/external/db_drivers/liblmdb/mdb_dump.1
index dd545049b..5a647ba2e 100644
--- a/external/db_drivers/liblmdb32/mdb_dump.1
+++ b/external/db_drivers/liblmdb/mdb_dump.1
@@ -5,7 +5,6 @@
 mdb_dump \- LMDB environment export tool
 .SH SYNOPSIS
 .B mdb_dump
-.BR \ envpath
 [\c
 .BR \-V ]
 [\c
@@ -19,6 +18,7 @@ mdb_dump \- LMDB environment export tool
 [\c
 .BR \-a \ |
 .BI \-s \ subdb\fR]
+.BR \ envpath
 .SH DESCRIPTION
 The
 .B mdb_dump
diff --git a/external/db_drivers/liblmdb32/mdb_dump.c b/external/db_drivers/liblmdb/mdb_dump.c
index 7202d865b..72a469052 100644
--- a/external/db_drivers/liblmdb32/mdb_dump.c
+++ b/external/db_drivers/liblmdb/mdb_dump.c
@@ -25,6 +25,15 @@
 #else
 #define Z	"z"
 #endif
+#ifdef MDB_VL32
+#ifdef _WIN32
+#define	Y	"I64"
+#else
+#define	Y	"ll"
+#endif
+#else
+#define Y	Z
+#endif
 
 #define PRINT	1
 static int mode;
@@ -115,7 +124,7 @@ static int dumpit(MDB_txn *txn, MDB_dbi dbi, char *name)
 	if (name)
 		printf("database=%s\n", name);
 	printf("type=btree\n");
-	printf("mapsize=%" Z "u\n", info.me_mapsize);
+	printf("mapsize=%" Y "u\n", info.me_mapsize);
 	if (info.me_mapaddr)
 		printf("mapaddr=%p\n", info.me_mapaddr);
 	printf("maxreaders=%u\n", info.me_maxreaders);
@@ -155,7 +164,7 @@ static int dumpit(MDB_txn *txn, MDB_dbi dbi, char *name)
 
 static void usage(char *prog)
 {
-	fprintf(stderr, "usage: %s dbpath [-V] [-f output] [-l] [-n] [-p] [-a|-s subdb]\n", prog);
+	fprintf(stderr, "usage: %s [-V] [-f output] [-l] [-n] [-p] [-a|-s subdb] dbpath\n", prog);
 	exit(EXIT_FAILURE);
 }
 
diff --git a/external/db_drivers/liblmdb32/mdb_load.1 b/external/db_drivers/liblmdb/mdb_load.1
index 511ec552b..712ed0540 100644
--- a/external/db_drivers/liblmdb32/mdb_load.1
+++ b/external/db_drivers/liblmdb/mdb_load.1
@@ -5,7 +5,6 @@
 mdb_load \- LMDB environment import tool
 .SH SYNOPSIS
 .B mdb_load
-.BR \ envpath
 [\c
 .BR \-V ]
 [\c
@@ -18,6 +17,7 @@ mdb_load \- LMDB environment import tool
 .BR \-N ]
 [\c
 .BR \-T ]
+.BR \ envpath
 .SH DESCRIPTION
 The
 .B mdb_load
diff --git a/external/db_drivers/liblmdb32/mdb_load.c b/external/db_drivers/liblmdb/mdb_load.c
index 1f6ce0b7e..d1fda4bf5 100644
--- a/external/db_drivers/liblmdb32/mdb_load.c
+++ b/external/db_drivers/liblmdb/mdb_load.c
@@ -43,6 +43,15 @@ static MDB_val kbuf, dbuf;
 #else
 #define Z	"z"
 #endif
+#ifdef MDB_VL32
+#ifdef _WIN32
+#define	Y	"I64"
+#else
+#define	Y	"ll"
+#endif
+#else
+#define Y	Z
+#endif
 
 #define STRLENOF(s)	(sizeof(s)-1)
 
@@ -112,7 +121,7 @@ static void readhdr(void)
 			int i;
 			ptr = memchr(dbuf.mv_data, '\n', dbuf.mv_size);
 			if (ptr) *ptr = '\0';
-			i = sscanf((char *)dbuf.mv_data+STRLENOF("mapsize="), "%" Z "u", &info.me_mapsize);
+			i = sscanf((char *)dbuf.mv_data+STRLENOF("mapsize="), "%" Y "u", &info.me_mapsize);
 			if (i != 1) {
 				fprintf(stderr, "%s: line %" Z "d: invalid mapsize %s\n",
 					prog, lineno, (char *)dbuf.mv_data+STRLENOF("mapsize="));
@@ -276,7 +285,7 @@ badend:
 
 static void usage(void)
 {
-	fprintf(stderr, "usage: %s dbpath [-V] [-f input] [-n] [-s name] [-N] [-T]\n", prog);
+	fprintf(stderr, "usage: %s [-V] [-f input] [-n] [-s name] [-N] [-T] dbpath\n", prog);
 	exit(EXIT_FAILURE);
 }
 
@@ -327,7 +336,7 @@ int main(int argc, char *argv[])
 			putflags = MDB_NOOVERWRITE|MDB_NODUPDATA;
 			break;
 		case 'T':
-			mode |= NOHDR;
+			mode |= NOHDR | PRINT;
 			break;
 		default:
 			usage();
@@ -400,20 +409,22 @@ int main(int argc, char *argv[])
 
 		while(1) {
 			rc = readline(&key, &kbuf);
-			if (rc == EOF)
+			if (rc)  /* rc == EOF */
 				break;
-			if (rc)
-				goto txn_abort;
 
 			rc = readline(&data, &dbuf);
-			if (rc)
+			if (rc) {
+				fprintf(stderr, "%s: line %" Z "d: failed to read key value\n", prog, lineno);
 				goto txn_abort;
-			
+			}
+
 			rc = mdb_cursor_put(mc, &key, &data, putflags);
 			if (rc == MDB_KEYEXIST && putflags)
 				continue;
-			if (rc)
+			if (rc) {
+				fprintf(stderr, "mdb_cursor_put failed, error %d %s\n", rc, mdb_strerror(rc));
 				goto txn_abort;
+			}
 			batch++;
 			if (batch == 100) {
 				rc = mdb_txn_commit(txn);
diff --git a/external/db_drivers/liblmdb32/mdb_stat.1 b/external/db_drivers/liblmdb/mdb_stat.1
index e6ee5ad58..351c01757 100644
--- a/external/db_drivers/liblmdb32/mdb_stat.1
+++ b/external/db_drivers/liblmdb/mdb_stat.1
@@ -5,7 +5,6 @@
 mdb_stat \- LMDB environment status tool
 .SH SYNOPSIS
 .B mdb_stat
-.BR \ envpath
 [\c
 .BR \-V ]
 [\c
@@ -19,6 +18,7 @@ mdb_stat \- LMDB environment status tool
 [\c
 .BR \-a \ |
 .BI \-s \ subdb\fR]
+.BR \ envpath
 .SH DESCRIPTION
 The
 .B mdb_stat
diff --git a/external/db_drivers/liblmdb64/mdb_stat.c b/external/db_drivers/liblmdb/mdb_stat.c
index 210609b32..b785e7acf 100644
--- a/external/db_drivers/liblmdb64/mdb_stat.c
+++ b/external/db_drivers/liblmdb/mdb_stat.c
@@ -22,6 +22,15 @@
 #else
 #define	Z	"z"
 #endif
+#ifdef MDB_VL32
+#ifdef _WIN32
+#define	Y	"I64"
+#else
+#define	Y	"ll"
+#endif
+#else
+#define Y	Z
+#endif
 
 static void prstat(MDB_stat *ms)
 {
@@ -29,15 +38,15 @@ static void prstat(MDB_stat *ms)
 	printf("  Page size: %u\n", ms->ms_psize);
 #endif
 	printf("  Tree depth: %u\n", ms->ms_depth);
-	printf("  Branch pages: %"Z"u\n", ms->ms_branch_pages);
-	printf("  Leaf pages: %"Z"u\n", ms->ms_leaf_pages);
-	printf("  Overflow pages: %"Z"u\n", ms->ms_overflow_pages);
-	printf("  Entries: %"Z"u\n", ms->ms_entries);
+	printf("  Branch pages: %"Y"u\n", ms->ms_branch_pages);
+	printf("  Leaf pages: %"Y"u\n", ms->ms_leaf_pages);
+	printf("  Overflow pages: %"Y"u\n", ms->ms_overflow_pages);
+	printf("  Entries: %"Y"u\n", ms->ms_entries);
 }
 
 static void usage(char *prog)
 {
-	fprintf(stderr, "usage: %s dbpath [-V] [-n] [-e] [-r[r]] [-f[f[f]]] [-a|-s subdb]\n", prog);
+	fprintf(stderr, "usage: %s [-V] [-n] [-e] [-r[r]] [-f[f[f]]] [-a|-s subdb] dbpath\n", prog);
 	exit(EXIT_FAILURE);
 }
 
@@ -125,11 +134,11 @@ int main(int argc, char *argv[])
 		(void)mdb_env_info(env, &mei);
 		printf("Environment Info\n");
 		printf("  Map address: %p\n", mei.me_mapaddr);
-		printf("  Map size: %"Z"u\n", mei.me_mapsize);
+		printf("  Map size: %"Y"u\n", mei.me_mapsize);
 		printf("  Page size: %u\n", mst.ms_psize);
-		printf("  Max pages: %"Z"u\n", mei.me_mapsize / mst.ms_psize);
-		printf("  Number of pages used: %"Z"u\n", mei.me_last_pgno+1);
-		printf("  Last transaction ID: %"Z"u\n", mei.me_last_txnid);
+		printf("  Max pages: %"Y"u\n", mei.me_mapsize / mst.ms_psize);
+		printf("  Number of pages used: %"Y"u\n", mei.me_last_pgno+1);
+		printf("  Last transaction ID: %"Y"u\n", mei.me_last_txnid);
 		printf("  Max readers: %u\n", mei.me_maxreaders);
 		printf("  Number of readers used: %u\n", mei.me_numreaders);
 	}
diff --git a/external/db_drivers/liblmdb64/midl.c b/external/db_drivers/liblmdb/midl.c
index 16782dcaf..e2005d16c 100644
--- a/external/db_drivers/liblmdb64/midl.c
+++ b/external/db_drivers/liblmdb/midl.c
@@ -116,7 +116,7 @@ void mdb_midl_free(MDB_IDL ids)
 		free(ids-1);
 }
 
-int mdb_midl_shrink( MDB_IDL *idp )
+void mdb_midl_shrink( MDB_IDL *idp )
 {
 	MDB_IDL ids = *idp;
 	if (*(--ids) > MDB_IDL_UM_MAX &&
@@ -124,9 +124,7 @@ int mdb_midl_shrink( MDB_IDL *idp )
 	{
 		*ids++ = MDB_IDL_UM_MAX;
 		*idp = ids;
-		return 1;
 	}
-	return 0;
 }
 
 static int mdb_midl_grow( MDB_IDL *idp, int num )
@@ -356,5 +354,67 @@ int mdb_mid2l_append( MDB_ID2L ids, MDB_ID2 *id )
 	return 0;
 }
 
+#ifdef MDB_VL32
+unsigned mdb_mid3l_search( MDB_ID3L ids, MDB_ID id )
+{
+	/*
+	 * binary search of id in ids
+	 * if found, returns position of id
+	 * if not found, returns first position greater than id
+	 */
+	unsigned base = 0;
+	unsigned cursor = 1;
+	int val = 0;
+	unsigned n = (unsigned)ids[0].mid;
+
+	while( 0 < n ) {
+		unsigned pivot = n >> 1;
+		cursor = base + pivot + 1;
+		val = CMP( id, ids[cursor].mid );
+
+		if( val < 0 ) {
+			n = pivot;
+
+		} else if ( val > 0 ) {
+			base = cursor;
+			n -= pivot + 1;
+
+		} else {
+			return cursor;
+		}
+	}
+
+	if( val > 0 ) {
+		++cursor;
+	}
+	return cursor;
+}
+
+int mdb_mid3l_insert( MDB_ID3L ids, MDB_ID3 *id )
+{
+	unsigned x, i;
+
+	x = mdb_mid3l_search( ids, id->mid );
+
+	if( x < 1 ) {
+		/* internal error */
+		return -2;
+	}
+
+	if ( x <= ids[0].mid && ids[x].mid == id->mid ) {
+		/* duplicate */
+		return -1;
+	}
+
+	/* insert id */
+	ids[0].mid++;
+	for (i=(unsigned)ids[0].mid; i>x; i--)
+		ids[i] = ids[i-1];
+	ids[x] = *id;
+
+	return 0;
+}
+#endif /* MDB_VL32 */
+
 /** @} */
 /** @} */
diff --git a/external/db_drivers/liblmdb32/midl.h b/external/db_drivers/liblmdb/midl.h
index 1e5fee797..ed1d75e36 100644
--- a/external/db_drivers/liblmdb32/midl.h
+++ b/external/db_drivers/liblmdb/midl.h
@@ -27,6 +27,7 @@
 #define _MDB_MIDL_H_
 
 #include <stddef.h>
+#include <inttypes.h>
 
 #ifdef __cplusplus
 extern "C" {
@@ -42,7 +43,11 @@ extern "C" {
 	/** A generic unsigned ID number. These were entryIDs in back-bdb.
 	 *	Preferably it should have the same size as a pointer.
 	 */
+#ifdef MDB_VL32
+typedef uint64_t MDB_ID;
+#else
 typedef size_t MDB_ID;
+#endif
 
 	/** An IDL is an ID List, a sorted array of IDs. The first
 	 * element of the array is a counter for how many actual
@@ -55,10 +60,10 @@ typedef MDB_ID *MDB_IDL;
 /* IDL sizes - likely should be even bigger
  *   limiting factors: sizeof(ID), thread stack size
  */
-#ifdef VL32
+#ifdef MDB_VL32
 #define	MDB_IDL_LOGN	10	/* DB_SIZE is 2^10, UM_SIZE is 2^11 */
 #else
- #define	MDB_IDL_LOGN	16	/* DB_SIZE is 2^16, UM_SIZE is 2^17 */
+#define	MDB_IDL_LOGN	16	/* DB_SIZE is 2^16, UM_SIZE is 2^17 */
 #endif
 #define MDB_IDL_DB_SIZE		(1<<MDB_IDL_LOGN)
 #define MDB_IDL_UM_SIZE		(1<<(MDB_IDL_LOGN+1))
@@ -102,9 +107,8 @@ void mdb_midl_free(MDB_IDL ids);
 	/** Shrink an IDL.
 	 * Return the IDL to the default size if it has grown larger.
 	 * @param[in,out] idp	Address of the IDL to shrink.
-	 * @return	0 on no change, non-zero if shrunk.
 	 */
-int mdb_midl_shrink(MDB_IDL *idp);
+void mdb_midl_shrink(MDB_IDL *idp);
 
 	/** Make room for num additional elements in an IDL.
 	 * @param[in,out] idp	Address of the IDL.
@@ -182,6 +186,20 @@ int mdb_mid2l_insert( MDB_ID2L ids, MDB_ID2 *id );
 	 */
 int mdb_mid2l_append( MDB_ID2L ids, MDB_ID2 *id );
 
+#ifdef MDB_VL32
+typedef struct MDB_ID3 {
+	MDB_ID mid;		/**< The ID */
+	void *mptr;		/**< The pointer */
+	unsigned int mcnt;		/**< Number of pages */
+	unsigned int mref;		/**< Refcounter */
+} MDB_ID3;
+
+typedef MDB_ID3 *MDB_ID3L;
+
+unsigned mdb_mid3l_search( MDB_ID3L ids, MDB_ID id );
+int mdb_mid3l_insert( MDB_ID3L ids, MDB_ID3 *id );
+
+#endif /* MDB_VL32 */
 /** @} */
 /** @} */
 #ifdef __cplusplus
diff --git a/external/db_drivers/liblmdb64/mtest.c b/external/db_drivers/liblmdb/mtest.c
index 9d15088b0..9d15088b0 100644
--- a/external/db_drivers/liblmdb64/mtest.c
+++ b/external/db_drivers/liblmdb/mtest.c
diff --git a/external/db_drivers/liblmdb32/mtest2.c b/external/db_drivers/liblmdb/mtest2.c
index eacbe59d5..eacbe59d5 100644
--- a/external/db_drivers/liblmdb32/mtest2.c
+++ b/external/db_drivers/liblmdb/mtest2.c
diff --git a/external/db_drivers/liblmdb32/mtest3.c b/external/db_drivers/liblmdb/mtest3.c
index 9db79e625..9db79e625 100644
--- a/external/db_drivers/liblmdb32/mtest3.c
+++ b/external/db_drivers/liblmdb/mtest3.c
diff --git a/external/db_drivers/liblmdb32/mtest4.c b/external/db_drivers/liblmdb/mtest4.c
index 6df890e2d..6df890e2d 100644
--- a/external/db_drivers/liblmdb32/mtest4.c
+++ b/external/db_drivers/liblmdb/mtest4.c
diff --git a/external/db_drivers/liblmdb32/mtest5.c b/external/db_drivers/liblmdb/mtest5.c
index 14e3c0da4..14e3c0da4 100644
--- a/external/db_drivers/liblmdb32/mtest5.c
+++ b/external/db_drivers/liblmdb/mtest5.c
diff --git a/external/db_drivers/liblmdb32/mtest6.c b/external/db_drivers/liblmdb/mtest6.c
index ae3c7f264..ae3c7f264 100644
--- a/external/db_drivers/liblmdb32/mtest6.c
+++ b/external/db_drivers/liblmdb/mtest6.c
diff --git a/external/db_drivers/liblmdb32/sample-bdb.txt b/external/db_drivers/liblmdb/sample-bdb.txt
index 563807a2b..563807a2b 100644
--- a/external/db_drivers/liblmdb32/sample-bdb.txt
+++ b/external/db_drivers/liblmdb/sample-bdb.txt
diff --git a/external/db_drivers/liblmdb32/sample-mdb.txt b/external/db_drivers/liblmdb/sample-mdb.txt
index 10a256870..10a256870 100644
--- a/external/db_drivers/liblmdb32/sample-mdb.txt
+++ b/external/db_drivers/liblmdb/sample-mdb.txt
diff --git a/external/db_drivers/liblmdb32/tooltag b/external/db_drivers/liblmdb/tooltag
index 229bf16ba..229bf16ba 100644
--- a/external/db_drivers/liblmdb32/tooltag
+++ b/external/db_drivers/liblmdb/tooltag
diff --git a/external/db_drivers/liblmdb32/.gitignore b/external/db_drivers/liblmdb32/.gitignore
deleted file mode 100644
index f3277afe4..000000000
--- a/external/db_drivers/liblmdb32/.gitignore
+++ /dev/null
@@ -1,20 +0,0 @@
-mtest
-mtest[23456]
-testdb
-mdb_copy
-mdb_stat
-*.[ao]
-*.so
-*.exe
-*[~#]
-*.bak
-*.orig
-*.rej
-*.gcov
-*.gcda
-*.gcno
-core
-core.*
-valgrind.*
-man/
-html/
diff --git a/external/db_drivers/liblmdb32/CHANGES b/external/db_drivers/liblmdb32/CHANGES
deleted file mode 100644
index 957742e75..000000000
--- a/external/db_drivers/liblmdb32/CHANGES
+++ /dev/null
@@ -1,140 +0,0 @@
-LMDB 0.9 Change Log
-
-LMDB 0.9.15 Release (2015/06/19)
-	Fix txn init (ITS#7961,#7987)
-	Fix MDB_PREV_DUP (ITS#7955,#7671)
-	Fix compact of empty env (ITS#7956)
-	Fix mdb_copy file mode
-	Fix mdb_env_close() after failed mdb_env_open()
-	Fix mdb_rebalance collapsing root (ITS#8062)
-	Fix mdb_load with large values (ITS#8066)
-	Fix to retry writes on EINTR (ITS#8106)
-	Fix mdb_cursor_del on empty DB (ITS#8109)
-	Fix MDB_INTEGERDUP key compare (ITS#8117)
-	Fix error handling (ITS#7959,#8157,etc.)
-	Fix race conditions (ITS#7969,7970)
-	Added workaround for fdatasync bug in ext3fs
-	Build
-		Don't use -fPIC for static lib
-		Update .gitignore (ITS#7952,#7953)
-		Cleanup for "make test" (ITS#7841), "make clean", mtest*.c
-		Misc. Android/Windows cleanup
-	Documentation
-		Fix MDB_APPEND doc
-		Fix MDB_MAXKEYSIZE doc (ITS#8156)
-		Fix mdb_cursor_put,mdb_cursor_del EACCES description
-		Fix mdb_env_sync(MDB_RDONLY env) doc (ITS#8021)
-		Clarify MDB_WRITEMAP doc (ITS#8021)
-		Clarify mdb_env_open doc
-		Clarify mdb_dbi_open doc
-
-LMDB 0.9.14 Release (2014/09/20)
-	Fix to support 64K page size (ITS#7713)
-	Fix to persist decreased as well as increased mapsizes (ITS#7789)
-	Fix cursor bug when deleting last node of a DUPSORT key
-	Fix mdb_env_info to return FIXEDMAP address
-	Fix ambiguous error code from writing to closed DBI (ITS#7825)
-	Fix mdb_copy copying past end of file (ITS#7886)
-	Fix cursor bugs from page_merge/rebalance
-	Fix to dirty fewer pages in deletes (mdb_page_loose())
-	Fix mdb_dbi_open creating subDBs (ITS#7917)
-	Fix mdb_cursor_get(_DUP) with single value (ITS#7913)
-	Fix Windows compat issues in mtests (ITS#7879)
-	Add compacting variant of mdb_copy
-	Add BigEndian integer key compare code
-	Add mdb_dump/mdb_load utilities
-
-LMDB 0.9.13 Release (2014/06/18)
-	Fix mdb_page_alloc unlimited overflow page search
-	Documentation
-		Re-fix MDB_CURRENT doc (ITS#7793)
-		Fix MDB_GET_MULTIPLE/MDB_NEXT_MULTIPLE doc
-
-LMDB 0.9.12 Release (2014/06/13)
-	Fix MDB_GET_BOTH regression (ITS#7875,#7681)
-	Fix MDB_MULTIPLE writing multiple keys (ITS#7834)
-	Fix mdb_rebalance (ITS#7829)
-	Fix mdb_page_split (ITS#7815)
-	Fix md_entries count (ITS#7861,#7828,#7793)
-	Fix MDB_CURRENT (ITS#7793)
-	Fix possible crash on Windows DLL detach
-	Misc code cleanup
-	Documentation
-		mdb_cursor_put: cursor moves on error (ITS#7771)
-
-
-LMDB 0.9.11 Release (2014/01/15)
-	Add mdb_env_set_assert() (ITS#7775)
-	Fix: invalidate txn on page allocation errors (ITS#7377)
-	Fix xcursor tracking in mdb_cursor_del0() (ITS#7771)
-	Fix corruption from deletes (ITS#7756)
-	Fix Windows/MSVC build issues
-	Raise safe limit of max MDB_MAXKEYSIZE
-	Misc code cleanup
-	Documentation
-		Remove spurious note about non-overlapping flags (ITS#7665)
-
-LMDB 0.9.10 Release (2013/11/12)
-	Add MDB_NOMEMINIT option
-	Fix mdb_page_split() again (ITS#7589)
-	Fix MDB_NORDAHEAD definition (ITS#7734)
-	Fix mdb_cursor_del() positioning (ITS#7733)
-	Partial fix for larger page sizes (ITS#7713)
-	Fix Windows64/MSVC build issues
-
-LMDB 0.9.9 Release (2013/10/24)
-	Add mdb_env_get_fd()
-	Add MDB_NORDAHEAD option
-	Add MDB_NOLOCK option
-	Avoid wasting space in mdb_page_split() (ITS#7589)
-	Fix mdb_page_merge() cursor fixup (ITS#7722)
-	Fix mdb_cursor_del() on last delete (ITS#7718)
-	Fix adding WRITEMAP on existing env (ITS#7715)
-	Fix nested txns (ITS#7515)
-	Fix mdb_env_copy() O_DIRECT bug (ITS#7682)
-	Fix mdb_cursor_set(SET_RANGE) return code (ITS#7681)
-	Fix mdb_rebalance() cursor fixup (ITS#7701)
-	Misc code cleanup
-	Documentation
-		Note that by default, readers need write access
-
-
-LMDB 0.9.8 Release (2013/09/09)
-	Allow mdb_env_set_mapsize() on an open environment
-	Fix mdb_dbi_flags() (ITS#7672)
-	Fix mdb_page_unspill() in nested txns
-	Fix mdb_cursor_get(CURRENT|NEXT) after a delete
-	Fix mdb_cursor_get(DUP) to always return key (ITS#7671)
-	Fix mdb_cursor_del() to always advance to next item (ITS#7670)
-	Fix mdb_cursor_set(SET_RANGE) for tree with single page (ITS#7681)
-	Fix mdb_env_copy() retry open if O_DIRECT fails (ITS#7682)
-	Tweak mdb_page_spill() to be less aggressive
-	Documentation
-		Update caveats since mdb_reader_check() added in 0.9.7
-
-LMDB 0.9.7 Release (2013/08/17)
-	Don't leave stale lockfile on failed RDONLY open (ITS#7664)
-	Fix mdb_page_split() ref beyond cursor depth
-	Fix read txn data race (ITS#7635)
-	Fix mdb_rebalance (ITS#7536, #7538)
-	Fix mdb_drop() (ITS#7561)
-	Misc DEBUG macro fixes
-	Add MDB_NOTLS envflag
-	Add mdb_env_copyfd()
-	Add mdb_txn_env() (ITS#7660)
-	Add mdb_dbi_flags() (ITS#7661)
-	Add mdb_env_get_maxkeysize()
-	Add mdb_env_reader_list()/mdb_env_reader_check()
-	Add mdb_page_spill/unspill, remove hard txn size limit
-	Use shorter names for semaphores (ITS#7615)
-	Build
-		Fix install target (ITS#7656)
-	Documentation
-		Misc updates for cursors, DB handles, data lifetime
-
-LMDB 0.9.6 Release (2013/02/25)
-	Many fixes/enhancements
-
-LMDB 0.9.5 Release (2012/11/30)
-	Renamed from libmdb to liblmdb
-	Many fixes/enhancements
diff --git a/external/db_drivers/liblmdb32/Makefile b/external/db_drivers/liblmdb32/Makefile
deleted file mode 100644
index 26b6203af..000000000
--- a/external/db_drivers/liblmdb32/Makefile
+++ /dev/null
@@ -1,105 +0,0 @@
-# Makefile for liblmdb (Lightning memory-mapped database library).
-
-########################################################################
-# Configuration. The compiler options must enable threaded compilation.
-#
-# Preprocessor macros (for CPPFLAGS) of interest...
-# Note that the defaults should already be correct for most
-# platforms; you should not need to change any of these.
-# Read their descriptions in mdb.c if you do:
-#
-# - MDB_USE_POSIX_SEM
-# - MDB_DSYNC
-# - MDB_FDATASYNC
-# - MDB_FDATASYNC_WORKS
-# - MDB_USE_PWRITEV
-#
-# There may be other macros in mdb.c of interest. You should
-# read mdb.c before changing any of them.
-#
-CC	= gcc
-W	= -W -Wall -Wno-unused-parameter -Wbad-function-cast -Wuninitialized
-THREADS = -pthread
-OPT = -O2 -g
-CFLAGS	= $(THREADS) $(OPT) $(W) $(XCFLAGS)
-LDLIBS	=
-SOLIBS	=
-prefix	= /usr/local
-XCFLAGS = -DVL32
-
-########################################################################
-
-IHDRS	= lmdb.h
-ILIBS	= liblmdb.a liblmdb.so
-IPROGS	= mdb_stat mdb_copy mdb_dump mdb_load
-IDOCS	= mdb_stat.1 mdb_copy.1 mdb_dump.1 mdb_load.1
-PROGS	= $(IPROGS) mtest mtest2 mtest3 mtest4 mtest5
-all:	$(ILIBS) $(PROGS)
-
-install: $(ILIBS) $(IPROGS) $(IHDRS)
-	for f in $(IPROGS); do cp $$f $(DESTDIR)$(prefix)/bin; done
-	for f in $(ILIBS); do cp $$f $(DESTDIR)$(prefix)/lib; done
-	for f in $(IHDRS); do cp $$f $(DESTDIR)$(prefix)/include; done
-	for f in $(IDOCS); do cp $$f $(DESTDIR)$(prefix)/man/man1; done
-
-clean:
-	rm -rf $(PROGS) *.[ao] *.[ls]o *~ testdb
-
-test:	all
-	rm -rf testdb && mkdir testdb
-	./mtest && ./mdb_stat testdb
-
-liblmdb.a:	mdb.o midl.o
-	ar rs $@ mdb.o midl.o
-
-liblmdb.so:	mdb.lo midl.lo
-#	$(CC) $(LDFLAGS) -pthread -shared -Wl,-Bsymbolic -o $@ mdb.o midl.o $(SOLIBS)
-	$(CC) $(LDFLAGS) -pthread -shared -o $@ mdb.lo midl.lo $(SOLIBS)
-
-mdb_stat: mdb_stat.o liblmdb.a
-mdb_copy: mdb_copy.o liblmdb.a
-mdb_dump: mdb_dump.o liblmdb.a
-mdb_load: mdb_load.o liblmdb.a
-mtest:    mtest.o    liblmdb.a
-mtest2:	mtest2.o liblmdb.a
-mtest3:	mtest3.o liblmdb.a
-mtest4:	mtest4.o liblmdb.a
-mtest5:	mtest5.o liblmdb.a
-mtest6:	mtest6.o liblmdb.a
-
-mdb.o: mdb.c lmdb.h midl.h
-	$(CC) $(CFLAGS) $(CPPFLAGS) -c mdb.c
-
-midl.o: midl.c midl.h
-	$(CC) $(CFLAGS) $(CPPFLAGS) -c midl.c
-
-mdb.lo: mdb.c lmdb.h midl.h
-	$(CC) $(CFLAGS) -fPIC $(CPPFLAGS) -c mdb.c -o $@
-
-midl.lo: midl.c midl.h
-	$(CC) $(CFLAGS) -fPIC $(CPPFLAGS) -c midl.c -o $@
-
-%:	%.o
-	$(CC) $(CFLAGS) $(LDFLAGS) $^ $(LDLIBS) -o $@
-
-%.o:	%.c lmdb.h
-	$(CC) $(CFLAGS) $(CPPFLAGS) -c $<
-
-COV_FLAGS=-fprofile-arcs -ftest-coverage
-COV_OBJS=xmdb.o xmidl.o
-
-coverage: xmtest
-	for i in mtest*.c [0-9]*.c; do j=`basename \$$i .c`; $(MAKE) $$j.o; \
-		gcc -o x$$j $$j.o $(COV_OBJS) -pthread $(COV_FLAGS); \
-		rm -rf testdb; mkdir testdb; ./x$$j; done
-	gcov xmdb.c
-	gcov xmidl.c
-
-xmtest:	mtest.o xmdb.o xmidl.o
-	gcc -o xmtest mtest.o xmdb.o xmidl.o -pthread $(COV_FLAGS)
-
-xmdb.o: mdb.c lmdb.h midl.h
-	$(CC) $(CFLAGS) -fPIC $(CPPFLAGS) -O0 $(COV_FLAGS) -c mdb.c -o $@
-
-xmidl.o: midl.c midl.h
-	$(CC) $(CFLAGS) -fPIC $(CPPFLAGS) -O0 $(COV_FLAGS) -c midl.c -o $@
diff --git a/external/db_drivers/liblmdb32/mdb_stat.c b/external/db_drivers/liblmdb32/mdb_stat.c
deleted file mode 100644
index 210609b32..000000000
--- a/external/db_drivers/liblmdb32/mdb_stat.c
+++ /dev/null
@@ -1,263 +0,0 @@
-/* mdb_stat.c - memory-mapped database status tool */
-/*
- * Copyright 2011-2015 Howard Chu, Symas Corp.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted only as authorized by the OpenLDAP
- * Public License.
- *
- * A copy of this license is available in the file LICENSE in the
- * top-level directory of the distribution or, alternatively, at
- * <http://www.OpenLDAP.org/license.html>.
- */
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-#include "lmdb.h"
-
-#ifdef	_WIN32
-#define	Z	"I"
-#else
-#define	Z	"z"
-#endif
-
-static void prstat(MDB_stat *ms)
-{
-#if 0
-	printf("  Page size: %u\n", ms->ms_psize);
-#endif
-	printf("  Tree depth: %u\n", ms->ms_depth);
-	printf("  Branch pages: %"Z"u\n", ms->ms_branch_pages);
-	printf("  Leaf pages: %"Z"u\n", ms->ms_leaf_pages);
-	printf("  Overflow pages: %"Z"u\n", ms->ms_overflow_pages);
-	printf("  Entries: %"Z"u\n", ms->ms_entries);
-}
-
-static void usage(char *prog)
-{
-	fprintf(stderr, "usage: %s dbpath [-V] [-n] [-e] [-r[r]] [-f[f[f]]] [-a|-s subdb]\n", prog);
-	exit(EXIT_FAILURE);
-}
-
-int main(int argc, char *argv[])
-{
-	int i, rc;
-	MDB_env *env;
-	MDB_txn *txn;
-	MDB_dbi dbi;
-	MDB_stat mst;
-	MDB_envinfo mei;
-	char *prog = argv[0];
-	char *envname;
-	char *subname = NULL;
-	int alldbs = 0, envinfo = 0, envflags = 0, freinfo = 0, rdrinfo = 0;
-
-	if (argc < 2) {
-		usage(prog);
-	}
-
-	/* -a: print stat of main DB and all subDBs
-	 * -s: print stat of only the named subDB
-	 * -e: print env info
-	 * -f: print freelist info
-	 * -r: print reader info
-	 * -n: use NOSUBDIR flag on env_open
-	 * -V: print version and exit
-	 * (default) print stat of only the main DB
-	 */
-	while ((i = getopt(argc, argv, "Vaefnrs:")) != EOF) {
-		switch(i) {
-		case 'V':
-			printf("%s\n", MDB_VERSION_STRING);
-			exit(0);
-			break;
-		case 'a':
-			if (subname)
-				usage(prog);
-			alldbs++;
-			break;
-		case 'e':
-			envinfo++;
-			break;
-		case 'f':
-			freinfo++;
-			break;
-		case 'n':
-			envflags |= MDB_NOSUBDIR;
-			break;
-		case 'r':
-			rdrinfo++;
-			break;
-		case 's':
-			if (alldbs)
-				usage(prog);
-			subname = optarg;
-			break;
-		default:
-			usage(prog);
-		}
-	}
-
-	if (optind != argc - 1)
-		usage(prog);
-
-	envname = argv[optind];
-	rc = mdb_env_create(&env);
-	if (rc) {
-		fprintf(stderr, "mdb_env_create failed, error %d %s\n", rc, mdb_strerror(rc));
-		return EXIT_FAILURE;
-	}
-
-	if (alldbs || subname) {
-		mdb_env_set_maxdbs(env, 4);
-	}
-
-	rc = mdb_env_open(env, envname, envflags | MDB_RDONLY, 0664);
-	if (rc) {
-		fprintf(stderr, "mdb_env_open failed, error %d %s\n", rc, mdb_strerror(rc));
-		goto env_close;
-	}
-
-	if (envinfo) {
-		(void)mdb_env_stat(env, &mst);
-		(void)mdb_env_info(env, &mei);
-		printf("Environment Info\n");
-		printf("  Map address: %p\n", mei.me_mapaddr);
-		printf("  Map size: %"Z"u\n", mei.me_mapsize);
-		printf("  Page size: %u\n", mst.ms_psize);
-		printf("  Max pages: %"Z"u\n", mei.me_mapsize / mst.ms_psize);
-		printf("  Number of pages used: %"Z"u\n", mei.me_last_pgno+1);
-		printf("  Last transaction ID: %"Z"u\n", mei.me_last_txnid);
-		printf("  Max readers: %u\n", mei.me_maxreaders);
-		printf("  Number of readers used: %u\n", mei.me_numreaders);
-	}
-
-	if (rdrinfo) {
-		printf("Reader Table Status\n");
-		rc = mdb_reader_list(env, (MDB_msg_func *)fputs, stdout);
-		if (rdrinfo > 1) {
-			int dead;
-			mdb_reader_check(env, &dead);
-			printf("  %d stale readers cleared.\n", dead);
-			rc = mdb_reader_list(env, (MDB_msg_func *)fputs, stdout);
-		}
-		if (!(subname || alldbs || freinfo))
-			goto env_close;
-	}
-
-	rc = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
-	if (rc) {
-		fprintf(stderr, "mdb_txn_begin failed, error %d %s\n", rc, mdb_strerror(rc));
-		goto env_close;
-	}
-
-	if (freinfo) {
-		MDB_cursor *cursor;
-		MDB_val key, data;
-		size_t pages = 0, *iptr;
-
-		printf("Freelist Status\n");
-		dbi = 0;
-		rc = mdb_cursor_open(txn, dbi, &cursor);
-		if (rc) {
-			fprintf(stderr, "mdb_cursor_open failed, error %d %s\n", rc, mdb_strerror(rc));
-			goto txn_abort;
-		}
-		rc = mdb_stat(txn, dbi, &mst);
-		if (rc) {
-			fprintf(stderr, "mdb_stat failed, error %d %s\n", rc, mdb_strerror(rc));
-			goto txn_abort;
-		}
-		prstat(&mst);
-		while ((rc = mdb_cursor_get(cursor, &key, &data, MDB_NEXT)) == 0) {
-			iptr = data.mv_data;
-			pages += *iptr;
-			if (freinfo > 1) {
-				char *bad = "";
-				size_t pg, prev;
-				ssize_t i, j, span = 0;
-				j = *iptr++;
-				for (i = j, prev = 1; --i >= 0; ) {
-					pg = iptr[i];
-					if (pg <= prev)
-						bad = " [bad sequence]";
-					prev = pg;
-					pg += span;
-					for (; i >= span && iptr[i-span] == pg; span++, pg++) ;
-				}
-				printf("    Transaction %"Z"u, %"Z"d pages, maxspan %"Z"d%s\n",
-					*(size_t *)key.mv_data, j, span, bad);
-				if (freinfo > 2) {
-					for (--j; j >= 0; ) {
-						pg = iptr[j];
-						for (span=1; --j >= 0 && iptr[j] == pg+span; span++) ;
-						printf(span>1 ? "     %9"Z"u[%"Z"d]\n" : "     %9"Z"u\n",
-							pg, span);
-					}
-				}
-			}
-		}
-		mdb_cursor_close(cursor);
-		printf("  Free pages: %"Z"u\n", pages);
-	}
-
-	rc = mdb_open(txn, subname, 0, &dbi);
-	if (rc) {
-		fprintf(stderr, "mdb_open failed, error %d %s\n", rc, mdb_strerror(rc));
-		goto txn_abort;
-	}
-
-	rc = mdb_stat(txn, dbi, &mst);
-	if (rc) {
-		fprintf(stderr, "mdb_stat failed, error %d %s\n", rc, mdb_strerror(rc));
-		goto txn_abort;
-	}
-	printf("Status of %s\n", subname ? subname : "Main DB");
-	prstat(&mst);
-
-	if (alldbs) {
-		MDB_cursor *cursor;
-		MDB_val key;
-
-		rc = mdb_cursor_open(txn, dbi, &cursor);
-		if (rc) {
-			fprintf(stderr, "mdb_cursor_open failed, error %d %s\n", rc, mdb_strerror(rc));
-			goto txn_abort;
-		}
-		while ((rc = mdb_cursor_get(cursor, &key, NULL, MDB_NEXT_NODUP)) == 0) {
-			char *str;
-			MDB_dbi db2;
-			if (memchr(key.mv_data, '\0', key.mv_size))
-				continue;
-			str = malloc(key.mv_size+1);
-			memcpy(str, key.mv_data, key.mv_size);
-			str[key.mv_size] = '\0';
-			rc = mdb_open(txn, str, 0, &db2);
-			if (rc == MDB_SUCCESS)
-				printf("Status of %s\n", str);
-			free(str);
-			if (rc) continue;
-			rc = mdb_stat(txn, db2, &mst);
-			if (rc) {
-				fprintf(stderr, "mdb_stat failed, error %d %s\n", rc, mdb_strerror(rc));
-				goto txn_abort;
-			}
-			prstat(&mst);
-			mdb_close(env, db2);
-		}
-		mdb_cursor_close(cursor);
-	}
-
-	if (rc == MDB_NOTFOUND)
-		rc = MDB_SUCCESS;
-
-	mdb_close(env, dbi);
-txn_abort:
-	mdb_txn_abort(txn);
-env_close:
-	mdb_env_close(env);
-
-	return rc ? EXIT_FAILURE : EXIT_SUCCESS;
-}
diff --git a/external/db_drivers/liblmdb32/midl.c b/external/db_drivers/liblmdb32/midl.c
deleted file mode 100644
index 16782dcaf..000000000
--- a/external/db_drivers/liblmdb32/midl.c
+++ /dev/null
@@ -1,360 +0,0 @@
-/**	@file midl.c
- *	@brief ldap bdb back-end ID List functions */
-/* $OpenLDAP$ */
-/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
- *
- * Copyright 2000-2015 The OpenLDAP Foundation.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted only as authorized by the OpenLDAP
- * Public License.
- *
- * A copy of this license is available in the file LICENSE in the
- * top-level directory of the distribution or, alternatively, at
- * <http://www.OpenLDAP.org/license.html>.
- */
-
-#include <limits.h>
-#include <string.h>
-#include <stdlib.h>
-#include <errno.h>
-#include <sys/types.h>
-#include "midl.h"
-
-/** @defgroup internal	LMDB Internals
- *	@{
- */
-/** @defgroup idls	ID List Management
- *	@{
- */
-#define CMP(x,y)	 ( (x) < (y) ? -1 : (x) > (y) )
-
-unsigned mdb_midl_search( MDB_IDL ids, MDB_ID id )
-{
-	/*
-	 * binary search of id in ids
-	 * if found, returns position of id
-	 * if not found, returns first position greater than id
-	 */
-	unsigned base = 0;
-	unsigned cursor = 1;
-	int val = 0;
-	unsigned n = ids[0];
-
-	while( 0 < n ) {
-		unsigned pivot = n >> 1;
-		cursor = base + pivot + 1;
-		val = CMP( ids[cursor], id );
-
-		if( val < 0 ) {
-			n = pivot;
-
-		} else if ( val > 0 ) {
-			base = cursor;
-			n -= pivot + 1;
-
-		} else {
-			return cursor;
-		}
-	}
-
-	if( val > 0 ) {
-		++cursor;
-	}
-	return cursor;
-}
-
-#if 0	/* superseded by append/sort */
-int mdb_midl_insert( MDB_IDL ids, MDB_ID id )
-{
-	unsigned x, i;
-
-	x = mdb_midl_search( ids, id );
-	assert( x > 0 );
-
-	if( x < 1 ) {
-		/* internal error */
-		return -2;
-	}
-
-	if ( x <= ids[0] && ids[x] == id ) {
-		/* duplicate */
-		assert(0);
-		return -1;
-	}
-
-	if ( ++ids[0] >= MDB_IDL_DB_MAX ) {
-		/* no room */
-		--ids[0];
-		return -2;
-
-	} else {
-		/* insert id */
-		for (i=ids[0]; i>x; i--)
-			ids[i] = ids[i-1];
-		ids[x] = id;
-	}
-
-	return 0;
-}
-#endif
-
-MDB_IDL mdb_midl_alloc(int num)
-{
-	MDB_IDL ids = malloc((num+2) * sizeof(MDB_ID));
-	if (ids) {
-		*ids++ = num;
-		*ids = 0;
-	}
-	return ids;
-}
-
-void mdb_midl_free(MDB_IDL ids)
-{
-	if (ids)
-		free(ids-1);
-}
-
-int mdb_midl_shrink( MDB_IDL *idp )
-{
-	MDB_IDL ids = *idp;
-	if (*(--ids) > MDB_IDL_UM_MAX &&
-		(ids = realloc(ids, (MDB_IDL_UM_MAX+1) * sizeof(MDB_ID))))
-	{
-		*ids++ = MDB_IDL_UM_MAX;
-		*idp = ids;
-		return 1;
-	}
-	return 0;
-}
-
-static int mdb_midl_grow( MDB_IDL *idp, int num )
-{
-	MDB_IDL idn = *idp-1;
-	/* grow it */
-	idn = realloc(idn, (*idn + num + 2) * sizeof(MDB_ID));
-	if (!idn)
-		return ENOMEM;
-	*idn++ += num;
-	*idp = idn;
-	return 0;
-}
-
-int mdb_midl_need( MDB_IDL *idp, unsigned num )
-{
-	MDB_IDL ids = *idp;
-	num += ids[0];
-	if (num > ids[-1]) {
-		num = (num + num/4 + (256 + 2)) & -256;
-		if (!(ids = realloc(ids-1, num * sizeof(MDB_ID))))
-			return ENOMEM;
-		*ids++ = num - 2;
-		*idp = ids;
-	}
-	return 0;
-}
-
-int mdb_midl_append( MDB_IDL *idp, MDB_ID id )
-{
-	MDB_IDL ids = *idp;
-	/* Too big? */
-	if (ids[0] >= ids[-1]) {
-		if (mdb_midl_grow(idp, MDB_IDL_UM_MAX))
-			return ENOMEM;
-		ids = *idp;
-	}
-	ids[0]++;
-	ids[ids[0]] = id;
-	return 0;
-}
-
-int mdb_midl_append_list( MDB_IDL *idp, MDB_IDL app )
-{
-	MDB_IDL ids = *idp;
-	/* Too big? */
-	if (ids[0] + app[0] >= ids[-1]) {
-		if (mdb_midl_grow(idp, app[0]))
-			return ENOMEM;
-		ids = *idp;
-	}
-	memcpy(&ids[ids[0]+1], &app[1], app[0] * sizeof(MDB_ID));
-	ids[0] += app[0];
-	return 0;
-}
-
-int mdb_midl_append_range( MDB_IDL *idp, MDB_ID id, unsigned n )
-{
-	MDB_ID *ids = *idp, len = ids[0];
-	/* Too big? */
-	if (len + n > ids[-1]) {
-		if (mdb_midl_grow(idp, n | MDB_IDL_UM_MAX))
-			return ENOMEM;
-		ids = *idp;
-	}
-	ids[0] = len + n;
-	ids += len;
-	while (n)
-		ids[n--] = id++;
-	return 0;
-}
-
-void mdb_midl_xmerge( MDB_IDL idl, MDB_IDL merge )
-{
-	MDB_ID old_id, merge_id, i = merge[0], j = idl[0], k = i+j, total = k;
-	idl[0] = (MDB_ID)-1;		/* delimiter for idl scan below */
-	old_id = idl[j];
-	while (i) {
-		merge_id = merge[i--];
-		for (; old_id < merge_id; old_id = idl[--j])
-			idl[k--] = old_id;
-		idl[k--] = merge_id;
-	}
-	idl[0] = total;
-}
-
-/* Quicksort + Insertion sort for small arrays */
-
-#define SMALL	8
-#define	MIDL_SWAP(a,b)	{ itmp=(a); (a)=(b); (b)=itmp; }
-
-void
-mdb_midl_sort( MDB_IDL ids )
-{
-	/* Max possible depth of int-indexed tree * 2 items/level */
-	int istack[sizeof(int)*CHAR_BIT * 2];
-	int i,j,k,l,ir,jstack;
-	MDB_ID a, itmp;
-
-	ir = (int)ids[0];
-	l = 1;
-	jstack = 0;
-	for(;;) {
-		if (ir - l < SMALL) {	/* Insertion sort */
-			for (j=l+1;j<=ir;j++) {
-				a = ids[j];
-				for (i=j-1;i>=1;i--) {
-					if (ids[i] >= a) break;
-					ids[i+1] = ids[i];
-				}
-				ids[i+1] = a;
-			}
-			if (jstack == 0) break;
-			ir = istack[jstack--];
-			l = istack[jstack--];
-		} else {
-			k = (l + ir) >> 1;	/* Choose median of left, center, right */
-			MIDL_SWAP(ids[k], ids[l+1]);
-			if (ids[l] < ids[ir]) {
-				MIDL_SWAP(ids[l], ids[ir]);
-			}
-			if (ids[l+1] < ids[ir]) {
-				MIDL_SWAP(ids[l+1], ids[ir]);
-			}
-			if (ids[l] < ids[l+1]) {
-				MIDL_SWAP(ids[l], ids[l+1]);
-			}
-			i = l+1;
-			j = ir;
-			a = ids[l+1];
-			for(;;) {
-				do i++; while(ids[i] > a);
-				do j--; while(ids[j] < a);
-				if (j < i) break;
-				MIDL_SWAP(ids[i],ids[j]);
-			}
-			ids[l+1] = ids[j];
-			ids[j] = a;
-			jstack += 2;
-			if (ir-i+1 >= j-l) {
-				istack[jstack] = ir;
-				istack[jstack-1] = i;
-				ir = j-1;
-			} else {
-				istack[jstack] = j-1;
-				istack[jstack-1] = l;
-				l = i;
-			}
-		}
-	}
-}
-
-unsigned mdb_mid2l_search( MDB_ID2L ids, MDB_ID id )
-{
-	/*
-	 * binary search of id in ids
-	 * if found, returns position of id
-	 * if not found, returns first position greater than id
-	 */
-	unsigned base = 0;
-	unsigned cursor = 1;
-	int val = 0;
-	unsigned n = (unsigned)ids[0].mid;
-
-	while( 0 < n ) {
-		unsigned pivot = n >> 1;
-		cursor = base + pivot + 1;
-		val = CMP( id, ids[cursor].mid );
-
-		if( val < 0 ) {
-			n = pivot;
-
-		} else if ( val > 0 ) {
-			base = cursor;
-			n -= pivot + 1;
-
-		} else {
-			return cursor;
-		}
-	}
-
-	if( val > 0 ) {
-		++cursor;
-	}
-	return cursor;
-}
-
-int mdb_mid2l_insert( MDB_ID2L ids, MDB_ID2 *id )
-{
-	unsigned x, i;
-
-	x = mdb_mid2l_search( ids, id->mid );
-
-	if( x < 1 ) {
-		/* internal error */
-		return -2;
-	}
-
-	if ( x <= ids[0].mid && ids[x].mid == id->mid ) {
-		/* duplicate */
-		return -1;
-	}
-
-	if ( ids[0].mid >= MDB_IDL_UM_MAX ) {
-		/* too big */
-		return -2;
-
-	} else {
-		/* insert id */
-		ids[0].mid++;
-		for (i=(unsigned)ids[0].mid; i>x; i--)
-			ids[i] = ids[i-1];
-		ids[x] = *id;
-	}
-
-	return 0;
-}
-
-int mdb_mid2l_append( MDB_ID2L ids, MDB_ID2 *id )
-{
-	/* Too big? */
-	if (ids[0].mid >= MDB_IDL_UM_MAX) {
-		return -2;
-	}
-	ids[0].mid++;
-	ids[ids[0].mid] = *id;
-	return 0;
-}
-
-/** @} */
-/** @} */
diff --git a/external/db_drivers/liblmdb32/mtest.c b/external/db_drivers/liblmdb32/mtest.c
deleted file mode 100644
index 0b53bc4d0..000000000
--- a/external/db_drivers/liblmdb32/mtest.c
+++ /dev/null
@@ -1,177 +0,0 @@
-/* mtest.c - memory-mapped database tester/toy */
-/*
- * Copyright 2011-2015 Howard Chu, Symas Corp.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted only as authorized by the OpenLDAP
- * Public License.
- *
- * A copy of this license is available in the file LICENSE in the
- * top-level directory of the distribution or, alternatively, at
- * <http://www.OpenLDAP.org/license.html>.
- */
-#include <stdio.h>
-#include <stdlib.h>
-#include <time.h>
-#include "lmdb.h"
-
-#define E(expr) CHECK((rc = (expr)) == MDB_SUCCESS, #expr)
-#define RES(err, expr) ((rc = expr) == (err) || (CHECK(!rc, #expr), 0))
-#define CHECK(test, msg) ((test) ? (void)0 : ((void)fprintf(stderr, \
-	"%s:%d: %s: %s\n", __FILE__, __LINE__, msg, mdb_strerror(rc)), abort()))
-
-int main(int argc,char * argv[])
-{
-	int i = 0, j = 0, rc;
-	MDB_env *env;
-	MDB_dbi dbi;
-	MDB_val key, data;
-	MDB_txn *txn;
-	MDB_stat mst;
-	MDB_cursor *cursor, *cur2;
-	MDB_cursor_op op;
-	int count;
-	int *values;
-	char sval[32] = "";
-
-	srand(time(NULL));
-
-	    count = (rand()%384) + 64;
-	    values = (int *)malloc(count*sizeof(int));
-
-	    for(i = 0;i<count;i++) {
-			values[i] = rand()%1024;
-	    }
-    
-		E(mdb_env_create(&env));
-		E(mdb_env_set_maxreaders(env, 1));
-		E(mdb_env_set_mapsize(env, 10485760));
-		E(mdb_env_open(env, "./testdb", 0 /* MDB_FIXEDMAP |MDB_NOSYNC*/, 0664));
-
-		E(mdb_txn_begin(env, NULL, 0, &txn));
-		E(mdb_dbi_open(txn, NULL, 0, &dbi));
-   
-		key.mv_size = sizeof(int);
-		key.mv_data = sval;
-
-		printf("Adding %d values\n", count);
-	    for (i=0;i<count;i++) {	
-			sprintf(sval, "%03x %d foo bar", values[i], values[i]);
-			/* Set <data> in each iteration, since MDB_NOOVERWRITE may modify it */
-			data.mv_size = sizeof(sval);
-			data.mv_data = sval;
-			if (RES(MDB_KEYEXIST, mdb_put(txn, dbi, &key, &data, MDB_NOOVERWRITE))) {
-				j++;
-				data.mv_size = sizeof(sval);
-				data.mv_data = sval;
-			}
-	    }
-		if (j) printf("%d duplicates skipped\n", j);
-		E(mdb_txn_commit(txn));
-		E(mdb_env_stat(env, &mst));
-
-		E(mdb_txn_begin(env, NULL, MDB_RDONLY, &txn));
-		E(mdb_cursor_open(txn, dbi, &cursor));
-		while ((rc = mdb_cursor_get(cursor, &key, &data, MDB_NEXT)) == 0) {
-			printf("key: %p %.*s, data: %p %.*s\n",
-				key.mv_data,  (int) key.mv_size,  (char *) key.mv_data,
-				data.mv_data, (int) data.mv_size, (char *) data.mv_data);
-		}
-		CHECK(rc == MDB_NOTFOUND, "mdb_cursor_get");
-		mdb_cursor_close(cursor);
-		mdb_txn_abort(txn);
-
-		j=0;
-		key.mv_data = sval;
-	    for (i= count - 1; i > -1; i-= (rand()%5)) {
-			j++;
-			txn=NULL;
-			E(mdb_txn_begin(env, NULL, 0, &txn));
-			sprintf(sval, "%03x ", values[i]);
-			if (RES(MDB_NOTFOUND, mdb_del(txn, dbi, &key, NULL))) {
-				j--;
-				mdb_txn_abort(txn);
-			} else {
-				E(mdb_txn_commit(txn));
-			}
-	    }
-	    free(values);
-		printf("Deleted %d values\n", j);
-
-		E(mdb_env_stat(env, &mst));
-		E(mdb_txn_begin(env, NULL, MDB_RDONLY, &txn));
-		E(mdb_cursor_open(txn, dbi, &cursor));
-		printf("Cursor next\n");
-		while ((rc = mdb_cursor_get(cursor, &key, &data, MDB_NEXT)) == 0) {
-			printf("key: %.*s, data: %.*s\n",
-				(int) key.mv_size,  (char *) key.mv_data,
-				(int) data.mv_size, (char *) data.mv_data);
-		}
-		CHECK(rc == MDB_NOTFOUND, "mdb_cursor_get");
-		printf("Cursor last\n");
-		E(mdb_cursor_get(cursor, &key, &data, MDB_LAST));
-		printf("key: %.*s, data: %.*s\n",
-			(int) key.mv_size,  (char *) key.mv_data,
-			(int) data.mv_size, (char *) data.mv_data);
-		printf("Cursor prev\n");
-		while ((rc = mdb_cursor_get(cursor, &key, &data, MDB_PREV)) == 0) {
-			printf("key: %.*s, data: %.*s\n",
-				(int) key.mv_size,  (char *) key.mv_data,
-				(int) data.mv_size, (char *) data.mv_data);
-		}
-		CHECK(rc == MDB_NOTFOUND, "mdb_cursor_get");
-		printf("Cursor last/prev\n");
-		E(mdb_cursor_get(cursor, &key, &data, MDB_LAST));
-			printf("key: %.*s, data: %.*s\n",
-				(int) key.mv_size,  (char *) key.mv_data,
-				(int) data.mv_size, (char *) data.mv_data);
-		E(mdb_cursor_get(cursor, &key, &data, MDB_PREV));
-			printf("key: %.*s, data: %.*s\n",
-				(int) key.mv_size,  (char *) key.mv_data,
-				(int) data.mv_size, (char *) data.mv_data);
-
-		mdb_cursor_close(cursor);
-		mdb_txn_abort(txn);
-
-		printf("Deleting with cursor\n");
-		E(mdb_txn_begin(env, NULL, 0, &txn));
-		E(mdb_cursor_open(txn, dbi, &cur2));
-		for (i=0; i<50; i++) {
-			if (RES(MDB_NOTFOUND, mdb_cursor_get(cur2, &key, &data, MDB_NEXT)))
-				break;
-			printf("key: %p %.*s, data: %p %.*s\n",
-				key.mv_data,  (int) key.mv_size,  (char *) key.mv_data,
-				data.mv_data, (int) data.mv_size, (char *) data.mv_data);
-			E(mdb_del(txn, dbi, &key, NULL));
-		}
-
-		printf("Restarting cursor in txn\n");
-		for (op=MDB_FIRST, i=0; i<=32; op=MDB_NEXT, i++) {
-			if (RES(MDB_NOTFOUND, mdb_cursor_get(cur2, &key, &data, op)))
-				break;
-			printf("key: %p %.*s, data: %p %.*s\n",
-				key.mv_data,  (int) key.mv_size,  (char *) key.mv_data,
-				data.mv_data, (int) data.mv_size, (char *) data.mv_data);
-		}
-		mdb_cursor_close(cur2);
-		E(mdb_txn_commit(txn));
-
-		printf("Restarting cursor outside txn\n");
-		E(mdb_txn_begin(env, NULL, 0, &txn));
-		E(mdb_cursor_open(txn, dbi, &cursor));
-		for (op=MDB_FIRST, i=0; i<=32; op=MDB_NEXT, i++) {
-			if (RES(MDB_NOTFOUND, mdb_cursor_get(cursor, &key, &data, op)))
-				break;
-			printf("key: %p %.*s, data: %p %.*s\n",
-				key.mv_data,  (int) key.mv_size,  (char *) key.mv_data,
-				data.mv_data, (int) data.mv_size, (char *) data.mv_data);
-		}
-		mdb_cursor_close(cursor);
-		mdb_txn_abort(txn);
-
-		mdb_dbi_close(env, dbi);
-		mdb_env_close(env);
-
-	return 0;
-}
diff --git a/external/db_drivers/liblmdb64/CMakeLists.txt b/external/db_drivers/liblmdb64/CMakeLists.txt
deleted file mode 100644
index bca7ff51e..000000000
--- a/external/db_drivers/liblmdb64/CMakeLists.txt
+++ /dev/null
@@ -1,43 +0,0 @@
-# Copyright (c) 2014-2015, The Monero Project
-# 
-# All rights reserved.
-# 
-# Redistribution and use in source and binary forms, with or without modification, are
-# permitted provided that the following conditions are met:
-# 
-# 1. Redistributions of source code must retain the above copyright notice, this list of
-#    conditions and the following disclaimer.
-# 
-# 2. Redistributions in binary form must reproduce the above copyright notice, this list
-#    of conditions and the following disclaimer in the documentation and/or other
-#    materials provided with the distribution.
-# 
-# 3. Neither the name of the copyright holder nor the names of its contributors may be
-#    used to endorse or promote products derived from this software without specific
-#    prior written permission.
-# 
-# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
-# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
-# MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
-# THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
-# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
-# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
-# STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
-# THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-if(FREEBSD)
-  set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -DMDB_DSYNC=O_SYNC")
-endif()
-
-set (lmdb_sources
-mdb.c
-midl.c)
-
-include_directories("${CMAKE_CURRENT_SOURCE_DIR}")
-
-add_library(lmdb
-  ${lmdb_sources})
-target_link_libraries(lmdb
-  LINK_PRIVATE
-    ${CMAKE_THREAD_LIBS_INIT})
diff --git a/external/db_drivers/liblmdb64/COPYRIGHT b/external/db_drivers/liblmdb64/COPYRIGHT
deleted file mode 100644
index 722d1a515..000000000
--- a/external/db_drivers/liblmdb64/COPYRIGHT
+++ /dev/null
@@ -1,20 +0,0 @@
-Copyright 2011-2015 Howard Chu, Symas Corp.
-All rights reserved.
-
-Redistribution and use in source and binary forms, with or without
-modification, are permitted only as authorized by the OpenLDAP
-Public License.
-
-A copy of this license is available in the file LICENSE in the
-top-level directory of the distribution or, alternatively, at
-<http://www.OpenLDAP.org/license.html>.
-
-OpenLDAP is a registered trademark of the OpenLDAP Foundation.
-
-Individual files and/or contributed packages may be copyright by
-other parties and/or subject to additional restrictions.
-
-This work also contains materials derived from public sources.
-
-Additional information about OpenLDAP can be obtained at
-<http://www.openldap.org/>.
diff --git a/external/db_drivers/liblmdb64/Doxyfile b/external/db_drivers/liblmdb64/Doxyfile
deleted file mode 100644
index 92d17b09e..000000000
--- a/external/db_drivers/liblmdb64/Doxyfile
+++ /dev/null
@@ -1,1631 +0,0 @@
-# Doxyfile 1.7.1
-
-# This file describes the settings to be used by the documentation system
-# doxygen (www.doxygen.org) for a project
-#
-# All text after a hash (#) is considered a comment and will be ignored
-# The format is:
-#       TAG = value [value, ...]
-# For lists items can also be appended using:
-#       TAG += value [value, ...]
-# Values that contain spaces should be placed between quotes (" ")
-
-#---------------------------------------------------------------------------
-# Project related configuration options
-#---------------------------------------------------------------------------
-
-# This tag specifies the encoding used for all characters in the config file
-# that follow. The default is UTF-8 which is also the encoding used for all
-# text before the first occurrence of this tag. Doxygen uses libiconv (or the
-# iconv built into libc) for the transcoding. See
-# http://www.gnu.org/software/libiconv for the list of possible encodings.
-
-DOXYFILE_ENCODING      = UTF-8
-
-# The PROJECT_NAME tag is a single word (or a sequence of words surrounded
-# by quotes) that should identify the project.
-
-PROJECT_NAME           = LMDB
-
-# The PROJECT_NUMBER tag can be used to enter a project or revision number.
-# This could be handy for archiving the generated documentation or
-# if some version control system is used.
-
-PROJECT_NUMBER         =
-
-# The OUTPUT_DIRECTORY tag is used to specify the (relative or absolute)
-# base path where the generated documentation will be put.
-# If a relative path is entered, it will be relative to the location
-# where doxygen was started. If left blank the current directory will be used.
-
-OUTPUT_DIRECTORY       =
-
-# If the CREATE_SUBDIRS tag is set to YES, then doxygen will create
-# 4096 sub-directories (in 2 levels) under the output directory of each output
-# format and will distribute the generated files over these directories.
-# Enabling this option can be useful when feeding doxygen a huge amount of
-# source files, where putting all generated files in the same directory would
-# otherwise cause performance problems for the file system.
-
-CREATE_SUBDIRS         = NO
-
-# The OUTPUT_LANGUAGE tag is used to specify the language in which all
-# documentation generated by doxygen is written. Doxygen will use this
-# information to generate all constant output in the proper language.
-# The default language is English, other supported languages are:
-# Afrikaans, Arabic, Brazilian, Catalan, Chinese, Chinese-Traditional,
-# Croatian, Czech, Danish, Dutch, Esperanto, Farsi, Finnish, French, German,
-# Greek, Hungarian, Italian, Japanese, Japanese-en (Japanese with English
-# messages), Korean, Korean-en, Lithuanian, Norwegian, Macedonian, Persian,
-# Polish, Portuguese, Romanian, Russian, Serbian, Serbian-Cyrilic, Slovak,
-# Slovene, Spanish, Swedish, Ukrainian, and Vietnamese.
-
-OUTPUT_LANGUAGE        = English
-
-# If the BRIEF_MEMBER_DESC tag is set to YES (the default) Doxygen will
-# include brief member descriptions after the members that are listed in
-# the file and class documentation (similar to JavaDoc).
-# Set to NO to disable this.
-
-BRIEF_MEMBER_DESC      = YES
-
-# If the REPEAT_BRIEF tag is set to YES (the default) Doxygen will prepend
-# the brief description of a member or function before the detailed description.
-# Note: if both HIDE_UNDOC_MEMBERS and BRIEF_MEMBER_DESC are set to NO, the
-# brief descriptions will be completely suppressed.
-
-REPEAT_BRIEF           = YES
-
-# This tag implements a quasi-intelligent brief description abbreviator
-# that is used to form the text in various listings. Each string
-# in this list, if found as the leading text of the brief description, will be
-# stripped from the text and the result after processing the whole list, is
-# used as the annotated text. Otherwise, the brief description is used as-is.
-# If left blank, the following values are used ("$name" is automatically
-# replaced with the name of the entity): "The $name class" "The $name widget"
-# "The $name file" "is" "provides" "specifies" "contains"
-# "represents" "a" "an" "the"
-
-ABBREVIATE_BRIEF       =
-
-# If the ALWAYS_DETAILED_SEC and REPEAT_BRIEF tags are both set to YES then
-# Doxygen will generate a detailed section even if there is only a brief
-# description.
-
-ALWAYS_DETAILED_SEC    = NO
-
-# If the INLINE_INHERITED_MEMB tag is set to YES, doxygen will show all
-# inherited members of a class in the documentation of that class as if those
-# members were ordinary class members. Constructors, destructors and assignment
-# operators of the base classes will not be shown.
-
-INLINE_INHERITED_MEMB  = NO
-
-# If the FULL_PATH_NAMES tag is set to YES then Doxygen will prepend the full
-# path before files name in the file list and in the header files. If set
-# to NO the shortest path that makes the file name unique will be used.
-
-FULL_PATH_NAMES        = YES
-
-# If the FULL_PATH_NAMES tag is set to YES then the STRIP_FROM_PATH tag
-# can be used to strip a user-defined part of the path. Stripping is
-# only done if one of the specified strings matches the left-hand part of
-# the path. The tag can be used to show relative paths in the file list.
-# If left blank the directory from which doxygen is run is used as the
-# path to strip.
-
-STRIP_FROM_PATH        =
-
-# The STRIP_FROM_INC_PATH tag can be used to strip a user-defined part of
-# the path mentioned in the documentation of a class, which tells
-# the reader which header file to include in order to use a class.
-# If left blank only the name of the header file containing the class
-# definition is used. Otherwise one should specify the include paths that
-# are normally passed to the compiler using the -I flag.
-
-STRIP_FROM_INC_PATH    =
-
-# If the SHORT_NAMES tag is set to YES, doxygen will generate much shorter
-# (but less readable) file names. This can be useful is your file systems
-# doesn't support long names like on DOS, Mac, or CD-ROM.
-
-SHORT_NAMES            = NO
-
-# If the JAVADOC_AUTOBRIEF tag is set to YES then Doxygen
-# will interpret the first line (until the first dot) of a JavaDoc-style
-# comment as the brief description. If set to NO, the JavaDoc
-# comments will behave just like regular Qt-style comments
-# (thus requiring an explicit @brief command for a brief description.)
-
-JAVADOC_AUTOBRIEF      = NO
-
-# If the QT_AUTOBRIEF tag is set to YES then Doxygen will
-# interpret the first line (until the first dot) of a Qt-style
-# comment as the brief description. If set to NO, the comments
-# will behave just like regular Qt-style comments (thus requiring
-# an explicit \brief command for a brief description.)
-
-QT_AUTOBRIEF           = NO
-
-# The MULTILINE_CPP_IS_BRIEF tag can be set to YES to make Doxygen
-# treat a multi-line C++ special comment block (i.e. a block of //! or ///
-# comments) as a brief description. This used to be the default behaviour.
-# The new default is to treat a multi-line C++ comment block as a detailed
-# description. Set this tag to YES if you prefer the old behaviour instead.
-
-MULTILINE_CPP_IS_BRIEF = NO
-
-# If the INHERIT_DOCS tag is set to YES (the default) then an undocumented
-# member inherits the documentation from any documented member that it
-# re-implements.
-
-INHERIT_DOCS           = YES
-
-# If the SEPARATE_MEMBER_PAGES tag is set to YES, then doxygen will produce
-# a new page for each member. If set to NO, the documentation of a member will
-# be part of the file/class/namespace that contains it.
-
-SEPARATE_MEMBER_PAGES  = NO
-
-# The TAB_SIZE tag can be used to set the number of spaces in a tab.
-# Doxygen uses this value to replace tabs by spaces in code fragments.
-
-TAB_SIZE               = 4
-
-# This tag can be used to specify a number of aliases that acts
-# as commands in the documentation. An alias has the form "name=value".
-# For example adding "sideeffect=\par Side Effects:\n" will allow you to
-# put the command \sideeffect (or @sideeffect) in the documentation, which
-# will result in a user-defined paragraph with heading "Side Effects:".
-# You can put \n's in the value part of an alias to insert newlines.
-
-ALIASES                =
-
-# Set the OPTIMIZE_OUTPUT_FOR_C tag to YES if your project consists of C
-# sources only. Doxygen will then generate output that is more tailored for C.
-# For instance, some of the names that are used will be different. The list
-# of all members will be omitted, etc.
-
-OPTIMIZE_OUTPUT_FOR_C  = YES
-
-# Set the OPTIMIZE_OUTPUT_JAVA tag to YES if your project consists of Java
-# sources only. Doxygen will then generate output that is more tailored for
-# Java. For instance, namespaces will be presented as packages, qualified
-# scopes will look different, etc.
-
-OPTIMIZE_OUTPUT_JAVA   = NO
-
-# Set the OPTIMIZE_FOR_FORTRAN tag to YES if your project consists of Fortran
-# sources only. Doxygen will then generate output that is more tailored for
-# Fortran.
-
-OPTIMIZE_FOR_FORTRAN   = NO
-
-# Set the OPTIMIZE_OUTPUT_VHDL tag to YES if your project consists of VHDL
-# sources. Doxygen will then generate output that is tailored for
-# VHDL.
-
-OPTIMIZE_OUTPUT_VHDL   = NO
-
-# Doxygen selects the parser to use depending on the extension of the files it
-# parses. With this tag you can assign which parser to use for a given extension.
-# Doxygen has a built-in mapping, but you can override or extend it using this
-# tag. The format is ext=language, where ext is a file extension, and language
-# is one of the parsers supported by doxygen: IDL, Java, Javascript, CSharp, C,
-# C++, D, PHP, Objective-C, Python, Fortran, VHDL, C, C++. For instance to make
-# doxygen treat .inc files as Fortran files (default is PHP), and .f files as C
-# (default is Fortran), use: inc=Fortran f=C. Note that for custom extensions
-# you also need to set FILE_PATTERNS otherwise the files are not read by doxygen.
-
-EXTENSION_MAPPING      =
-
-# If you use STL classes (i.e. std::string, std::vector, etc.) but do not want
-# to include (a tag file for) the STL sources as input, then you should
-# set this tag to YES in order to let doxygen match functions declarations and
-# definitions whose arguments contain STL classes (e.g. func(std::string); v.s.
-# func(std::string) {}). This also make the inheritance and collaboration
-# diagrams that involve STL classes more complete and accurate.
-
-BUILTIN_STL_SUPPORT    = NO
-
-# If you use Microsoft's C++/CLI language, you should set this option to YES to
-# enable parsing support.
-
-CPP_CLI_SUPPORT        = NO
-
-# Set the SIP_SUPPORT tag to YES if your project consists of sip sources only.
-# Doxygen will parse them like normal C++ but will assume all classes use public
-# instead of private inheritance when no explicit protection keyword is present.
-
-SIP_SUPPORT            = NO
-
-# For Microsoft's IDL there are propget and propput attributes to indicate getter
-# and setter methods for a property. Setting this option to YES (the default)
-# will make doxygen to replace the get and set methods by a property in the
-# documentation. This will only work if the methods are indeed getting or
-# setting a simple type. If this is not the case, or you want to show the
-# methods anyway, you should set this option to NO.
-
-IDL_PROPERTY_SUPPORT   = YES
-
-# If member grouping is used in the documentation and the DISTRIBUTE_GROUP_DOC
-# tag is set to YES, then doxygen will reuse the documentation of the first
-# member in the group (if any) for the other members of the group. By default
-# all members of a group must be documented explicitly.
-
-DISTRIBUTE_GROUP_DOC   = NO
-
-# Set the SUBGROUPING tag to YES (the default) to allow class member groups of
-# the same type (for instance a group of public functions) to be put as a
-# subgroup of that type (e.g. under the Public Functions section). Set it to
-# NO to prevent subgrouping. Alternatively, this can be done per class using
-# the \nosubgrouping command.
-
-SUBGROUPING            = YES
-
-INLINE_GROUPED_CLASSES = YES
-# When TYPEDEF_HIDES_STRUCT is enabled, a typedef of a struct, union, or enum
-# is documented as struct, union, or enum with the name of the typedef. So
-# typedef struct TypeS {} TypeT, will appear in the documentation as a struct
-# with name TypeT. When disabled the typedef will appear as a member of a file,
-# namespace, or class. And the struct will be named TypeS. This can typically
-# be useful for C code in case the coding convention dictates that all compound
-# types are typedef'ed and only the typedef is referenced, never the tag name.
-
-TYPEDEF_HIDES_STRUCT   = YES
-
-# The SYMBOL_CACHE_SIZE determines the size of the internal cache use to
-# determine which symbols to keep in memory and which to flush to disk.
-# When the cache is full, less often used symbols will be written to disk.
-# For small to medium size projects (<1000 input files) the default value is
-# probably good enough. For larger projects a too small cache size can cause
-# doxygen to be busy swapping symbols to and from disk most of the time
-# causing a significant performance penality.
-# If the system has enough physical memory increasing the cache will improve the
-# performance by keeping more symbols in memory. Note that the value works on
-# a logarithmic scale so increasing the size by one will rougly double the
-# memory usage. The cache size is given by this formula:
-# 2^(16+SYMBOL_CACHE_SIZE). The valid range is 0..9, the default is 0,
-# corresponding to a cache size of 2^16 = 65536 symbols
-
-SYMBOL_CACHE_SIZE      = 0
-
-#---------------------------------------------------------------------------
-# Build related configuration options
-#---------------------------------------------------------------------------
-
-# If the EXTRACT_ALL tag is set to YES doxygen will assume all entities in
-# documentation are documented, even if no documentation was available.
-# Private class members and static file members will be hidden unless
-# the EXTRACT_PRIVATE and EXTRACT_STATIC tags are set to YES
-
-EXTRACT_ALL            = NO
-
-# If the EXTRACT_PRIVATE tag is set to YES all private members of a class
-# will be included in the documentation.
-
-EXTRACT_PRIVATE        = NO
-
-# If the EXTRACT_STATIC tag is set to YES all static members of a file
-# will be included in the documentation.
-
-EXTRACT_STATIC         = YES
-
-# If the EXTRACT_LOCAL_CLASSES tag is set to YES classes (and structs)
-# defined locally in source files will be included in the documentation.
-# If set to NO only classes defined in header files are included.
-
-EXTRACT_LOCAL_CLASSES  = YES
-
-# This flag is only useful for Objective-C code. When set to YES local
-# methods, which are defined in the implementation section but not in
-# the interface are included in the documentation.
-# If set to NO (the default) only methods in the interface are included.
-
-EXTRACT_LOCAL_METHODS  = NO
-
-# If this flag is set to YES, the members of anonymous namespaces will be
-# extracted and appear in the documentation as a namespace called
-# 'anonymous_namespace{file}', where file will be replaced with the base
-# name of the file that contains the anonymous namespace. By default
-# anonymous namespace are hidden.
-
-EXTRACT_ANON_NSPACES   = NO
-
-# If the HIDE_UNDOC_MEMBERS tag is set to YES, Doxygen will hide all
-# undocumented members of documented classes, files or namespaces.
-# If set to NO (the default) these members will be included in the
-# various overviews, but no documentation section is generated.
-# This option has no effect if EXTRACT_ALL is enabled.
-
-HIDE_UNDOC_MEMBERS     = NO
-
-# If the HIDE_UNDOC_CLASSES tag is set to YES, Doxygen will hide all
-# undocumented classes that are normally visible in the class hierarchy.
-# If set to NO (the default) these classes will be included in the various
-# overviews. This option has no effect if EXTRACT_ALL is enabled.
-
-HIDE_UNDOC_CLASSES     = NO
-
-# If the HIDE_FRIEND_COMPOUNDS tag is set to YES, Doxygen will hide all
-# friend (class|struct|union) declarations.
-# If set to NO (the default) these declarations will be included in the
-# documentation.
-
-HIDE_FRIEND_COMPOUNDS  = NO
-
-# If the HIDE_IN_BODY_DOCS tag is set to YES, Doxygen will hide any
-# documentation blocks found inside the body of a function.
-# If set to NO (the default) these blocks will be appended to the
-# function's detailed documentation block.
-
-HIDE_IN_BODY_DOCS      = NO
-
-# The INTERNAL_DOCS tag determines if documentation
-# that is typed after a \internal command is included. If the tag is set
-# to NO (the default) then the documentation will be excluded.
-# Set it to YES to include the internal documentation.
-
-INTERNAL_DOCS          = NO
-
-# If the CASE_SENSE_NAMES tag is set to NO then Doxygen will only generate
-# file names in lower-case letters. If set to YES upper-case letters are also
-# allowed. This is useful if you have classes or files whose names only differ
-# in case and if your file system supports case sensitive file names. Windows
-# and Mac users are advised to set this option to NO.
-
-CASE_SENSE_NAMES       = YES
-
-# If the HIDE_SCOPE_NAMES tag is set to NO (the default) then Doxygen
-# will show members with their full class and namespace scopes in the
-# documentation. If set to YES the scope will be hidden.
-
-HIDE_SCOPE_NAMES       = NO
-
-# If the SHOW_INCLUDE_FILES tag is set to YES (the default) then Doxygen
-# will put a list of the files that are included by a file in the documentation
-# of that file.
-
-SHOW_INCLUDE_FILES     = YES
-
-# If the FORCE_LOCAL_INCLUDES tag is set to YES then Doxygen
-# will list include files with double quotes in the documentation
-# rather than with sharp brackets.
-
-FORCE_LOCAL_INCLUDES   = NO
-
-# If the INLINE_INFO tag is set to YES (the default) then a tag [inline]
-# is inserted in the documentation for inline members.
-
-INLINE_INFO            = YES
-
-# If the SORT_MEMBER_DOCS tag is set to YES (the default) then doxygen
-# will sort the (detailed) documentation of file and class members
-# alphabetically by member name. If set to NO the members will appear in
-# declaration order.
-
-SORT_MEMBER_DOCS       = NO
-
-# If the SORT_BRIEF_DOCS tag is set to YES then doxygen will sort the
-# brief documentation of file, namespace and class members alphabetically
-# by member name. If set to NO (the default) the members will appear in
-# declaration order.
-
-SORT_BRIEF_DOCS        = NO
-
-# If the SORT_MEMBERS_CTORS_1ST tag is set to YES then doxygen
-# will sort the (brief and detailed) documentation of class members so that
-# constructors and destructors are listed first. If set to NO (the default)
-# the constructors will appear in the respective orders defined by
-# SORT_MEMBER_DOCS and SORT_BRIEF_DOCS.
-# This tag will be ignored for brief docs if SORT_BRIEF_DOCS is set to NO
-# and ignored for detailed docs if SORT_MEMBER_DOCS is set to NO.
-
-SORT_MEMBERS_CTORS_1ST = NO
-
-# If the SORT_GROUP_NAMES tag is set to YES then doxygen will sort the
-# hierarchy of group names into alphabetical order. If set to NO (the default)
-# the group names will appear in their defined order.
-
-SORT_GROUP_NAMES       = NO
-
-# If the SORT_BY_SCOPE_NAME tag is set to YES, the class list will be
-# sorted by fully-qualified names, including namespaces. If set to
-# NO (the default), the class list will be sorted only by class name,
-# not including the namespace part.
-# Note: This option is not very useful if HIDE_SCOPE_NAMES is set to YES.
-# Note: This option applies only to the class list, not to the
-# alphabetical list.
-
-SORT_BY_SCOPE_NAME     = NO
-
-# The GENERATE_TODOLIST tag can be used to enable (YES) or
-# disable (NO) the todo list. This list is created by putting \todo
-# commands in the documentation.
-
-GENERATE_TODOLIST      = YES
-
-# The GENERATE_TESTLIST tag can be used to enable (YES) or
-# disable (NO) the test list. This list is created by putting \test
-# commands in the documentation.
-
-GENERATE_TESTLIST      = YES
-
-# The GENERATE_BUGLIST tag can be used to enable (YES) or
-# disable (NO) the bug list. This list is created by putting \bug
-# commands in the documentation.
-
-GENERATE_BUGLIST       = YES
-
-# The GENERATE_DEPRECATEDLIST tag can be used to enable (YES) or
-# disable (NO) the deprecated list. This list is created by putting
-# \deprecated commands in the documentation.
-
-GENERATE_DEPRECATEDLIST= YES
-
-# The ENABLED_SECTIONS tag can be used to enable conditional
-# documentation sections, marked by \if sectionname ... \endif.
-
-ENABLED_SECTIONS       =
-
-# The MAX_INITIALIZER_LINES tag determines the maximum number of lines
-# the initial value of a variable or define consists of for it to appear in
-# the documentation. If the initializer consists of more lines than specified
-# here it will be hidden. Use a value of 0 to hide initializers completely.
-# The appearance of the initializer of individual variables and defines in the
-# documentation can be controlled using \showinitializer or \hideinitializer
-# command in the documentation regardless of this setting.
-
-MAX_INITIALIZER_LINES  = 30
-
-# Set the SHOW_USED_FILES tag to NO to disable the list of files generated
-# at the bottom of the documentation of classes and structs. If set to YES the
-# list will mention the files that were used to generate the documentation.
-
-SHOW_USED_FILES        = YES
-
-# If the sources in your project are distributed over multiple directories
-# then setting the SHOW_DIRECTORIES tag to YES will show the directory hierarchy
-# in the documentation. The default is NO.
-
-SHOW_DIRECTORIES       = NO
-
-# Set the SHOW_FILES tag to NO to disable the generation of the Files page.
-# This will remove the Files entry from the Quick Index and from the
-# Folder Tree View (if specified). The default is YES.
-
-SHOW_FILES             = YES
-
-# Set the SHOW_NAMESPACES tag to NO to disable the generation of the
-# Namespaces page.
-# This will remove the Namespaces entry from the Quick Index
-# and from the Folder Tree View (if specified). The default is YES.
-
-SHOW_NAMESPACES        = YES
-
-# The FILE_VERSION_FILTER tag can be used to specify a program or script that
-# doxygen should invoke to get the current version for each file (typically from
-# the version control system). Doxygen will invoke the program by executing (via
-# popen()) the command <command> <input-file>, where <command> is the value of
-# the FILE_VERSION_FILTER tag, and <input-file> is the name of an input file
-# provided by doxygen. Whatever the program writes to standard output
-# is used as the file version. See the manual for examples.
-
-FILE_VERSION_FILTER    =
-
-# The LAYOUT_FILE tag can be used to specify a layout file which will be parsed
-# by doxygen. The layout file controls the global structure of the generated
-# output files in an output format independent way. The create the layout file
-# that represents doxygen's defaults, run doxygen with the -l option.
-# You can optionally specify a file name after the option, if omitted
-# DoxygenLayout.xml will be used as the name of the layout file.
-
-LAYOUT_FILE            =
-
-#---------------------------------------------------------------------------
-# configuration options related to warning and progress messages
-#---------------------------------------------------------------------------
-
-# The QUIET tag can be used to turn on/off the messages that are generated
-# by doxygen. Possible values are YES and NO. If left blank NO is used.
-
-QUIET                  = NO
-
-# The WARNINGS tag can be used to turn on/off the warning messages that are
-# generated by doxygen. Possible values are YES and NO. If left blank
-# NO is used.
-
-WARNINGS               = YES
-
-# If WARN_IF_UNDOCUMENTED is set to YES, then doxygen will generate warnings
-# for undocumented members. If EXTRACT_ALL is set to YES then this flag will
-# automatically be disabled.
-
-WARN_IF_UNDOCUMENTED   = YES
-
-# If WARN_IF_DOC_ERROR is set to YES, doxygen will generate warnings for
-# potential errors in the documentation, such as not documenting some
-# parameters in a documented function, or documenting parameters that
-# don't exist or using markup commands wrongly.
-
-WARN_IF_DOC_ERROR      = YES
-
-# This WARN_NO_PARAMDOC option can be abled to get warnings for
-# functions that are documented, but have no documentation for their parameters
-# or return value. If set to NO (the default) doxygen will only warn about
-# wrong or incomplete parameter documentation, but not about the absence of
-# documentation.
-
-WARN_NO_PARAMDOC       = NO
-
-# The WARN_FORMAT tag determines the format of the warning messages that
-# doxygen can produce. The string should contain the $file, $line, and $text
-# tags, which will be replaced by the file and line number from which the
-# warning originated and the warning text. Optionally the format may contain
-# $version, which will be replaced by the version of the file (if it could
-# be obtained via FILE_VERSION_FILTER)
-
-WARN_FORMAT            = "$file:$line: $text"
-
-# The WARN_LOGFILE tag can be used to specify a file to which warning
-# and error messages should be written. If left blank the output is written
-# to stderr.
-
-WARN_LOGFILE           =
-
-#---------------------------------------------------------------------------
-# configuration options related to the input files
-#---------------------------------------------------------------------------
-
-# The INPUT tag can be used to specify the files and/or directories that contain
-# documented source files. You may enter file names like "myfile.cpp" or
-# directories like "/usr/src/myproject". Separate the files or directories
-# with spaces.
-
-INPUT                  = lmdb.h midl.h mdb.c midl.c
-
-# This tag can be used to specify the character encoding of the source files
-# that doxygen parses. Internally doxygen uses the UTF-8 encoding, which is
-# also the default input encoding. Doxygen uses libiconv (or the iconv built
-# into libc) for the transcoding. See http://www.gnu.org/software/libiconv for
-# the list of possible encodings.
-
-INPUT_ENCODING         = UTF-8
-
-# If the value of the INPUT tag contains directories, you can use the
-# FILE_PATTERNS tag to specify one or more wildcard pattern (like *.cpp
-# and *.h) to filter out the source-files in the directories. If left
-# blank the following patterns are tested:
-# *.c *.cc *.cxx *.cpp *.c++ *.java *.ii *.ixx *.ipp *.i++ *.inl *.h *.hh *.hxx
-# *.hpp *.h++ *.idl *.odl *.cs *.php *.php3 *.inc *.m *.mm *.py *.f90
-
-FILE_PATTERNS          =
-
-# The RECURSIVE tag can be used to turn specify whether or not subdirectories
-# should be searched for input files as well. Possible values are YES and NO.
-# If left blank NO is used.
-
-RECURSIVE              = NO
-
-# The EXCLUDE tag can be used to specify files and/or directories that should
-# excluded from the INPUT source files. This way you can easily exclude a
-# subdirectory from a directory tree whose root is specified with the INPUT tag.
-
-EXCLUDE                =
-
-# The EXCLUDE_SYMLINKS tag can be used select whether or not files or
-# directories that are symbolic links (a Unix filesystem feature) are excluded
-# from the input.
-
-EXCLUDE_SYMLINKS       = NO
-
-# If the value of the INPUT tag contains directories, you can use the
-# EXCLUDE_PATTERNS tag to specify one or more wildcard patterns to exclude
-# certain files from those directories. Note that the wildcards are matched
-# against the file with absolute path, so to exclude all test directories
-# for example use the pattern */test/*
-
-EXCLUDE_PATTERNS       =
-
-# The EXCLUDE_SYMBOLS tag can be used to specify one or more symbol names
-# (namespaces, classes, functions, etc.) that should be excluded from the
-# output. The symbol name can be a fully qualified name, a word, or if the
-# wildcard * is used, a substring. Examples: ANamespace, AClass,
-# AClass::ANamespace, ANamespace::*Test
-
-EXCLUDE_SYMBOLS        =
-
-# The EXAMPLE_PATH tag can be used to specify one or more files or
-# directories that contain example code fragments that are included (see
-# the \include command).
-
-EXAMPLE_PATH           =
-
-# If the value of the EXAMPLE_PATH tag contains directories, you can use the
-# EXAMPLE_PATTERNS tag to specify one or more wildcard pattern (like *.cpp
-# and *.h) to filter out the source-files in the directories. If left
-# blank all files are included.
-
-EXAMPLE_PATTERNS       =
-
-# If the EXAMPLE_RECURSIVE tag is set to YES then subdirectories will be
-# searched for input files to be used with the \include or \dontinclude
-# commands irrespective of the value of the RECURSIVE tag.
-# Possible values are YES and NO. If left blank NO is used.
-
-EXAMPLE_RECURSIVE      = NO
-
-# The IMAGE_PATH tag can be used to specify one or more files or
-# directories that contain image that are included in the documentation (see
-# the \image command).
-
-IMAGE_PATH             =
-
-# The INPUT_FILTER tag can be used to specify a program that doxygen should
-# invoke to filter for each input file. Doxygen will invoke the filter program
-# by executing (via popen()) the command <filter> <input-file>, where <filter>
-# is the value of the INPUT_FILTER tag, and <input-file> is the name of an
-# input file. Doxygen will then use the output that the filter program writes
-# to standard output.
-# If FILTER_PATTERNS is specified, this tag will be
-# ignored.
-
-INPUT_FILTER           =
-
-# The FILTER_PATTERNS tag can be used to specify filters on a per file pattern
-# basis.
-# Doxygen will compare the file name with each pattern and apply the
-# filter if there is a match.
-# The filters are a list of the form:
-# pattern=filter (like *.cpp=my_cpp_filter). See INPUT_FILTER for further
-# info on how filters are used. If FILTER_PATTERNS is empty, INPUT_FILTER
-# is applied to all files.
-
-FILTER_PATTERNS        =
-
-# If the FILTER_SOURCE_FILES tag is set to YES, the input filter (if set using
-# INPUT_FILTER) will be used to filter the input files when producing source
-# files to browse (i.e. when SOURCE_BROWSER is set to YES).
-
-FILTER_SOURCE_FILES    = NO
-
-#---------------------------------------------------------------------------
-# configuration options related to source browsing
-#---------------------------------------------------------------------------
-
-# If the SOURCE_BROWSER tag is set to YES then a list of source files will
-# be generated. Documented entities will be cross-referenced with these sources.
-# Note: To get rid of all source code in the generated output, make sure also
-# VERBATIM_HEADERS is set to NO.
-
-SOURCE_BROWSER         = NO
-
-# Setting the INLINE_SOURCES tag to YES will include the body
-# of functions and classes directly in the documentation.
-
-INLINE_SOURCES         = NO
-
-# Setting the STRIP_CODE_COMMENTS tag to YES (the default) will instruct
-# doxygen to hide any special comment blocks from generated source code
-# fragments. Normal C and C++ comments will always remain visible.
-
-STRIP_CODE_COMMENTS    = YES
-
-# If the REFERENCED_BY_RELATION tag is set to YES
-# then for each documented function all documented
-# functions referencing it will be listed.
-
-REFERENCED_BY_RELATION = NO
-
-# If the REFERENCES_RELATION tag is set to YES
-# then for each documented function all documented entities
-# called/used by that function will be listed.
-
-REFERENCES_RELATION    = NO
-
-# If the REFERENCES_LINK_SOURCE tag is set to YES (the default)
-# and SOURCE_BROWSER tag is set to YES, then the hyperlinks from
-# functions in REFERENCES_RELATION and REFERENCED_BY_RELATION lists will
-# link to the source code.
-# Otherwise they will link to the documentation.
-
-REFERENCES_LINK_SOURCE = YES
-
-# If the USE_HTAGS tag is set to YES then the references to source code
-# will point to the HTML generated by the htags(1) tool instead of doxygen
-# built-in source browser. The htags tool is part of GNU's global source
-# tagging system (see http://www.gnu.org/software/global/global.html). You
-# will need version 4.8.6 or higher.
-
-USE_HTAGS              = NO
-
-# If the VERBATIM_HEADERS tag is set to YES (the default) then Doxygen
-# will generate a verbatim copy of the header file for each class for
-# which an include is specified. Set to NO to disable this.
-
-VERBATIM_HEADERS       = YES
-
-#---------------------------------------------------------------------------
-# configuration options related to the alphabetical class index
-#---------------------------------------------------------------------------
-
-# If the ALPHABETICAL_INDEX tag is set to YES, an alphabetical index
-# of all compounds will be generated. Enable this if the project
-# contains a lot of classes, structs, unions or interfaces.
-
-ALPHABETICAL_INDEX     = YES
-
-# If the alphabetical index is enabled (see ALPHABETICAL_INDEX) then
-# the COLS_IN_ALPHA_INDEX tag can be used to specify the number of columns
-# in which this list will be split (can be a number in the range [1..20])
-
-COLS_IN_ALPHA_INDEX    = 5
-
-# In case all classes in a project start with a common prefix, all
-# classes will be put under the same header in the alphabetical index.
-# The IGNORE_PREFIX tag can be used to specify one or more prefixes that
-# should be ignored while generating the index headers.
-
-IGNORE_PREFIX          =
-
-#---------------------------------------------------------------------------
-# configuration options related to the HTML output
-#---------------------------------------------------------------------------
-
-# If the GENERATE_HTML tag is set to YES (the default) Doxygen will
-# generate HTML output.
-
-GENERATE_HTML          = YES
-
-# The HTML_OUTPUT tag is used to specify where the HTML docs will be put.
-# If a relative path is entered the value of OUTPUT_DIRECTORY will be
-# put in front of it. If left blank `html' will be used as the default path.
-
-HTML_OUTPUT            = html
-
-# The HTML_FILE_EXTENSION tag can be used to specify the file extension for
-# each generated HTML page (for example: .htm,.php,.asp). If it is left blank
-# doxygen will generate files with .html extension.
-
-HTML_FILE_EXTENSION    = .html
-
-# The HTML_HEADER tag can be used to specify a personal HTML header for
-# each generated HTML page. If it is left blank doxygen will generate a
-# standard header.
-
-HTML_HEADER            =
-
-# The HTML_FOOTER tag can be used to specify a personal HTML footer for
-# each generated HTML page. If it is left blank doxygen will generate a
-# standard footer.
-
-HTML_FOOTER            =
-
-# The HTML_STYLESHEET tag can be used to specify a user-defined cascading
-# style sheet that is used by each HTML page. It can be used to
-# fine-tune the look of the HTML output. If the tag is left blank doxygen
-# will generate a default style sheet. Note that doxygen will try to copy
-# the style sheet file to the HTML output directory, so don't put your own
-# stylesheet in the HTML output directory as well, or it will be erased!
-
-HTML_STYLESHEET        =
-
-# The HTML_COLORSTYLE_HUE tag controls the color of the HTML output.
-# Doxygen will adjust the colors in the stylesheet and background images
-# according to this color. Hue is specified as an angle on a colorwheel,
-# see http://en.wikipedia.org/wiki/Hue for more information.
-# For instance the value 0 represents red, 60 is yellow, 120 is green,
-# 180 is cyan, 240 is blue, 300 purple, and 360 is red again.
-# The allowed range is 0 to 359.
-
-HTML_COLORSTYLE_HUE    = 220
-
-# The HTML_COLORSTYLE_SAT tag controls the purity (or saturation) of
-# the colors in the HTML output. For a value of 0 the output will use
-# grayscales only. A value of 255 will produce the most vivid colors.
-
-HTML_COLORSTYLE_SAT    = 100
-
-# The HTML_COLORSTYLE_GAMMA tag controls the gamma correction applied to
-# the luminance component of the colors in the HTML output. Values below
-# 100 gradually make the output lighter, whereas values above 100 make
-# the output darker. The value divided by 100 is the actual gamma applied,
-# so 80 represents a gamma of 0.8, The value 220 represents a gamma of 2.2,
-# and 100 does not change the gamma.
-
-HTML_COLORSTYLE_GAMMA  = 80
-
-# If the HTML_TIMESTAMP tag is set to YES then the footer of each generated HTML
-# page will contain the date and time when the page was generated. Setting
-# this to NO can help when comparing the output of multiple runs.
-
-HTML_TIMESTAMP         = YES
-
-# If the HTML_ALIGN_MEMBERS tag is set to YES, the members of classes,
-# files or namespaces will be aligned in HTML using tables. If set to
-# NO a bullet list will be used.
-
-HTML_ALIGN_MEMBERS     = YES
-
-# If the HTML_DYNAMIC_SECTIONS tag is set to YES then the generated HTML
-# documentation will contain sections that can be hidden and shown after the
-# page has loaded. For this to work a browser that supports
-# JavaScript and DHTML is required (for instance Mozilla 1.0+, Firefox
-# Netscape 6.0+, Internet explorer 5.0+, Konqueror, or Safari).
-
-HTML_DYNAMIC_SECTIONS  = NO
-
-# If the GENERATE_DOCSET tag is set to YES, additional index files
-# will be generated that can be used as input for Apple's Xcode 3
-# integrated development environment, introduced with OSX 10.5 (Leopard).
-# To create a documentation set, doxygen will generate a Makefile in the
-# HTML output directory. Running make will produce the docset in that
-# directory and running "make install" will install the docset in
-# ~/Library/Developer/Shared/Documentation/DocSets so that Xcode will find
-# it at startup.
-# See http://developer.apple.com/tools/creatingdocsetswithdoxygen.html
-# for more information.
-
-GENERATE_DOCSET        = NO
-
-# When GENERATE_DOCSET tag is set to YES, this tag determines the name of the
-# feed. A documentation feed provides an umbrella under which multiple
-# documentation sets from a single provider (such as a company or product suite)
-# can be grouped.
-
-DOCSET_FEEDNAME        = "Doxygen generated docs"
-
-# When GENERATE_DOCSET tag is set to YES, this tag specifies a string that
-# should uniquely identify the documentation set bundle. This should be a
-# reverse domain-name style string, e.g. com.mycompany.MyDocSet. Doxygen
-# will append .docset to the name.
-
-DOCSET_BUNDLE_ID       = org.doxygen.Project
-
-# When GENERATE_PUBLISHER_ID tag specifies a string that should uniquely identify
-# the documentation publisher. This should be a reverse domain-name style
-# string, e.g. com.mycompany.MyDocSet.documentation.
-
-DOCSET_PUBLISHER_ID    = org.doxygen.Publisher
-
-# The GENERATE_PUBLISHER_NAME tag identifies the documentation publisher.
-
-DOCSET_PUBLISHER_NAME  = Publisher
-
-# If the GENERATE_HTMLHELP tag is set to YES, additional index files
-# will be generated that can be used as input for tools like the
-# Microsoft HTML help workshop to generate a compiled HTML help file (.chm)
-# of the generated HTML documentation.
-
-GENERATE_HTMLHELP      = NO
-
-# If the GENERATE_HTMLHELP tag is set to YES, the CHM_FILE tag can
-# be used to specify the file name of the resulting .chm file. You
-# can add a path in front of the file if the result should not be
-# written to the html output directory.
-
-CHM_FILE               =
-
-# If the GENERATE_HTMLHELP tag is set to YES, the HHC_LOCATION tag can
-# be used to specify the location (absolute path including file name) of
-# the HTML help compiler (hhc.exe). If non-empty doxygen will try to run
-# the HTML help compiler on the generated index.hhp.
-
-HHC_LOCATION           =
-
-# If the GENERATE_HTMLHELP tag is set to YES, the GENERATE_CHI flag
-# controls if a separate .chi index file is generated (YES) or that
-# it should be included in the master .chm file (NO).
-
-GENERATE_CHI           = NO
-
-# If the GENERATE_HTMLHELP tag is set to YES, the CHM_INDEX_ENCODING
-# is used to encode HtmlHelp index (hhk), content (hhc) and project file
-# content.
-
-CHM_INDEX_ENCODING     =
-
-# If the GENERATE_HTMLHELP tag is set to YES, the BINARY_TOC flag
-# controls whether a binary table of contents is generated (YES) or a
-# normal table of contents (NO) in the .chm file.
-
-BINARY_TOC             = NO
-
-# The TOC_EXPAND flag can be set to YES to add extra items for group members
-# to the contents of the HTML help documentation and to the tree view.
-
-TOC_EXPAND             = NO
-
-# If the GENERATE_QHP tag is set to YES and both QHP_NAMESPACE and
-# QHP_VIRTUAL_FOLDER are set, an additional index file will be generated
-# that can be used as input for Qt's qhelpgenerator to generate a
-# Qt Compressed Help (.qch) of the generated HTML documentation.
-
-GENERATE_QHP           = NO
-
-# If the QHG_LOCATION tag is specified, the QCH_FILE tag can
-# be used to specify the file name of the resulting .qch file.
-# The path specified is relative to the HTML output folder.
-
-QCH_FILE               =
-
-# The QHP_NAMESPACE tag specifies the namespace to use when generating
-# Qt Help Project output. For more information please see
-# http://doc.trolltech.com/qthelpproject.html#namespace
-
-QHP_NAMESPACE          = org.doxygen.Project
-
-# The QHP_VIRTUAL_FOLDER tag specifies the namespace to use when generating
-# Qt Help Project output. For more information please see
-# http://doc.trolltech.com/qthelpproject.html#virtual-folders
-
-QHP_VIRTUAL_FOLDER     = doc
-
-# If QHP_CUST_FILTER_NAME is set, it specifies the name of a custom filter to
-# add. For more information please see
-# http://doc.trolltech.com/qthelpproject.html#custom-filters
-
-QHP_CUST_FILTER_NAME   =
-
-# The QHP_CUST_FILT_ATTRS tag specifies the list of the attributes of the
-# custom filter to add. For more information please see
-# <a href="http://doc.trolltech.com/qthelpproject.html#custom-filters">
-# Qt Help Project / Custom Filters</a>.
-
-QHP_CUST_FILTER_ATTRS  =
-
-# The QHP_SECT_FILTER_ATTRS tag specifies the list of the attributes this
-# project's
-# filter section matches.
-# <a href="http://doc.trolltech.com/qthelpproject.html#filter-attributes">
-# Qt Help Project / Filter Attributes</a>.
-
-QHP_SECT_FILTER_ATTRS  =
-
-# If the GENERATE_QHP tag is set to YES, the QHG_LOCATION tag can
-# be used to specify the location of Qt's qhelpgenerator.
-# If non-empty doxygen will try to run qhelpgenerator on the generated
-# .qhp file.
-
-QHG_LOCATION           =
-
-# If the GENERATE_ECLIPSEHELP tag is set to YES, additional index files
-#  will be generated, which together with the HTML files, form an Eclipse help
-# plugin. To install this plugin and make it available under the help contents
-# menu in Eclipse, the contents of the directory containing the HTML and XML
-# files needs to be copied into the plugins directory of eclipse. The name of
-# the directory within the plugins directory should be the same as
-# the ECLIPSE_DOC_ID value. After copying Eclipse needs to be restarted before
-# the help appears.
-
-GENERATE_ECLIPSEHELP   = NO
-
-# A unique identifier for the eclipse help plugin. When installing the plugin
-# the directory name containing the HTML and XML files should also have
-# this name.
-
-ECLIPSE_DOC_ID         = org.doxygen.Project
-
-# The DISABLE_INDEX tag can be used to turn on/off the condensed index at
-# top of each HTML page. The value NO (the default) enables the index and
-# the value YES disables it.
-
-DISABLE_INDEX          = NO
-
-# This tag can be used to set the number of enum values (range [1..20])
-# that doxygen will group on one line in the generated HTML documentation.
-
-ENUM_VALUES_PER_LINE   = 4
-
-# The GENERATE_TREEVIEW tag is used to specify whether a tree-like index
-# structure should be generated to display hierarchical information.
-# If the tag value is set to YES, a side panel will be generated
-# containing a tree-like index structure (just like the one that
-# is generated for HTML Help). For this to work a browser that supports
-# JavaScript, DHTML, CSS and frames is required (i.e. any modern browser).
-# Windows users are probably better off using the HTML help feature.
-
-GENERATE_TREEVIEW      = NO
-
-# By enabling USE_INLINE_TREES, doxygen will generate the Groups, Directories,
-# and Class Hierarchy pages using a tree view instead of an ordered list.
-
-USE_INLINE_TREES       = NO
-
-# If the treeview is enabled (see GENERATE_TREEVIEW) then this tag can be
-# used to set the initial width (in pixels) of the frame in which the tree
-# is shown.
-
-TREEVIEW_WIDTH         = 250
-
-# When the EXT_LINKS_IN_WINDOW option is set to YES doxygen will open
-# links to external symbols imported via tag files in a separate window.
-
-EXT_LINKS_IN_WINDOW    = NO
-
-# Use this tag to change the font size of Latex formulas included
-# as images in the HTML documentation. The default is 10. Note that
-# when you change the font size after a successful doxygen run you need
-# to manually remove any form_*.png images from the HTML output directory
-# to force them to be regenerated.
-
-FORMULA_FONTSIZE       = 10
-
-# Use the FORMULA_TRANPARENT tag to determine whether or not the images
-# generated for formulas are transparent PNGs. Transparent PNGs are
-# not supported properly for IE 6.0, but are supported on all modern browsers.
-# Note that when changing this option you need to delete any form_*.png files
-# in the HTML output before the changes have effect.
-
-FORMULA_TRANSPARENT    = YES
-
-# When the SEARCHENGINE tag is enabled doxygen will generate a search box
-# for the HTML output. The underlying search engine uses javascript
-# and DHTML and should work on any modern browser. Note that when using
-# HTML help (GENERATE_HTMLHELP), Qt help (GENERATE_QHP), or docsets
-# (GENERATE_DOCSET) there is already a search function so this one should
-# typically be disabled. For large projects the javascript based search engine
-# can be slow, then enabling SERVER_BASED_SEARCH may provide a better solution.
-
-SEARCHENGINE           = YES
-
-# When the SERVER_BASED_SEARCH tag is enabled the search engine will be
-# implemented using a PHP enabled web server instead of at the web client
-# using Javascript. Doxygen will generate the search PHP script and index
-# file to put on the web server. The advantage of the server
-# based approach is that it scales better to large projects and allows
-# full text search. The disadvances is that it is more difficult to setup
-# and does not have live searching capabilities.
-
-SERVER_BASED_SEARCH    = NO
-
-#---------------------------------------------------------------------------
-# configuration options related to the LaTeX output
-#---------------------------------------------------------------------------
-
-# If the GENERATE_LATEX tag is set to YES (the default) Doxygen will
-# generate Latex output.
-
-GENERATE_LATEX         = NO
-
-# The LATEX_OUTPUT tag is used to specify where the LaTeX docs will be put.
-# If a relative path is entered the value of OUTPUT_DIRECTORY will be
-# put in front of it. If left blank `latex' will be used as the default path.
-
-LATEX_OUTPUT           = latex
-
-# The LATEX_CMD_NAME tag can be used to specify the LaTeX command name to be
-# invoked. If left blank `latex' will be used as the default command name.
-# Note that when enabling USE_PDFLATEX this option is only used for
-# generating bitmaps for formulas in the HTML output, but not in the
-# Makefile that is written to the output directory.
-
-LATEX_CMD_NAME         = latex
-
-# The MAKEINDEX_CMD_NAME tag can be used to specify the command name to
-# generate index for LaTeX. If left blank `makeindex' will be used as the
-# default command name.
-
-MAKEINDEX_CMD_NAME     = makeindex
-
-# If the COMPACT_LATEX tag is set to YES Doxygen generates more compact
-# LaTeX documents. This may be useful for small projects and may help to
-# save some trees in general.
-
-COMPACT_LATEX          = NO
-
-# The PAPER_TYPE tag can be used to set the paper type that is used
-# by the printer. Possible values are: a4, a4wide, letter, legal and
-# executive. If left blank a4wide will be used.
-
-PAPER_TYPE             = a4wide
-
-# The EXTRA_PACKAGES tag can be to specify one or more names of LaTeX
-# packages that should be included in the LaTeX output.
-
-EXTRA_PACKAGES         =
-
-# The LATEX_HEADER tag can be used to specify a personal LaTeX header for
-# the generated latex document. The header should contain everything until
-# the first chapter. If it is left blank doxygen will generate a
-# standard header. Notice: only use this tag if you know what you are doing!
-
-LATEX_HEADER           =
-
-# If the PDF_HYPERLINKS tag is set to YES, the LaTeX that is generated
-# is prepared for conversion to pdf (using ps2pdf). The pdf file will
-# contain links (just like the HTML output) instead of page references
-# This makes the output suitable for online browsing using a pdf viewer.
-
-PDF_HYPERLINKS         = YES
-
-# If the USE_PDFLATEX tag is set to YES, pdflatex will be used instead of
-# plain latex in the generated Makefile. Set this option to YES to get a
-# higher quality PDF documentation.
-
-USE_PDFLATEX           = YES
-
-# If the LATEX_BATCHMODE tag is set to YES, doxygen will add the \\batchmode.
-# command to the generated LaTeX files. This will instruct LaTeX to keep
-# running if errors occur, instead of asking the user for help.
-# This option is also used when generating formulas in HTML.
-
-LATEX_BATCHMODE        = NO
-
-# If LATEX_HIDE_INDICES is set to YES then doxygen will not
-# include the index chapters (such as File Index, Compound Index, etc.)
-# in the output.
-
-LATEX_HIDE_INDICES     = NO
-
-# If LATEX_SOURCE_CODE is set to YES then doxygen will include
-# source code with syntax highlighting in the LaTeX output.
-# Note that which sources are shown also depends on other settings
-# such as SOURCE_BROWSER.
-
-LATEX_SOURCE_CODE      = NO
-
-#---------------------------------------------------------------------------
-# configuration options related to the RTF output
-#---------------------------------------------------------------------------
-
-# If the GENERATE_RTF tag is set to YES Doxygen will generate RTF output
-# The RTF output is optimized for Word 97 and may not look very pretty with
-# other RTF readers or editors.
-
-GENERATE_RTF           = NO
-
-# The RTF_OUTPUT tag is used to specify where the RTF docs will be put.
-# If a relative path is entered the value of OUTPUT_DIRECTORY will be
-# put in front of it. If left blank `rtf' will be used as the default path.
-
-RTF_OUTPUT             = rtf
-
-# If the COMPACT_RTF tag is set to YES Doxygen generates more compact
-# RTF documents. This may be useful for small projects and may help to
-# save some trees in general.
-
-COMPACT_RTF            = NO
-
-# If the RTF_HYPERLINKS tag is set to YES, the RTF that is generated
-# will contain hyperlink fields. The RTF file will
-# contain links (just like the HTML output) instead of page references.
-# This makes the output suitable for online browsing using WORD or other
-# programs which support those fields.
-# Note: wordpad (write) and others do not support links.
-
-RTF_HYPERLINKS         = NO
-
-# Load stylesheet definitions from file. Syntax is similar to doxygen's
-# config file, i.e. a series of assignments. You only have to provide
-# replacements, missing definitions are set to their default value.
-
-RTF_STYLESHEET_FILE    =
-
-# Set optional variables used in the generation of an rtf document.
-# Syntax is similar to doxygen's config file.
-
-RTF_EXTENSIONS_FILE    =
-
-#---------------------------------------------------------------------------
-# configuration options related to the man page output
-#---------------------------------------------------------------------------
-
-# If the GENERATE_MAN tag is set to YES (the default) Doxygen will
-# generate man pages
-
-GENERATE_MAN           = YES
-
-# The MAN_OUTPUT tag is used to specify where the man pages will be put.
-# If a relative path is entered the value of OUTPUT_DIRECTORY will be
-# put in front of it. If left blank `man' will be used as the default path.
-
-MAN_OUTPUT             = man
-
-# The MAN_EXTENSION tag determines the extension that is added to
-# the generated man pages (default is the subroutine's section .3)
-
-MAN_EXTENSION          = .3
-
-# If the MAN_LINKS tag is set to YES and Doxygen generates man output,
-# then it will generate one additional man file for each entity
-# documented in the real man page(s). These additional files
-# only source the real man page, but without them the man command
-# would be unable to find the correct page. The default is NO.
-
-MAN_LINKS              = NO
-
-#---------------------------------------------------------------------------
-# configuration options related to the XML output
-#---------------------------------------------------------------------------
-
-# If the GENERATE_XML tag is set to YES Doxygen will
-# generate an XML file that captures the structure of
-# the code including all documentation.
-
-GENERATE_XML           = NO
-
-# The XML_OUTPUT tag is used to specify where the XML pages will be put.
-# If a relative path is entered the value of OUTPUT_DIRECTORY will be
-# put in front of it. If left blank `xml' will be used as the default path.
-
-XML_OUTPUT             = xml
-
-# The XML_SCHEMA tag can be used to specify an XML schema,
-# which can be used by a validating XML parser to check the
-# syntax of the XML files.
-
-XML_SCHEMA             =
-
-# The XML_DTD tag can be used to specify an XML DTD,
-# which can be used by a validating XML parser to check the
-# syntax of the XML files.
-
-XML_DTD                =
-
-# If the XML_PROGRAMLISTING tag is set to YES Doxygen will
-# dump the program listings (including syntax highlighting
-# and cross-referencing information) to the XML output. Note that
-# enabling this will significantly increase the size of the XML output.
-
-XML_PROGRAMLISTING     = YES
-
-#---------------------------------------------------------------------------
-# configuration options for the AutoGen Definitions output
-#---------------------------------------------------------------------------
-
-# If the GENERATE_AUTOGEN_DEF tag is set to YES Doxygen will
-# generate an AutoGen Definitions (see autogen.sf.net) file
-# that captures the structure of the code including all
-# documentation. Note that this feature is still experimental
-# and incomplete at the moment.
-
-GENERATE_AUTOGEN_DEF   = NO
-
-#---------------------------------------------------------------------------
-# configuration options related to the Perl module output
-#---------------------------------------------------------------------------
-
-# If the GENERATE_PERLMOD tag is set to YES Doxygen will
-# generate a Perl module file that captures the structure of
-# the code including all documentation. Note that this
-# feature is still experimental and incomplete at the
-# moment.
-
-GENERATE_PERLMOD       = NO
-
-# If the PERLMOD_LATEX tag is set to YES Doxygen will generate
-# the necessary Makefile rules, Perl scripts and LaTeX code to be able
-# to generate PDF and DVI output from the Perl module output.
-
-PERLMOD_LATEX          = NO
-
-# If the PERLMOD_PRETTY tag is set to YES the Perl module output will be
-# nicely formatted so it can be parsed by a human reader.
-# This is useful
-# if you want to understand what is going on.
-# On the other hand, if this
-# tag is set to NO the size of the Perl module output will be much smaller
-# and Perl will parse it just the same.
-
-PERLMOD_PRETTY         = YES
-
-# The names of the make variables in the generated doxyrules.make file
-# are prefixed with the string contained in PERLMOD_MAKEVAR_PREFIX.
-# This is useful so different doxyrules.make files included by the same
-# Makefile don't overwrite each other's variables.
-
-PERLMOD_MAKEVAR_PREFIX =
-
-#---------------------------------------------------------------------------
-# Configuration options related to the preprocessor
-#---------------------------------------------------------------------------
-
-# If the ENABLE_PREPROCESSING tag is set to YES (the default) Doxygen will
-# evaluate all C-preprocessor directives found in the sources and include
-# files.
-
-ENABLE_PREPROCESSING   = YES
-
-# If the MACRO_EXPANSION tag is set to YES Doxygen will expand all macro
-# names in the source code. If set to NO (the default) only conditional
-# compilation will be performed. Macro expansion can be done in a controlled
-# way by setting EXPAND_ONLY_PREDEF to YES.
-
-MACRO_EXPANSION        = NO
-
-# If the EXPAND_ONLY_PREDEF and MACRO_EXPANSION tags are both set to YES
-# then the macro expansion is limited to the macros specified with the
-# PREDEFINED and EXPAND_AS_DEFINED tags.
-
-EXPAND_ONLY_PREDEF     = NO
-
-# If the SEARCH_INCLUDES tag is set to YES (the default) the includes files
-# in the INCLUDE_PATH (see below) will be search if a #include is found.
-
-SEARCH_INCLUDES        = YES
-
-# The INCLUDE_PATH tag can be used to specify one or more directories that
-# contain include files that are not input files but should be processed by
-# the preprocessor.
-
-INCLUDE_PATH           =
-
-# You can use the INCLUDE_FILE_PATTERNS tag to specify one or more wildcard
-# patterns (like *.h and *.hpp) to filter out the header-files in the
-# directories. If left blank, the patterns specified with FILE_PATTERNS will
-# be used.
-
-INCLUDE_FILE_PATTERNS  =
-
-# The PREDEFINED tag can be used to specify one or more macro names that
-# are defined before the preprocessor is started (similar to the -D option of
-# gcc). The argument of the tag is a list of macros of the form: name
-# or name=definition (no spaces). If the definition and the = are
-# omitted =1 is assumed. To prevent a macro definition from being
-# undefined via #undef or recursively expanded use the := operator
-# instead of the = operator.
-
-PREDEFINED             = DEBUG=2 __GNUC__=1
-
-# If the MACRO_EXPANSION and EXPAND_ONLY_PREDEF tags are set to YES then
-# this tag can be used to specify a list of macro names that should be expanded.
-# The macro definition that is found in the sources will be used.
-# Use the PREDEFINED tag if you want to use a different macro definition.
-
-EXPAND_AS_DEFINED      =
-
-# If the SKIP_FUNCTION_MACROS tag is set to YES (the default) then
-# doxygen's preprocessor will remove all function-like macros that are alone
-# on a line, have an all uppercase name, and do not end with a semicolon. Such
-# function macros are typically used for boiler-plate code, and will confuse
-# the parser if not removed.
-
-SKIP_FUNCTION_MACROS   = YES
-
-#---------------------------------------------------------------------------
-# Configuration::additions related to external references
-#---------------------------------------------------------------------------
-
-# The TAGFILES option can be used to specify one or more tagfiles.
-# Optionally an initial location of the external documentation
-# can be added for each tagfile. The format of a tag file without
-# this location is as follows:
-#
-# TAGFILES = file1 file2 ...
-# Adding location for the tag files is done as follows:
-#
-# TAGFILES = file1=loc1 "file2 = loc2" ...
-# where "loc1" and "loc2" can be relative or absolute paths or
-# URLs. If a location is present for each tag, the installdox tool
-# does not have to be run to correct the links.
-# Note that each tag file must have a unique name
-# (where the name does NOT include the path)
-# If a tag file is not located in the directory in which doxygen
-# is run, you must also specify the path to the tagfile here.
-
-TAGFILES               = tooltag=./man1
-
-# When a file name is specified after GENERATE_TAGFILE, doxygen will create
-# a tag file that is based on the input files it reads.
-
-GENERATE_TAGFILE       =
-
-# If the ALLEXTERNALS tag is set to YES all external classes will be listed
-# in the class index. If set to NO only the inherited external classes
-# will be listed.
-
-ALLEXTERNALS           = NO
-
-# If the EXTERNAL_GROUPS tag is set to YES all external groups will be listed
-# in the modules index. If set to NO, only the current project's groups will
-# be listed.
-
-EXTERNAL_GROUPS        = YES
-
-# The PERL_PATH should be the absolute path and name of the perl script
-# interpreter (i.e. the result of `which perl').
-
-PERL_PATH              = /usr/bin/perl
-
-#---------------------------------------------------------------------------
-# Configuration options related to the dot tool
-#---------------------------------------------------------------------------
-
-# If the CLASS_DIAGRAMS tag is set to YES (the default) Doxygen will
-# generate a inheritance diagram (in HTML, RTF and LaTeX) for classes with base
-# or super classes. Setting the tag to NO turns the diagrams off. Note that
-# this option is superseded by the HAVE_DOT option below. This is only a
-# fallback. It is recommended to install and use dot, since it yields more
-# powerful graphs.
-
-CLASS_DIAGRAMS         = YES
-
-# You can define message sequence charts within doxygen comments using the \msc
-# command. Doxygen will then run the mscgen tool (see
-# http://www.mcternan.me.uk/mscgen/) to produce the chart and insert it in the
-# documentation. The MSCGEN_PATH tag allows you to specify the directory where
-# the mscgen tool resides. If left empty the tool is assumed to be found in the
-# default search path.
-
-MSCGEN_PATH            =
-
-# If set to YES, the inheritance and collaboration graphs will hide
-# inheritance and usage relations if the target is undocumented
-# or is not a class.
-
-HIDE_UNDOC_RELATIONS   = YES
-
-# If you set the HAVE_DOT tag to YES then doxygen will assume the dot tool is
-# available from the path. This tool is part of Graphviz, a graph visualization
-# toolkit from AT&T and Lucent Bell Labs. The other options in this section
-# have no effect if this option is set to NO (the default)
-
-HAVE_DOT               = NO
-
-# The DOT_NUM_THREADS specifies the number of dot invocations doxygen is
-# allowed to run in parallel. When set to 0 (the default) doxygen will
-# base this on the number of processors available in the system. You can set it
-# explicitly to a value larger than 0 to get control over the balance
-# between CPU load and processing speed.
-
-DOT_NUM_THREADS        = 0
-
-# By default doxygen will write a font called FreeSans.ttf to the output
-# directory and reference it in all dot files that doxygen generates. This
-# font does not include all possible unicode characters however, so when you need
-# these (or just want a differently looking font) you can specify the font name
-# using DOT_FONTNAME. You need need to make sure dot is able to find the font,
-# which can be done by putting it in a standard location or by setting the
-# DOTFONTPATH environment variable or by setting DOT_FONTPATH to the directory
-# containing the font.
-
-DOT_FONTNAME           = FreeSans.ttf
-
-# The DOT_FONTSIZE tag can be used to set the size of the font of dot graphs.
-# The default size is 10pt.
-
-DOT_FONTSIZE           = 10
-
-# By default doxygen will tell dot to use the output directory to look for the
-# FreeSans.ttf font (which doxygen will put there itself). If you specify a
-# different font using DOT_FONTNAME you can set the path where dot
-# can find it using this tag.
-
-DOT_FONTPATH           =
-
-# If the CLASS_GRAPH and HAVE_DOT tags are set to YES then doxygen
-# will generate a graph for each documented class showing the direct and
-# indirect inheritance relations. Setting this tag to YES will force the
-# the CLASS_DIAGRAMS tag to NO.
-
-CLASS_GRAPH            = YES
-
-# If the COLLABORATION_GRAPH and HAVE_DOT tags are set to YES then doxygen
-# will generate a graph for each documented class showing the direct and
-# indirect implementation dependencies (inheritance, containment, and
-# class references variables) of the class with other documented classes.
-
-COLLABORATION_GRAPH    = YES
-
-# If the GROUP_GRAPHS and HAVE_DOT tags are set to YES then doxygen
-# will generate a graph for groups, showing the direct groups dependencies
-
-GROUP_GRAPHS           = YES
-
-# If the UML_LOOK tag is set to YES doxygen will generate inheritance and
-# collaboration diagrams in a style similar to the OMG's Unified Modeling
-# Language.
-
-UML_LOOK               = NO
-
-# If set to YES, the inheritance and collaboration graphs will show the
-# relations between templates and their instances.
-
-TEMPLATE_RELATIONS     = NO
-
-# If the ENABLE_PREPROCESSING, SEARCH_INCLUDES, INCLUDE_GRAPH, and HAVE_DOT
-# tags are set to YES then doxygen will generate a graph for each documented
-# file showing the direct and indirect include dependencies of the file with
-# other documented files.
-
-INCLUDE_GRAPH          = YES
-
-# If the ENABLE_PREPROCESSING, SEARCH_INCLUDES, INCLUDED_BY_GRAPH, and
-# HAVE_DOT tags are set to YES then doxygen will generate a graph for each
-# documented header file showing the documented files that directly or
-# indirectly include this file.
-
-INCLUDED_BY_GRAPH      = YES
-
-# If the CALL_GRAPH and HAVE_DOT options are set to YES then
-# doxygen will generate a call dependency graph for every global function
-# or class method. Note that enabling this option will significantly increase
-# the time of a run. So in most cases it will be better to enable call graphs
-# for selected functions only using the \callgraph command.
-
-CALL_GRAPH             = NO
-
-# If the CALLER_GRAPH and HAVE_DOT tags are set to YES then
-# doxygen will generate a caller dependency graph for every global function
-# or class method. Note that enabling this option will significantly increase
-# the time of a run. So in most cases it will be better to enable caller
-# graphs for selected functions only using the \callergraph command.
-
-CALLER_GRAPH           = NO
-
-# If the GRAPHICAL_HIERARCHY and HAVE_DOT tags are set to YES then doxygen
-# will graphical hierarchy of all classes instead of a textual one.
-
-GRAPHICAL_HIERARCHY    = YES
-
-# If the DIRECTORY_GRAPH, SHOW_DIRECTORIES and HAVE_DOT tags are set to YES
-# then doxygen will show the dependencies a directory has on other directories
-# in a graphical way. The dependency relations are determined by the #include
-# relations between the files in the directories.
-
-DIRECTORY_GRAPH        = YES
-
-# The DOT_IMAGE_FORMAT tag can be used to set the image format of the images
-# generated by dot. Possible values are png, jpg, or gif
-# If left blank png will be used.
-
-DOT_IMAGE_FORMAT       = png
-
-# The tag DOT_PATH can be used to specify the path where the dot tool can be
-# found. If left blank, it is assumed the dot tool can be found in the path.
-
-DOT_PATH               =
-
-# The DOTFILE_DIRS tag can be used to specify one or more directories that
-# contain dot files that are included in the documentation (see the
-# \dotfile command).
-
-DOTFILE_DIRS           =
-
-# The DOT_GRAPH_MAX_NODES tag can be used to set the maximum number of
-# nodes that will be shown in the graph. If the number of nodes in a graph
-# becomes larger than this value, doxygen will truncate the graph, which is
-# visualized by representing a node as a red box. Note that doxygen if the
-# number of direct children of the root node in a graph is already larger than
-# DOT_GRAPH_MAX_NODES then the graph will not be shown at all. Also note
-# that the size of a graph can be further restricted by MAX_DOT_GRAPH_DEPTH.
-
-DOT_GRAPH_MAX_NODES    = 50
-
-# The MAX_DOT_GRAPH_DEPTH tag can be used to set the maximum depth of the
-# graphs generated by dot. A depth value of 3 means that only nodes reachable
-# from the root by following a path via at most 3 edges will be shown. Nodes
-# that lay further from the root node will be omitted. Note that setting this
-# option to 1 or 2 may greatly reduce the computation time needed for large
-# code bases. Also note that the size of a graph can be further restricted by
-# DOT_GRAPH_MAX_NODES. Using a depth of 0 means no depth restriction.
-
-MAX_DOT_GRAPH_DEPTH    = 0
-
-# Set the DOT_TRANSPARENT tag to YES to generate images with a transparent
-# background. This is disabled by default, because dot on Windows does not
-# seem to support this out of the box. Warning: Depending on the platform used,
-# enabling this option may lead to badly anti-aliased labels on the edges of
-# a graph (i.e. they become hard to read).
-
-DOT_TRANSPARENT        = NO
-
-# Set the DOT_MULTI_TARGETS tag to YES allow dot to generate multiple output
-# files in one run (i.e. multiple -o and -T options on the command line). This
-# makes dot run faster, but since only newer versions of dot (>1.8.10)
-# support this, this feature is disabled by default.
-
-DOT_MULTI_TARGETS      = YES
-
-# If the GENERATE_LEGEND tag is set to YES (the default) Doxygen will
-# generate a legend page explaining the meaning of the various boxes and
-# arrows in the dot generated graphs.
-
-GENERATE_LEGEND        = YES
-
-# If the DOT_CLEANUP tag is set to YES (the default) Doxygen will
-# remove the intermediate dot files that are used to generate
-# the various graphs.
-
-DOT_CLEANUP            = YES
diff --git a/external/db_drivers/liblmdb64/LICENSE b/external/db_drivers/liblmdb64/LICENSE
deleted file mode 100644
index 05ad7571e..000000000
--- a/external/db_drivers/liblmdb64/LICENSE
+++ /dev/null
@@ -1,47 +0,0 @@
-The OpenLDAP Public License
-  Version 2.8, 17 August 2003
-
-Redistribution and use of this software and associated documentation
-("Software"), with or without modification, are permitted provided
-that the following conditions are met:
-
-1. Redistributions in source form must retain copyright statements
-   and notices,
-
-2. Redistributions in binary form must reproduce applicable copyright
-   statements and notices, this list of conditions, and the following
-   disclaimer in the documentation and/or other materials provided
-   with the distribution, and
-
-3. Redistributions must contain a verbatim copy of this document.
-
-The OpenLDAP Foundation may revise this license from time to time.
-Each revision is distinguished by a version number.  You may use
-this Software under terms of this license revision or under the
-terms of any subsequent revision of the license.
-
-THIS SOFTWARE IS PROVIDED BY THE OPENLDAP FOUNDATION AND ITS
-CONTRIBUTORS ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
-INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
-AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT
-SHALL THE OPENLDAP FOUNDATION, ITS CONTRIBUTORS, OR THE AUTHOR(S)
-OR OWNER(S) OF THE SOFTWARE BE LIABLE FOR ANY DIRECT, INDIRECT,
-INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
-BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
-LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
-CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
-LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
-ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
-POSSIBILITY OF SUCH DAMAGE.
-
-The names of the authors and copyright holders must not be used in
-advertising or otherwise to promote the sale, use or other dealing
-in this Software without specific, written prior permission.  Title
-to copyright in this Software shall at all times remain with copyright
-holders.
-
-OpenLDAP is a registered trademark of the OpenLDAP Foundation.
-
-Copyright 1999-2003 The OpenLDAP Foundation, Redwood City,
-California, USA.  All Rights Reserved.  Permission to copy and
-distribute verbatim copies of this document is granted.
diff --git a/external/db_drivers/liblmdb64/lmdb.h b/external/db_drivers/liblmdb64/lmdb.h
deleted file mode 100644
index 2f523579c..000000000
--- a/external/db_drivers/liblmdb64/lmdb.h
+++ /dev/null
@@ -1,1556 +0,0 @@
-/** @file lmdb.h
- *	@brief Lightning memory-mapped database library
- *
- *	@mainpage	Lightning Memory-Mapped Database Manager (LMDB)
- *
- *	@section intro_sec Introduction
- *	LMDB is a Btree-based database management library modeled loosely on the
- *	BerkeleyDB API, but much simplified. The entire database is exposed
- *	in a memory map, and all data fetches return data directly
- *	from the mapped memory, so no malloc's or memcpy's occur during
- *	data fetches. As such, the library is extremely simple because it
- *	requires no page caching layer of its own, and it is extremely high
- *	performance and memory-efficient. It is also fully transactional with
- *	full ACID semantics, and when the memory map is read-only, the
- *	database integrity cannot be corrupted by stray pointer writes from
- *	application code.
- *
- *	The library is fully thread-aware and supports concurrent read/write
- *	access from multiple processes and threads. Data pages use a copy-on-
- *	write strategy so no active data pages are ever overwritten, which
- *	also provides resistance to corruption and eliminates the need of any
- *	special recovery procedures after a system crash. Writes are fully
- *	serialized; only one write transaction may be active at a time, which
- *	guarantees that writers can never deadlock. The database structure is
- *	multi-versioned so readers run with no locks; writers cannot block
- *	readers, and readers don't block writers.
- *
- *	Unlike other well-known database mechanisms which use either write-ahead
- *	transaction logs or append-only data writes, LMDB requires no maintenance
- *	during operation. Both write-ahead loggers and append-only databases
- *	require periodic checkpointing and/or compaction of their log or database
- *	files otherwise they grow without bound. LMDB tracks free pages within
- *	the database and re-uses them for new write operations, so the database
- *	size does not grow without bound in normal use.
- *
- *	The memory map can be used as a read-only or read-write map. It is
- *	read-only by default as this provides total immunity to corruption.
- *	Using read-write mode offers much higher write performance, but adds
- *	the possibility for stray application writes thru pointers to silently
- *	corrupt the database. Of course if your application code is known to
- *	be bug-free (...) then this is not an issue.
- *
- *	@section caveats_sec Caveats
- *	Troubleshooting the lock file, plus semaphores on BSD systems:
- *
- *	- A broken lockfile can cause sync issues.
- *	  Stale reader transactions left behind by an aborted program
- *	  cause further writes to grow the database quickly, and
- *	  stale locks can block further operation.
- *
- *	  Fix: Check for stale readers periodically, using the
- *	  #mdb_reader_check function or the \ref mdb_stat_1 "mdb_stat" tool. Or just
- *	  make all programs using the database close it; the lockfile
- *	  is always reset on first open of the environment.
- *
- *	- On BSD systems or others configured with MDB_USE_POSIX_SEM,
- *	  startup can fail due to semaphores owned by another userid.
- *
- *	  Fix: Open and close the database as the user which owns the
- *	  semaphores (likely last user) or as root, while no other
- *	  process is using the database.
- *
- *	Restrictions/caveats (in addition to those listed for some functions):
- *
- *	- Only the database owner should normally use the database on
- *	  BSD systems or when otherwise configured with MDB_USE_POSIX_SEM.
- *	  Multiple users can cause startup to fail later, as noted above.
- *
- *	- There is normally no pure read-only mode, since readers need write
- *	  access to locks and lock file. Exceptions: On read-only filesystems
- *	  or with the #MDB_NOLOCK flag described under #mdb_env_open().
- *
- *	- By default, in versions before 0.9.10, unused portions of the data
- *	  file might receive garbage data from memory freed by other code.
- *	  (This does not happen when using the #MDB_WRITEMAP flag.) As of
- *	  0.9.10 the default behavior is to initialize such memory before
- *	  writing to the data file. Since there may be a slight performance
- *	  cost due to this initialization, applications may disable it using
- *	  the #MDB_NOMEMINIT flag. Applications handling sensitive data
- *	  which must not be written should not use this flag. This flag is
- *	  irrelevant when using #MDB_WRITEMAP.
- *
- *	- A thread can only use one transaction at a time, plus any child
- *	  transactions.  Each transaction belongs to one thread.  See below.
- *	  The #MDB_NOTLS flag changes this for read-only transactions.
- *
- *	- Use an MDB_env* in the process which opened it, without fork()ing.
- *
- *	- Do not have open an LMDB database twice in the same process at
- *	  the same time.  Not even from a plain open() call - close()ing it
- *	  breaks flock() advisory locking.
- *
- *	- Avoid long-lived transactions.  Read transactions prevent
- *	  reuse of pages freed by newer write transactions, thus the
- *	  database can grow quickly.  Write transactions prevent
- *	  other write transactions, since writes are serialized.
- *
- *	- Avoid suspending a process with active transactions.  These
- *	  would then be "long-lived" as above.  Also read transactions
- *	  suspended when writers commit could sometimes see wrong data.
- *
- *	...when several processes can use a database concurrently:
- *
- *	- Avoid aborting a process with an active transaction.
- *	  The transaction becomes "long-lived" as above until a check
- *	  for stale readers is performed or the lockfile is reset,
- *	  since the process may not remove it from the lockfile.
- *
- *	- If you do that anyway, do a periodic check for stale readers. Or
- *	  close the environment once in a while, so the lockfile can get reset.
- *
- *	- Do not use LMDB databases on remote filesystems, even between
- *	  processes on the same host.  This breaks flock() on some OSes,
- *	  possibly memory map sync, and certainly sync between programs
- *	  on different hosts.
- *
- *	- Opening a database can fail if another process is opening or
- *	  closing it at exactly the same time.
- *
- *	@author	Howard Chu, Symas Corporation.
- *
- *	@copyright Copyright 2011-2015 Howard Chu, Symas Corp. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted only as authorized by the OpenLDAP
- * Public License.
- *
- * A copy of this license is available in the file LICENSE in the
- * top-level directory of the distribution or, alternatively, at
- * <http://www.OpenLDAP.org/license.html>.
- *
- *	@par Derived From:
- * This code is derived from btree.c written by Martin Hedenfalk.
- *
- * Copyright (c) 2009, 2010 Martin Hedenfalk <martin@bzero.se>
- *
- * Permission to use, copy, modify, and distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
- *
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
- * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
- * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
- * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
- * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
- * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
- */
-#ifndef _LMDB_H_
-#define _LMDB_H_
-
-#include <sys/types.h>
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-/** Unix permissions for creating files, or dummy definition for Windows */
-#ifdef _MSC_VER
-typedef	int	mdb_mode_t;
-#else
-typedef	mode_t	mdb_mode_t;
-#endif
-
-/** An abstraction for a file handle.
- *	On POSIX systems file handles are small integers. On Windows
- *	they're opaque pointers.
- */
-#ifdef _WIN32
-typedef	void *mdb_filehandle_t;
-#else
-typedef int mdb_filehandle_t;
-#endif
-
-/** @defgroup mdb LMDB API
- *	@{
- *	@brief OpenLDAP Lightning Memory-Mapped Database Manager
- */
-/** @defgroup Version Version Macros
- *	@{
- */
-/** Library major version */
-#define MDB_VERSION_MAJOR	0
-/** Library minor version */
-#define MDB_VERSION_MINOR	9
-/** Library patch version */
-#define MDB_VERSION_PATCH	15
-
-/** Combine args a,b,c into a single integer for easy version comparisons */
-#define MDB_VERINT(a,b,c)	(((a) << 24) | ((b) << 16) | (c))
-
-/** The full library version as a single integer */
-#define MDB_VERSION_FULL	\
-	MDB_VERINT(MDB_VERSION_MAJOR,MDB_VERSION_MINOR,MDB_VERSION_PATCH)
-
-/** The release date of this library version */
-#define MDB_VERSION_DATE	"June 19, 2015"
-
-/** A stringifier for the version info */
-#define MDB_VERSTR(a,b,c,d)	"LMDB " #a "." #b "." #c ": (" d ")"
-
-/** A helper for the stringifier macro */
-#define MDB_VERFOO(a,b,c,d)	MDB_VERSTR(a,b,c,d)
-
-/** The full library version as a C string */
-#define	MDB_VERSION_STRING	\
-	MDB_VERFOO(MDB_VERSION_MAJOR,MDB_VERSION_MINOR,MDB_VERSION_PATCH,MDB_VERSION_DATE)
-/**	@} */
-
-/** @brief Opaque structure for a database environment.
- *
- * A DB environment supports multiple databases, all residing in the same
- * shared-memory map.
- */
-typedef struct MDB_env MDB_env;
-
-/** @brief Opaque structure for a transaction handle.
- *
- * All database operations require a transaction handle. Transactions may be
- * read-only or read-write.
- */
-typedef struct MDB_txn MDB_txn;
-
-/** @brief A handle for an individual database in the DB environment. */
-typedef unsigned int	MDB_dbi;
-
-/** @brief Opaque structure for navigating through a database */
-typedef struct MDB_cursor MDB_cursor;
-
-/** @brief Generic structure used for passing keys and data in and out
- * of the database.
- *
- * Values returned from the database are valid only until a subsequent
- * update operation, or the end of the transaction. Do not modify or
- * free them, they commonly point into the database itself.
- *
- * Key sizes must be between 1 and #mdb_env_get_maxkeysize() inclusive.
- * The same applies to data sizes in databases with the #MDB_DUPSORT flag.
- * Other data items can in theory be from 0 to 0xffffffff bytes long.
- */
-typedef struct MDB_val {
-	size_t		 mv_size;	/**< size of the data item */
-	void		*mv_data;	/**< address of the data item */
-} MDB_val;
-
-/** @brief A callback function used to compare two keys in a database */
-typedef int  (MDB_cmp_func)(const MDB_val *a, const MDB_val *b);
-
-/** @brief A callback function used to relocate a position-dependent data item
- * in a fixed-address database.
- *
- * The \b newptr gives the item's desired address in
- * the memory map, and \b oldptr gives its previous address. The item's actual
- * data resides at the address in \b item.  This callback is expected to walk
- * through the fields of the record in \b item and modify any
- * values based at the \b oldptr address to be relative to the \b newptr address.
- * @param[in,out] item The item that is to be relocated.
- * @param[in] oldptr The previous address.
- * @param[in] newptr The new address to relocate to.
- * @param[in] relctx An application-provided context, set by #mdb_set_relctx().
- * @todo This feature is currently unimplemented.
- */
-typedef void (MDB_rel_func)(MDB_val *item, void *oldptr, void *newptr, void *relctx);
-
-/** @defgroup	mdb_env	Environment Flags
- *	@{
- */
-	/** mmap at a fixed address (experimental) */
-#define MDB_FIXEDMAP	0x01
-	/** no environment directory */
-#define MDB_NOSUBDIR	0x4000
-	/** don't fsync after commit */
-#define MDB_NOSYNC		0x10000
-	/** read only */
-#define MDB_RDONLY		0x20000
-	/** don't fsync metapage after commit */
-#define MDB_NOMETASYNC		0x40000
-	/** use writable mmap */
-#define MDB_WRITEMAP		0x80000
-	/** use asynchronous msync when #MDB_WRITEMAP is used */
-#define MDB_MAPASYNC		0x100000
-	/** tie reader locktable slots to #MDB_txn objects instead of to threads */
-#define MDB_NOTLS		0x200000
-	/** don't do any locking, caller must manage their own locks */
-#define MDB_NOLOCK		0x400000
-	/** don't do readahead (no effect on Windows) */
-#define MDB_NORDAHEAD	0x800000
-	/** don't initialize malloc'd memory before writing to datafile */
-#define MDB_NOMEMINIT	0x1000000
-/** @} */
-
-/**	@defgroup	mdb_dbi_open	Database Flags
- *	@{
- */
-	/** use reverse string keys */
-#define MDB_REVERSEKEY	0x02
-	/** use sorted duplicates */
-#define MDB_DUPSORT		0x04
-	/** numeric keys in native byte order: either unsigned int or size_t.
-	 *  The keys must all be of the same size. */
-#define MDB_INTEGERKEY	0x08
-	/** with #MDB_DUPSORT, sorted dup items have fixed size */
-#define MDB_DUPFIXED	0x10
-	/** with #MDB_DUPSORT, dups are #MDB_INTEGERKEY-style integers */
-#define MDB_INTEGERDUP	0x20
-	/** with #MDB_DUPSORT, use reverse string dups */
-#define MDB_REVERSEDUP	0x40
-	/** create DB if not already existing */
-#define MDB_CREATE		0x40000
-/** @} */
-
-/**	@defgroup mdb_put	Write Flags
- *	@{
- */
-/** For put: Don't write if the key already exists. */
-#define MDB_NOOVERWRITE	0x10
-/** Only for #MDB_DUPSORT<br>
- * For put: don't write if the key and data pair already exist.<br>
- * For mdb_cursor_del: remove all duplicate data items.
- */
-#define MDB_NODUPDATA	0x20
-/** For mdb_cursor_put: overwrite the current key/data pair */
-#define MDB_CURRENT	0x40
-/** For put: Just reserve space for data, don't copy it. Return a
- * pointer to the reserved space.
- */
-#define MDB_RESERVE	0x10000
-/** Data is being appended, don't split full pages. */
-#define MDB_APPEND	0x20000
-/** Duplicate data is being appended, don't split full pages. */
-#define MDB_APPENDDUP	0x40000
-/** Store multiple data items in one call. Only for #MDB_DUPFIXED. */
-#define MDB_MULTIPLE	0x80000
-/*	@} */
-
-/**	@defgroup mdb_copy	Copy Flags
- *	@{
- */
-/** Compacting copy: Omit free space from copy, and renumber all
- * pages sequentially.
- */
-#define MDB_CP_COMPACT	0x01
-/*	@} */
-
-/** @brief Cursor Get operations.
- *
- *	This is the set of all operations for retrieving data
- *	using a cursor.
- */
-typedef enum MDB_cursor_op {
-	MDB_FIRST,				/**< Position at first key/data item */
-	MDB_FIRST_DUP,			/**< Position at first data item of current key.
-								Only for #MDB_DUPSORT */
-	MDB_GET_BOTH,			/**< Position at key/data pair. Only for #MDB_DUPSORT */
-	MDB_GET_BOTH_RANGE,		/**< position at key, nearest data. Only for #MDB_DUPSORT */
-	MDB_GET_CURRENT,		/**< Return key/data at current cursor position */
-	MDB_GET_MULTIPLE,		/**< Return key and up to a page of duplicate data items
-								from current cursor position. Move cursor to prepare
-								for #MDB_NEXT_MULTIPLE. Only for #MDB_DUPFIXED */
-	MDB_LAST,				/**< Position at last key/data item */
-	MDB_LAST_DUP,			/**< Position at last data item of current key.
-								Only for #MDB_DUPSORT */
-	MDB_NEXT,				/**< Position at next data item */
-	MDB_NEXT_DUP,			/**< Position at next data item of current key.
-								Only for #MDB_DUPSORT */
-	MDB_NEXT_MULTIPLE,		/**< Return key and up to a page of duplicate data items
-								from next cursor position. Move cursor to prepare
-								for #MDB_NEXT_MULTIPLE. Only for #MDB_DUPFIXED */
-	MDB_NEXT_NODUP,			/**< Position at first data item of next key */
-	MDB_PREV,				/**< Position at previous data item */
-	MDB_PREV_DUP,			/**< Position at previous data item of current key.
-								Only for #MDB_DUPSORT */
-	MDB_PREV_NODUP,			/**< Position at last data item of previous key */
-	MDB_SET,				/**< Position at specified key */
-	MDB_SET_KEY,			/**< Position at specified key, return key + data */
-	MDB_SET_RANGE			/**< Position at first key greater than or equal to specified key. */
-} MDB_cursor_op;
-
-/** @defgroup  errors	Return Codes
- *
- *	BerkeleyDB uses -30800 to -30999, we'll go under them
- *	@{
- */
-	/**	Successful result */
-#define MDB_SUCCESS	 0
-	/** key/data pair already exists */
-#define MDB_KEYEXIST	(-30799)
-	/** key/data pair not found (EOF) */
-#define MDB_NOTFOUND	(-30798)
-	/** Requested page not found - this usually indicates corruption */
-#define MDB_PAGE_NOTFOUND	(-30797)
-	/** Located page was wrong type */
-#define MDB_CORRUPTED	(-30796)
-	/** Update of meta page failed, probably I/O error */
-#define MDB_PANIC		(-30795)
-	/** Environment version mismatch */
-#define MDB_VERSION_MISMATCH	(-30794)
-	/** File is not a valid LMDB file */
-#define MDB_INVALID	(-30793)
-	/** Environment mapsize reached */
-#define MDB_MAP_FULL	(-30792)
-	/** Environment maxdbs reached */
-#define MDB_DBS_FULL	(-30791)
-	/** Environment maxreaders reached */
-#define MDB_READERS_FULL	(-30790)
-	/** Too many TLS keys in use - Windows only */
-#define MDB_TLS_FULL	(-30789)
-	/** Txn has too many dirty pages */
-#define MDB_TXN_FULL	(-30788)
-	/** Cursor stack too deep - internal error */
-#define MDB_CURSOR_FULL	(-30787)
-	/** Page has not enough space - internal error */
-#define MDB_PAGE_FULL	(-30786)
-	/** Database contents grew beyond environment mapsize */
-#define MDB_MAP_RESIZED	(-30785)
-	/** MDB_INCOMPATIBLE: Operation and DB incompatible, or DB flags changed */
-#define MDB_INCOMPATIBLE	(-30784)
-	/** Invalid reuse of reader locktable slot */
-#define MDB_BAD_RSLOT		(-30783)
-	/** Transaction cannot recover - it must be aborted */
-#define MDB_BAD_TXN			(-30782)
-	/** Unsupported size of key/DB name/data, or wrong DUPFIXED size */
-#define MDB_BAD_VALSIZE		(-30781)
-	/** The specified DBI was changed unexpectedly */
-#define MDB_BAD_DBI		(-30780)
-	/** The last defined error code */
-#define MDB_LAST_ERRCODE	MDB_BAD_DBI
-/** @} */
-
-/** @brief Statistics for a database in the environment */
-typedef struct MDB_stat {
-	unsigned int	ms_psize;			/**< Size of a database page.
-											This is currently the same for all databases. */
-	unsigned int	ms_depth;			/**< Depth (height) of the B-tree */
-	size_t		ms_branch_pages;	/**< Number of internal (non-leaf) pages */
-	size_t		ms_leaf_pages;		/**< Number of leaf pages */
-	size_t		ms_overflow_pages;	/**< Number of overflow pages */
-	size_t		ms_entries;			/**< Number of data items */
-} MDB_stat;
-
-/** @brief Information about the environment */
-typedef struct MDB_envinfo {
-	void	*me_mapaddr;			/**< Address of map, if fixed */
-	size_t	me_mapsize;				/**< Size of the data memory map */
-	size_t	me_last_pgno;			/**< ID of the last used page */
-	size_t	me_last_txnid;			/**< ID of the last committed transaction */
-	unsigned int me_maxreaders;		/**< max reader slots in the environment */
-	unsigned int me_numreaders;		/**< max reader slots used in the environment */
-} MDB_envinfo;
-
-	/** @brief Return the LMDB library version information.
-	 *
-	 * @param[out] major if non-NULL, the library major version number is copied here
-	 * @param[out] minor if non-NULL, the library minor version number is copied here
-	 * @param[out] patch if non-NULL, the library patch version number is copied here
-	 * @retval "version string" The library version as a string
-	 */
-char *mdb_version(int *major, int *minor, int *patch);
-
-	/** @brief Return a string describing a given error code.
-	 *
-	 * This function is a superset of the ANSI C X3.159-1989 (ANSI C) strerror(3)
-	 * function. If the error code is greater than or equal to 0, then the string
-	 * returned by the system function strerror(3) is returned. If the error code
-	 * is less than 0, an error string corresponding to the LMDB library error is
-	 * returned. See @ref errors for a list of LMDB-specific error codes.
-	 * @param[in] err The error code
-	 * @retval "error message" The description of the error
-	 */
-char *mdb_strerror(int err);
-
-	/** @brief Create an LMDB environment handle.
-	 *
-	 * This function allocates memory for a #MDB_env structure. To release
-	 * the allocated memory and discard the handle, call #mdb_env_close().
-	 * Before the handle may be used, it must be opened using #mdb_env_open().
-	 * Various other options may also need to be set before opening the handle,
-	 * e.g. #mdb_env_set_mapsize(), #mdb_env_set_maxreaders(), #mdb_env_set_maxdbs(),
-	 * depending on usage requirements.
-	 * @param[out] env The address where the new handle will be stored
-	 * @return A non-zero error value on failure and 0 on success.
-	 */
-int  mdb_env_create(MDB_env **env);
-
-	/** @brief Open an environment handle.
-	 *
-	 * If this function fails, #mdb_env_close() must be called to discard the #MDB_env handle.
-	 * @param[in] env An environment handle returned by #mdb_env_create()
-	 * @param[in] path The directory in which the database files reside. This
-	 * directory must already exist and be writable.
-	 * @param[in] flags Special options for this environment. This parameter
-	 * must be set to 0 or by bitwise OR'ing together one or more of the
-	 * values described here.
-	 * Flags set by mdb_env_set_flags() are also used.
-	 * <ul>
-	 *	<li>#MDB_FIXEDMAP
-	 *      use a fixed address for the mmap region. This flag must be specified
-	 *      when creating the environment, and is stored persistently in the environment.
-	 *		If successful, the memory map will always reside at the same virtual address
-	 *		and pointers used to reference data items in the database will be constant
-	 *		across multiple invocations. This option may not always work, depending on
-	 *		how the operating system has allocated memory to shared libraries and other uses.
-	 *		The feature is highly experimental.
-	 *	<li>#MDB_NOSUBDIR
-	 *		By default, LMDB creates its environment in a directory whose
-	 *		pathname is given in \b path, and creates its data and lock files
-	 *		under that directory. With this option, \b path is used as-is for
-	 *		the database main data file. The database lock file is the \b path
-	 *		with "-lock" appended.
-	 *	<li>#MDB_RDONLY
-	 *		Open the environment in read-only mode. No write operations will be
-	 *		allowed. LMDB will still modify the lock file - except on read-only
-	 *		filesystems, where LMDB does not use locks.
-	 *	<li>#MDB_WRITEMAP
-	 *		Use a writeable memory map unless MDB_RDONLY is set. This is faster
-	 *		and uses fewer mallocs, but loses protection from application bugs
-	 *		like wild pointer writes and other bad updates into the database.
-	 *		Incompatible with nested transactions.
-	 *		Do not mix processes with and without MDB_WRITEMAP on the same
-	 *		environment.  This can defeat durability (#mdb_env_sync etc).
-	 *	<li>#MDB_NOMETASYNC
-	 *		Flush system buffers to disk only once per transaction, omit the
-	 *		metadata flush. Defer that until the system flushes files to disk,
-	 *		or next non-MDB_RDONLY commit or #mdb_env_sync(). This optimization
-	 *		maintains database integrity, but a system crash may undo the last
-	 *		committed transaction. I.e. it preserves the ACI (atomicity,
-	 *		consistency, isolation) but not D (durability) database property.
-	 *		This flag may be changed at any time using #mdb_env_set_flags().
-	 *	<li>#MDB_NOSYNC
-	 *		Don't flush system buffers to disk when committing a transaction.
-	 *		This optimization means a system crash can corrupt the database or
-	 *		lose the last transactions if buffers are not yet flushed to disk.
-	 *		The risk is governed by how often the system flushes dirty buffers
-	 *		to disk and how often #mdb_env_sync() is called.  However, if the
-	 *		filesystem preserves write order and the #MDB_WRITEMAP flag is not
-	 *		used, transactions exhibit ACI (atomicity, consistency, isolation)
-	 *		properties and only lose D (durability).  I.e. database integrity
-	 *		is maintained, but a system crash may undo the final transactions.
-	 *		Note that (#MDB_NOSYNC | #MDB_WRITEMAP) leaves the system with no
-	 *		hint for when to write transactions to disk, unless #mdb_env_sync()
-	 *		is called. (#MDB_MAPASYNC | #MDB_WRITEMAP) may be preferable.
-	 *		This flag may be changed at any time using #mdb_env_set_flags().
-	 *	<li>#MDB_MAPASYNC
-	 *		When using #MDB_WRITEMAP, use asynchronous flushes to disk.
-	 *		As with #MDB_NOSYNC, a system crash can then corrupt the
-	 *		database or lose the last transactions. Calling #mdb_env_sync()
-	 *		ensures on-disk database integrity until next commit.
-	 *		This flag may be changed at any time using #mdb_env_set_flags().
-	 *	<li>#MDB_NOTLS
-	 *		Don't use Thread-Local Storage. Tie reader locktable slots to
-	 *		#MDB_txn objects instead of to threads. I.e. #mdb_txn_reset() keeps
-	 *		the slot reseved for the #MDB_txn object. A thread may use parallel
-	 *		read-only transactions. A read-only transaction may span threads if
-	 *		the user synchronizes its use. Applications that multiplex many
-	 *		user threads over individual OS threads need this option. Such an
-	 *		application must also serialize the write transactions in an OS
-	 *		thread, since LMDB's write locking is unaware of the user threads.
-	 *	<li>#MDB_NOLOCK
-	 *		Don't do any locking. If concurrent access is anticipated, the
-	 *		caller must manage all concurrency itself. For proper operation
-	 *		the caller must enforce single-writer semantics, and must ensure
-	 *		that no readers are using old transactions while a writer is
-	 *		active. The simplest approach is to use an exclusive lock so that
-	 *		no readers may be active at all when a writer begins.
-	 *	<li>#MDB_NORDAHEAD
-	 *		Turn off readahead. Most operating systems perform readahead on
-	 *		read requests by default. This option turns it off if the OS
-	 *		supports it. Turning it off may help random read performance
-	 *		when the DB is larger than RAM and system RAM is full.
-	 *		The option is not implemented on Windows.
-	 *	<li>#MDB_NOMEMINIT
-	 *		Don't initialize malloc'd memory before writing to unused spaces
-	 *		in the data file. By default, memory for pages written to the data
-	 *		file is obtained using malloc. While these pages may be reused in
-	 *		subsequent transactions, freshly malloc'd pages will be initialized
-	 *		to zeroes before use. This avoids persisting leftover data from other
-	 *		code (that used the heap and subsequently freed the memory) into the
-	 *		data file. Note that many other system libraries may allocate
-	 *		and free memory from the heap for arbitrary uses. E.g., stdio may
-	 *		use the heap for file I/O buffers. This initialization step has a
-	 *		modest performance cost so some applications may want to disable
-	 *		it using this flag. This option can be a problem for applications
-	 *		which handle sensitive data like passwords, and it makes memory
-	 *		checkers like Valgrind noisy. This flag is not needed with #MDB_WRITEMAP,
-	 *		which writes directly to the mmap instead of using malloc for pages. The
-	 *		initialization is also skipped if #MDB_RESERVE is used; the
-	 *		caller is expected to overwrite all of the memory that was
-	 *		reserved in that case.
-	 *		This flag may be changed at any time using #mdb_env_set_flags().
-	 * </ul>
-	 * @param[in] mode The UNIX permissions to set on created files and semaphores.
-	 * This parameter is ignored on Windows.
-	 * @return A non-zero error value on failure and 0 on success. Some possible
-	 * errors are:
-	 * <ul>
-	 *	<li>#MDB_VERSION_MISMATCH - the version of the LMDB library doesn't match the
-	 *	version that created the database environment.
-	 *	<li>#MDB_INVALID - the environment file headers are corrupted.
-	 *	<li>ENOENT - the directory specified by the path parameter doesn't exist.
-	 *	<li>EACCES - the user didn't have permission to access the environment files.
-	 *	<li>EAGAIN - the environment was locked by another process.
-	 * </ul>
-	 */
-int  mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mdb_mode_t mode);
-
-	/** @brief Copy an LMDB environment to the specified path.
-	 *
-	 * This function may be used to make a backup of an existing environment.
-	 * No lockfile is created, since it gets recreated at need.
-	 * @note This call can trigger significant file size growth if run in
-	 * parallel with write transactions, because it employs a read-only
-	 * transaction. See long-lived transactions under @ref caveats_sec.
-	 * @param[in] env An environment handle returned by #mdb_env_create(). It
-	 * must have already been opened successfully.
-	 * @param[in] path The directory in which the copy will reside. This
-	 * directory must already exist and be writable but must otherwise be
-	 * empty.
-	 * @return A non-zero error value on failure and 0 on success.
-	 */
-int  mdb_env_copy(MDB_env *env, const char *path);
-
-	/** @brief Copy an LMDB environment to the specified file descriptor.
-	 *
-	 * This function may be used to make a backup of an existing environment.
-	 * No lockfile is created, since it gets recreated at need.
-	 * @note This call can trigger significant file size growth if run in
-	 * parallel with write transactions, because it employs a read-only
-	 * transaction. See long-lived transactions under @ref caveats_sec.
-	 * @param[in] env An environment handle returned by #mdb_env_create(). It
-	 * must have already been opened successfully.
-	 * @param[in] fd The filedescriptor to write the copy to. It must
-	 * have already been opened for Write access.
-	 * @return A non-zero error value on failure and 0 on success.
-	 */
-int  mdb_env_copyfd(MDB_env *env, mdb_filehandle_t fd);
-
-	/** @brief Copy an LMDB environment to the specified path, with options.
-	 *
-	 * This function may be used to make a backup of an existing environment.
-	 * No lockfile is created, since it gets recreated at need.
-	 * @note This call can trigger significant file size growth if run in
-	 * parallel with write transactions, because it employs a read-only
-	 * transaction. See long-lived transactions under @ref caveats_sec.
-	 * @param[in] env An environment handle returned by #mdb_env_create(). It
-	 * must have already been opened successfully.
-	 * @param[in] path The directory in which the copy will reside. This
-	 * directory must already exist and be writable but must otherwise be
-	 * empty.
-	 * @param[in] flags Special options for this operation. This parameter
-	 * must be set to 0 or by bitwise OR'ing together one or more of the
-	 * values described here.
-	 * <ul>
-	 *	<li>#MDB_CP_COMPACT - Perform compaction while copying: omit free
-	 *		pages and sequentially renumber all pages in output. This option
-	 *		consumes more CPU and runs more slowly than the default.
-	 * </ul>
-	 * @return A non-zero error value on failure and 0 on success.
-	 */
-int  mdb_env_copy2(MDB_env *env, const char *path, unsigned int flags);
-
-	/** @brief Copy an LMDB environment to the specified file descriptor,
-	 *	with options.
-	 *
-	 * This function may be used to make a backup of an existing environment.
-	 * No lockfile is created, since it gets recreated at need. See
-	 * #mdb_env_copy2() for further details.
-	 * @note This call can trigger significant file size growth if run in
-	 * parallel with write transactions, because it employs a read-only
-	 * transaction. See long-lived transactions under @ref caveats_sec.
-	 * @param[in] env An environment handle returned by #mdb_env_create(). It
-	 * must have already been opened successfully.
-	 * @param[in] fd The filedescriptor to write the copy to. It must
-	 * have already been opened for Write access.
-	 * @param[in] flags Special options for this operation.
-	 * See #mdb_env_copy2() for options.
-	 * @return A non-zero error value on failure and 0 on success.
-	 */
-int  mdb_env_copyfd2(MDB_env *env, mdb_filehandle_t fd, unsigned int flags);
-
-	/** @brief Return statistics about the LMDB environment.
-	 *
-	 * @param[in] env An environment handle returned by #mdb_env_create()
-	 * @param[out] stat The address of an #MDB_stat structure
-	 * 	where the statistics will be copied
-	 */
-int  mdb_env_stat(MDB_env *env, MDB_stat *stat);
-
-	/** @brief Return information about the LMDB environment.
-	 *
-	 * @param[in] env An environment handle returned by #mdb_env_create()
-	 * @param[out] stat The address of an #MDB_envinfo structure
-	 * 	where the information will be copied
-	 */
-int  mdb_env_info(MDB_env *env, MDB_envinfo *stat);
-
-	/** @brief Flush the data buffers to disk.
-	 *
-	 * Data is always written to disk when #mdb_txn_commit() is called,
-	 * but the operating system may keep it buffered. LMDB always flushes
-	 * the OS buffers upon commit as well, unless the environment was
-	 * opened with #MDB_NOSYNC or in part #MDB_NOMETASYNC. This call is
-	 * not valid if the environment was opened with #MDB_RDONLY.
-	 * @param[in] env An environment handle returned by #mdb_env_create()
-	 * @param[in] force If non-zero, force a synchronous flush.  Otherwise
-	 *  if the environment has the #MDB_NOSYNC flag set the flushes
-	 *	will be omitted, and with #MDB_MAPASYNC they will be asynchronous.
-	 * @return A non-zero error value on failure and 0 on success. Some possible
-	 * errors are:
-	 * <ul>
-	 *	<li>EACCES - the environment is read-only.
-	 *	<li>EINVAL - an invalid parameter was specified.
-	 *	<li>EIO - an error occurred during synchronization.
-	 * </ul>
-	 */
-int  mdb_env_sync(MDB_env *env, int force);
-
-	/** @brief Close the environment and release the memory map.
-	 *
-	 * Only a single thread may call this function. All transactions, databases,
-	 * and cursors must already be closed before calling this function. Attempts to
-	 * use any such handles after calling this function will cause a SIGSEGV.
-	 * The environment handle will be freed and must not be used again after this call.
-	 * @param[in] env An environment handle returned by #mdb_env_create()
-	 */
-void mdb_env_close(MDB_env *env);
-
-	/** @brief Set environment flags.
-	 *
-	 * This may be used to set some flags in addition to those from
-	 * #mdb_env_open(), or to unset these flags.  If several threads
-	 * change the flags at the same time, the result is undefined.
-	 * @param[in] env An environment handle returned by #mdb_env_create()
-	 * @param[in] flags The flags to change, bitwise OR'ed together
-	 * @param[in] onoff A non-zero value sets the flags, zero clears them.
-	 * @return A non-zero error value on failure and 0 on success. Some possible
-	 * errors are:
-	 * <ul>
-	 *	<li>EINVAL - an invalid parameter was specified.
-	 * </ul>
-	 */
-int  mdb_env_set_flags(MDB_env *env, unsigned int flags, int onoff);
-
-	/** @brief Get environment flags.
-	 *
-	 * @param[in] env An environment handle returned by #mdb_env_create()
-	 * @param[out] flags The address of an integer to store the flags
-	 * @return A non-zero error value on failure and 0 on success. Some possible
-	 * errors are:
-	 * <ul>
-	 *	<li>EINVAL - an invalid parameter was specified.
-	 * </ul>
-	 */
-int  mdb_env_get_flags(MDB_env *env, unsigned int *flags);
-
-	/** @brief Return the path that was used in #mdb_env_open().
-	 *
-	 * @param[in] env An environment handle returned by #mdb_env_create()
-	 * @param[out] path Address of a string pointer to contain the path. This
-	 * is the actual string in the environment, not a copy. It should not be
-	 * altered in any way.
-	 * @return A non-zero error value on failure and 0 on success. Some possible
-	 * errors are:
-	 * <ul>
-	 *	<li>EINVAL - an invalid parameter was specified.
-	 * </ul>
-	 */
-int  mdb_env_get_path(MDB_env *env, const char **path);
-
-	/** @brief Return the filedescriptor for the given environment.
-	 *
-	 * @param[in] env An environment handle returned by #mdb_env_create()
-	 * @param[out] fd Address of a mdb_filehandle_t to contain the descriptor.
-	 * @return A non-zero error value on failure and 0 on success. Some possible
-	 * errors are:
-	 * <ul>
-	 *	<li>EINVAL - an invalid parameter was specified.
-	 * </ul>
-	 */
-int  mdb_env_get_fd(MDB_env *env, mdb_filehandle_t *fd);
-
-	/** @brief Set the size of the memory map to use for this environment.
-	 *
-	 * The size should be a multiple of the OS page size. The default is
-	 * 10485760 bytes. The size of the memory map is also the maximum size
-	 * of the database. The value should be chosen as large as possible,
-	 * to accommodate future growth of the database.
-	 * This function should be called after #mdb_env_create() and before #mdb_env_open().
-	 * It may be called at later times if no transactions are active in
-	 * this process. Note that the library does not check for this condition,
-	 * the caller must ensure it explicitly.
-	 *
-	 * The new size takes effect immediately for the current process but
-	 * will not be persisted to any others until a write transaction has been
-	 * committed by the current process. Also, only mapsize increases are
-	 * persisted into the environment.
-	 *
-	 * If the mapsize is increased by another process, and data has grown
-	 * beyond the range of the current mapsize, #mdb_txn_begin() will
-	 * return #MDB_MAP_RESIZED. This function may be called with a size
-	 * of zero to adopt the new size.
-	 *
-	 * Any attempt to set a size smaller than the space already consumed
-	 * by the environment will be silently changed to the current size of the used space.
-	 * @param[in] env An environment handle returned by #mdb_env_create()
-	 * @param[in] size The size in bytes
-	 * @return A non-zero error value on failure and 0 on success. Some possible
-	 * errors are:
-	 * <ul>
-	 *	<li>EINVAL - an invalid parameter was specified, or the environment has
-	 *   	an active write transaction.
-	 * </ul>
-	 */
-int  mdb_env_set_mapsize(MDB_env *env, size_t size);
-
-	/** @brief Set the maximum number of threads/reader slots for the environment.
-	 *
-	 * This defines the number of slots in the lock table that is used to track readers in the
-	 * the environment. The default is 126.
-	 * Starting a read-only transaction normally ties a lock table slot to the
-	 * current thread until the environment closes or the thread exits. If
-	 * MDB_NOTLS is in use, #mdb_txn_begin() instead ties the slot to the
-	 * MDB_txn object until it or the #MDB_env object is destroyed.
-	 * This function may only be called after #mdb_env_create() and before #mdb_env_open().
-	 * @param[in] env An environment handle returned by #mdb_env_create()
-	 * @param[in] readers The maximum number of reader lock table slots
-	 * @return A non-zero error value on failure and 0 on success. Some possible
-	 * errors are:
-	 * <ul>
-	 *	<li>EINVAL - an invalid parameter was specified, or the environment is already open.
-	 * </ul>
-	 */
-int  mdb_env_set_maxreaders(MDB_env *env, unsigned int readers);
-
-	/** @brief Get the maximum number of threads/reader slots for the environment.
-	 *
-	 * @param[in] env An environment handle returned by #mdb_env_create()
-	 * @param[out] readers Address of an integer to store the number of readers
-	 * @return A non-zero error value on failure and 0 on success. Some possible
-	 * errors are:
-	 * <ul>
-	 *	<li>EINVAL - an invalid parameter was specified.
-	 * </ul>
-	 */
-int  mdb_env_get_maxreaders(MDB_env *env, unsigned int *readers);
-
-	/** @brief Set the maximum number of named databases for the environment.
-	 *
-	 * This function is only needed if multiple databases will be used in the
-	 * environment. Simpler applications that use the environment as a single
-	 * unnamed database can ignore this option.
-	 * This function may only be called after #mdb_env_create() and before #mdb_env_open().
-	 *
-	 * Currently a moderate number of slots are cheap but a huge number gets
-	 * expensive: 7-120 words per transaction, and every #mdb_dbi_open()
-	 * does a linear search of the opened slots.
-	 * @param[in] env An environment handle returned by #mdb_env_create()
-	 * @param[in] dbs The maximum number of databases
-	 * @return A non-zero error value on failure and 0 on success. Some possible
-	 * errors are:
-	 * <ul>
-	 *	<li>EINVAL - an invalid parameter was specified, or the environment is already open.
-	 * </ul>
-	 */
-int  mdb_env_set_maxdbs(MDB_env *env, MDB_dbi dbs);
-
-	/** @brief Get the maximum size of keys and #MDB_DUPSORT data we can write.
-	 *
-	 * Depends on the compile-time constant #MDB_MAXKEYSIZE. Default 511.
-	 * See @ref MDB_val.
-	 * @param[in] env An environment handle returned by #mdb_env_create()
-	 * @return The maximum size of a key we can write
-	 */
-int  mdb_env_get_maxkeysize(MDB_env *env);
-
-	/** @brief Set application information associated with the #MDB_env.
-	 *
-	 * @param[in] env An environment handle returned by #mdb_env_create()
-	 * @param[in] ctx An arbitrary pointer for whatever the application needs.
-	 * @return A non-zero error value on failure and 0 on success.
-	 */
-int  mdb_env_set_userctx(MDB_env *env, void *ctx);
-
-	/** @brief Get the application information associated with the #MDB_env.
-	 *
-	 * @param[in] env An environment handle returned by #mdb_env_create()
-	 * @return The pointer set by #mdb_env_set_userctx().
-	 */
-void *mdb_env_get_userctx(MDB_env *env);
-
-	/** @brief A callback function for most LMDB assert() failures,
-	 * called before printing the message and aborting.
-	 *
-	 * @param[in] env An environment handle returned by #mdb_env_create().
-	 * @param[in] msg The assertion message, not including newline.
-	 */
-typedef void MDB_assert_func(MDB_env *env, const char *msg);
-
-	/** Set or reset the assert() callback of the environment.
-	 * Disabled if liblmdb is buillt with NDEBUG.
-	 * @note This hack should become obsolete as lmdb's error handling matures.
-	 * @param[in] env An environment handle returned by #mdb_env_create().
-	 * @param[in] func An #MDB_assert_func function, or 0.
-	 * @return A non-zero error value on failure and 0 on success.
-	 */
-int  mdb_env_set_assert(MDB_env *env, MDB_assert_func *func);
-
-	/** @brief Create a transaction for use with the environment.
-	 *
-	 * The transaction handle may be discarded using #mdb_txn_abort() or #mdb_txn_commit().
-	 * @note A transaction and its cursors must only be used by a single
-	 * thread, and a thread may only have a single transaction at a time.
-	 * If #MDB_NOTLS is in use, this does not apply to read-only transactions.
-	 * @note Cursors may not span transactions.
-	 * @param[in] env An environment handle returned by #mdb_env_create()
-	 * @param[in] parent If this parameter is non-NULL, the new transaction
-	 * will be a nested transaction, with the transaction indicated by \b parent
-	 * as its parent. Transactions may be nested to any level. A parent
-	 * transaction and its cursors may not issue any other operations than
-	 * mdb_txn_commit and mdb_txn_abort while it has active child transactions.
-	 * @param[in] flags Special options for this transaction. This parameter
-	 * must be set to 0 or by bitwise OR'ing together one or more of the
-	 * values described here.
-	 * <ul>
-	 *	<li>#MDB_RDONLY
-	 *		This transaction will not perform any write operations.
-	 * </ul>
-	 * @param[out] txn Address where the new #MDB_txn handle will be stored
-	 * @return A non-zero error value on failure and 0 on success. Some possible
-	 * errors are:
-	 * <ul>
-	 *	<li>#MDB_PANIC - a fatal error occurred earlier and the environment
-	 *		must be shut down.
-	 *	<li>#MDB_MAP_RESIZED - another process wrote data beyond this MDB_env's
-	 *		mapsize and this environment's map must be resized as well.
-	 *		See #mdb_env_set_mapsize().
-	 *	<li>#MDB_READERS_FULL - a read-only transaction was requested and
-	 *		the reader lock table is full. See #mdb_env_set_maxreaders().
-	 *	<li>ENOMEM - out of memory.
-	 * </ul>
-	 */
-int  mdb_txn_begin(MDB_env *env, MDB_txn *parent, unsigned int flags, MDB_txn **txn);
-
-	/** @brief Returns the transaction's #MDB_env
-	 *
-	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()
-	 */
-MDB_env *mdb_txn_env(MDB_txn *txn);
-
-	/** @brief Commit all the operations of a transaction into the database.
-	 *
-	 * The transaction handle is freed. It and its cursors must not be used
-	 * again after this call, except with #mdb_cursor_renew().
-	 * @note Earlier documentation incorrectly said all cursors would be freed.
-	 * Only write-transactions free cursors.
-	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()
-	 * @return A non-zero error value on failure and 0 on success. Some possible
-	 * errors are:
-	 * <ul>
-	 *	<li>EINVAL - an invalid parameter was specified.
-	 *	<li>ENOSPC - no more disk space.
-	 *	<li>EIO - a low-level I/O error occurred while writing.
-	 *	<li>ENOMEM - out of memory.
-	 * </ul>
-	 */
-int  mdb_txn_commit(MDB_txn *txn);
-
-	/** @brief Abandon all the operations of the transaction instead of saving them.
-	 *
-	 * The transaction handle is freed. It and its cursors must not be used
-	 * again after this call, except with #mdb_cursor_renew().
-	 * @note Earlier documentation incorrectly said all cursors would be freed.
-	 * Only write-transactions free cursors.
-	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()
-	 */
-void mdb_txn_abort(MDB_txn *txn);
-
-	/** @brief Reset a read-only transaction.
-	 *
-	 * Abort the transaction like #mdb_txn_abort(), but keep the transaction
-	 * handle. #mdb_txn_renew() may reuse the handle. This saves allocation
-	 * overhead if the process will start a new read-only transaction soon,
-	 * and also locking overhead if #MDB_NOTLS is in use. The reader table
-	 * lock is released, but the table slot stays tied to its thread or
-	 * #MDB_txn. Use mdb_txn_abort() to discard a reset handle, and to free
-	 * its lock table slot if MDB_NOTLS is in use.
-	 * Cursors opened within the transaction must not be used
-	 * again after this call, except with #mdb_cursor_renew().
-	 * Reader locks generally don't interfere with writers, but they keep old
-	 * versions of database pages allocated. Thus they prevent the old pages
-	 * from being reused when writers commit new data, and so under heavy load
-	 * the database size may grow much more rapidly than otherwise.
-	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()
-	 */
-void mdb_txn_reset(MDB_txn *txn);
-
-	/** @brief Renew a read-only transaction.
-	 *
-	 * This acquires a new reader lock for a transaction handle that had been
-	 * released by #mdb_txn_reset(). It must be called before a reset transaction
-	 * may be used again.
-	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()
-	 * @return A non-zero error value on failure and 0 on success. Some possible
-	 * errors are:
-	 * <ul>
-	 *	<li>#MDB_PANIC - a fatal error occurred earlier and the environment
-	 *		must be shut down.
-	 *	<li>EINVAL - an invalid parameter was specified.
-	 * </ul>
-	 */
-int  mdb_txn_renew(MDB_txn *txn);
-
-/** Compat with version <= 0.9.4, avoid clash with libmdb from MDB Tools project */
-#define mdb_open(txn,name,flags,dbi)	mdb_dbi_open(txn,name,flags,dbi)
-/** Compat with version <= 0.9.4, avoid clash with libmdb from MDB Tools project */
-#define mdb_close(env,dbi)				mdb_dbi_close(env,dbi)
-
-	/** @brief Open a database in the environment.
-	 *
-	 * A database handle denotes the name and parameters of a database,
-	 * independently of whether such a database exists.
-	 * The database handle may be discarded by calling #mdb_dbi_close().
-	 * The old database handle is returned if the database was already open.
-	 * The handle may only be closed once.
-	 *
-	 * The database handle will be private to the current transaction until
-	 * the transaction is successfully committed. If the transaction is
-	 * aborted the handle will be closed automatically.
-	 * After a successful commit the handle will reside in the shared
-	 * environment, and may be used by other transactions.
-	 *
-	 * This function must not be called from multiple concurrent
-	 * transactions in the same process. A transaction that uses
-	 * this function must finish (either commit or abort) before
-	 * any other transaction in the process may use this function.
-	 *
-	 * To use named databases (with name != NULL), #mdb_env_set_maxdbs()
-	 * must be called before opening the environment.  Database names
-	 * are kept as keys in the unnamed database.
-	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()
-	 * @param[in] name The name of the database to open. If only a single
-	 * 	database is needed in the environment, this value may be NULL.
-	 * @param[in] flags Special options for this database. This parameter
-	 * must be set to 0 or by bitwise OR'ing together one or more of the
-	 * values described here.
-	 * <ul>
-	 *	<li>#MDB_REVERSEKEY
-	 *		Keys are strings to be compared in reverse order, from the end
-	 *		of the strings to the beginning. By default, Keys are treated as strings and
-	 *		compared from beginning to end.
-	 *	<li>#MDB_DUPSORT
-	 *		Duplicate keys may be used in the database. (Or, from another perspective,
-	 *		keys may have multiple data items, stored in sorted order.) By default
-	 *		keys must be unique and may have only a single data item.
-	 *	<li>#MDB_INTEGERKEY
-	 *		Keys are binary integers in native byte order, either unsigned int
-	 *		or size_t, and will be sorted as such.
-	 *		The keys must all be of the same size.
-	 *	<li>#MDB_DUPFIXED
-	 *		This flag may only be used in combination with #MDB_DUPSORT. This option
-	 *		tells the library that the data items for this database are all the same
-	 *		size, which allows further optimizations in storage and retrieval. When
-	 *		all data items are the same size, the #MDB_GET_MULTIPLE and #MDB_NEXT_MULTIPLE
-	 *		cursor operations may be used to retrieve multiple items at once.
-	 *	<li>#MDB_INTEGERDUP
-	 *		This option specifies that duplicate data items are binary integers,
-	 *		similar to #MDB_INTEGERKEY keys.
-	 *	<li>#MDB_REVERSEDUP
-	 *		This option specifies that duplicate data items should be compared as
-	 *		strings in reverse order.
-	 *	<li>#MDB_CREATE
-	 *		Create the named database if it doesn't exist. This option is not
-	 *		allowed in a read-only transaction or a read-only environment.
-	 * </ul>
-	 * @param[out] dbi Address where the new #MDB_dbi handle will be stored
-	 * @return A non-zero error value on failure and 0 on success. Some possible
-	 * errors are:
-	 * <ul>
-	 *	<li>#MDB_NOTFOUND - the specified database doesn't exist in the environment
-	 *		and #MDB_CREATE was not specified.
-	 *	<li>#MDB_DBS_FULL - too many databases have been opened. See #mdb_env_set_maxdbs().
-	 * </ul>
-	 */
-int  mdb_dbi_open(MDB_txn *txn, const char *name, unsigned int flags, MDB_dbi *dbi);
-
-	/** @brief Retrieve statistics for a database.
-	 *
-	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()
-	 * @param[in] dbi A database handle returned by #mdb_dbi_open()
-	 * @param[out] stat The address of an #MDB_stat structure
-	 * 	where the statistics will be copied
-	 * @return A non-zero error value on failure and 0 on success. Some possible
-	 * errors are:
-	 * <ul>
-	 *	<li>EINVAL - an invalid parameter was specified.
-	 * </ul>
-	 */
-int  mdb_stat(MDB_txn *txn, MDB_dbi dbi, MDB_stat *stat);
-
-	/** @brief Retrieve the DB flags for a database handle.
-	 *
-	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()
-	 * @param[in] dbi A database handle returned by #mdb_dbi_open()
-	 * @param[out] flags Address where the flags will be returned.
-	 * @return A non-zero error value on failure and 0 on success.
-	 */
-int mdb_dbi_flags(MDB_txn *txn, MDB_dbi dbi, unsigned int *flags);
-
-	/** @brief Close a database handle. Normally unnecessary. Use with care:
-	 *
-	 * This call is not mutex protected. Handles should only be closed by
-	 * a single thread, and only if no other threads are going to reference
-	 * the database handle or one of its cursors any further. Do not close
-	 * a handle if an existing transaction has modified its database.
-	 * Doing so can cause misbehavior from database corruption to errors
-	 * like MDB_BAD_VALSIZE (since the DB name is gone).
-	 *
-	 * Closing a database handle is not necessary, but lets #mdb_dbi_open()
-	 * reuse the handle value.  Usually it's better to set a bigger
-	 * #mdb_env_set_maxdbs(), unless that value would be large.
-	 *
-	 * @param[in] env An environment handle returned by #mdb_env_create()
-	 * @param[in] dbi A database handle returned by #mdb_dbi_open()
-	 */
-void mdb_dbi_close(MDB_env *env, MDB_dbi dbi);
-
-	/** @brief Empty or delete+close a database.
-	 *
-	 * See #mdb_dbi_close() for restrictions about closing the DB handle.
-	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()
-	 * @param[in] dbi A database handle returned by #mdb_dbi_open()
-	 * @param[in] del 0 to empty the DB, 1 to delete it from the
-	 * environment and close the DB handle.
-	 * @return A non-zero error value on failure and 0 on success.
-	 */
-int  mdb_drop(MDB_txn *txn, MDB_dbi dbi, int del);
-
-	/** @brief Set a custom key comparison function for a database.
-	 *
-	 * The comparison function is called whenever it is necessary to compare a
-	 * key specified by the application with a key currently stored in the database.
-	 * If no comparison function is specified, and no special key flags were specified
-	 * with #mdb_dbi_open(), the keys are compared lexically, with shorter keys collating
-	 * before longer keys.
-	 * @warning This function must be called before any data access functions are used,
-	 * otherwise data corruption may occur. The same comparison function must be used by every
-	 * program accessing the database, every time the database is used.
-	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()
-	 * @param[in] dbi A database handle returned by #mdb_dbi_open()
-	 * @param[in] cmp A #MDB_cmp_func function
-	 * @return A non-zero error value on failure and 0 on success. Some possible
-	 * errors are:
-	 * <ul>
-	 *	<li>EINVAL - an invalid parameter was specified.
-	 * </ul>
-	 */
-int  mdb_set_compare(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp);
-
-	/** @brief Set a custom data comparison function for a #MDB_DUPSORT database.
-	 *
-	 * This comparison function is called whenever it is necessary to compare a data
-	 * item specified by the application with a data item currently stored in the database.
-	 * This function only takes effect if the database was opened with the #MDB_DUPSORT
-	 * flag.
-	 * If no comparison function is specified, and no special key flags were specified
-	 * with #mdb_dbi_open(), the data items are compared lexically, with shorter items collating
-	 * before longer items.
-	 * @warning This function must be called before any data access functions are used,
-	 * otherwise data corruption may occur. The same comparison function must be used by every
-	 * program accessing the database, every time the database is used.
-	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()
-	 * @param[in] dbi A database handle returned by #mdb_dbi_open()
-	 * @param[in] cmp A #MDB_cmp_func function
-	 * @return A non-zero error value on failure and 0 on success. Some possible
-	 * errors are:
-	 * <ul>
-	 *	<li>EINVAL - an invalid parameter was specified.
-	 * </ul>
-	 */
-int  mdb_set_dupsort(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp);
-
-	/** @brief Set a relocation function for a #MDB_FIXEDMAP database.
-	 *
-	 * @todo The relocation function is called whenever it is necessary to move the data
-	 * of an item to a different position in the database (e.g. through tree
-	 * balancing operations, shifts as a result of adds or deletes, etc.). It is
-	 * intended to allow address/position-dependent data items to be stored in
-	 * a database in an environment opened with the #MDB_FIXEDMAP option.
-	 * Currently the relocation feature is unimplemented and setting
-	 * this function has no effect.
-	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()
-	 * @param[in] dbi A database handle returned by #mdb_dbi_open()
-	 * @param[in] rel A #MDB_rel_func function
-	 * @return A non-zero error value on failure and 0 on success. Some possible
-	 * errors are:
-	 * <ul>
-	 *	<li>EINVAL - an invalid parameter was specified.
-	 * </ul>
-	 */
-int  mdb_set_relfunc(MDB_txn *txn, MDB_dbi dbi, MDB_rel_func *rel);
-
-	/** @brief Set a context pointer for a #MDB_FIXEDMAP database's relocation function.
-	 *
-	 * See #mdb_set_relfunc and #MDB_rel_func for more details.
-	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()
-	 * @param[in] dbi A database handle returned by #mdb_dbi_open()
-	 * @param[in] ctx An arbitrary pointer for whatever the application needs.
-	 * It will be passed to the callback function set by #mdb_set_relfunc
-	 * as its \b relctx parameter whenever the callback is invoked.
-	 * @return A non-zero error value on failure and 0 on success. Some possible
-	 * errors are:
-	 * <ul>
-	 *	<li>EINVAL - an invalid parameter was specified.
-	 * </ul>
-	 */
-int  mdb_set_relctx(MDB_txn *txn, MDB_dbi dbi, void *ctx);
-
-	/** @brief Get items from a database.
-	 *
-	 * This function retrieves key/data pairs from the database. The address
-	 * and length of the data associated with the specified \b key are returned
-	 * in the structure to which \b data refers.
-	 * If the database supports duplicate keys (#MDB_DUPSORT) then the
-	 * first data item for the key will be returned. Retrieval of other
-	 * items requires the use of #mdb_cursor_get().
-	 *
-	 * @note The memory pointed to by the returned values is owned by the
-	 * database. The caller need not dispose of the memory, and may not
-	 * modify it in any way. For values returned in a read-only transaction
-	 * any modification attempts will cause a SIGSEGV.
-	 * @note Values returned from the database are valid only until a
-	 * subsequent update operation, or the end of the transaction.
-	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()
-	 * @param[in] dbi A database handle returned by #mdb_dbi_open()
-	 * @param[in] key The key to search for in the database
-	 * @param[out] data The data corresponding to the key
-	 * @return A non-zero error value on failure and 0 on success. Some possible
-	 * errors are:
-	 * <ul>
-	 *	<li>#MDB_NOTFOUND - the key was not in the database.
-	 *	<li>EINVAL - an invalid parameter was specified.
-	 * </ul>
-	 */
-int  mdb_get(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data);
-
-	/** @brief Store items into a database.
-	 *
-	 * This function stores key/data pairs in the database. The default behavior
-	 * is to enter the new key/data pair, replacing any previously existing key
-	 * if duplicates are disallowed, or adding a duplicate data item if
-	 * duplicates are allowed (#MDB_DUPSORT).
-	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()
-	 * @param[in] dbi A database handle returned by #mdb_dbi_open()
-	 * @param[in] key The key to store in the database
-	 * @param[in,out] data The data to store
-	 * @param[in] flags Special options for this operation. This parameter
-	 * must be set to 0 or by bitwise OR'ing together one or more of the
-	 * values described here.
-	 * <ul>
-	 *	<li>#MDB_NODUPDATA - enter the new key/data pair only if it does not
-	 *		already appear in the database. This flag may only be specified
-	 *		if the database was opened with #MDB_DUPSORT. The function will
-	 *		return #MDB_KEYEXIST if the key/data pair already appears in the
-	 *		database.
-	 *	<li>#MDB_NOOVERWRITE - enter the new key/data pair only if the key
-	 *		does not already appear in the database. The function will return
-	 *		#MDB_KEYEXIST if the key already appears in the database, even if
-	 *		the database supports duplicates (#MDB_DUPSORT). The \b data
-	 *		parameter will be set to point to the existing item.
-	 *	<li>#MDB_RESERVE - reserve space for data of the given size, but
-	 *		don't copy the given data. Instead, return a pointer to the
-	 *		reserved space, which the caller can fill in later - before
-	 *		the next update operation or the transaction ends. This saves
-	 *		an extra memcpy if the data is being generated later.
-	 *		LMDB does nothing else with this memory, the caller is expected
-	 *		to modify all of the space requested.
-	 *	<li>#MDB_APPEND - append the given key/data pair to the end of the
-	 *		database. This option allows fast bulk loading when keys are
-	 *		already known to be in the correct order. Loading unsorted keys
-	 *		with this flag will cause a #MDB_KEYEXIST error.
-	 *	<li>#MDB_APPENDDUP - as above, but for sorted dup data.
-	 * </ul>
-	 * @return A non-zero error value on failure and 0 on success. Some possible
-	 * errors are:
-	 * <ul>
-	 *	<li>#MDB_MAP_FULL - the database is full, see #mdb_env_set_mapsize().
-	 *	<li>#MDB_TXN_FULL - the transaction has too many dirty pages.
-	 *	<li>EACCES - an attempt was made to write in a read-only transaction.
-	 *	<li>EINVAL - an invalid parameter was specified.
-	 * </ul>
-	 */
-int  mdb_put(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data,
-			    unsigned int flags);
-
-	/** @brief Delete items from a database.
-	 *
-	 * This function removes key/data pairs from the database.
-	 * If the database does not support sorted duplicate data items
-	 * (#MDB_DUPSORT) the data parameter is ignored.
-	 * If the database supports sorted duplicates and the data parameter
-	 * is NULL, all of the duplicate data items for the key will be
-	 * deleted. Otherwise, if the data parameter is non-NULL
-	 * only the matching data item will be deleted.
-	 * This function will return #MDB_NOTFOUND if the specified key/data
-	 * pair is not in the database.
-	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()
-	 * @param[in] dbi A database handle returned by #mdb_dbi_open()
-	 * @param[in] key The key to delete from the database
-	 * @param[in] data The data to delete
-	 * @return A non-zero error value on failure and 0 on success. Some possible
-	 * errors are:
-	 * <ul>
-	 *	<li>EACCES - an attempt was made to write in a read-only transaction.
-	 *	<li>EINVAL - an invalid parameter was specified.
-	 * </ul>
-	 */
-int  mdb_del(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data);
-
-	/** @brief Create a cursor handle.
-	 *
-	 * A cursor is associated with a specific transaction and database.
-	 * A cursor cannot be used when its database handle is closed.  Nor
-	 * when its transaction has ended, except with #mdb_cursor_renew().
-	 * It can be discarded with #mdb_cursor_close().
-	 * A cursor in a write-transaction can be closed before its transaction
-	 * ends, and will otherwise be closed when its transaction ends.
-	 * A cursor in a read-only transaction must be closed explicitly, before
-	 * or after its transaction ends. It can be reused with
-	 * #mdb_cursor_renew() before finally closing it.
-	 * @note Earlier documentation said that cursors in every transaction
-	 * were closed when the transaction committed or aborted.
-	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()
-	 * @param[in] dbi A database handle returned by #mdb_dbi_open()
-	 * @param[out] cursor Address where the new #MDB_cursor handle will be stored
-	 * @return A non-zero error value on failure and 0 on success. Some possible
-	 * errors are:
-	 * <ul>
-	 *	<li>EINVAL - an invalid parameter was specified.
-	 * </ul>
-	 */
-int  mdb_cursor_open(MDB_txn *txn, MDB_dbi dbi, MDB_cursor **cursor);
-
-	/** @brief Close a cursor handle.
-	 *
-	 * The cursor handle will be freed and must not be used again after this call.
-	 * Its transaction must still be live if it is a write-transaction.
-	 * @param[in] cursor A cursor handle returned by #mdb_cursor_open()
-	 */
-void mdb_cursor_close(MDB_cursor *cursor);
-
-	/** @brief Renew a cursor handle.
-	 *
-	 * A cursor is associated with a specific transaction and database.
-	 * Cursors that are only used in read-only
-	 * transactions may be re-used, to avoid unnecessary malloc/free overhead.
-	 * The cursor may be associated with a new read-only transaction, and
-	 * referencing the same database handle as it was created with.
-	 * This may be done whether the previous transaction is live or dead.
-	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()
-	 * @param[in] cursor A cursor handle returned by #mdb_cursor_open()
-	 * @return A non-zero error value on failure and 0 on success. Some possible
-	 * errors are:
-	 * <ul>
-	 *	<li>EINVAL - an invalid parameter was specified.
-	 * </ul>
-	 */
-int  mdb_cursor_renew(MDB_txn *txn, MDB_cursor *cursor);
-
-	/** @brief Return the cursor's transaction handle.
-	 *
-	 * @param[in] cursor A cursor handle returned by #mdb_cursor_open()
-	 */
-MDB_txn *mdb_cursor_txn(MDB_cursor *cursor);
-
-	/** @brief Return the cursor's database handle.
-	 *
-	 * @param[in] cursor A cursor handle returned by #mdb_cursor_open()
-	 */
-MDB_dbi mdb_cursor_dbi(MDB_cursor *cursor);
-
-	/** @brief Retrieve by cursor.
-	 *
-	 * This function retrieves key/data pairs from the database. The address and length
-	 * of the key are returned in the object to which \b key refers (except for the
-	 * case of the #MDB_SET option, in which the \b key object is unchanged), and
-	 * the address and length of the data are returned in the object to which \b data
-	 * refers.
-	 * See #mdb_get() for restrictions on using the output values.
-	 * @param[in] cursor A cursor handle returned by #mdb_cursor_open()
-	 * @param[in,out] key The key for a retrieved item
-	 * @param[in,out] data The data of a retrieved item
-	 * @param[in] op A cursor operation #MDB_cursor_op
-	 * @return A non-zero error value on failure and 0 on success. Some possible
-	 * errors are:
-	 * <ul>
-	 *	<li>#MDB_NOTFOUND - no matching key found.
-	 *	<li>EINVAL - an invalid parameter was specified.
-	 * </ul>
-	 */
-int  mdb_cursor_get(MDB_cursor *cursor, MDB_val *key, MDB_val *data,
-			    MDB_cursor_op op);
-
-	/** @brief Store by cursor.
-	 *
-	 * This function stores key/data pairs into the database.
-	 * The cursor is positioned at the new item, or on failure usually near it.
-	 * @note Earlier documentation incorrectly said errors would leave the
-	 * state of the cursor unchanged.
-	 * @param[in] cursor A cursor handle returned by #mdb_cursor_open()
-	 * @param[in] key The key operated on.
-	 * @param[in] data The data operated on.
-	 * @param[in] flags Options for this operation. This parameter
-	 * must be set to 0 or one of the values described here.
-	 * <ul>
-	 *	<li>#MDB_CURRENT - replace the item at the current cursor position.
-	 *		The \b key parameter must still be provided, and must match it.
-	 *		If using sorted duplicates (#MDB_DUPSORT) the data item must still
-	 *		sort into the same place. This is intended to be used when the
-	 *		new data is the same size as the old. Otherwise it will simply
-	 *		perform a delete of the old record followed by an insert.
-	 *	<li>#MDB_NODUPDATA - enter the new key/data pair only if it does not
-	 *		already appear in the database. This flag may only be specified
-	 *		if the database was opened with #MDB_DUPSORT. The function will
-	 *		return #MDB_KEYEXIST if the key/data pair already appears in the
-	 *		database.
-	 *	<li>#MDB_NOOVERWRITE - enter the new key/data pair only if the key
-	 *		does not already appear in the database. The function will return
-	 *		#MDB_KEYEXIST if the key already appears in the database, even if
-	 *		the database supports duplicates (#MDB_DUPSORT).
-	 *	<li>#MDB_RESERVE - reserve space for data of the given size, but
-	 *		don't copy the given data. Instead, return a pointer to the
-	 *		reserved space, which the caller can fill in later. This saves
-	 *		an extra memcpy if the data is being generated later.
-	 *	<li>#MDB_APPEND - append the given key/data pair to the end of the
-	 *		database. No key comparisons are performed. This option allows
-	 *		fast bulk loading when keys are already known to be in the
-	 *		correct order. Loading unsorted keys with this flag will cause
-	 *		data corruption.
-	 *	<li>#MDB_APPENDDUP - as above, but for sorted dup data.
-	 *	<li>#MDB_MULTIPLE - store multiple contiguous data elements in a
-	 *		single request. This flag may only be specified if the database
-	 *		was opened with #MDB_DUPFIXED. The \b data argument must be an
-	 *		array of two MDB_vals. The mv_size of the first MDB_val must be
-	 *		the size of a single data element. The mv_data of the first MDB_val
-	 *		must point to the beginning of the array of contiguous data elements.
-	 *		The mv_size of the second MDB_val must be the count of the number
-	 *		of data elements to store. On return this field will be set to
-	 *		the count of the number of elements actually written. The mv_data
-	 *		of the second MDB_val is unused.
-	 * </ul>
-	 * @return A non-zero error value on failure and 0 on success. Some possible
-	 * errors are:
-	 * <ul>
-	 *	<li>#MDB_MAP_FULL - the database is full, see #mdb_env_set_mapsize().
-	 *	<li>#MDB_TXN_FULL - the transaction has too many dirty pages.
-	 *	<li>EACCES - an attempt was made to write in a read-only transaction.
-	 *	<li>EINVAL - an invalid parameter was specified.
-	 * </ul>
-	 */
-int  mdb_cursor_put(MDB_cursor *cursor, MDB_val *key, MDB_val *data,
-				unsigned int flags);
-
-	/** @brief Delete current key/data pair
-	 *
-	 * This function deletes the key/data pair to which the cursor refers.
-	 * @param[in] cursor A cursor handle returned by #mdb_cursor_open()
-	 * @param[in] flags Options for this operation. This parameter
-	 * must be set to 0 or one of the values described here.
-	 * <ul>
-	 *	<li>#MDB_NODUPDATA - delete all of the data items for the current key.
-	 *		This flag may only be specified if the database was opened with #MDB_DUPSORT.
-	 * </ul>
-	 * @return A non-zero error value on failure and 0 on success. Some possible
-	 * errors are:
-	 * <ul>
-	 *	<li>EACCES - an attempt was made to write in a read-only transaction.
-	 *	<li>EINVAL - an invalid parameter was specified.
-	 * </ul>
-	 */
-int  mdb_cursor_del(MDB_cursor *cursor, unsigned int flags);
-
-	/** @brief Return count of duplicates for current key.
-	 *
-	 * This call is only valid on databases that support sorted duplicate
-	 * data items #MDB_DUPSORT.
-	 * @param[in] cursor A cursor handle returned by #mdb_cursor_open()
-	 * @param[out] countp Address where the count will be stored
-	 * @return A non-zero error value on failure and 0 on success. Some possible
-	 * errors are:
-	 * <ul>
-	 *	<li>EINVAL - cursor is not initialized, or an invalid parameter was specified.
-	 * </ul>
-	 */
-int  mdb_cursor_count(MDB_cursor *cursor, size_t *countp);
-
-	/** @brief Compare two data items according to a particular database.
-	 *
-	 * This returns a comparison as if the two data items were keys in the
-	 * specified database.
-	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()
-	 * @param[in] dbi A database handle returned by #mdb_dbi_open()
-	 * @param[in] a The first item to compare
-	 * @param[in] b The second item to compare
-	 * @return < 0 if a < b, 0 if a == b, > 0 if a > b
-	 */
-int  mdb_cmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b);
-
-	/** @brief Compare two data items according to a particular database.
-	 *
-	 * This returns a comparison as if the two items were data items of
-	 * the specified database. The database must have the #MDB_DUPSORT flag.
-	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()
-	 * @param[in] dbi A database handle returned by #mdb_dbi_open()
-	 * @param[in] a The first item to compare
-	 * @param[in] b The second item to compare
-	 * @return < 0 if a < b, 0 if a == b, > 0 if a > b
-	 */
-int  mdb_dcmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b);
-
-	/** @brief A callback function used to print a message from the library.
-	 *
-	 * @param[in] msg The string to be printed.
-	 * @param[in] ctx An arbitrary context pointer for the callback.
-	 * @return < 0 on failure, >= 0 on success.
-	 */
-typedef int (MDB_msg_func)(const char *msg, void *ctx);
-
-	/** @brief Dump the entries in the reader lock table.
-	 *
-	 * @param[in] env An environment handle returned by #mdb_env_create()
-	 * @param[in] func A #MDB_msg_func function
-	 * @param[in] ctx Anything the message function needs
-	 * @return < 0 on failure, >= 0 on success.
-	 */
-int	mdb_reader_list(MDB_env *env, MDB_msg_func *func, void *ctx);
-
-	/** @brief Check for stale entries in the reader lock table.
-	 *
-	 * @param[in] env An environment handle returned by #mdb_env_create()
-	 * @param[out] dead Number of stale slots that were cleared
-	 * @return 0 on success, non-zero on failure.
-	 */
-int	mdb_reader_check(MDB_env *env, int *dead);
-/**	@} */
-
-#ifdef __cplusplus
-}
-#endif
-/** @page tools LMDB Command Line Tools
-	The following describes the command line tools that are available for LMDB.
-	\li \ref mdb_copy_1
-	\li \ref mdb_dump_1
-	\li \ref mdb_load_1
-	\li \ref mdb_stat_1
-*/
-
-#endif /* _LMDB_H_ */
diff --git a/external/db_drivers/liblmdb64/mdb.c b/external/db_drivers/liblmdb64/mdb.c
deleted file mode 100644
index 6bdf3151d..000000000
--- a/external/db_drivers/liblmdb64/mdb.c
+++ /dev/null
@@ -1,9555 +0,0 @@
-/** @file mdb.c
- *	@brief Lightning memory-mapped database library
- *
- *	A Btree-based database management library modeled loosely on the
- *	BerkeleyDB API, but much simplified.
- */
-/*
- * Copyright 2011-2015 Howard Chu, Symas Corp.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted only as authorized by the OpenLDAP
- * Public License.
- *
- * A copy of this license is available in the file LICENSE in the
- * top-level directory of the distribution or, alternatively, at
- * <http://www.OpenLDAP.org/license.html>.
- *
- * This code is derived from btree.c written by Martin Hedenfalk.
- *
- * Copyright (c) 2009, 2010 Martin Hedenfalk <martin@bzero.se>
- *
- * Permission to use, copy, modify, and distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
- *
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
- * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
- * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
- * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
- * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
- * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
- */
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE 1
-#endif
-#ifdef _WIN32
-#include <malloc.h>
-#include <windows.h>
-/** getpid() returns int; MinGW defines pid_t but MinGW64 typedefs it
- *  as int64 which is wrong. MSVC doesn't define it at all, so just
- *  don't use it.
- */
-#define MDB_PID_T	int
-#define MDB_THR_T	DWORD
-#include <sys/types.h>
-#include <sys/stat.h>
-#ifdef __GNUC__
-# include <sys/param.h>
-#else
-# define LITTLE_ENDIAN	1234
-# define BIG_ENDIAN	4321
-# define BYTE_ORDER	LITTLE_ENDIAN
-# ifndef SSIZE_MAX
-#  define SSIZE_MAX	INT_MAX
-# endif
-#endif
-#else
-#include <sys/types.h>
-#include <sys/stat.h>
-#define MDB_PID_T	pid_t
-#define MDB_THR_T	pthread_t
-#include <sys/param.h>
-#include <sys/uio.h>
-#include <sys/mman.h>
-#ifdef HAVE_SYS_FILE_H
-#include <sys/file.h>
-#endif
-#include <fcntl.h>
-#endif
-
-#if defined(__mips) && defined(__linux)
-/* MIPS has cache coherency issues, requires explicit cache control */
-#include <asm/cachectl.h>
-extern int cacheflush(char *addr, int nbytes, int cache);
-#define CACHEFLUSH(addr, bytes, cache)	cacheflush(addr, bytes, cache)
-#else
-#define CACHEFLUSH(addr, bytes, cache)
-#endif
-
-#if defined(__linux) && !defined(MDB_FDATASYNC_WORKS)
-/** fdatasync is broken on ext3/ext4fs on older kernels, see
- *	description in #mdb_env_open2 comments. You can safely
- *	define MDB_FDATASYNC_WORKS if this code will only be run
- *	on kernels 3.6 and newer.
- */
-#define	BROKEN_FDATASYNC
-#endif
-
-#include <errno.h>
-#include <limits.h>
-#include <stddef.h>
-#include <inttypes.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <time.h>
-#include <unistd.h>
-
-#if defined(__sun) || defined(ANDROID)
-/* Most platforms have posix_memalign, older may only have memalign */
-#define HAVE_MEMALIGN	1
-#include <malloc.h>
-#endif
-
-#if !(defined(BYTE_ORDER) || defined(__BYTE_ORDER))
-#include <netinet/in.h>
-#include <resolv.h>	/* defines BYTE_ORDER on HPUX and Solaris */
-#endif
-
-#if defined(__APPLE__) || defined (BSD)
-# define MDB_USE_POSIX_SEM	1
-# define MDB_FDATASYNC		fsync
-#elif defined(ANDROID)
-# define MDB_FDATASYNC		fsync
-#endif
-
-#ifndef _WIN32
-#include <pthread.h>
-#ifdef MDB_USE_POSIX_SEM
-# define MDB_USE_HASH		1
-#include <semaphore.h>
-#endif
-#endif
-
-#ifdef USE_VALGRIND
-#include <valgrind/memcheck.h>
-#define VGMEMP_CREATE(h,r,z)    VALGRIND_CREATE_MEMPOOL(h,r,z)
-#define VGMEMP_ALLOC(h,a,s) VALGRIND_MEMPOOL_ALLOC(h,a,s)
-#define VGMEMP_FREE(h,a) VALGRIND_MEMPOOL_FREE(h,a)
-#define VGMEMP_DESTROY(h)	VALGRIND_DESTROY_MEMPOOL(h)
-#define VGMEMP_DEFINED(a,s)	VALGRIND_MAKE_MEM_DEFINED(a,s)
-#else
-#define VGMEMP_CREATE(h,r,z)
-#define VGMEMP_ALLOC(h,a,s)
-#define VGMEMP_FREE(h,a)
-#define VGMEMP_DESTROY(h)
-#define VGMEMP_DEFINED(a,s)
-#endif
-
-#ifndef BYTE_ORDER
-# if (defined(_LITTLE_ENDIAN) || defined(_BIG_ENDIAN)) && !(defined(_LITTLE_ENDIAN) && defined(_BIG_ENDIAN))
-/* Solaris just defines one or the other */
-#  define LITTLE_ENDIAN	1234
-#  define BIG_ENDIAN	4321
-#  ifdef _LITTLE_ENDIAN
-#   define BYTE_ORDER  LITTLE_ENDIAN
-#  else
-#   define BYTE_ORDER  BIG_ENDIAN
-#  endif
-# else
-#  define BYTE_ORDER   __BYTE_ORDER
-# endif
-#endif
-
-#ifndef LITTLE_ENDIAN
-#define LITTLE_ENDIAN	__LITTLE_ENDIAN
-#endif
-#ifndef BIG_ENDIAN
-#define BIG_ENDIAN	__BIG_ENDIAN
-#endif
-
-#if defined(__i386) || defined(__x86_64) || defined(_M_IX86)
-#define MISALIGNED_OK	1
-#endif
-
-#include "lmdb.h"
-#include "midl.h"
-
-#if (BYTE_ORDER == LITTLE_ENDIAN) == (BYTE_ORDER == BIG_ENDIAN)
-# error "Unknown or unsupported endianness (BYTE_ORDER)"
-#elif (-6 & 5) || CHAR_BIT != 8 || UINT_MAX < 0xffffffff || ULONG_MAX % 0xFFFF
-# error "Two's complement, reasonably sized integer types, please"
-#endif
-
-#ifdef __GNUC__
-/** Put infrequently used env functions in separate section */
-# ifdef __APPLE__
-#  define	ESECT	__attribute__ ((section("__TEXT,text_env")))
-# else
-#  define	ESECT	__attribute__ ((section("text_env")))
-# endif
-#else
-#define ESECT
-#endif
-
-/** @defgroup internal	LMDB Internals
- *	@{
- */
-/** @defgroup compat	Compatibility Macros
- *	A bunch of macros to minimize the amount of platform-specific ifdefs
- *	needed throughout the rest of the code. When the features this library
- *	needs are similar enough to POSIX to be hidden in a one-or-two line
- *	replacement, this macro approach is used.
- *	@{
- */
-
-	/** Features under development */
-#ifndef MDB_DEVEL
-#define MDB_DEVEL 0
-#endif
-
-	/** Wrapper around __func__, which is a C99 feature */
-#if __STDC_VERSION__ >= 199901L
-# define mdb_func_	__func__
-#elif __GNUC__ >= 2 || _MSC_VER >= 1300
-# define mdb_func_	__FUNCTION__
-#else
-/* If a debug message says <mdb_unknown>(), update the #if statements above */
-# define mdb_func_	"<mdb_unknown>"
-#endif
-
-#ifdef _WIN32
-#define MDB_USE_HASH	1
-#define MDB_PIDLOCK	0
-#define THREAD_RET	DWORD
-#define pthread_t	HANDLE
-#define pthread_mutex_t	HANDLE
-#define pthread_cond_t	HANDLE
-#define pthread_key_t	DWORD
-#define pthread_self()	GetCurrentThreadId()
-#define pthread_key_create(x,y)	\
-	((*(x) = TlsAlloc()) == TLS_OUT_OF_INDEXES ? ErrCode() : 0)
-#define pthread_key_delete(x)	TlsFree(x)
-#define pthread_getspecific(x)	TlsGetValue(x)
-#define pthread_setspecific(x,y)	(TlsSetValue(x,y) ? 0 : ErrCode())
-#define pthread_mutex_unlock(x)	ReleaseMutex(*x)
-#define pthread_mutex_lock(x)	WaitForSingleObject(*x, INFINITE)
-#define pthread_cond_signal(x)	SetEvent(*x)
-#define pthread_cond_wait(cond,mutex)	do{SignalObjectAndWait(*mutex, *cond, INFINITE, FALSE); WaitForSingleObject(*mutex, INFINITE);}while(0)
-#define THREAD_CREATE(thr,start,arg)	thr=CreateThread(NULL,0,start,arg,0,NULL)
-#define THREAD_FINISH(thr)	WaitForSingleObject(thr, INFINITE)
-#define LOCK_MUTEX_R(env)	pthread_mutex_lock(&(env)->me_rmutex)
-#define UNLOCK_MUTEX_R(env)	pthread_mutex_unlock(&(env)->me_rmutex)
-#define LOCK_MUTEX_W(env)	pthread_mutex_lock(&(env)->me_wmutex)
-#define UNLOCK_MUTEX_W(env)	pthread_mutex_unlock(&(env)->me_wmutex)
-#define getpid()	GetCurrentProcessId()
-#define	MDB_FDATASYNC(fd)	(!FlushFileBuffers(fd))
-#define	MDB_MSYNC(addr,len,flags)	(!FlushViewOfFile(addr,len))
-#define	ErrCode()	GetLastError()
-#define GET_PAGESIZE(x) {SYSTEM_INFO si; GetSystemInfo(&si); (x) = si.dwPageSize;}
-#define	close(fd)	(CloseHandle(fd) ? 0 : -1)
-#define	munmap(ptr,len)	UnmapViewOfFile(ptr)
-#ifdef PROCESS_QUERY_LIMITED_INFORMATION
-#define MDB_PROCESS_QUERY_LIMITED_INFORMATION PROCESS_QUERY_LIMITED_INFORMATION
-#else
-#define MDB_PROCESS_QUERY_LIMITED_INFORMATION 0x1000
-#endif
-#define	Z	"I"
-#else
-#define THREAD_RET	void *
-#define THREAD_CREATE(thr,start,arg)	pthread_create(&thr,NULL,start,arg)
-#define THREAD_FINISH(thr)	pthread_join(thr,NULL)
-#define	Z	"z"			/**< printf format modifier for size_t */
-
-	/** For MDB_LOCK_FORMAT: True if readers take a pid lock in the lockfile */
-#define MDB_PIDLOCK			1
-
-#ifdef MDB_USE_POSIX_SEM
-
-#define LOCK_MUTEX_R(env)	mdb_sem_wait((env)->me_rmutex)
-#define UNLOCK_MUTEX_R(env)	sem_post((env)->me_rmutex)
-#define LOCK_MUTEX_W(env)	mdb_sem_wait((env)->me_wmutex)
-#define UNLOCK_MUTEX_W(env)	sem_post((env)->me_wmutex)
-
-static int
-mdb_sem_wait(sem_t *sem)
-{
-   int rc;
-   while ((rc = sem_wait(sem)) && (rc = errno) == EINTR) ;
-   return rc;
-}
-
-#else
-	/** Lock the reader mutex.
-	 */
-#define LOCK_MUTEX_R(env)	pthread_mutex_lock(&(env)->me_txns->mti_mutex)
-	/** Unlock the reader mutex.
-	 */
-#define UNLOCK_MUTEX_R(env)	pthread_mutex_unlock(&(env)->me_txns->mti_mutex)
-
-	/** Lock the writer mutex.
-	 *	Only a single write transaction is allowed at a time. Other writers
-	 *	will block waiting for this mutex.
-	 */
-#define LOCK_MUTEX_W(env)	pthread_mutex_lock(&(env)->me_txns->mti_wmutex)
-	/** Unlock the writer mutex.
-	 */
-#define UNLOCK_MUTEX_W(env)	pthread_mutex_unlock(&(env)->me_txns->mti_wmutex)
-#endif	/* MDB_USE_POSIX_SEM */
-
-	/** Get the error code for the last failed system function.
-	 */
-#define	ErrCode()	errno
-
-	/** An abstraction for a file handle.
-	 *	On POSIX systems file handles are small integers. On Windows
-	 *	they're opaque pointers.
-	 */
-#define	HANDLE	int
-
-	/**	A value for an invalid file handle.
-	 *	Mainly used to initialize file variables and signify that they are
-	 *	unused.
-	 */
-#define INVALID_HANDLE_VALUE	(-1)
-
-	/** Get the size of a memory page for the system.
-	 *	This is the basic size that the platform's memory manager uses, and is
-	 *	fundamental to the use of memory-mapped files.
-	 */
-#define	GET_PAGESIZE(x)	((x) = sysconf(_SC_PAGE_SIZE))
-#endif
-
-#if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
-#define MNAME_LEN	32
-#else
-#define MNAME_LEN	(sizeof(pthread_mutex_t))
-#endif
-
-/** @} */
-
-#ifndef _WIN32
-/**	A flag for opening a file and requesting synchronous data writes.
- *	This is only used when writing a meta page. It's not strictly needed;
- *	we could just do a normal write and then immediately perform a flush.
- *	But if this flag is available it saves us an extra system call.
- *
- *	@note If O_DSYNC is undefined but exists in /usr/include,
- * preferably set some compiler flag to get the definition.
- * Otherwise compile with the less efficient -DMDB_DSYNC=O_SYNC.
- */
-#ifndef MDB_DSYNC
-# define MDB_DSYNC	O_DSYNC
-#endif
-#endif
-
-/** Function for flushing the data of a file. Define this to fsync
- *	if fdatasync() is not supported.
- */
-#ifndef MDB_FDATASYNC
-# define MDB_FDATASYNC	fdatasync
-#endif
-
-#ifndef MDB_MSYNC
-# define MDB_MSYNC(addr,len,flags)	msync(addr,len,flags)
-#endif
-
-#ifndef MS_SYNC
-#define	MS_SYNC	1
-#endif
-
-#ifndef MS_ASYNC
-#define	MS_ASYNC	0
-#endif
-
-	/** A page number in the database.
-	 *	Note that 64 bit page numbers are overkill, since pages themselves
-	 *	already represent 12-13 bits of addressable memory, and the OS will
-	 *	always limit applications to a maximum of 63 bits of address space.
-	 *
-	 *	@note In the #MDB_node structure, we only store 48 bits of this value,
-	 *	which thus limits us to only 60 bits of addressable data.
-	 */
-typedef MDB_ID	pgno_t;
-
-	/** A transaction ID.
-	 *	See struct MDB_txn.mt_txnid for details.
-	 */
-typedef MDB_ID	txnid_t;
-
-/** @defgroup debug	Debug Macros
- *	@{
- */
-#ifndef MDB_DEBUG
-	/**	Enable debug output.  Needs variable argument macros (a C99 feature).
-	 *	Set this to 1 for copious tracing. Set to 2 to add dumps of all IDLs
-	 *	read from and written to the database (used for free space management).
-	 */
-#define MDB_DEBUG 0
-#endif
-
-#if MDB_DEBUG
-static int mdb_debug;
-static txnid_t mdb_debug_start;
-
-	/**	Print a debug message with printf formatting.
-	 *	Requires double parenthesis around 2 or more args.
-	 */
-# define DPRINTF(args) ((void) ((mdb_debug) && DPRINTF0 args))
-# define DPRINTF0(fmt, ...) \
-	fprintf(stderr, "%s:%d " fmt "\n", mdb_func_, __LINE__, __VA_ARGS__)
-#else
-# define DPRINTF(args)	((void) 0)
-#endif
-	/**	Print a debug string.
-	 *	The string is printed literally, with no format processing.
-	 */
-#define DPUTS(arg)	DPRINTF(("%s", arg))
-	/** Debuging output value of a cursor DBI: Negative in a sub-cursor. */
-#define DDBI(mc) \
-	(((mc)->mc_flags & C_SUB) ? -(int)(mc)->mc_dbi : (int)(mc)->mc_dbi)
-/** @} */
-
-	/**	@brief The maximum size of a database page.
-	 *
-	 *	It is 32k or 64k, since value-PAGEBASE must fit in
-	 *	#MDB_page.%mp_upper.
-	 *
-	 *	LMDB will use database pages < OS pages if needed.
-	 *	That causes more I/O in write transactions: The OS must
-	 *	know (read) the whole page before writing a partial page.
-	 *
-	 *	Note that we don't currently support Huge pages. On Linux,
-	 *	regular data files cannot use Huge pages, and in general
-	 *	Huge pages aren't actually pageable. We rely on the OS
-	 *	demand-pager to read our data and page it out when memory
-	 *	pressure from other processes is high. So until OSs have
-	 *	actual paging support for Huge pages, they're not viable.
-	 */
-#define MAX_PAGESIZE	 (PAGEBASE ? 0x10000 : 0x8000)
-
-	/** The minimum number of keys required in a database page.
-	 *	Setting this to a larger value will place a smaller bound on the
-	 *	maximum size of a data item. Data items larger than this size will
-	 *	be pushed into overflow pages instead of being stored directly in
-	 *	the B-tree node. This value used to default to 4. With a page size
-	 *	of 4096 bytes that meant that any item larger than 1024 bytes would
-	 *	go into an overflow page. That also meant that on average 2-3KB of
-	 *	each overflow page was wasted space. The value cannot be lower than
-	 *	2 because then there would no longer be a tree structure. With this
-	 *	value, items larger than 2KB will go into overflow pages, and on
-	 *	average only 1KB will be wasted.
-	 */
-#define MDB_MINKEYS	 2
-
-	/**	A stamp that identifies a file as an LMDB file.
-	 *	There's nothing special about this value other than that it is easily
-	 *	recognizable, and it will reflect any byte order mismatches.
-	 */
-#define MDB_MAGIC	 0xBEEFC0DE
-
-	/**	The version number for a database's datafile format. */
-#define MDB_DATA_VERSION	 ((MDB_DEVEL) ? 999 : 1)
-	/**	The version number for a database's lockfile format. */
-#define MDB_LOCK_VERSION	 1
-
-	/**	@brief The max size of a key we can write, or 0 for computed max.
-	 *
-	 *	This macro should normally be left alone or set to 0.
-	 *	Note that a database with big keys or dupsort data cannot be
-	 *	reliably modified by a liblmdb which uses a smaller max.
-	 *	The default is 511 for backwards compat, or 0 when #MDB_DEVEL.
-	 *
-	 *	Other values are allowed, for backwards compat.  However:
-	 *	A value bigger than the computed max can break if you do not
-	 *	know what you are doing, and liblmdb <= 0.9.10 can break when
-	 *	modifying a DB with keys/dupsort data bigger than its max.
-	 *
-	 *	Data items in an #MDB_DUPSORT database are also limited to
-	 *	this size, since they're actually keys of a sub-DB.  Keys and
-	 *	#MDB_DUPSORT data items must fit on a node in a regular page.
-	 */
-#ifndef MDB_MAXKEYSIZE
-#define MDB_MAXKEYSIZE	 ((MDB_DEVEL) ? 0 : 511)
-#endif
-
-	/**	The maximum size of a key we can write to the environment. */
-#if MDB_MAXKEYSIZE
-#define ENV_MAXKEY(env)	(MDB_MAXKEYSIZE)
-#else
-#define ENV_MAXKEY(env)	((env)->me_maxkey)
-#endif
-
-	/**	@brief The maximum size of a data item.
-	 *
-	 *	We only store a 32 bit value for node sizes.
-	 */
-#define MAXDATASIZE	0xffffffffUL
-
-#if MDB_DEBUG
-	/**	Key size which fits in a #DKBUF.
-	 *	@ingroup debug
-	 */
-#define DKBUF_MAXKEYSIZE ((MDB_MAXKEYSIZE) > 0 ? (MDB_MAXKEYSIZE) : 511)
-	/**	A key buffer.
-	 *	@ingroup debug
-	 *	This is used for printing a hex dump of a key's contents.
-	 */
-#define DKBUF	char kbuf[DKBUF_MAXKEYSIZE*2+1]
-	/**	Display a key in hex.
-	 *	@ingroup debug
-	 *	Invoke a function to display a key in hex.
-	 */
-#define	DKEY(x)	mdb_dkey(x, kbuf)
-#else
-#define	DKBUF
-#define DKEY(x)	0
-#endif
-
-	/** An invalid page number.
-	 *	Mainly used to denote an empty tree.
-	 */
-#define P_INVALID	 (~(pgno_t)0)
-
-	/** Test if the flags \b f are set in a flag word \b w. */
-#define F_ISSET(w, f)	 (((w) & (f)) == (f))
-
-	/** Round \b n up to an even number. */
-#define EVEN(n)		(((n) + 1U) & -2) /* sign-extending -2 to match n+1U */
-
-	/**	Used for offsets within a single page.
-	 *	Since memory pages are typically 4 or 8KB in size, 12-13 bits,
-	 *	this is plenty.
-	 */
-typedef uint16_t	 indx_t;
-
-	/**	Default size of memory map.
-	 *	This is certainly too small for any actual applications. Apps should always set
-	 *	the size explicitly using #mdb_env_set_mapsize().
-	 */
-#define DEFAULT_MAPSIZE	1048576
-
-/**	@defgroup readers	Reader Lock Table
- *	Readers don't acquire any locks for their data access. Instead, they
- *	simply record their transaction ID in the reader table. The reader
- *	mutex is needed just to find an empty slot in the reader table. The
- *	slot's address is saved in thread-specific data so that subsequent read
- *	transactions started by the same thread need no further locking to proceed.
- *
- *	If #MDB_NOTLS is set, the slot address is not saved in thread-specific data.
- *
- *	No reader table is used if the database is on a read-only filesystem, or
- *	if #MDB_NOLOCK is set.
- *
- *	Since the database uses multi-version concurrency control, readers don't
- *	actually need any locking. This table is used to keep track of which
- *	readers are using data from which old transactions, so that we'll know
- *	when a particular old transaction is no longer in use. Old transactions
- *	that have discarded any data pages can then have those pages reclaimed
- *	for use by a later write transaction.
- *
- *	The lock table is constructed such that reader slots are aligned with the
- *	processor's cache line size. Any slot is only ever used by one thread.
- *	This alignment guarantees that there will be no contention or cache
- *	thrashing as threads update their own slot info, and also eliminates
- *	any need for locking when accessing a slot.
- *
- *	A writer thread will scan every slot in the table to determine the oldest
- *	outstanding reader transaction. Any freed pages older than this will be
- *	reclaimed by the writer. The writer doesn't use any locks when scanning
- *	this table. This means that there's no guarantee that the writer will
- *	see the most up-to-date reader info, but that's not required for correct
- *	operation - all we need is to know the upper bound on the oldest reader,
- *	we don't care at all about the newest reader. So the only consequence of
- *	reading stale information here is that old pages might hang around a
- *	while longer before being reclaimed. That's actually good anyway, because
- *	the longer we delay reclaiming old pages, the more likely it is that a
- *	string of contiguous pages can be found after coalescing old pages from
- *	many old transactions together.
- *	@{
- */
-	/**	Number of slots in the reader table.
-	 *	This value was chosen somewhat arbitrarily. 126 readers plus a
-	 *	couple mutexes fit exactly into 8KB on my development machine.
-	 *	Applications should set the table size using #mdb_env_set_maxreaders().
-	 */
-#define DEFAULT_READERS	126
-
-	/**	The size of a CPU cache line in bytes. We want our lock structures
-	 *	aligned to this size to avoid false cache line sharing in the
-	 *	lock table.
-	 *	This value works for most CPUs. For Itanium this should be 128.
-	 */
-#ifndef CACHELINE
-#define CACHELINE	64
-#endif
-
-	/**	The information we store in a single slot of the reader table.
-	 *	In addition to a transaction ID, we also record the process and
-	 *	thread ID that owns a slot, so that we can detect stale information,
-	 *	e.g. threads or processes that went away without cleaning up.
-	 *	@note We currently don't check for stale records. We simply re-init
-	 *	the table when we know that we're the only process opening the
-	 *	lock file.
-	 */
-typedef struct MDB_rxbody {
-	/**	Current Transaction ID when this transaction began, or (txnid_t)-1.
-	 *	Multiple readers that start at the same time will probably have the
-	 *	same ID here. Again, it's not important to exclude them from
-	 *	anything; all we need to know is which version of the DB they
-	 *	started from so we can avoid overwriting any data used in that
-	 *	particular version.
-	 */
-	volatile txnid_t		mrb_txnid;
-	/** The process ID of the process owning this reader txn. */
-	volatile MDB_PID_T	mrb_pid;
-	/** The thread ID of the thread owning this txn. */
-	volatile MDB_THR_T	mrb_tid;
-} MDB_rxbody;
-
-	/** The actual reader record, with cacheline padding. */
-typedef struct MDB_reader {
-	union {
-		MDB_rxbody mrx;
-		/** shorthand for mrb_txnid */
-#define	mr_txnid	mru.mrx.mrb_txnid
-#define	mr_pid	mru.mrx.mrb_pid
-#define	mr_tid	mru.mrx.mrb_tid
-		/** cache line alignment */
-		char pad[(sizeof(MDB_rxbody)+CACHELINE-1) & ~(CACHELINE-1)];
-	} mru;
-} MDB_reader;
-
-	/** The header for the reader table.
-	 *	The table resides in a memory-mapped file. (This is a different file
-	 *	than is used for the main database.)
-	 *
-	 *	For POSIX the actual mutexes reside in the shared memory of this
-	 *	mapped file. On Windows, mutexes are named objects allocated by the
-	 *	kernel; we store the mutex names in this mapped file so that other
-	 *	processes can grab them. This same approach is also used on
-	 *	MacOSX/Darwin (using named semaphores) since MacOSX doesn't support
-	 *	process-shared POSIX mutexes. For these cases where a named object
-	 *	is used, the object name is derived from a 64 bit FNV hash of the
-	 *	environment pathname. As such, naming collisions are extremely
-	 *	unlikely. If a collision occurs, the results are unpredictable.
-	 */
-typedef struct MDB_txbody {
-		/** Stamp identifying this as an LMDB file. It must be set
-		 *	to #MDB_MAGIC. */
-	uint32_t	mtb_magic;
-		/** Format of this lock file. Must be set to #MDB_LOCK_FORMAT. */
-	uint32_t	mtb_format;
-#if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
-	char	mtb_rmname[MNAME_LEN];
-#else
-		/** Mutex protecting access to this table.
-		 *	This is the reader lock that #LOCK_MUTEX_R acquires.
-		 */
-	pthread_mutex_t	mtb_mutex;
-#endif
-		/**	The ID of the last transaction committed to the database.
-		 *	This is recorded here only for convenience; the value can always
-		 *	be determined by reading the main database meta pages.
-		 */
-	volatile txnid_t		mtb_txnid;
-		/** The number of slots that have been used in the reader table.
-		 *	This always records the maximum count, it is not decremented
-		 *	when readers release their slots.
-		 */
-	volatile unsigned	mtb_numreaders;
-} MDB_txbody;
-
-	/** The actual reader table definition. */
-typedef struct MDB_txninfo {
-	union {
-		MDB_txbody mtb;
-#define mti_magic	mt1.mtb.mtb_magic
-#define mti_format	mt1.mtb.mtb_format
-#define mti_mutex	mt1.mtb.mtb_mutex
-#define mti_rmname	mt1.mtb.mtb_rmname
-#define mti_txnid	mt1.mtb.mtb_txnid
-#define mti_numreaders	mt1.mtb.mtb_numreaders
-		char pad[(sizeof(MDB_txbody)+CACHELINE-1) & ~(CACHELINE-1)];
-	} mt1;
-	union {
-#if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
-		char mt2_wmname[MNAME_LEN];
-#define	mti_wmname	mt2.mt2_wmname
-#else
-		pthread_mutex_t	mt2_wmutex;
-#define mti_wmutex	mt2.mt2_wmutex
-#endif
-		char pad[(MNAME_LEN+CACHELINE-1) & ~(CACHELINE-1)];
-	} mt2;
-	MDB_reader	mti_readers[1];
-} MDB_txninfo;
-
-	/** Lockfile format signature: version, features and field layout */
-#define MDB_LOCK_FORMAT \
-	((uint32_t) \
-	 ((MDB_LOCK_VERSION) \
-	  /* Flags which describe functionality */ \
-	  + (((MDB_PIDLOCK) != 0) << 16)))
-/** @} */
-
-/** Common header for all page types.
- * Overflow records occupy a number of contiguous pages with no
- * headers on any page after the first.
- */
-typedef struct MDB_page {
-#define	mp_pgno	mp_p.p_pgno
-#define	mp_next	mp_p.p_next
-	union {
-		pgno_t		p_pgno;	/**< page number */
-		struct MDB_page *p_next; /**< for in-memory list of freed pages */
-	} mp_p;
-	uint16_t	mp_pad;
-/**	@defgroup mdb_page	Page Flags
- *	@ingroup internal
- *	Flags for the page headers.
- *	@{
- */
-#define	P_BRANCH	 0x01		/**< branch page */
-#define	P_LEAF		 0x02		/**< leaf page */
-#define	P_OVERFLOW	 0x04		/**< overflow page */
-#define	P_META		 0x08		/**< meta page */
-#define	P_DIRTY		 0x10		/**< dirty page, also set for #P_SUBP pages */
-#define	P_LEAF2		 0x20		/**< for #MDB_DUPFIXED records */
-#define	P_SUBP		 0x40		/**< for #MDB_DUPSORT sub-pages */
-#define	P_LOOSE		 0x4000		/**< page was dirtied then freed, can be reused */
-#define	P_KEEP		 0x8000		/**< leave this page alone during spill */
-/** @} */
-	uint16_t	mp_flags;		/**< @ref mdb_page */
-#define mp_lower	mp_pb.pb.pb_lower
-#define mp_upper	mp_pb.pb.pb_upper
-#define mp_pages	mp_pb.pb_pages
-	union {
-		struct {
-			indx_t		pb_lower;		/**< lower bound of free space */
-			indx_t		pb_upper;		/**< upper bound of free space */
-		} pb;
-		uint32_t	pb_pages;	/**< number of overflow pages */
-	} mp_pb;
-	indx_t		mp_ptrs[1];		/**< dynamic size */
-} MDB_page;
-
-	/** Size of the page header, excluding dynamic data at the end */
-#define PAGEHDRSZ	 ((unsigned) offsetof(MDB_page, mp_ptrs))
-
-	/** Address of first usable data byte in a page, after the header */
-#define METADATA(p)	 ((void *)((char *)(p) + PAGEHDRSZ))
-
-	/** ITS#7713, change PAGEBASE to handle 65536 byte pages */
-#define	PAGEBASE	((MDB_DEVEL) ? PAGEHDRSZ : 0)
-
-	/** Number of nodes on a page */
-#define NUMKEYS(p)	 (((p)->mp_lower - (PAGEHDRSZ-PAGEBASE)) >> 1)
-
-	/** The amount of space remaining in the page */
-#define SIZELEFT(p)	 (indx_t)((p)->mp_upper - (p)->mp_lower)
-
-	/** The percentage of space used in the page, in tenths of a percent. */
-#define PAGEFILL(env, p) (1000L * ((env)->me_psize - PAGEHDRSZ - SIZELEFT(p)) / \
-				((env)->me_psize - PAGEHDRSZ))
-	/** The minimum page fill factor, in tenths of a percent.
-	 *	Pages emptier than this are candidates for merging.
-	 */
-#define FILL_THRESHOLD	 250
-
-	/** Test if a page is a leaf page */
-#define IS_LEAF(p)	 F_ISSET((p)->mp_flags, P_LEAF)
-	/** Test if a page is a LEAF2 page */
-#define IS_LEAF2(p)	 F_ISSET((p)->mp_flags, P_LEAF2)
-	/** Test if a page is a branch page */
-#define IS_BRANCH(p)	 F_ISSET((p)->mp_flags, P_BRANCH)
-	/** Test if a page is an overflow page */
-#define IS_OVERFLOW(p)	 F_ISSET((p)->mp_flags, P_OVERFLOW)
-	/** Test if a page is a sub page */
-#define IS_SUBP(p)	 F_ISSET((p)->mp_flags, P_SUBP)
-
-	/** The number of overflow pages needed to store the given size. */
-#define OVPAGES(size, psize)	((PAGEHDRSZ-1 + (size)) / (psize) + 1)
-
-	/** Link in #MDB_txn.%mt_loose_pgs list */
-#define NEXT_LOOSE_PAGE(p)		(*(MDB_page **)((p) + 2))
-
-	/** Header for a single key/data pair within a page.
-	 * Used in pages of type #P_BRANCH and #P_LEAF without #P_LEAF2.
-	 * We guarantee 2-byte alignment for 'MDB_node's.
-	 */
-typedef struct MDB_node {
-	/** lo and hi are used for data size on leaf nodes and for
-	 * child pgno on branch nodes. On 64 bit platforms, flags
-	 * is also used for pgno. (Branch nodes have no flags).
-	 * They are in host byte order in case that lets some
-	 * accesses be optimized into a 32-bit word access.
-	 */
-#if BYTE_ORDER == LITTLE_ENDIAN
-	unsigned short	mn_lo, mn_hi;	/**< part of data size or pgno */
-#else
-	unsigned short	mn_hi, mn_lo;
-#endif
-/** @defgroup mdb_node Node Flags
- *	@ingroup internal
- *	Flags for node headers.
- *	@{
- */
-#define F_BIGDATA	 0x01			/**< data put on overflow page */
-#define F_SUBDATA	 0x02			/**< data is a sub-database */
-#define F_DUPDATA	 0x04			/**< data has duplicates */
-
-/** valid flags for #mdb_node_add() */
-#define	NODE_ADD_FLAGS	(F_DUPDATA|F_SUBDATA|MDB_RESERVE|MDB_APPEND)
-
-/** @} */
-	unsigned short	mn_flags;		/**< @ref mdb_node */
-	unsigned short	mn_ksize;		/**< key size */
-	char		mn_data[1];			/**< key and data are appended here */
-} MDB_node;
-
-	/** Size of the node header, excluding dynamic data at the end */
-#define NODESIZE	 offsetof(MDB_node, mn_data)
-
-	/** Bit position of top word in page number, for shifting mn_flags */
-#define PGNO_TOPWORD ((pgno_t)-1 > 0xffffffffu ? 32 : 0)
-
-	/** Size of a node in a branch page with a given key.
-	 *	This is just the node header plus the key, there is no data.
-	 */
-#define INDXSIZE(k)	 (NODESIZE + ((k) == NULL ? 0 : (k)->mv_size))
-
-	/** Size of a node in a leaf page with a given key and data.
-	 *	This is node header plus key plus data size.
-	 */
-#define LEAFSIZE(k, d)	 (NODESIZE + (k)->mv_size + (d)->mv_size)
-
-	/** Address of node \b i in page \b p */
-#define NODEPTR(p, i)	 ((MDB_node *)((char *)(p) + (p)->mp_ptrs[i] + PAGEBASE))
-
-	/** Address of the key for the node */
-#define NODEKEY(node)	 (void *)((node)->mn_data)
-
-	/** Address of the data for a node */
-#define NODEDATA(node)	 (void *)((char *)(node)->mn_data + (node)->mn_ksize)
-
-	/** Get the page number pointed to by a branch node */
-#define NODEPGNO(node) \
-	((node)->mn_lo | ((pgno_t) (node)->mn_hi << 16) | \
-	 (PGNO_TOPWORD ? ((pgno_t) (node)->mn_flags << PGNO_TOPWORD) : 0))
-	/** Set the page number in a branch node */
-#define SETPGNO(node,pgno)	do { \
-	(node)->mn_lo = (pgno) & 0xffff; (node)->mn_hi = (pgno) >> 16; \
-	if (PGNO_TOPWORD) (node)->mn_flags = (pgno) >> PGNO_TOPWORD; } while(0)
-
-	/** Get the size of the data in a leaf node */
-#define NODEDSZ(node)	 ((node)->mn_lo | ((unsigned)(node)->mn_hi << 16))
-	/** Set the size of the data for a leaf node */
-#define SETDSZ(node,size)	do { \
-	(node)->mn_lo = (size) & 0xffff; (node)->mn_hi = (size) >> 16;} while(0)
-	/** The size of a key in a node */
-#define NODEKSZ(node)	 ((node)->mn_ksize)
-
-	/** Copy a page number from src to dst */
-#ifdef MISALIGNED_OK
-#define COPY_PGNO(dst,src)	dst = src
-#else
-#if SIZE_MAX > 4294967295UL
-#define COPY_PGNO(dst,src)	do { \
-	unsigned short *s, *d;	\
-	s = (unsigned short *)&(src);	\
-	d = (unsigned short *)&(dst);	\
-	*d++ = *s++;	\
-	*d++ = *s++;	\
-	*d++ = *s++;	\
-	*d = *s;	\
-} while (0)
-#else
-#define COPY_PGNO(dst,src)	do { \
-	unsigned short *s, *d;	\
-	s = (unsigned short *)&(src);	\
-	d = (unsigned short *)&(dst);	\
-	*d++ = *s++;	\
-	*d = *s;	\
-} while (0)
-#endif
-#endif
-	/** The address of a key in a LEAF2 page.
-	 *	LEAF2 pages are used for #MDB_DUPFIXED sorted-duplicate sub-DBs.
-	 *	There are no node headers, keys are stored contiguously.
-	 */
-#define LEAF2KEY(p, i, ks)	((char *)(p) + PAGEHDRSZ + ((i)*(ks)))
-
-	/** Set the \b node's key into \b keyptr, if requested. */
-#define MDB_GET_KEY(node, keyptr)	{ if ((keyptr) != NULL) { \
-	(keyptr)->mv_size = NODEKSZ(node); (keyptr)->mv_data = NODEKEY(node); } }
-
-	/** Set the \b node's key into \b key. */
-#define MDB_GET_KEY2(node, key)	{ key.mv_size = NODEKSZ(node); key.mv_data = NODEKEY(node); }
-
-	/** Information about a single database in the environment. */
-typedef struct MDB_db {
-	uint32_t	md_pad;		/**< also ksize for LEAF2 pages */
-	uint16_t	md_flags;	/**< @ref mdb_dbi_open */
-	uint16_t	md_depth;	/**< depth of this tree */
-	pgno_t		md_branch_pages;	/**< number of internal pages */
-	pgno_t		md_leaf_pages;		/**< number of leaf pages */
-	pgno_t		md_overflow_pages;	/**< number of overflow pages */
-	size_t		md_entries;		/**< number of data items */
-	pgno_t		md_root;		/**< the root page of this tree */
-} MDB_db;
-
-	/** mdb_dbi_open flags */
-#define MDB_VALID	0x8000		/**< DB handle is valid, for me_dbflags */
-#define PERSISTENT_FLAGS	(0xffff & ~(MDB_VALID))
-#define VALID_FLAGS	(MDB_REVERSEKEY|MDB_DUPSORT|MDB_INTEGERKEY|MDB_DUPFIXED|\
-	MDB_INTEGERDUP|MDB_REVERSEDUP|MDB_CREATE)
-
-	/** Handle for the DB used to track free pages. */
-#define	FREE_DBI	0
-	/** Handle for the default DB. */
-#define	MAIN_DBI	1
-
-	/** Meta page content.
-	 *	A meta page is the start point for accessing a database snapshot.
-	 *	Pages 0-1 are meta pages. Transaction N writes meta page #(N % 2).
-	 */
-typedef struct MDB_meta {
-		/** Stamp identifying this as an LMDB file. It must be set
-		 *	to #MDB_MAGIC. */
-	uint32_t	mm_magic;
-		/** Version number of this file. Must be set to #MDB_DATA_VERSION. */
-	uint32_t	mm_version;
-	void		*mm_address;		/**< address for fixed mapping */
-	size_t		mm_mapsize;			/**< size of mmap region */
-	MDB_db		mm_dbs[2];			/**< first is free space, 2nd is main db */
-	/** The size of pages used in this DB */
-#define	mm_psize	mm_dbs[0].md_pad
-	/** Any persistent environment flags. @ref mdb_env */
-#define	mm_flags	mm_dbs[0].md_flags
-	pgno_t		mm_last_pg;			/**< last used page in file */
-	volatile txnid_t	mm_txnid;	/**< txnid that committed this page */
-} MDB_meta;
-
-	/** Buffer for a stack-allocated meta page.
-	 *	The members define size and alignment, and silence type
-	 *	aliasing warnings.  They are not used directly; that could
-	 *	mean incorrectly using several union members in parallel.
-	 */
-typedef union MDB_metabuf {
-	MDB_page	mb_page;
-	struct {
-		char		mm_pad[PAGEHDRSZ];
-		MDB_meta	mm_meta;
-	} mb_metabuf;
-} MDB_metabuf;
-
-	/** Auxiliary DB info.
-	 *	The information here is mostly static/read-only. There is
-	 *	only a single copy of this record in the environment.
-	 */
-typedef struct MDB_dbx {
-	MDB_val		md_name;		/**< name of the database */
-	MDB_cmp_func	*md_cmp;	/**< function for comparing keys */
-	MDB_cmp_func	*md_dcmp;	/**< function for comparing data items */
-	MDB_rel_func	*md_rel;	/**< user relocate function */
-	void		*md_relctx;		/**< user-provided context for md_rel */
-} MDB_dbx;
-
-	/** A database transaction.
-	 *	Every operation requires a transaction handle.
-	 */
-struct MDB_txn {
-	MDB_txn		*mt_parent;		/**< parent of a nested txn */
-	MDB_txn		*mt_child;		/**< nested txn under this txn */
-	pgno_t		mt_next_pgno;	/**< next unallocated page */
-	/** The ID of this transaction. IDs are integers incrementing from 1.
-	 *	Only committed write transactions increment the ID. If a transaction
-	 *	aborts, the ID may be re-used by the next writer.
-	 */
-	txnid_t		mt_txnid;
-	MDB_env		*mt_env;		/**< the DB environment */
-	/** The list of pages that became unused during this transaction.
-	 */
-	MDB_IDL		mt_free_pgs;
-	/** The list of loose pages that became unused and may be reused
-	 *	in this transaction, linked through #NEXT_LOOSE_PAGE(page).
-	 */
-	MDB_page	*mt_loose_pgs;
-	/* #Number of loose pages (#mt_loose_pgs) */
-	int			mt_loose_count;
-	/** The sorted list of dirty pages we temporarily wrote to disk
-	 *	because the dirty list was full. page numbers in here are
-	 *	shifted left by 1, deleted slots have the LSB set.
-	 */
-	MDB_IDL		mt_spill_pgs;
-	union {
-		/** For write txns: Modified pages. Sorted when not MDB_WRITEMAP. */
-		MDB_ID2L	dirty_list;
-		/** For read txns: This thread/txn's reader table slot, or NULL. */
-		MDB_reader	*reader;
-	} mt_u;
-	/** Array of records for each DB known in the environment. */
-	MDB_dbx		*mt_dbxs;
-	/** Array of MDB_db records for each known DB */
-	MDB_db		*mt_dbs;
-	/** Array of sequence numbers for each DB handle */
-	unsigned int	*mt_dbiseqs;
-/** @defgroup mt_dbflag	Transaction DB Flags
- *	@ingroup internal
- * @{
- */
-#define DB_DIRTY	0x01		/**< DB was modified or is DUPSORT data */
-#define DB_STALE	0x02		/**< Named-DB record is older than txnID */
-#define DB_NEW		0x04		/**< Named-DB handle opened in this txn */
-#define DB_VALID	0x08		/**< DB handle is valid, see also #MDB_VALID */
-/** @} */
-	/** In write txns, array of cursors for each DB */
-	MDB_cursor	**mt_cursors;
-	/** Array of flags for each DB */
-	unsigned char	*mt_dbflags;
-	/**	Number of DB records in use. This number only ever increments;
-	 *	we don't decrement it when individual DB handles are closed.
-	 */
-	MDB_dbi		mt_numdbs;
-
-/** @defgroup mdb_txn	Transaction Flags
- *	@ingroup internal
- *	@{
- */
-#define MDB_TXN_RDONLY		0x01		/**< read-only transaction */
-#define MDB_TXN_ERROR		0x02		/**< txn is unusable after an error */
-#define MDB_TXN_DIRTY		0x04		/**< must write, even if dirty list is empty */
-#define MDB_TXN_SPILLS		0x08		/**< txn or a parent has spilled pages */
-/** @} */
-	unsigned int	mt_flags;		/**< @ref mdb_txn */
-	/** #dirty_list room: Array size - \#dirty pages visible to this txn.
-	 *	Includes ancestor txns' dirty pages not hidden by other txns'
-	 *	dirty/spilled pages. Thus commit(nested txn) has room to merge
-	 *	dirty_list into mt_parent after freeing hidden mt_parent pages.
-	 */
-	unsigned int	mt_dirty_room;
-};
-
-/** Enough space for 2^32 nodes with minimum of 2 keys per node. I.e., plenty.
- * At 4 keys per node, enough for 2^64 nodes, so there's probably no need to
- * raise this on a 64 bit machine.
- */
-#define CURSOR_STACK		 32
-
-struct MDB_xcursor;
-
-	/** Cursors are used for all DB operations.
-	 *	A cursor holds a path of (page pointer, key index) from the DB
-	 *	root to a position in the DB, plus other state. #MDB_DUPSORT
-	 *	cursors include an xcursor to the current data item. Write txns
-	 *	track their cursors and keep them up to date when data moves.
-	 *	Exception: An xcursor's pointer to a #P_SUBP page can be stale.
-	 *	(A node with #F_DUPDATA but no #F_SUBDATA contains a subpage).
-	 */
-struct MDB_cursor {
-	/** Next cursor on this DB in this txn */
-	MDB_cursor	*mc_next;
-	/** Backup of the original cursor if this cursor is a shadow */
-	MDB_cursor	*mc_backup;
-	/** Context used for databases with #MDB_DUPSORT, otherwise NULL */
-	struct MDB_xcursor	*mc_xcursor;
-	/** The transaction that owns this cursor */
-	MDB_txn		*mc_txn;
-	/** The database handle this cursor operates on */
-	MDB_dbi		mc_dbi;
-	/** The database record for this cursor */
-	MDB_db		*mc_db;
-	/** The database auxiliary record for this cursor */
-	MDB_dbx		*mc_dbx;
-	/** The @ref mt_dbflag for this database */
-	unsigned char	*mc_dbflag;
-	unsigned short 	mc_snum;	/**< number of pushed pages */
-	unsigned short	mc_top;		/**< index of top page, normally mc_snum-1 */
-/** @defgroup mdb_cursor	Cursor Flags
- *	@ingroup internal
- *	Cursor state flags.
- *	@{
- */
-#define C_INITIALIZED	0x01	/**< cursor has been initialized and is valid */
-#define C_EOF	0x02			/**< No more data */
-#define C_SUB	0x04			/**< Cursor is a sub-cursor */
-#define C_DEL	0x08			/**< last op was a cursor_del */
-#define C_SPLITTING	0x20		/**< Cursor is in page_split */
-#define C_UNTRACK	0x40		/**< Un-track cursor when closing */
-/** @} */
-	unsigned int	mc_flags;	/**< @ref mdb_cursor */
-	MDB_page	*mc_pg[CURSOR_STACK];	/**< stack of pushed pages */
-	indx_t		mc_ki[CURSOR_STACK];	/**< stack of page indices */
-};
-
-	/** Context for sorted-dup records.
-	 *	We could have gone to a fully recursive design, with arbitrarily
-	 *	deep nesting of sub-databases. But for now we only handle these
-	 *	levels - main DB, optional sub-DB, sorted-duplicate DB.
-	 */
-typedef struct MDB_xcursor {
-	/** A sub-cursor for traversing the Dup DB */
-	MDB_cursor mx_cursor;
-	/** The database record for this Dup DB */
-	MDB_db	mx_db;
-	/**	The auxiliary DB record for this Dup DB */
-	MDB_dbx	mx_dbx;
-	/** The @ref mt_dbflag for this Dup DB */
-	unsigned char mx_dbflag;
-} MDB_xcursor;
-
-	/** State of FreeDB old pages, stored in the MDB_env */
-typedef struct MDB_pgstate {
-	pgno_t		*mf_pghead;	/**< Reclaimed freeDB pages, or NULL before use */
-	txnid_t		mf_pglast;	/**< ID of last used record, or 0 if !mf_pghead */
-} MDB_pgstate;
-
-	/** The database environment. */
-struct MDB_env {
-	HANDLE		me_fd;		/**< The main data file */
-	HANDLE		me_lfd;		/**< The lock file */
-	HANDLE		me_mfd;			/**< just for writing the meta pages */
-	/** Failed to update the meta page. Probably an I/O error. */
-#define	MDB_FATAL_ERROR	0x80000000U
-	/** Some fields are initialized. */
-#define	MDB_ENV_ACTIVE	0x20000000U
-	/** me_txkey is set */
-#define	MDB_ENV_TXKEY	0x10000000U
-	/** fdatasync is unreliable */
-#define	MDB_FSYNCONLY	0x08000000U
-	uint32_t 	me_flags;		/**< @ref mdb_env */
-	unsigned int	me_psize;	/**< DB page size, inited from me_os_psize */
-	unsigned int	me_os_psize;	/**< OS page size, from #GET_PAGESIZE */
-	unsigned int	me_maxreaders;	/**< size of the reader table */
-	unsigned int	me_numreaders;	/**< max numreaders set by this env */
-	MDB_dbi		me_numdbs;		/**< number of DBs opened */
-	MDB_dbi		me_maxdbs;		/**< size of the DB table */
-	MDB_PID_T	me_pid;		/**< process ID of this env */
-	char		*me_path;		/**< path to the DB files */
-	char		*me_map;		/**< the memory map of the data file */
-	MDB_txninfo	*me_txns;		/**< the memory map of the lock file or NULL */
-	MDB_meta	*me_metas[2];	/**< pointers to the two meta pages */
-	void		*me_pbuf;		/**< scratch area for DUPSORT put() */
-	MDB_txn		*me_txn;		/**< current write transaction */
-	MDB_txn		*me_txn0;		/**< prealloc'd write transaction */
-	size_t		me_mapsize;		/**< size of the data memory map */
-	off_t		me_size;		/**< current file size */
-	pgno_t		me_maxpg;		/**< me_mapsize / me_psize */
-	MDB_dbx		*me_dbxs;		/**< array of static DB info */
-	uint16_t	*me_dbflags;	/**< array of flags from MDB_db.md_flags */
-	unsigned int	*me_dbiseqs;	/**< array of dbi sequence numbers */
-	pthread_key_t	me_txkey;	/**< thread-key for readers */
-	txnid_t		me_pgoldest;	/**< ID of oldest reader last time we looked */
-	MDB_pgstate	me_pgstate;		/**< state of old pages from freeDB */
-#	define		me_pglast	me_pgstate.mf_pglast
-#	define		me_pghead	me_pgstate.mf_pghead
-	MDB_page	*me_dpages;		/**< list of malloc'd blocks for re-use */
-	/** IDL of pages that became unused in a write txn */
-	MDB_IDL		me_free_pgs;
-	/** ID2L of pages written during a write txn. Length MDB_IDL_UM_SIZE. */
-	MDB_ID2L	me_dirty_list;
-	/** Max number of freelist items that can fit in a single overflow page */
-	int			me_maxfree_1pg;
-	/** Max size of a node on a page */
-	unsigned int	me_nodemax;
-#if !(MDB_MAXKEYSIZE)
-	unsigned int	me_maxkey;	/**< max size of a key */
-#endif
-	int		me_live_reader;		/**< have liveness lock in reader table */
-#ifdef _WIN32
-	int		me_pidquery;		/**< Used in OpenProcess */
-	HANDLE		me_rmutex;		/* Windows mutexes don't reside in shared mem */
-	HANDLE		me_wmutex;
-#elif defined(MDB_USE_POSIX_SEM)
-	sem_t		*me_rmutex;		/* Shared mutexes are not supported */
-	sem_t		*me_wmutex;
-#endif
-	void		*me_userctx;	 /**< User-settable context */
-	MDB_assert_func *me_assert_func; /**< Callback for assertion failures */
-};
-
-	/** Nested transaction */
-typedef struct MDB_ntxn {
-	MDB_txn		mnt_txn;		/**< the transaction */
-	MDB_pgstate	mnt_pgstate;	/**< parent transaction's saved freestate */
-} MDB_ntxn;
-
-	/** max number of pages to commit in one writev() call */
-#define MDB_COMMIT_PAGES	 64
-#if defined(IOV_MAX) && IOV_MAX < MDB_COMMIT_PAGES
-#undef MDB_COMMIT_PAGES
-#define MDB_COMMIT_PAGES	IOV_MAX
-#endif
-
-	/** max bytes to write in one call */
-#define MAX_WRITE		(0x80000000U >> (sizeof(ssize_t) == 4))
-
-	/** Check \b txn and \b dbi arguments to a function */
-#define TXN_DBI_EXIST(txn, dbi) \
-	((txn) && (dbi) < (txn)->mt_numdbs && ((txn)->mt_dbflags[dbi] & DB_VALID))
-
-	/** Check for misused \b dbi handles */
-#define TXN_DBI_CHANGED(txn, dbi) \
-	((txn)->mt_dbiseqs[dbi] != (txn)->mt_env->me_dbiseqs[dbi])
-
-static int  mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp);
-static int  mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp);
-static int  mdb_page_touch(MDB_cursor *mc);
-
-static int  mdb_page_get(MDB_txn *txn, pgno_t pgno, MDB_page **mp, int *lvl);
-static int  mdb_page_search_root(MDB_cursor *mc,
-			    MDB_val *key, int modify);
-#define MDB_PS_MODIFY	1
-#define MDB_PS_ROOTONLY	2
-#define MDB_PS_FIRST	4
-#define MDB_PS_LAST		8
-static int  mdb_page_search(MDB_cursor *mc,
-			    MDB_val *key, int flags);
-static int	mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst);
-
-#define MDB_SPLIT_REPLACE	MDB_APPENDDUP	/**< newkey is not new */
-static int	mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata,
-				pgno_t newpgno, unsigned int nflags);
-
-static int  mdb_env_read_header(MDB_env *env, MDB_meta *meta);
-static int  mdb_env_pick_meta(const MDB_env *env);
-static int  mdb_env_write_meta(MDB_txn *txn);
-#if !(defined(_WIN32) || defined(MDB_USE_POSIX_SEM)) /* Drop unused excl arg */
-# define mdb_env_close0(env, excl) mdb_env_close1(env)
-#endif
-static void mdb_env_close0(MDB_env *env, int excl);
-
-static MDB_node *mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp);
-static int  mdb_node_add(MDB_cursor *mc, indx_t indx,
-			    MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags);
-static void mdb_node_del(MDB_cursor *mc, int ksize);
-static void mdb_node_shrink(MDB_page *mp, indx_t indx);
-static int	mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst);
-static int  mdb_node_read(MDB_txn *txn, MDB_node *leaf, MDB_val *data);
-static size_t	mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data);
-static size_t	mdb_branch_size(MDB_env *env, MDB_val *key);
-
-static int	mdb_rebalance(MDB_cursor *mc);
-static int	mdb_update_key(MDB_cursor *mc, MDB_val *key);
-
-static void	mdb_cursor_pop(MDB_cursor *mc);
-static int	mdb_cursor_push(MDB_cursor *mc, MDB_page *mp);
-
-static int	mdb_cursor_del0(MDB_cursor *mc);
-static int	mdb_del0(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data, unsigned flags);
-static int	mdb_cursor_sibling(MDB_cursor *mc, int move_right);
-static int	mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op);
-static int	mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op);
-static int	mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op,
-				int *exactp);
-static int	mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data);
-static int	mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data);
-
-static void	mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx);
-static void	mdb_xcursor_init0(MDB_cursor *mc);
-static void	mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node);
-
-static int	mdb_drop0(MDB_cursor *mc, int subs);
-static void mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi);
-
-/** @cond */
-static MDB_cmp_func	mdb_cmp_memn, mdb_cmp_memnr, mdb_cmp_int, mdb_cmp_cint, mdb_cmp_long;
-/** @endcond */
-
-/** Compare two items pointing at size_t's of unknown alignment. */
-#ifdef MISALIGNED_OK
-# define mdb_cmp_clong mdb_cmp_long
-#else
-# define mdb_cmp_clong mdb_cmp_cint
-#endif
-
-#ifdef _WIN32
-static SECURITY_DESCRIPTOR mdb_null_sd;
-static SECURITY_ATTRIBUTES mdb_all_sa;
-static int mdb_sec_inited;
-#endif
-
-/** Return the library version info. */
-char *
-mdb_version(int *major, int *minor, int *patch)
-{
-	if (major) *major = MDB_VERSION_MAJOR;
-	if (minor) *minor = MDB_VERSION_MINOR;
-	if (patch) *patch = MDB_VERSION_PATCH;
-	return MDB_VERSION_STRING;
-}
-
-/** Table of descriptions for LMDB @ref errors */
-static char *const mdb_errstr[] = {
-	"MDB_KEYEXIST: Key/data pair already exists",
-	"MDB_NOTFOUND: No matching key/data pair found",
-	"MDB_PAGE_NOTFOUND: Requested page not found",
-	"MDB_CORRUPTED: Located page was wrong type",
-	"MDB_PANIC: Update of meta page failed",
-	"MDB_VERSION_MISMATCH: Database environment version mismatch",
-	"MDB_INVALID: File is not an LMDB file",
-	"MDB_MAP_FULL: Environment mapsize limit reached",
-	"MDB_DBS_FULL: Environment maxdbs limit reached",
-	"MDB_READERS_FULL: Environment maxreaders limit reached",
-	"MDB_TLS_FULL: Thread-local storage keys full - too many environments open",
-	"MDB_TXN_FULL: Transaction has too many dirty pages - transaction too big",
-	"MDB_CURSOR_FULL: Internal error - cursor stack limit reached",
-	"MDB_PAGE_FULL: Internal error - page has no more space",
-	"MDB_MAP_RESIZED: Database contents grew beyond environment mapsize",
-	"MDB_INCOMPATIBLE: Operation and DB incompatible, or DB flags changed",
-	"MDB_BAD_RSLOT: Invalid reuse of reader locktable slot",
-	"MDB_BAD_TXN: Transaction cannot recover - it must be aborted",
-	"MDB_BAD_VALSIZE: Unsupported size of key/DB name/data, or wrong DUPFIXED size",
-	"MDB_BAD_DBI: The specified DBI handle was closed/changed unexpectedly",
-};
-
-char *
-mdb_strerror(int err)
-{
-#ifdef _WIN32
-	/** HACK: pad 4KB on stack over the buf. Return system msgs in buf.
-	 *	This works as long as no function between the call to mdb_strerror
-	 *	and the actual use of the message uses more than 4K of stack.
-	 */
-	char pad[4096];
-	char buf[1024], *ptr = buf;
-#endif
-	int i;
-	if (!err)
-		return ("Successful return: 0");
-
-	if (err >= MDB_KEYEXIST && err <= MDB_LAST_ERRCODE) {
-		i = err - MDB_KEYEXIST;
-		return mdb_errstr[i];
-	}
-
-#ifdef _WIN32
-	/* These are the C-runtime error codes we use. The comment indicates
-	 * their numeric value, and the Win32 error they would correspond to
-	 * if the error actually came from a Win32 API. A major mess, we should
-	 * have used LMDB-specific error codes for everything.
-	 */
-	switch(err) {
-	case ENOENT:	/* 2, FILE_NOT_FOUND */
-	case EIO:		/* 5, ACCESS_DENIED */
-	case ENOMEM:	/* 12, INVALID_ACCESS */
-	case EACCES:	/* 13, INVALID_DATA */
-	case EBUSY:		/* 16, CURRENT_DIRECTORY */
-	case EINVAL:	/* 22, BAD_COMMAND */
-	case ENOSPC:	/* 28, OUT_OF_PAPER */
-		return strerror(err);
-	default:
-		;
-	}
-	buf[0] = 0;
-	FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM |
-		FORMAT_MESSAGE_IGNORE_INSERTS,
-		NULL, err, 0, ptr, sizeof(buf), (va_list *)pad);
-	return ptr;
-#else
-	return strerror(err);
-#endif
-}
-
-/** assert(3) variant in cursor context */
-#define mdb_cassert(mc, expr)	mdb_assert0((mc)->mc_txn->mt_env, expr, #expr)
-/** assert(3) variant in transaction context */
-#define mdb_tassert(mc, expr)	mdb_assert0((txn)->mt_env, expr, #expr)
-/** assert(3) variant in environment context */
-#define mdb_eassert(env, expr)	mdb_assert0(env, expr, #expr)
-
-#ifndef NDEBUG
-# define mdb_assert0(env, expr, expr_txt) ((expr) ? (void)0 : \
-		mdb_assert_fail(env, expr_txt, mdb_func_, __FILE__, __LINE__))
-
-static void
-mdb_assert_fail(MDB_env *env, const char *expr_txt,
-	const char *func, const char *file, int line)
-{
-	char buf[400];
-	sprintf(buf, "%.100s:%d: Assertion '%.200s' failed in %.40s()",
-		file, line, expr_txt, func);
-	if (env->me_assert_func)
-		env->me_assert_func(env, buf);
-	fprintf(stderr, "%s\n", buf);
-	abort();
-}
-#else
-# define mdb_assert0(env, expr, expr_txt) ((void) 0)
-#endif /* NDEBUG */
-
-#if MDB_DEBUG
-/** Return the page number of \b mp which may be sub-page, for debug output */
-static pgno_t
-mdb_dbg_pgno(MDB_page *mp)
-{
-	pgno_t ret;
-	COPY_PGNO(ret, mp->mp_pgno);
-	return ret;
-}
-
-/** Display a key in hexadecimal and return the address of the result.
- * @param[in] key the key to display
- * @param[in] buf the buffer to write into. Should always be #DKBUF.
- * @return The key in hexadecimal form.
- */
-char *
-mdb_dkey(MDB_val *key, char *buf)
-{
-	char *ptr = buf;
-	unsigned char *c = key->mv_data;
-	unsigned int i;
-
-	if (!key)
-		return "";
-
-	if (key->mv_size > DKBUF_MAXKEYSIZE)
-		return "MDB_MAXKEYSIZE";
-	/* may want to make this a dynamic check: if the key is mostly
-	 * printable characters, print it as-is instead of converting to hex.
-	 */
-#if 1
-	buf[0] = '\0';
-	for (i=0; i<key->mv_size; i++)
-		ptr += sprintf(ptr, "%02x", *c++);
-#else
-	sprintf(buf, "%.*s", key->mv_size, key->mv_data);
-#endif
-	return buf;
-}
-
-static const char *
-mdb_leafnode_type(MDB_node *n)
-{
-	static char *const tp[2][2] = {{"", ": DB"}, {": sub-page", ": sub-DB"}};
-	return F_ISSET(n->mn_flags, F_BIGDATA) ? ": overflow page" :
-		tp[F_ISSET(n->mn_flags, F_DUPDATA)][F_ISSET(n->mn_flags, F_SUBDATA)];
-}
-
-/** Display all the keys in the page. */
-void
-mdb_page_list(MDB_page *mp)
-{
-	pgno_t pgno = mdb_dbg_pgno(mp);
-	const char *type, *state = (mp->mp_flags & P_DIRTY) ? ", dirty" : "";
-	MDB_node *node;
-	unsigned int i, nkeys, nsize, total = 0;
-	MDB_val key;
-	DKBUF;
-
-	switch (mp->mp_flags & (P_BRANCH|P_LEAF|P_LEAF2|P_META|P_OVERFLOW|P_SUBP)) {
-	case P_BRANCH:              type = "Branch page";		break;
-	case P_LEAF:                type = "Leaf page";			break;
-	case P_LEAF|P_SUBP:         type = "Sub-page";			break;
-	case P_LEAF|P_LEAF2:        type = "LEAF2 page";		break;
-	case P_LEAF|P_LEAF2|P_SUBP: type = "LEAF2 sub-page";	break;
-	case P_OVERFLOW:
-		fprintf(stderr, "Overflow page %"Z"u pages %u%s\n",
-			pgno, mp->mp_pages, state);
-		return;
-	case P_META:
-		fprintf(stderr, "Meta-page %"Z"u txnid %"Z"u\n",
-			pgno, ((MDB_meta *)METADATA(mp))->mm_txnid);
-		return;
-	default:
-		fprintf(stderr, "Bad page %"Z"u flags 0x%u\n", pgno, mp->mp_flags);
-		return;
-	}
-
-	nkeys = NUMKEYS(mp);
-	fprintf(stderr, "%s %"Z"u numkeys %d%s\n", type, pgno, nkeys, state);
-
-	for (i=0; i<nkeys; i++) {
-		if (IS_LEAF2(mp)) {	/* LEAF2 pages have no mp_ptrs[] or node headers */
-			key.mv_size = nsize = mp->mp_pad;
-			key.mv_data = LEAF2KEY(mp, i, nsize);
-			total += nsize;
-			fprintf(stderr, "key %d: nsize %d, %s\n", i, nsize, DKEY(&key));
-			continue;
-		}
-		node = NODEPTR(mp, i);
-		key.mv_size = node->mn_ksize;
-		key.mv_data = node->mn_data;
-		nsize = NODESIZE + key.mv_size;
-		if (IS_BRANCH(mp)) {
-			fprintf(stderr, "key %d: page %"Z"u, %s\n", i, NODEPGNO(node),
-				DKEY(&key));
-			total += nsize;
-		} else {
-			if (F_ISSET(node->mn_flags, F_BIGDATA))
-				nsize += sizeof(pgno_t);
-			else
-				nsize += NODEDSZ(node);
-			total += nsize;
-			nsize += sizeof(indx_t);
-			fprintf(stderr, "key %d: nsize %d, %s%s\n",
-				i, nsize, DKEY(&key), mdb_leafnode_type(node));
-		}
-		total = EVEN(total);
-	}
-	fprintf(stderr, "Total: header %d + contents %d + unused %d\n",
-		IS_LEAF2(mp) ? PAGEHDRSZ : PAGEBASE + mp->mp_lower, total, SIZELEFT(mp));
-}
-
-void
-mdb_cursor_chk(MDB_cursor *mc)
-{
-	unsigned int i;
-	MDB_node *node;
-	MDB_page *mp;
-
-	if (!mc->mc_snum && !(mc->mc_flags & C_INITIALIZED)) return;
-	for (i=0; i<mc->mc_top; i++) {
-		mp = mc->mc_pg[i];
-		node = NODEPTR(mp, mc->mc_ki[i]);
-		if (NODEPGNO(node) != mc->mc_pg[i+1]->mp_pgno)
-			printf("oops!\n");
-	}
-	if (mc->mc_ki[i] >= NUMKEYS(mc->mc_pg[i]))
-		printf("ack!\n");
-}
-#endif
-
-#if (MDB_DEBUG) > 2
-/** Count all the pages in each DB and in the freelist
- *  and make sure it matches the actual number of pages
- *  being used.
- *  All named DBs must be open for a correct count.
- */
-static void mdb_audit(MDB_txn *txn)
-{
-	MDB_cursor mc;
-	MDB_val key, data;
-	MDB_ID freecount, count;
-	MDB_dbi i;
-	int rc;
-
-	freecount = 0;
-	mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
-	while ((rc = mdb_cursor_get(&mc, &key, &data, MDB_NEXT)) == 0)
-		freecount += *(MDB_ID *)data.mv_data;
-	mdb_tassert(txn, rc == MDB_NOTFOUND);
-
-	count = 0;
-	for (i = 0; i<txn->mt_numdbs; i++) {
-		MDB_xcursor mx;
-		if (!(txn->mt_dbflags[i] & DB_VALID))
-			continue;
-		mdb_cursor_init(&mc, txn, i, &mx);
-		if (txn->mt_dbs[i].md_root == P_INVALID)
-			continue;
-		count += txn->mt_dbs[i].md_branch_pages +
-			txn->mt_dbs[i].md_leaf_pages +
-			txn->mt_dbs[i].md_overflow_pages;
-		if (txn->mt_dbs[i].md_flags & MDB_DUPSORT) {
-			rc = mdb_page_search(&mc, NULL, MDB_PS_FIRST);
-			for (; rc == MDB_SUCCESS; rc = mdb_cursor_sibling(&mc, 1)) {
-				unsigned j;
-				MDB_page *mp;
-				mp = mc.mc_pg[mc.mc_top];
-				for (j=0; j<NUMKEYS(mp); j++) {
-					MDB_node *leaf = NODEPTR(mp, j);
-					if (leaf->mn_flags & F_SUBDATA) {
-						MDB_db db;
-						memcpy(&db, NODEDATA(leaf), sizeof(db));
-						count += db.md_branch_pages + db.md_leaf_pages +
-							db.md_overflow_pages;
-					}
-				}
-			}
-			mdb_tassert(txn, rc == MDB_NOTFOUND);
-		}
-	}
-	if (freecount + count + 2 /* metapages */ != txn->mt_next_pgno) {
-		fprintf(stderr, "audit: %lu freecount: %lu count: %lu total: %lu next_pgno: %lu\n",
-			txn->mt_txnid, freecount, count+2, freecount+count+2, txn->mt_next_pgno);
-	}
-}
-#endif
-
-int
-mdb_cmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
-{
-	return txn->mt_dbxs[dbi].md_cmp(a, b);
-}
-
-int
-mdb_dcmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
-{
-	MDB_cmp_func *dcmp = txn->mt_dbxs[dbi].md_dcmp;
-#if UINT_MAX < SIZE_MAX
-	if (dcmp == mdb_cmp_int && a->mv_size == sizeof(size_t))
-		dcmp = mdb_cmp_clong;
-#endif
-	return dcmp(a, b);
-}
-
-/** Allocate memory for a page.
- * Re-use old malloc'd pages first for singletons, otherwise just malloc.
- */
-static MDB_page *
-mdb_page_malloc(MDB_txn *txn, unsigned num)
-{
-	MDB_env *env = txn->mt_env;
-	MDB_page *ret = env->me_dpages;
-	size_t psize = env->me_psize, sz = psize, off;
-	/* For ! #MDB_NOMEMINIT, psize counts how much to init.
-	 * For a single page alloc, we init everything after the page header.
-	 * For multi-page, we init the final page; if the caller needed that
-	 * many pages they will be filling in at least up to the last page.
-	 */
-	if (num == 1) {
-		if (ret) {
-			VGMEMP_ALLOC(env, ret, sz);
-			VGMEMP_DEFINED(ret, sizeof(ret->mp_next));
-			env->me_dpages = ret->mp_next;
-			return ret;
-		}
-		psize -= off = PAGEHDRSZ;
-	} else {
-		sz *= num;
-		off = sz - psize;
-	}
-	if ((ret = malloc(sz)) != NULL) {
-		VGMEMP_ALLOC(env, ret, sz);
-		if (!(env->me_flags & MDB_NOMEMINIT)) {
-			memset((char *)ret + off, 0, psize);
-			ret->mp_pad = 0;
-		}
-	} else {
-		txn->mt_flags |= MDB_TXN_ERROR;
-	}
-	return ret;
-}
-/** Free a single page.
- * Saves single pages to a list, for future reuse.
- * (This is not used for multi-page overflow pages.)
- */
-static void
-mdb_page_free(MDB_env *env, MDB_page *mp)
-{
-	mp->mp_next = env->me_dpages;
-	VGMEMP_FREE(env, mp);
-	env->me_dpages = mp;
-}
-
-/** Free a dirty page */
-static void
-mdb_dpage_free(MDB_env *env, MDB_page *dp)
-{
-	if (!IS_OVERFLOW(dp) || dp->mp_pages == 1) {
-		mdb_page_free(env, dp);
-	} else {
-		/* large pages just get freed directly */
-		VGMEMP_FREE(env, dp);
-		free(dp);
-	}
-}
-
-/**	Return all dirty pages to dpage list */
-static void
-mdb_dlist_free(MDB_txn *txn)
-{
-	MDB_env *env = txn->mt_env;
-	MDB_ID2L dl = txn->mt_u.dirty_list;
-	unsigned i, n = dl[0].mid;
-
-	for (i = 1; i <= n; i++) {
-		mdb_dpage_free(env, dl[i].mptr);
-	}
-	dl[0].mid = 0;
-}
-
-/** Loosen or free a single page.
- * Saves single pages to a list for future reuse
- * in this same txn. It has been pulled from the freeDB
- * and already resides on the dirty list, but has been
- * deleted. Use these pages first before pulling again
- * from the freeDB.
- *
- * If the page wasn't dirtied in this txn, just add it
- * to this txn's free list.
- */
-static int
-mdb_page_loose(MDB_cursor *mc, MDB_page *mp)
-{
-	int loose = 0;
-	pgno_t pgno = mp->mp_pgno;
-	MDB_txn *txn = mc->mc_txn;
-
-	if ((mp->mp_flags & P_DIRTY) && mc->mc_dbi != FREE_DBI) {
-		if (txn->mt_parent) {
-			MDB_ID2 *dl = txn->mt_u.dirty_list;
-			/* If txn has a parent, make sure the page is in our
-			 * dirty list.
-			 */
-			if (dl[0].mid) {
-				unsigned x = mdb_mid2l_search(dl, pgno);
-				if (x <= dl[0].mid && dl[x].mid == pgno) {
-					if (mp != dl[x].mptr) { /* bad cursor? */
-						mc->mc_flags &= ~(C_INITIALIZED|C_EOF);
-						txn->mt_flags |= MDB_TXN_ERROR;
-						return MDB_CORRUPTED;
-					}
-					/* ok, it's ours */
-					loose = 1;
-				}
-			}
-		} else {
-			/* no parent txn, so it's just ours */
-			loose = 1;
-		}
-	}
-	if (loose) {
-		DPRINTF(("loosen db %d page %"Z"u", DDBI(mc),
-			mp->mp_pgno));
-		NEXT_LOOSE_PAGE(mp) = txn->mt_loose_pgs;
-		txn->mt_loose_pgs = mp;
-		txn->mt_loose_count++;
-		mp->mp_flags |= P_LOOSE;
-	} else {
-		int rc = mdb_midl_append(&txn->mt_free_pgs, pgno);
-		if (rc)
-			return rc;
-	}
-
-	return MDB_SUCCESS;
-}
-
-/** Set or clear P_KEEP in dirty, non-overflow, non-sub pages watched by txn.
- * @param[in] mc A cursor handle for the current operation.
- * @param[in] pflags Flags of the pages to update:
- * P_DIRTY to set P_KEEP, P_DIRTY|P_KEEP to clear it.
- * @param[in] all No shortcuts. Needed except after a full #mdb_page_flush().
- * @return 0 on success, non-zero on failure.
- */
-static int
-mdb_pages_xkeep(MDB_cursor *mc, unsigned pflags, int all)
-{
-	enum { Mask = P_SUBP|P_DIRTY|P_LOOSE|P_KEEP };
-	MDB_txn *txn = mc->mc_txn;
-	MDB_cursor *m3;
-	MDB_xcursor *mx;
-	MDB_page *dp, *mp;
-	MDB_node *leaf;
-	unsigned i, j;
-	int rc = MDB_SUCCESS, level;
-
-	/* Mark pages seen by cursors */
-	if (mc->mc_flags & C_UNTRACK)
-		mc = NULL;				/* will find mc in mt_cursors */
-	for (i = txn->mt_numdbs;; mc = txn->mt_cursors[--i]) {
-		for (; mc; mc=mc->mc_next) {
-			if (!(mc->mc_flags & C_INITIALIZED))
-				continue;
-			for (m3 = mc;; m3 = &mx->mx_cursor) {
-				mp = NULL;
-				for (j=0; j<m3->mc_snum; j++) {
-					mp = m3->mc_pg[j];
-					if ((mp->mp_flags & Mask) == pflags)
-						mp->mp_flags ^= P_KEEP;
-				}
-				mx = m3->mc_xcursor;
-				/* Proceed to mx if it is at a sub-database */
-				if (! (mx && (mx->mx_cursor.mc_flags & C_INITIALIZED)))
-					break;
-				if (! (mp && (mp->mp_flags & P_LEAF)))
-					break;
-				leaf = NODEPTR(mp, m3->mc_ki[j-1]);
-				if (!(leaf->mn_flags & F_SUBDATA))
-					break;
-			}
-		}
-		if (i == 0)
-			break;
-	}
-
-	if (all) {
-		/* Mark dirty root pages */
-		for (i=0; i<txn->mt_numdbs; i++) {
-			if (txn->mt_dbflags[i] & DB_DIRTY) {
-				pgno_t pgno = txn->mt_dbs[i].md_root;
-				if (pgno == P_INVALID)
-					continue;
-				if ((rc = mdb_page_get(txn, pgno, &dp, &level)) != MDB_SUCCESS)
-					break;
-				if ((dp->mp_flags & Mask) == pflags && level <= 1)
-					dp->mp_flags ^= P_KEEP;
-			}
-		}
-	}
-
-	return rc;
-}
-
-static int mdb_page_flush(MDB_txn *txn, int keep);
-
-/**	Spill pages from the dirty list back to disk.
- * This is intended to prevent running into #MDB_TXN_FULL situations,
- * but note that they may still occur in a few cases:
- *	1) our estimate of the txn size could be too small. Currently this
- *	 seems unlikely, except with a large number of #MDB_MULTIPLE items.
- *	2) child txns may run out of space if their parents dirtied a
- *	 lot of pages and never spilled them. TODO: we probably should do
- *	 a preemptive spill during #mdb_txn_begin() of a child txn, if
- *	 the parent's dirty_room is below a given threshold.
- *
- * Otherwise, if not using nested txns, it is expected that apps will
- * not run into #MDB_TXN_FULL any more. The pages are flushed to disk
- * the same way as for a txn commit, e.g. their P_DIRTY flag is cleared.
- * If the txn never references them again, they can be left alone.
- * If the txn only reads them, they can be used without any fuss.
- * If the txn writes them again, they can be dirtied immediately without
- * going thru all of the work of #mdb_page_touch(). Such references are
- * handled by #mdb_page_unspill().
- *
- * Also note, we never spill DB root pages, nor pages of active cursors,
- * because we'll need these back again soon anyway. And in nested txns,
- * we can't spill a page in a child txn if it was already spilled in a
- * parent txn. That would alter the parent txns' data even though
- * the child hasn't committed yet, and we'd have no way to undo it if
- * the child aborted.
- *
- * @param[in] m0 cursor A cursor handle identifying the transaction and
- *	database for which we are checking space.
- * @param[in] key For a put operation, the key being stored.
- * @param[in] data For a put operation, the data being stored.
- * @return 0 on success, non-zero on failure.
- */
-static int
-mdb_page_spill(MDB_cursor *m0, MDB_val *key, MDB_val *data)
-{
-	MDB_txn *txn = m0->mc_txn;
-	MDB_page *dp;
-	MDB_ID2L dl = txn->mt_u.dirty_list;
-	unsigned int i, j, need;
-	int rc;
-
-	if (m0->mc_flags & C_SUB)
-		return MDB_SUCCESS;
-
-	/* Estimate how much space this op will take */
-	i = m0->mc_db->md_depth;
-	/* Named DBs also dirty the main DB */
-	if (m0->mc_dbi > MAIN_DBI)
-		i += txn->mt_dbs[MAIN_DBI].md_depth;
-	/* For puts, roughly factor in the key+data size */
-	if (key)
-		i += (LEAFSIZE(key, data) + txn->mt_env->me_psize) / txn->mt_env->me_psize;
-	i += i;	/* double it for good measure */
-	need = i;
-
-	if (txn->mt_dirty_room > i)
-		return MDB_SUCCESS;
-
-	if (!txn->mt_spill_pgs) {
-		txn->mt_spill_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX);
-		if (!txn->mt_spill_pgs)
-			return ENOMEM;
-	} else {
-		/* purge deleted slots */
-		MDB_IDL sl = txn->mt_spill_pgs;
-		unsigned int num = sl[0];
-		j=0;
-		for (i=1; i<=num; i++) {
-			if (!(sl[i] & 1))
-				sl[++j] = sl[i];
-		}
-		sl[0] = j;
-	}
-
-	/* Preserve pages which may soon be dirtied again */
-	if ((rc = mdb_pages_xkeep(m0, P_DIRTY, 1)) != MDB_SUCCESS)
-		goto done;
-
-	/* Less aggressive spill - we originally spilled the entire dirty list,
-	 * with a few exceptions for cursor pages and DB root pages. But this
-	 * turns out to be a lot of wasted effort because in a large txn many
-	 * of those pages will need to be used again. So now we spill only 1/8th
-	 * of the dirty pages. Testing revealed this to be a good tradeoff,
-	 * better than 1/2, 1/4, or 1/10.
-	 */
-	if (need < MDB_IDL_UM_MAX / 8)
-		need = MDB_IDL_UM_MAX / 8;
-
-	/* Save the page IDs of all the pages we're flushing */
-	/* flush from the tail forward, this saves a lot of shifting later on. */
-	for (i=dl[0].mid; i && need; i--) {
-		MDB_ID pn = dl[i].mid << 1;
-		dp = dl[i].mptr;
-		if (dp->mp_flags & (P_LOOSE|P_KEEP))
-			continue;
-		/* Can't spill twice, make sure it's not already in a parent's
-		 * spill list.
-		 */
-		if (txn->mt_parent) {
-			MDB_txn *tx2;
-			for (tx2 = txn->mt_parent; tx2; tx2 = tx2->mt_parent) {
-				if (tx2->mt_spill_pgs) {
-					j = mdb_midl_search(tx2->mt_spill_pgs, pn);
-					if (j <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[j] == pn) {
-						dp->mp_flags |= P_KEEP;
-						break;
-					}
-				}
-			}
-			if (tx2)
-				continue;
-		}
-		if ((rc = mdb_midl_append(&txn->mt_spill_pgs, pn)))
-			goto done;
-		need--;
-	}
-	mdb_midl_sort(txn->mt_spill_pgs);
-
-	/* Flush the spilled part of dirty list */
-	if ((rc = mdb_page_flush(txn, i)) != MDB_SUCCESS)
-		goto done;
-
-	/* Reset any dirty pages we kept that page_flush didn't see */
-	rc = mdb_pages_xkeep(m0, P_DIRTY|P_KEEP, i);
-
-done:
-	txn->mt_flags |= rc ? MDB_TXN_ERROR : MDB_TXN_SPILLS;
-	return rc;
-}
-
-/** Find oldest txnid still referenced. Expects txn->mt_txnid > 0. */
-static txnid_t
-mdb_find_oldest(MDB_txn *txn)
-{
-	int i;
-	txnid_t mr, oldest = txn->mt_txnid - 1;
-	if (txn->mt_env->me_txns) {
-		MDB_reader *r = txn->mt_env->me_txns->mti_readers;
-		for (i = txn->mt_env->me_txns->mti_numreaders; --i >= 0; ) {
-			if (r[i].mr_pid) {
-				mr = r[i].mr_txnid;
-				if (oldest > mr)
-					oldest = mr;
-			}
-		}
-	}
-	return oldest;
-}
-
-/** Add a page to the txn's dirty list */
-static void
-mdb_page_dirty(MDB_txn *txn, MDB_page *mp)
-{
-	MDB_ID2 mid;
-	int rc, (*insert)(MDB_ID2L, MDB_ID2 *);
-
-	if (txn->mt_env->me_flags & MDB_WRITEMAP) {
-		insert = mdb_mid2l_append;
-	} else {
-		insert = mdb_mid2l_insert;
-	}
-	mid.mid = mp->mp_pgno;
-	mid.mptr = mp;
-	rc = insert(txn->mt_u.dirty_list, &mid);
-	mdb_tassert(txn, rc == 0);
-	txn->mt_dirty_room--;
-}
-
-/** Allocate page numbers and memory for writing.  Maintain me_pglast,
- * me_pghead and mt_next_pgno.
- *
- * If there are free pages available from older transactions, they
- * are re-used first. Otherwise allocate a new page at mt_next_pgno.
- * Do not modify the freedB, just merge freeDB records into me_pghead[]
- * and move me_pglast to say which records were consumed.  Only this
- * function can create me_pghead and move me_pglast/mt_next_pgno.
- * @param[in] mc cursor A cursor handle identifying the transaction and
- *	database for which we are allocating.
- * @param[in] num the number of pages to allocate.
- * @param[out] mp Address of the allocated page(s). Requests for multiple pages
- *  will always be satisfied by a single contiguous chunk of memory.
- * @return 0 on success, non-zero on failure.
- */
-static int
-mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp)
-{
-#ifdef MDB_PARANOID	/* Seems like we can ignore this now */
-	/* Get at most <Max_retries> more freeDB records once me_pghead
-	 * has enough pages.  If not enough, use new pages from the map.
-	 * If <Paranoid> and mc is updating the freeDB, only get new
-	 * records if me_pghead is empty. Then the freelist cannot play
-	 * catch-up with itself by growing while trying to save it.
-	 */
-	enum { Paranoid = 1, Max_retries = 500 };
-#else
-	enum { Paranoid = 0, Max_retries = INT_MAX /*infinite*/ };
-#endif
-	int rc, retry = num * 60;
-	MDB_txn *txn = mc->mc_txn;
-	MDB_env *env = txn->mt_env;
-	pgno_t pgno, *mop = env->me_pghead;
-	unsigned i, j, mop_len = mop ? mop[0] : 0, n2 = num-1;
-	MDB_page *np;
-	txnid_t oldest = 0, last;
-	MDB_cursor_op op;
-	MDB_cursor m2;
-	int found_old = 0;
-
-	/* If there are any loose pages, just use them */
-	if (num == 1 && txn->mt_loose_pgs) {
-		np = txn->mt_loose_pgs;
-		txn->mt_loose_pgs = NEXT_LOOSE_PAGE(np);
-		txn->mt_loose_count--;
-		DPRINTF(("db %d use loose page %"Z"u", DDBI(mc),
-				np->mp_pgno));
-		*mp = np;
-		return MDB_SUCCESS;
-	}
-
-	*mp = NULL;
-
-	/* If our dirty list is already full, we can't do anything */
-	if (txn->mt_dirty_room == 0) {
-		rc = MDB_TXN_FULL;
-		goto fail;
-	}
-
-	for (op = MDB_FIRST;; op = MDB_NEXT) {
-		MDB_val key, data;
-		MDB_node *leaf;
-		pgno_t *idl;
-
-		/* Seek a big enough contiguous page range. Prefer
-		 * pages at the tail, just truncating the list.
-		 */
-		if (mop_len > n2) {
-			i = mop_len;
-			do {
-				pgno = mop[i];
-				if (mop[i-n2] == pgno+n2)
-					goto search_done;
-			} while (--i > n2);
-			if (--retry < 0)
-				break;
-		}
-
-		if (op == MDB_FIRST) {	/* 1st iteration */
-			/* Prepare to fetch more and coalesce */
-			last = env->me_pglast;
-			oldest = env->me_pgoldest;
-			mdb_cursor_init(&m2, txn, FREE_DBI, NULL);
-			if (last) {
-				op = MDB_SET_RANGE;
-				key.mv_data = &last; /* will look up last+1 */
-				key.mv_size = sizeof(last);
-			}
-			if (Paranoid && mc->mc_dbi == FREE_DBI)
-				retry = -1;
-		}
-		if (Paranoid && retry < 0 && mop_len)
-			break;
-
-		last++;
-		/* Do not fetch more if the record will be too recent */
-		if (oldest <= last) {
-			if (!found_old) {
-				oldest = mdb_find_oldest(txn);
-				env->me_pgoldest = oldest;
-				found_old = 1;
-			}
-			if (oldest <= last)
-				break;
-		}
-		rc = mdb_cursor_get(&m2, &key, NULL, op);
-		if (rc) {
-			if (rc == MDB_NOTFOUND)
-				break;
-			goto fail;
-		}
-		last = *(txnid_t*)key.mv_data;
-		if (oldest <= last) {
-			if (!found_old) {
-				oldest = mdb_find_oldest(txn);
-				env->me_pgoldest = oldest;
-				found_old = 1;
-			}
-			if (oldest <= last)
-				break;
-		}
-		np = m2.mc_pg[m2.mc_top];
-		leaf = NODEPTR(np, m2.mc_ki[m2.mc_top]);
-		if ((rc = mdb_node_read(txn, leaf, &data)) != MDB_SUCCESS)
-			return rc;
-
-		idl = (MDB_ID *) data.mv_data;
-		i = idl[0];
-		if (!mop) {
-			if (!(env->me_pghead = mop = mdb_midl_alloc(i))) {
-				rc = ENOMEM;
-				goto fail;
-			}
-		} else {
-			if ((rc = mdb_midl_need(&env->me_pghead, i)) != 0)
-				goto fail;
-			mop = env->me_pghead;
-		}
-		env->me_pglast = last;
-#if (MDB_DEBUG) > 1
-		DPRINTF(("IDL read txn %"Z"u root %"Z"u num %u",
-			last, txn->mt_dbs[FREE_DBI].md_root, i));
-		for (j = i; j; j--)
-			DPRINTF(("IDL %"Z"u", idl[j]));
-#endif
-		/* Merge in descending sorted order */
-		mdb_midl_xmerge(mop, idl);
-		mop_len = mop[0];
-	}
-
-	/* Use new pages from the map when nothing suitable in the freeDB */
-	i = 0;
-	pgno = txn->mt_next_pgno;
-	if (pgno + num >= env->me_maxpg) {
-			DPUTS("DB size maxed out");
-			rc = MDB_MAP_FULL;
-			goto fail;
-	}
-
-search_done:
-	if (env->me_flags & MDB_WRITEMAP) {
-		np = (MDB_page *)(env->me_map + env->me_psize * pgno);
-	} else {
-		if (!(np = mdb_page_malloc(txn, num))) {
-			rc = ENOMEM;
-			goto fail;
-		}
-	}
-	if (i) {
-		mop[0] = mop_len -= num;
-		/* Move any stragglers down */
-		for (j = i-num; j < mop_len; )
-			mop[++j] = mop[++i];
-	} else {
-		txn->mt_next_pgno = pgno + num;
-	}
-	np->mp_pgno = pgno;
-	mdb_page_dirty(txn, np);
-	*mp = np;
-
-	return MDB_SUCCESS;
-
-fail:
-	txn->mt_flags |= MDB_TXN_ERROR;
-	return rc;
-}
-
-/** Copy the used portions of a non-overflow page.
- * @param[in] dst page to copy into
- * @param[in] src page to copy from
- * @param[in] psize size of a page
- */
-static void
-mdb_page_copy(MDB_page *dst, MDB_page *src, unsigned int psize)
-{
-	enum { Align = sizeof(pgno_t) };
-	indx_t upper = src->mp_upper, lower = src->mp_lower, unused = upper-lower;
-
-	/* If page isn't full, just copy the used portion. Adjust
-	 * alignment so memcpy may copy words instead of bytes.
-	 */
-	if ((unused &= -Align) && !IS_LEAF2(src)) {
-		upper = (upper + PAGEBASE) & -Align;
-		memcpy(dst, src, (lower + PAGEBASE + (Align-1)) & -Align);
-		memcpy((pgno_t *)((char *)dst+upper), (pgno_t *)((char *)src+upper),
-			psize - upper);
-	} else {
-		memcpy(dst, src, psize - unused);
-	}
-}
-
-/** Pull a page off the txn's spill list, if present.
- * If a page being referenced was spilled to disk in this txn, bring
- * it back and make it dirty/writable again.
- * @param[in] txn the transaction handle.
- * @param[in] mp the page being referenced. It must not be dirty.
- * @param[out] ret the writable page, if any. ret is unchanged if
- * mp wasn't spilled.
- */
-static int
-mdb_page_unspill(MDB_txn *txn, MDB_page *mp, MDB_page **ret)
-{
-	MDB_env *env = txn->mt_env;
-	const MDB_txn *tx2;
-	unsigned x;
-	pgno_t pgno = mp->mp_pgno, pn = pgno << 1;
-
-	for (tx2 = txn; tx2; tx2=tx2->mt_parent) {
-		if (!tx2->mt_spill_pgs)
-			continue;
-		x = mdb_midl_search(tx2->mt_spill_pgs, pn);
-		if (x <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[x] == pn) {
-			MDB_page *np;
-			int num;
-			if (txn->mt_dirty_room == 0)
-				return MDB_TXN_FULL;
-			if (IS_OVERFLOW(mp))
-				num = mp->mp_pages;
-			else
-				num = 1;
-			if (env->me_flags & MDB_WRITEMAP) {
-				np = mp;
-			} else {
-				np = mdb_page_malloc(txn, num);
-				if (!np)
-					return ENOMEM;
-				if (num > 1)
-					memcpy(np, mp, num * env->me_psize);
-				else
-					mdb_page_copy(np, mp, env->me_psize);
-			}
-			if (tx2 == txn) {
-				/* If in current txn, this page is no longer spilled.
-				 * If it happens to be the last page, truncate the spill list.
-				 * Otherwise mark it as deleted by setting the LSB.
-				 */
-				if (x == txn->mt_spill_pgs[0])
-					txn->mt_spill_pgs[0]--;
-				else
-					txn->mt_spill_pgs[x] |= 1;
-			}	/* otherwise, if belonging to a parent txn, the
-				 * page remains spilled until child commits
-				 */
-
-			mdb_page_dirty(txn, np);
-			np->mp_flags |= P_DIRTY;
-			*ret = np;
-			break;
-		}
-	}
-	return MDB_SUCCESS;
-}
-
-/** Touch a page: make it dirty and re-insert into tree with updated pgno.
- * @param[in] mc cursor pointing to the page to be touched
- * @return 0 on success, non-zero on failure.
- */
-static int
-mdb_page_touch(MDB_cursor *mc)
-{
-	MDB_page *mp = mc->mc_pg[mc->mc_top], *np;
-	MDB_txn *txn = mc->mc_txn;
-	MDB_cursor *m2, *m3;
-	pgno_t	pgno;
-	int rc;
-
-	if (!F_ISSET(mp->mp_flags, P_DIRTY)) {
-		if (txn->mt_flags & MDB_TXN_SPILLS) {
-			np = NULL;
-			rc = mdb_page_unspill(txn, mp, &np);
-			if (rc)
-				goto fail;
-			if (np)
-				goto done;
-		}
-		if ((rc = mdb_midl_need(&txn->mt_free_pgs, 1)) ||
-			(rc = mdb_page_alloc(mc, 1, &np)))
-			goto fail;
-		pgno = np->mp_pgno;
-		DPRINTF(("touched db %d page %"Z"u -> %"Z"u", DDBI(mc),
-			mp->mp_pgno, pgno));
-		mdb_cassert(mc, mp->mp_pgno != pgno);
-		mdb_midl_xappend(txn->mt_free_pgs, mp->mp_pgno);
-		/* Update the parent page, if any, to point to the new page */
-		if (mc->mc_top) {
-			MDB_page *parent = mc->mc_pg[mc->mc_top-1];
-			MDB_node *node = NODEPTR(parent, mc->mc_ki[mc->mc_top-1]);
-			SETPGNO(node, pgno);
-		} else {
-			mc->mc_db->md_root = pgno;
-		}
-	} else if (txn->mt_parent && !IS_SUBP(mp)) {
-		MDB_ID2 mid, *dl = txn->mt_u.dirty_list;
-		pgno = mp->mp_pgno;
-		/* If txn has a parent, make sure the page is in our
-		 * dirty list.
-		 */
-		if (dl[0].mid) {
-			unsigned x = mdb_mid2l_search(dl, pgno);
-			if (x <= dl[0].mid && dl[x].mid == pgno) {
-				if (mp != dl[x].mptr) { /* bad cursor? */
-					mc->mc_flags &= ~(C_INITIALIZED|C_EOF);
-					txn->mt_flags |= MDB_TXN_ERROR;
-					return MDB_CORRUPTED;
-				}
-				return 0;
-			}
-		}
-		mdb_cassert(mc, dl[0].mid < MDB_IDL_UM_MAX);
-		/* No - copy it */
-		np = mdb_page_malloc(txn, 1);
-		if (!np)
-			return ENOMEM;
-		mid.mid = pgno;
-		mid.mptr = np;
-		rc = mdb_mid2l_insert(dl, &mid);
-		mdb_cassert(mc, rc == 0);
-	} else {
-		return 0;
-	}
-
-	mdb_page_copy(np, mp, txn->mt_env->me_psize);
-	np->mp_pgno = pgno;
-	np->mp_flags |= P_DIRTY;
-
-done:
-	/* Adjust cursors pointing to mp */
-	mc->mc_pg[mc->mc_top] = np;
-	m2 = txn->mt_cursors[mc->mc_dbi];
-	if (mc->mc_flags & C_SUB) {
-		for (; m2; m2=m2->mc_next) {
-			m3 = &m2->mc_xcursor->mx_cursor;
-			if (m3->mc_snum < mc->mc_snum) continue;
-			if (m3->mc_pg[mc->mc_top] == mp)
-				m3->mc_pg[mc->mc_top] = np;
-		}
-	} else {
-		for (; m2; m2=m2->mc_next) {
-			if (m2->mc_snum < mc->mc_snum) continue;
-			if (m2->mc_pg[mc->mc_top] == mp) {
-				m2->mc_pg[mc->mc_top] = np;
-				if ((mc->mc_db->md_flags & MDB_DUPSORT) &&
-					IS_LEAF(np) &&
-					m2->mc_ki[mc->mc_top] == mc->mc_ki[mc->mc_top])
-				{
-					MDB_node *leaf = NODEPTR(np, mc->mc_ki[mc->mc_top]);
-					if (!(leaf->mn_flags & F_SUBDATA))
-						m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
-				}
-			}
-		}
-	}
-	return 0;
-
-fail:
-	txn->mt_flags |= MDB_TXN_ERROR;
-	return rc;
-}
-
-int
-mdb_env_sync(MDB_env *env, int force)
-{
-	int rc = 0;
-	if (env->me_flags & MDB_RDONLY)
-		return EACCES;
-	if (force || !F_ISSET(env->me_flags, MDB_NOSYNC)) {
-		if (env->me_flags & MDB_WRITEMAP) {
-			int flags = ((env->me_flags & MDB_MAPASYNC) && !force)
-				? MS_ASYNC : MS_SYNC;
-			if (MDB_MSYNC(env->me_map, env->me_mapsize, flags))
-				rc = ErrCode();
-#ifdef _WIN32
-			else if (flags == MS_SYNC && MDB_FDATASYNC(env->me_fd))
-				rc = ErrCode();
-#endif
-		} else {
-#ifdef BROKEN_FDATASYNC
-			if (env->me_flags & MDB_FSYNCONLY) {
-				if (fsync(env->me_fd))
-					rc = ErrCode();
-			} else
-#endif
-			if (MDB_FDATASYNC(env->me_fd))
-				rc = ErrCode();
-		}
-	}
-	return rc;
-}
-
-/** Back up parent txn's cursors, then grab the originals for tracking */
-static int
-mdb_cursor_shadow(MDB_txn *src, MDB_txn *dst)
-{
-	MDB_cursor *mc, *bk;
-	MDB_xcursor *mx;
-	size_t size;
-	int i;
-
-	for (i = src->mt_numdbs; --i >= 0; ) {
-		if ((mc = src->mt_cursors[i]) != NULL) {
-			size = sizeof(MDB_cursor);
-			if (mc->mc_xcursor)
-				size += sizeof(MDB_xcursor);
-			for (; mc; mc = bk->mc_next) {
-				bk = malloc(size);
-				if (!bk)
-					return ENOMEM;
-				*bk = *mc;
-				mc->mc_backup = bk;
-				mc->mc_db = &dst->mt_dbs[i];
-				/* Kill pointers into src - and dst to reduce abuse: The
-				 * user may not use mc until dst ends. Otherwise we'd...
-				 */
-				mc->mc_txn    = NULL;	/* ...set this to dst */
-				mc->mc_dbflag = NULL;	/* ...and &dst->mt_dbflags[i] */
-				if ((mx = mc->mc_xcursor) != NULL) {
-					*(MDB_xcursor *)(bk+1) = *mx;
-					mx->mx_cursor.mc_txn = NULL; /* ...and dst. */
-				}
-				mc->mc_next = dst->mt_cursors[i];
-				dst->mt_cursors[i] = mc;
-			}
-		}
-	}
-	return MDB_SUCCESS;
-}
-
-/** Close this write txn's cursors, give parent txn's cursors back to parent.
- * @param[in] txn the transaction handle.
- * @param[in] merge true to keep changes to parent cursors, false to revert.
- * @return 0 on success, non-zero on failure.
- */
-static void
-mdb_cursors_close(MDB_txn *txn, unsigned merge)
-{
-	MDB_cursor **cursors = txn->mt_cursors, *mc, *next, *bk;
-	MDB_xcursor *mx;
-	int i;
-
-	for (i = txn->mt_numdbs; --i >= 0; ) {
-		for (mc = cursors[i]; mc; mc = next) {
-			next = mc->mc_next;
-			if ((bk = mc->mc_backup) != NULL) {
-				if (merge) {
-					/* Commit changes to parent txn */
-					mc->mc_next = bk->mc_next;
-					mc->mc_backup = bk->mc_backup;
-					mc->mc_txn = bk->mc_txn;
-					mc->mc_db = bk->mc_db;
-					mc->mc_dbflag = bk->mc_dbflag;
-					if ((mx = mc->mc_xcursor) != NULL)
-						mx->mx_cursor.mc_txn = bk->mc_txn;
-				} else {
-					/* Abort nested txn */
-					*mc = *bk;
-					if ((mx = mc->mc_xcursor) != NULL)
-						*mx = *(MDB_xcursor *)(bk+1);
-				}
-				mc = bk;
-			}
-			/* Only malloced cursors are permanently tracked. */
-			free(mc);
-		}
-		cursors[i] = NULL;
-	}
-}
-
-#if !(MDB_DEBUG)
-#define mdb_txn_reset0(txn, act) mdb_txn_reset0(txn)
-#endif
-static void
-mdb_txn_reset0(MDB_txn *txn, const char *act);
-
-#if !(MDB_PIDLOCK)		/* Currently the same as defined(_WIN32) */
-enum Pidlock_op {
-	Pidset, Pidcheck
-};
-#else
-enum Pidlock_op {
-	Pidset = F_SETLK, Pidcheck = F_GETLK
-};
-#endif
-
-/** Set or check a pid lock. Set returns 0 on success.
- * Check returns 0 if the process is certainly dead, nonzero if it may
- * be alive (the lock exists or an error happened so we do not know).
- *
- * On Windows Pidset is a no-op, we merely check for the existence
- * of the process with the given pid. On POSIX we use a single byte
- * lock on the lockfile, set at an offset equal to the pid.
- */
-static int
-mdb_reader_pid(MDB_env *env, enum Pidlock_op op, MDB_PID_T pid)
-{
-#if !(MDB_PIDLOCK)		/* Currently the same as defined(_WIN32) */
-	int ret = 0;
-	HANDLE h;
-	if (op == Pidcheck) {
-		h = OpenProcess(env->me_pidquery, FALSE, pid);
-		/* No documented "no such process" code, but other program use this: */
-		if (!h)
-			return ErrCode() != ERROR_INVALID_PARAMETER;
-		/* A process exists until all handles to it close. Has it exited? */
-		ret = WaitForSingleObject(h, 0) != 0;
-		CloseHandle(h);
-	}
-	return ret;
-#else
-	for (;;) {
-		int rc;
-		struct flock lock_info;
-		memset(&lock_info, 0, sizeof(lock_info));
-		lock_info.l_type = F_WRLCK;
-		lock_info.l_whence = SEEK_SET;
-		lock_info.l_start = pid;
-		lock_info.l_len = 1;
-		if ((rc = fcntl(env->me_lfd, op, &lock_info)) == 0) {
-			if (op == F_GETLK && lock_info.l_type != F_UNLCK)
-				rc = -1;
-		} else if ((rc = ErrCode()) == EINTR) {
-			continue;
-		}
-		return rc;
-	}
-#endif
-}
-
-/** Common code for #mdb_txn_begin() and #mdb_txn_renew().
- * @param[in] txn the transaction handle to initialize
- * @return 0 on success, non-zero on failure.
- */
-static int
-mdb_txn_renew0(MDB_txn *txn)
-{
-	MDB_env *env = txn->mt_env;
-	MDB_txninfo *ti = env->me_txns;
-	MDB_meta *meta;
-	unsigned int i, nr, flags = txn->mt_flags;
-	uint16_t x;
-	int rc, new_notls = 0;
-
-	if ((flags &= MDB_TXN_RDONLY) != 0) {
-		if (!ti) {
-			meta = env->me_metas[ mdb_env_pick_meta(env) ];
-			txn->mt_txnid = meta->mm_txnid;
-			txn->mt_u.reader = NULL;
-		} else {
-			MDB_reader *r = (env->me_flags & MDB_NOTLS) ? txn->mt_u.reader :
-				pthread_getspecific(env->me_txkey);
-			if (r) {
-				if (r->mr_pid != env->me_pid || r->mr_txnid != (txnid_t)-1)
-					return MDB_BAD_RSLOT;
-			} else {
-				MDB_PID_T pid = env->me_pid;
-				MDB_THR_T tid = pthread_self();
-
-				if (!env->me_live_reader) {
-					rc = mdb_reader_pid(env, Pidset, pid);
-					if (rc)
-						return rc;
-					env->me_live_reader = 1;
-				}
-
-				LOCK_MUTEX_R(env);
-				nr = ti->mti_numreaders;
-				for (i=0; i<nr; i++)
-					if (ti->mti_readers[i].mr_pid == 0)
-						break;
-				if (i == env->me_maxreaders) {
-					UNLOCK_MUTEX_R(env);
-					return MDB_READERS_FULL;
-				}
-				ti->mti_readers[i].mr_pid = pid;
-				ti->mti_readers[i].mr_tid = tid;
-				if (i == nr)
-					ti->mti_numreaders = ++nr;
-				/* Save numreaders for un-mutexed mdb_env_close() */
-				env->me_numreaders = nr;
-				UNLOCK_MUTEX_R(env);
-
-				r = &ti->mti_readers[i];
-				new_notls = (env->me_flags & MDB_NOTLS);
-				if (!new_notls && (rc=pthread_setspecific(env->me_txkey, r))) {
-					r->mr_pid = 0;
-					return rc;
-				}
-			}
-			do /* LY: Retry on a race, ITS#7970. */
-				r->mr_txnid = ti->mti_txnid;
-			while(r->mr_txnid != ti->mti_txnid);
-			txn->mt_txnid = r->mr_txnid;
-			txn->mt_u.reader = r;
-			meta = env->me_metas[txn->mt_txnid & 1];
-		}
-		txn->mt_dbxs = env->me_dbxs;	/* mostly static anyway */
-	} else {
-		if (ti) {
-			LOCK_MUTEX_W(env);
-
-			txn->mt_txnid = ti->mti_txnid;
-			meta = env->me_metas[txn->mt_txnid & 1];
-		} else {
-			meta = env->me_metas[ mdb_env_pick_meta(env) ];
-			txn->mt_txnid = meta->mm_txnid;
-		}
-		txn->mt_txnid++;
-#if MDB_DEBUG
-		if (txn->mt_txnid == mdb_debug_start)
-			mdb_debug = 1;
-#endif
-		txn->mt_child = NULL;
-		txn->mt_loose_pgs = NULL;
-		txn->mt_loose_count = 0;
-		txn->mt_dirty_room = MDB_IDL_UM_MAX;
-		txn->mt_u.dirty_list = env->me_dirty_list;
-		txn->mt_u.dirty_list[0].mid = 0;
-		txn->mt_free_pgs = env->me_free_pgs;
-		txn->mt_free_pgs[0] = 0;
-		txn->mt_spill_pgs = NULL;
-		env->me_txn = txn;
-		memcpy(txn->mt_dbiseqs, env->me_dbiseqs, env->me_maxdbs * sizeof(unsigned int));
-	}
-
-	/* Copy the DB info and flags */
-	memcpy(txn->mt_dbs, meta->mm_dbs, 2 * sizeof(MDB_db));
-
-	/* Moved to here to avoid a data race in read TXNs */
-	txn->mt_next_pgno = meta->mm_last_pg+1;
-
-	txn->mt_flags = flags;
-
-	/* Setup db info */
-	txn->mt_numdbs = env->me_numdbs;
-	for (i=2; i<txn->mt_numdbs; i++) {
-		x = env->me_dbflags[i];
-		txn->mt_dbs[i].md_flags = x & PERSISTENT_FLAGS;
-		txn->mt_dbflags[i] = (x & MDB_VALID) ? DB_VALID|DB_STALE : 0;
-	}
-	txn->mt_dbflags[0] = txn->mt_dbflags[1] = DB_VALID;
-
-	if (env->me_maxpg < txn->mt_next_pgno) {
-		mdb_txn_reset0(txn, "renew0-mapfail");
-		if (new_notls) {
-			txn->mt_u.reader->mr_pid = 0;
-			txn->mt_u.reader = NULL;
-		}
-		return MDB_MAP_RESIZED;
-	}
-
-	return MDB_SUCCESS;
-}
-
-int
-mdb_txn_renew(MDB_txn *txn)
-{
-	int rc;
-
-	if (!txn || txn->mt_dbxs)	/* A reset txn has mt_dbxs==NULL */
-		return EINVAL;
-
-	if (txn->mt_env->me_flags & MDB_FATAL_ERROR) {
-		DPUTS("environment had fatal error, must shutdown!");
-		return MDB_PANIC;
-	}
-
-	rc = mdb_txn_renew0(txn);
-	if (rc == MDB_SUCCESS) {
-		DPRINTF(("renew txn %"Z"u%c %p on mdbenv %p, root page %"Z"u",
-			txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
-			(void *)txn, (void *)txn->mt_env, txn->mt_dbs[MAIN_DBI].md_root));
-	}
-	return rc;
-}
-
-int
-mdb_txn_begin(MDB_env *env, MDB_txn *parent, unsigned int flags, MDB_txn **ret)
-{
-	MDB_txn *txn;
-	MDB_ntxn *ntxn;
-	int rc, size, tsize = sizeof(MDB_txn);
-
-	if (env->me_flags & MDB_FATAL_ERROR) {
-		DPUTS("environment had fatal error, must shutdown!");
-		return MDB_PANIC;
-	}
-	if ((env->me_flags & MDB_RDONLY) && !(flags & MDB_RDONLY))
-		return EACCES;
-	if (parent) {
-		/* Nested transactions: Max 1 child, write txns only, no writemap */
-		if (parent->mt_child ||
-			(flags & MDB_RDONLY) ||
-			(parent->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_ERROR)) ||
-			(env->me_flags & MDB_WRITEMAP))
-		{
-			return (parent->mt_flags & MDB_TXN_RDONLY) ? EINVAL : MDB_BAD_TXN;
-		}
-		tsize = sizeof(MDB_ntxn);
-	}
-	size = tsize;
-	if (!(flags & MDB_RDONLY)) {
-		if (!parent) {
-			txn = env->me_txn0;	/* just reuse preallocated write txn */
-			goto ok;
-		}
-		/* child txns use own copy of cursors */
-		size += env->me_maxdbs * sizeof(MDB_cursor *);
-	}
-	size += env->me_maxdbs * (sizeof(MDB_db)+1);
-
-	if ((txn = calloc(1, size)) == NULL) {
-		DPRINTF(("calloc: %s", strerror(errno)));
-		return ENOMEM;
-	}
-	txn->mt_dbs = (MDB_db *) ((char *)txn + tsize);
-	if (flags & MDB_RDONLY) {
-		txn->mt_flags |= MDB_TXN_RDONLY;
-		txn->mt_dbflags = (unsigned char *)(txn->mt_dbs + env->me_maxdbs);
-		txn->mt_dbiseqs = env->me_dbiseqs;
-	} else {
-		txn->mt_cursors = (MDB_cursor **)(txn->mt_dbs + env->me_maxdbs);
-		if (parent) {
-			txn->mt_dbiseqs = parent->mt_dbiseqs;
-			txn->mt_dbflags = (unsigned char *)(txn->mt_cursors + env->me_maxdbs);
-		} else {
-			txn->mt_dbiseqs = (unsigned int *)(txn->mt_cursors + env->me_maxdbs);
-			txn->mt_dbflags = (unsigned char *)(txn->mt_dbiseqs + env->me_maxdbs);
-		}
-	}
-	txn->mt_env = env;
-
-ok:
-	if (parent) {
-		unsigned int i;
-		txn->mt_u.dirty_list = malloc(sizeof(MDB_ID2)*MDB_IDL_UM_SIZE);
-		if (!txn->mt_u.dirty_list ||
-			!(txn->mt_free_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX)))
-		{
-			free(txn->mt_u.dirty_list);
-			free(txn);
-			return ENOMEM;
-		}
-		txn->mt_txnid = parent->mt_txnid;
-		txn->mt_dirty_room = parent->mt_dirty_room;
-		txn->mt_u.dirty_list[0].mid = 0;
-		txn->mt_spill_pgs = NULL;
-		txn->mt_next_pgno = parent->mt_next_pgno;
-		parent->mt_child = txn;
-		txn->mt_parent = parent;
-		txn->mt_numdbs = parent->mt_numdbs;
-		txn->mt_flags = parent->mt_flags;
-		txn->mt_dbxs = parent->mt_dbxs;
-		memcpy(txn->mt_dbs, parent->mt_dbs, txn->mt_numdbs * sizeof(MDB_db));
-		/* Copy parent's mt_dbflags, but clear DB_NEW */
-		for (i=0; i<txn->mt_numdbs; i++)
-			txn->mt_dbflags[i] = parent->mt_dbflags[i] & ~DB_NEW;
-		rc = 0;
-		ntxn = (MDB_ntxn *)txn;
-		ntxn->mnt_pgstate = env->me_pgstate; /* save parent me_pghead & co */
-		if (env->me_pghead) {
-			size = MDB_IDL_SIZEOF(env->me_pghead);
-			env->me_pghead = mdb_midl_alloc(env->me_pghead[0]);
-			if (env->me_pghead)
-				memcpy(env->me_pghead, ntxn->mnt_pgstate.mf_pghead, size);
-			else
-				rc = ENOMEM;
-		}
-		if (!rc)
-			rc = mdb_cursor_shadow(parent, txn);
-		if (rc)
-			mdb_txn_reset0(txn, "beginchild-fail");
-	} else {
-		rc = mdb_txn_renew0(txn);
-	}
-	if (rc) {
-		if (txn != env->me_txn0)
-			free(txn);
-	} else {
-		*ret = txn;
-		DPRINTF(("begin txn %"Z"u%c %p on mdbenv %p, root page %"Z"u",
-			txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
-			(void *) txn, (void *) env, txn->mt_dbs[MAIN_DBI].md_root));
-	}
-
-	return rc;
-}
-
-MDB_env *
-mdb_txn_env(MDB_txn *txn)
-{
-	if(!txn) return NULL;
-	return txn->mt_env;
-}
-
-/** Export or close DBI handles opened in this txn. */
-static void
-mdb_dbis_update(MDB_txn *txn, int keep)
-{
-	int i;
-	MDB_dbi n = txn->mt_numdbs;
-	MDB_env *env = txn->mt_env;
-	unsigned char *tdbflags = txn->mt_dbflags;
-
-	for (i = n; --i >= 2;) {
-		if (tdbflags[i] & DB_NEW) {
-			if (keep) {
-				env->me_dbflags[i] = txn->mt_dbs[i].md_flags | MDB_VALID;
-			} else {
-				char *ptr = env->me_dbxs[i].md_name.mv_data;
-				if (ptr) {
-					env->me_dbxs[i].md_name.mv_data = NULL;
-					env->me_dbxs[i].md_name.mv_size = 0;
-					env->me_dbflags[i] = 0;
-					env->me_dbiseqs[i]++;
-					free(ptr);
-				}
-			}
-		}
-	}
-	if (keep && env->me_numdbs < n)
-		env->me_numdbs = n;
-}
-
-/** Common code for #mdb_txn_reset() and #mdb_txn_abort().
- * May be called twice for readonly txns: First reset it, then abort.
- * @param[in] txn the transaction handle to reset
- * @param[in] act why the transaction is being reset
- */
-static void
-mdb_txn_reset0(MDB_txn *txn, const char *act)
-{
-	MDB_env	*env = txn->mt_env;
-
-	/* Close any DBI handles opened in this txn */
-	mdb_dbis_update(txn, 0);
-
-	DPRINTF(("%s txn %"Z"u%c %p on mdbenv %p, root page %"Z"u",
-		act, txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
-		(void *) txn, (void *)env, txn->mt_dbs[MAIN_DBI].md_root));
-
-	if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
-		if (txn->mt_u.reader) {
-			txn->mt_u.reader->mr_txnid = (txnid_t)-1;
-			if (!(env->me_flags & MDB_NOTLS))
-				txn->mt_u.reader = NULL; /* txn does not own reader */
-		}
-		txn->mt_numdbs = 0;		/* close nothing if called again */
-		txn->mt_dbxs = NULL;	/* mark txn as reset */
-	} else {
-		pgno_t *pghead = env->me_pghead;
-
-		mdb_cursors_close(txn, 0);
-		if (!(env->me_flags & MDB_WRITEMAP)) {
-			mdb_dlist_free(txn);
-		}
-
-		if (!txn->mt_parent) {
-			if (mdb_midl_shrink(&txn->mt_free_pgs))
-				env->me_free_pgs = txn->mt_free_pgs;
-			/* me_pgstate: */
-			env->me_pghead = NULL;
-			env->me_pglast = 0;
-
-			env->me_txn = NULL;
-			/* The writer mutex was locked in mdb_txn_begin. */
-			if (env->me_txns)
-				UNLOCK_MUTEX_W(env);
-		} else {
-			txn->mt_parent->mt_child = NULL;
-			env->me_pgstate = ((MDB_ntxn *)txn)->mnt_pgstate;
-			mdb_midl_free(txn->mt_free_pgs);
-			mdb_midl_free(txn->mt_spill_pgs);
-			free(txn->mt_u.dirty_list);
-		}
-
-		mdb_midl_free(pghead);
-	}
-}
-
-void
-mdb_txn_reset(MDB_txn *txn)
-{
-	if (txn == NULL)
-		return;
-
-	/* This call is only valid for read-only txns */
-	if (!(txn->mt_flags & MDB_TXN_RDONLY))
-		return;
-
-	mdb_txn_reset0(txn, "reset");
-}
-
-void
-mdb_txn_abort(MDB_txn *txn)
-{
-	if (txn == NULL)
-		return;
-
-	if (txn->mt_child)
-		mdb_txn_abort(txn->mt_child);
-
-	mdb_txn_reset0(txn, "abort");
-	/* Free reader slot tied to this txn (if MDB_NOTLS && writable FS) */
-	if ((txn->mt_flags & MDB_TXN_RDONLY) && txn->mt_u.reader)
-		txn->mt_u.reader->mr_pid = 0;
-
-	if (txn != txn->mt_env->me_txn0)
-		free(txn);
-}
-
-/** Save the freelist as of this transaction to the freeDB.
- * This changes the freelist. Keep trying until it stabilizes.
- */
-static int
-mdb_freelist_save(MDB_txn *txn)
-{
-	/* env->me_pghead[] can grow and shrink during this call.
-	 * env->me_pglast and txn->mt_free_pgs[] can only grow.
-	 * Page numbers cannot disappear from txn->mt_free_pgs[].
-	 */
-	MDB_cursor mc;
-	MDB_env	*env = txn->mt_env;
-	int rc, maxfree_1pg = env->me_maxfree_1pg, more = 1;
-	txnid_t	pglast = 0, head_id = 0;
-	pgno_t	freecnt = 0, *free_pgs, *mop;
-	ssize_t	head_room = 0, total_room = 0, mop_len, clean_limit;
-
-	mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
-
-	if (env->me_pghead) {
-		/* Make sure first page of freeDB is touched and on freelist */
-		rc = mdb_page_search(&mc, NULL, MDB_PS_FIRST|MDB_PS_MODIFY);
-		if (rc && rc != MDB_NOTFOUND)
-			return rc;
-	}
-
-	if (!env->me_pghead && txn->mt_loose_pgs) {
-		/* Put loose page numbers in mt_free_pgs, since
-		 * we may be unable to return them to me_pghead.
-		 */
-		MDB_page *mp = txn->mt_loose_pgs;
-		if ((rc = mdb_midl_need(&txn->mt_free_pgs, txn->mt_loose_count)) != 0)
-			return rc;
-		for (; mp; mp = NEXT_LOOSE_PAGE(mp))
-			mdb_midl_xappend(txn->mt_free_pgs, mp->mp_pgno);
-		txn->mt_loose_pgs = NULL;
-		txn->mt_loose_count = 0;
-	}
-
-	/* MDB_RESERVE cancels meminit in ovpage malloc (when no WRITEMAP) */
-	clean_limit = (env->me_flags & (MDB_NOMEMINIT|MDB_WRITEMAP))
-		? SSIZE_MAX : maxfree_1pg;
-
-	for (;;) {
-		/* Come back here after each Put() in case freelist changed */
-		MDB_val key, data;
-		pgno_t *pgs;
-		ssize_t j;
-
-		/* If using records from freeDB which we have not yet
-		 * deleted, delete them and any we reserved for me_pghead.
-		 */
-		while (pglast < env->me_pglast) {
-			rc = mdb_cursor_first(&mc, &key, NULL);
-			if (rc)
-				return rc;
-			pglast = head_id = *(txnid_t *)key.mv_data;
-			total_room = head_room = 0;
-			mdb_tassert(txn, pglast <= env->me_pglast);
-			rc = mdb_cursor_del(&mc, 0);
-			if (rc)
-				return rc;
-		}
-
-		/* Save the IDL of pages freed by this txn, to a single record */
-		if (freecnt < txn->mt_free_pgs[0]) {
-			if (!freecnt) {
-				/* Make sure last page of freeDB is touched and on freelist */
-				rc = mdb_page_search(&mc, NULL, MDB_PS_LAST|MDB_PS_MODIFY);
-				if (rc && rc != MDB_NOTFOUND)
-					return rc;
-			}
-			free_pgs = txn->mt_free_pgs;
-			/* Write to last page of freeDB */
-			key.mv_size = sizeof(txn->mt_txnid);
-			key.mv_data = &txn->mt_txnid;
-			do {
-				freecnt = free_pgs[0];
-				data.mv_size = MDB_IDL_SIZEOF(free_pgs);
-				rc = mdb_cursor_put(&mc, &key, &data, MDB_RESERVE);
-				if (rc)
-					return rc;
-				/* Retry if mt_free_pgs[] grew during the Put() */
-				free_pgs = txn->mt_free_pgs;
-			} while (freecnt < free_pgs[0]);
-			mdb_midl_sort(free_pgs);
-			memcpy(data.mv_data, free_pgs, data.mv_size);
-#if (MDB_DEBUG) > 1
-			{
-				unsigned int i = free_pgs[0];
-				DPRINTF(("IDL write txn %"Z"u root %"Z"u num %u",
-					txn->mt_txnid, txn->mt_dbs[FREE_DBI].md_root, i));
-				for (; i; i--)
-					DPRINTF(("IDL %"Z"u", free_pgs[i]));
-			}
-#endif
-			continue;
-		}
-
-		mop = env->me_pghead;
-		mop_len = (mop ? mop[0] : 0) + txn->mt_loose_count;
-
-		/* Reserve records for me_pghead[]. Split it if multi-page,
-		 * to avoid searching freeDB for a page range. Use keys in
-		 * range [1,me_pglast]: Smaller than txnid of oldest reader.
-		 */
-		if (total_room >= mop_len) {
-			if (total_room == mop_len || --more < 0)
-				break;
-		} else if (head_room >= maxfree_1pg && head_id > 1) {
-			/* Keep current record (overflow page), add a new one */
-			head_id--;
-			head_room = 0;
-		}
-		/* (Re)write {key = head_id, IDL length = head_room} */
-		total_room -= head_room;
-		head_room = mop_len - total_room;
-		if (head_room > maxfree_1pg && head_id > 1) {
-			/* Overflow multi-page for part of me_pghead */
-			head_room /= head_id; /* amortize page sizes */
-			head_room += maxfree_1pg - head_room % (maxfree_1pg + 1);
-		} else if (head_room < 0) {
-			/* Rare case, not bothering to delete this record */
-			head_room = 0;
-		}
-		key.mv_size = sizeof(head_id);
-		key.mv_data = &head_id;
-		data.mv_size = (head_room + 1) * sizeof(pgno_t);
-		rc = mdb_cursor_put(&mc, &key, &data, MDB_RESERVE);
-		if (rc)
-			return rc;
-		/* IDL is initially empty, zero out at least the length */
-		pgs = (pgno_t *)data.mv_data;
-		j = head_room > clean_limit ? head_room : 0;
-		do {
-			pgs[j] = 0;
-		} while (--j >= 0);
-		total_room += head_room;
-	}
-
-	/* Return loose page numbers to me_pghead, though usually none are
-	 * left at this point.  The pages themselves remain in dirty_list.
-	 */
-	if (txn->mt_loose_pgs) {
-		MDB_page *mp = txn->mt_loose_pgs;
-		unsigned count = txn->mt_loose_count;
-		MDB_IDL loose;
-		/* Room for loose pages + temp IDL with same */
-		if ((rc = mdb_midl_need(&env->me_pghead, 2*count+1)) != 0)
-			return rc;
-		mop = env->me_pghead;
-		loose = mop + MDB_IDL_ALLOCLEN(mop) - count;
-		for (count = 0; mp; mp = NEXT_LOOSE_PAGE(mp))
-			loose[ ++count ] = mp->mp_pgno;
-		loose[0] = count;
-		mdb_midl_sort(loose);
-		mdb_midl_xmerge(mop, loose);
-		txn->mt_loose_pgs = NULL;
-		txn->mt_loose_count = 0;
-		mop_len = mop[0];
-	}
-
-	/* Fill in the reserved me_pghead records */
-	rc = MDB_SUCCESS;
-	if (mop_len) {
-		MDB_val key, data;
-
-		mop += mop_len;
-		rc = mdb_cursor_first(&mc, &key, &data);
-		for (; !rc; rc = mdb_cursor_next(&mc, &key, &data, MDB_NEXT)) {
-			txnid_t id = *(txnid_t *)key.mv_data;
-			ssize_t	len = (ssize_t)(data.mv_size / sizeof(MDB_ID)) - 1;
-			MDB_ID save;
-
-			mdb_tassert(txn, len >= 0 && id <= env->me_pglast);
-			key.mv_data = &id;
-			if (len > mop_len) {
-				len = mop_len;
-				data.mv_size = (len + 1) * sizeof(MDB_ID);
-			}
-			data.mv_data = mop -= len;
-			save = mop[0];
-			mop[0] = len;
-			rc = mdb_cursor_put(&mc, &key, &data, MDB_CURRENT);
-			mop[0] = save;
-			if (rc || !(mop_len -= len))
-				break;
-		}
-	}
-	return rc;
-}
-
-/** Flush (some) dirty pages to the map, after clearing their dirty flag.
- * @param[in] txn the transaction that's being committed
- * @param[in] keep number of initial pages in dirty_list to keep dirty.
- * @return 0 on success, non-zero on failure.
- */
-static int
-mdb_page_flush(MDB_txn *txn, int keep)
-{
-	MDB_env		*env = txn->mt_env;
-	MDB_ID2L	dl = txn->mt_u.dirty_list;
-	unsigned	psize = env->me_psize, j;
-	int			i, pagecount = dl[0].mid, rc;
-	size_t		size = 0, pos = 0;
-	pgno_t		pgno = 0;
-	MDB_page	*dp = NULL;
-#ifdef _WIN32
-	OVERLAPPED	ov;
-#else
-	struct iovec iov[MDB_COMMIT_PAGES];
-	ssize_t		wpos = 0, wsize = 0, wres;
-	size_t		next_pos = 1; /* impossible pos, so pos != next_pos */
-	int			n = 0;
-#endif
-
-	j = i = keep;
-
-	if (env->me_flags & MDB_WRITEMAP) {
-		/* Clear dirty flags */
-		while (++i <= pagecount) {
-			dp = dl[i].mptr;
-			/* Don't flush this page yet */
-			if (dp->mp_flags & (P_LOOSE|P_KEEP)) {
-				dp->mp_flags &= ~P_KEEP;
-				dl[++j] = dl[i];
-				continue;
-			}
-			dp->mp_flags &= ~P_DIRTY;
-		}
-		goto done;
-	}
-
-	/* Write the pages */
-	for (;;) {
-		if (++i <= pagecount) {
-			dp = dl[i].mptr;
-			/* Don't flush this page yet */
-			if (dp->mp_flags & (P_LOOSE|P_KEEP)) {
-				dp->mp_flags &= ~P_KEEP;
-				dl[i].mid = 0;
-				continue;
-			}
-			pgno = dl[i].mid;
-			/* clear dirty flag */
-			dp->mp_flags &= ~P_DIRTY;
-			pos = pgno * psize;
-			size = psize;
-			if (IS_OVERFLOW(dp)) size *= dp->mp_pages;
-		}
-#ifdef _WIN32
-		else break;
-
-		/* Windows actually supports scatter/gather I/O, but only on
-		 * unbuffered file handles. Since we're relying on the OS page
-		 * cache for all our data, that's self-defeating. So we just
-		 * write pages one at a time. We use the ov structure to set
-		 * the write offset, to at least save the overhead of a Seek
-		 * system call.
-		 */
-		DPRINTF(("committing page %"Z"u", pgno));
-		memset(&ov, 0, sizeof(ov));
-		ov.Offset = pos & 0xffffffff;
-		ov.OffsetHigh = pos >> 16 >> 16;
-		if (!WriteFile(env->me_fd, dp, size, NULL, &ov)) {
-			rc = ErrCode();
-			DPRINTF(("WriteFile: %d", rc));
-			return rc;
-		}
-#else
-		/* Write up to MDB_COMMIT_PAGES dirty pages at a time. */
-		if (pos!=next_pos || n==MDB_COMMIT_PAGES || wsize+size>MAX_WRITE) {
-			if (n) {
-retry_write:
-				/* Write previous page(s) */
-#ifdef MDB_USE_PWRITEV
-				wres = pwritev(env->me_fd, iov, n, wpos);
-#else
-				if (n == 1) {
-					wres = pwrite(env->me_fd, iov[0].iov_base, wsize, wpos);
-				} else {
-retry_seek:
-					if (lseek(env->me_fd, wpos, SEEK_SET) == -1) {
-						rc = ErrCode();
-						if (rc == EINTR)
-							goto retry_seek;
-						DPRINTF(("lseek: %s", strerror(rc)));
-						return rc;
-					}
-					wres = writev(env->me_fd, iov, n);
-				}
-#endif
-				if (wres != wsize) {
-					if (wres < 0) {
-						rc = ErrCode();
-						if (rc == EINTR)
-							goto retry_write;
-						DPRINTF(("Write error: %s", strerror(rc)));
-					} else {
-						rc = EIO; /* TODO: Use which error code? */
-						DPUTS("short write, filesystem full?");
-					}
-					return rc;
-				}
-				n = 0;
-			}
-			if (i > pagecount)
-				break;
-			wpos = pos;
-			wsize = 0;
-		}
-		DPRINTF(("committing page %"Z"u", pgno));
-		next_pos = pos + size;
-		iov[n].iov_len = size;
-		iov[n].iov_base = (char *)dp;
-		wsize += size;
-		n++;
-#endif	/* _WIN32 */
-	}
-
-	/* MIPS has cache coherency issues, this is a no-op everywhere else
-	 * Note: for any size >= on-chip cache size, entire on-chip cache is
-	 * flushed.
-	 */
-	CACHEFLUSH(env->me_map, txn->mt_next_pgno * env->me_psize, DCACHE);
-
-	for (i = keep; ++i <= pagecount; ) {
-		dp = dl[i].mptr;
-		/* This is a page we skipped above */
-		if (!dl[i].mid) {
-			dl[++j] = dl[i];
-			dl[j].mid = dp->mp_pgno;
-			continue;
-		}
-		mdb_dpage_free(env, dp);
-	}
-
-done:
-	i--;
-	txn->mt_dirty_room += i - j;
-	dl[0].mid = j;
-	return MDB_SUCCESS;
-}
-
-int
-mdb_txn_commit(MDB_txn *txn)
-{
-	int		rc;
-	unsigned int i;
-	MDB_env	*env;
-
-	if (txn == NULL || txn->mt_env == NULL)
-		return EINVAL;
-
-	if (txn->mt_child) {
-		rc = mdb_txn_commit(txn->mt_child);
-		txn->mt_child = NULL;
-		if (rc)
-			goto fail;
-	}
-
-	env = txn->mt_env;
-
-	if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
-		mdb_dbis_update(txn, 1);
-		txn->mt_numdbs = 2; /* so txn_abort() doesn't close any new handles */
-		mdb_txn_abort(txn);
-		return MDB_SUCCESS;
-	}
-
-	if (F_ISSET(txn->mt_flags, MDB_TXN_ERROR)) {
-		DPUTS("error flag is set, can't commit");
-		if (txn->mt_parent)
-			txn->mt_parent->mt_flags |= MDB_TXN_ERROR;
-		rc = MDB_BAD_TXN;
-		goto fail;
-	}
-
-	if (txn->mt_parent) {
-		MDB_txn *parent = txn->mt_parent;
-		MDB_page **lp;
-		MDB_ID2L dst, src;
-		MDB_IDL pspill;
-		unsigned x, y, len, ps_len;
-
-		/* Append our free list to parent's */
-		rc = mdb_midl_append_list(&parent->mt_free_pgs, txn->mt_free_pgs);
-		if (rc)
-			goto fail;
-		mdb_midl_free(txn->mt_free_pgs);
-		/* Failures after this must either undo the changes
-		 * to the parent or set MDB_TXN_ERROR in the parent.
-		 */
-
-		parent->mt_next_pgno = txn->mt_next_pgno;
-		parent->mt_flags = txn->mt_flags;
-
-		/* Merge our cursors into parent's and close them */
-		mdb_cursors_close(txn, 1);
-
-		/* Update parent's DB table. */
-		memcpy(parent->mt_dbs, txn->mt_dbs, txn->mt_numdbs * sizeof(MDB_db));
-		parent->mt_numdbs = txn->mt_numdbs;
-		parent->mt_dbflags[0] = txn->mt_dbflags[0];
-		parent->mt_dbflags[1] = txn->mt_dbflags[1];
-		for (i=2; i<txn->mt_numdbs; i++) {
-			/* preserve parent's DB_NEW status */
-			x = parent->mt_dbflags[i] & DB_NEW;
-			parent->mt_dbflags[i] = txn->mt_dbflags[i] | x;
-		}
-
-		dst = parent->mt_u.dirty_list;
-		src = txn->mt_u.dirty_list;
-		/* Remove anything in our dirty list from parent's spill list */
-		if ((pspill = parent->mt_spill_pgs) && (ps_len = pspill[0])) {
-			x = y = ps_len;
-			pspill[0] = (pgno_t)-1;
-			/* Mark our dirty pages as deleted in parent spill list */
-			for (i=0, len=src[0].mid; ++i <= len; ) {
-				MDB_ID pn = src[i].mid << 1;
-				while (pn > pspill[x])
-					x--;
-				if (pn == pspill[x]) {
-					pspill[x] = 1;
-					y = --x;
-				}
-			}
-			/* Squash deleted pagenums if we deleted any */
-			for (x=y; ++x <= ps_len; )
-				if (!(pspill[x] & 1))
-					pspill[++y] = pspill[x];
-			pspill[0] = y;
-		}
-
-		/* Find len = length of merging our dirty list with parent's */
-		x = dst[0].mid;
-		dst[0].mid = 0;		/* simplify loops */
-		if (parent->mt_parent) {
-			len = x + src[0].mid;
-			y = mdb_mid2l_search(src, dst[x].mid + 1) - 1;
-			for (i = x; y && i; y--) {
-				pgno_t yp = src[y].mid;
-				while (yp < dst[i].mid)
-					i--;
-				if (yp == dst[i].mid) {
-					i--;
-					len--;
-				}
-			}
-		} else { /* Simplify the above for single-ancestor case */
-			len = MDB_IDL_UM_MAX - txn->mt_dirty_room;
-		}
-		/* Merge our dirty list with parent's */
-		y = src[0].mid;
-		for (i = len; y; dst[i--] = src[y--]) {
-			pgno_t yp = src[y].mid;
-			while (yp < dst[x].mid)
-				dst[i--] = dst[x--];
-			if (yp == dst[x].mid)
-				free(dst[x--].mptr);
-		}
-		mdb_tassert(txn, i == x);
-		dst[0].mid = len;
-		free(txn->mt_u.dirty_list);
-		parent->mt_dirty_room = txn->mt_dirty_room;
-		if (txn->mt_spill_pgs) {
-			if (parent->mt_spill_pgs) {
-				/* TODO: Prevent failure here, so parent does not fail */
-				rc = mdb_midl_append_list(&parent->mt_spill_pgs, txn->mt_spill_pgs);
-				if (rc)
-					parent->mt_flags |= MDB_TXN_ERROR;
-				mdb_midl_free(txn->mt_spill_pgs);
-				mdb_midl_sort(parent->mt_spill_pgs);
-			} else {
-				parent->mt_spill_pgs = txn->mt_spill_pgs;
-			}
-		}
-
-		/* Append our loose page list to parent's */
-		for (lp = &parent->mt_loose_pgs; *lp; lp = &NEXT_LOOSE_PAGE(lp))
-			;
-		*lp = txn->mt_loose_pgs;
-		parent->mt_loose_count += txn->mt_loose_count;
-
-		parent->mt_child = NULL;
-		mdb_midl_free(((MDB_ntxn *)txn)->mnt_pgstate.mf_pghead);
-		free(txn);
-		return rc;
-	}
-
-	if (txn != env->me_txn) {
-		DPUTS("attempt to commit unknown transaction");
-		rc = EINVAL;
-		goto fail;
-	}
-
-	mdb_cursors_close(txn, 0);
-
-	if (!txn->mt_u.dirty_list[0].mid &&
-		!(txn->mt_flags & (MDB_TXN_DIRTY|MDB_TXN_SPILLS)))
-		goto done;
-
-	DPRINTF(("committing txn %"Z"u %p on mdbenv %p, root page %"Z"u",
-	    txn->mt_txnid, (void*)txn, (void*)env, txn->mt_dbs[MAIN_DBI].md_root));
-
-	/* Update DB root pointers */
-	if (txn->mt_numdbs > 2) {
-		MDB_cursor mc;
-		MDB_dbi i;
-		MDB_val data;
-		data.mv_size = sizeof(MDB_db);
-
-		mdb_cursor_init(&mc, txn, MAIN_DBI, NULL);
-		for (i = 2; i < txn->mt_numdbs; i++) {
-			if (txn->mt_dbflags[i] & DB_DIRTY) {
-				if (TXN_DBI_CHANGED(txn, i)) {
-					rc = MDB_BAD_DBI;
-					goto fail;
-				}
-				data.mv_data = &txn->mt_dbs[i];
-				rc = mdb_cursor_put(&mc, &txn->mt_dbxs[i].md_name, &data, 0);
-				if (rc)
-					goto fail;
-			}
-		}
-	}
-
-	rc = mdb_freelist_save(txn);
-	if (rc)
-		goto fail;
-
-	mdb_midl_free(env->me_pghead);
-	env->me_pghead = NULL;
-	if (mdb_midl_shrink(&txn->mt_free_pgs))
-		env->me_free_pgs = txn->mt_free_pgs;
-
-#if (MDB_DEBUG) > 2
-	mdb_audit(txn);
-#endif
-
-	if ((rc = mdb_page_flush(txn, 0)) ||
-		(rc = mdb_env_sync(env, 0)) ||
-		(rc = mdb_env_write_meta(txn)))
-		goto fail;
-
-	/* Free P_LOOSE pages left behind in dirty_list */
-	if (!(env->me_flags & MDB_WRITEMAP))
-		mdb_dlist_free(txn);
-
-done:
-	env->me_pglast = 0;
-	env->me_txn = NULL;
-	mdb_dbis_update(txn, 1);
-
-	if (env->me_txns)
-		UNLOCK_MUTEX_W(env);
-	if (txn != env->me_txn0)
-		free(txn);
-
-	return MDB_SUCCESS;
-
-fail:
-	mdb_txn_abort(txn);
-	return rc;
-}
-
-/** Read the environment parameters of a DB environment before
- * mapping it into memory.
- * @param[in] env the environment handle
- * @param[out] meta address of where to store the meta information
- * @return 0 on success, non-zero on failure.
- */
-static int ESECT
-mdb_env_read_header(MDB_env *env, MDB_meta *meta)
-{
-	MDB_metabuf	pbuf;
-	MDB_page	*p;
-	MDB_meta	*m;
-	int			i, rc, off;
-	enum { Size = sizeof(pbuf) };
-
-	/* We don't know the page size yet, so use a minimum value.
-	 * Read both meta pages so we can use the latest one.
-	 */
-
-	for (i=off=0; i<2; i++, off = meta->mm_psize) {
-#ifdef _WIN32
-		DWORD len;
-		OVERLAPPED ov;
-		memset(&ov, 0, sizeof(ov));
-		ov.Offset = off;
-		rc = ReadFile(env->me_fd, &pbuf, Size, &len, &ov) ? (int)len : -1;
-		if (rc == -1 && ErrCode() == ERROR_HANDLE_EOF)
-			rc = 0;
-#else
-		rc = pread(env->me_fd, &pbuf, Size, off);
-#endif
-		if (rc != Size) {
-			if (rc == 0 && off == 0)
-				return ENOENT;
-			rc = rc < 0 ? (int) ErrCode() : MDB_INVALID;
-			DPRINTF(("read: %s", mdb_strerror(rc)));
-			return rc;
-		}
-
-		p = (MDB_page *)&pbuf;
-
-		if (!F_ISSET(p->mp_flags, P_META)) {
-			DPRINTF(("page %"Z"u not a meta page", p->mp_pgno));
-			return MDB_INVALID;
-		}
-
-		m = METADATA(p);
-		if (m->mm_magic != MDB_MAGIC) {
-			DPUTS("meta has invalid magic");
-			return MDB_INVALID;
-		}
-
-		if (m->mm_version != MDB_DATA_VERSION) {
-			DPRINTF(("database is version %u, expected version %u",
-				m->mm_version, MDB_DATA_VERSION));
-			return MDB_VERSION_MISMATCH;
-		}
-
-		if (off == 0 || m->mm_txnid > meta->mm_txnid)
-			*meta = *m;
-	}
-	return 0;
-}
-
-static void ESECT
-mdb_env_init_meta0(MDB_env *env, MDB_meta *meta)
-{
-	meta->mm_magic = MDB_MAGIC;
-	meta->mm_version = MDB_DATA_VERSION;
-	meta->mm_mapsize = env->me_mapsize;
-	meta->mm_psize = env->me_psize;
-	meta->mm_last_pg = 1;
-	meta->mm_flags = env->me_flags & 0xffff;
-	meta->mm_flags |= MDB_INTEGERKEY;
-	meta->mm_dbs[0].md_root = P_INVALID;
-	meta->mm_dbs[1].md_root = P_INVALID;
-}
-
-/** Write the environment parameters of a freshly created DB environment.
- * @param[in] env the environment handle
- * @param[out] meta address of where to store the meta information
- * @return 0 on success, non-zero on failure.
- */
-static int ESECT
-mdb_env_init_meta(MDB_env *env, MDB_meta *meta)
-{
-	MDB_page *p, *q;
-	int rc;
-	unsigned int	 psize;
-#ifdef _WIN32
-	DWORD len;
-	OVERLAPPED ov;
-	memset(&ov, 0, sizeof(ov));
-#define DO_PWRITE(rc, fd, ptr, size, len, pos)	do { \
-	ov.Offset = pos;	\
-	rc = WriteFile(fd, ptr, size, &len, &ov);	} while(0)
-#else
-	int len;
-#define DO_PWRITE(rc, fd, ptr, size, len, pos)	do { \
-	len = pwrite(fd, ptr, size, pos);	\
-	if (len == -1 && ErrCode() == EINTR) continue; \
-	rc = (len >= 0); break; } while(1)
-#endif
-
-	DPUTS("writing new meta page");
-
-	psize = env->me_psize;
-
-	mdb_env_init_meta0(env, meta);
-
-	p = calloc(2, psize);
-	p->mp_pgno = 0;
-	p->mp_flags = P_META;
-	*(MDB_meta *)METADATA(p) = *meta;
-
-	q = (MDB_page *)((char *)p + psize);
-	q->mp_pgno = 1;
-	q->mp_flags = P_META;
-	*(MDB_meta *)METADATA(q) = *meta;
-
-	DO_PWRITE(rc, env->me_fd, p, psize * 2, len, 0);
-	if (!rc)
-		rc = ErrCode();
-	else if ((unsigned) len == psize * 2)
-		rc = MDB_SUCCESS;
-	else
-		rc = ENOSPC;
-	free(p);
-	return rc;
-}
-
-/** Update the environment info to commit a transaction.
- * @param[in] txn the transaction that's being committed
- * @return 0 on success, non-zero on failure.
- */
-static int
-mdb_env_write_meta(MDB_txn *txn)
-{
-	MDB_env *env;
-	MDB_meta	meta, metab, *mp;
-	size_t mapsize;
-	off_t off;
-	int rc, len, toggle;
-	char *ptr;
-	HANDLE mfd;
-#ifdef _WIN32
-	OVERLAPPED ov;
-#else
-	int r2;
-#endif
-
-	toggle = txn->mt_txnid & 1;
-	DPRINTF(("writing meta page %d for root page %"Z"u",
-		toggle, txn->mt_dbs[MAIN_DBI].md_root));
-
-	env = txn->mt_env;
-	mp = env->me_metas[toggle];
-	mapsize = env->me_metas[toggle ^ 1]->mm_mapsize;
-	/* Persist any increases of mapsize config */
-	if (mapsize < env->me_mapsize)
-		mapsize = env->me_mapsize;
-
-	if (env->me_flags & MDB_WRITEMAP) {
-		mp->mm_mapsize = mapsize;
-		mp->mm_dbs[0] = txn->mt_dbs[0];
-		mp->mm_dbs[1] = txn->mt_dbs[1];
-		mp->mm_last_pg = txn->mt_next_pgno - 1;
-		mp->mm_txnid = txn->mt_txnid;
-		if (!(env->me_flags & (MDB_NOMETASYNC|MDB_NOSYNC))) {
-			unsigned meta_size = env->me_psize;
-			rc = (env->me_flags & MDB_MAPASYNC) ? MS_ASYNC : MS_SYNC;
-			ptr = env->me_map;
-			if (toggle) {
-#ifndef _WIN32	/* POSIX msync() requires ptr = start of OS page */
-				if (meta_size < env->me_os_psize)
-					meta_size += meta_size;
-				else
-#endif
-					ptr += meta_size;
-			}
-			if (MDB_MSYNC(ptr, meta_size, rc)) {
-				rc = ErrCode();
-				goto fail;
-			}
-		}
-		goto done;
-	}
-	metab.mm_txnid = env->me_metas[toggle]->mm_txnid;
-	metab.mm_last_pg = env->me_metas[toggle]->mm_last_pg;
-
-	meta.mm_mapsize = mapsize;
-	meta.mm_dbs[0] = txn->mt_dbs[0];
-	meta.mm_dbs[1] = txn->mt_dbs[1];
-	meta.mm_last_pg = txn->mt_next_pgno - 1;
-	meta.mm_txnid = txn->mt_txnid;
-
-	off = offsetof(MDB_meta, mm_mapsize);
-	ptr = (char *)&meta + off;
-	len = sizeof(MDB_meta) - off;
-	if (toggle)
-		off += env->me_psize;
-	off += PAGEHDRSZ;
-
-	/* Write to the SYNC fd */
-	mfd = env->me_flags & (MDB_NOSYNC|MDB_NOMETASYNC) ?
-		env->me_fd : env->me_mfd;
-retry_write:
-#ifdef _WIN32
-	{
-		memset(&ov, 0, sizeof(ov));
-		ov.Offset = off;
-		if (!WriteFile(mfd, ptr, len, (DWORD *)&rc, &ov))
-			rc = -1;
-	}
-#else
-	rc = pwrite(mfd, ptr, len, off);
-#endif
-	if (rc != len) {
-		rc = rc < 0 ? ErrCode() : EIO;
-		if (rc == EINTR)
-			goto retry_write;
-		DPUTS("write failed, disk error?");
-		/* On a failure, the pagecache still contains the new data.
-		 * Write some old data back, to prevent it from being used.
-		 * Use the non-SYNC fd; we know it will fail anyway.
-		 */
-		meta.mm_last_pg = metab.mm_last_pg;
-		meta.mm_txnid = metab.mm_txnid;
-#ifdef _WIN32
-		memset(&ov, 0, sizeof(ov));
-		ov.Offset = off;
-		WriteFile(env->me_fd, ptr, len, NULL, &ov);
-#else
-		r2 = pwrite(env->me_fd, ptr, len, off);
-		(void)r2;	/* Silence warnings. We don't care about pwrite's return value */
-#endif
-fail:
-		env->me_flags |= MDB_FATAL_ERROR;
-		return rc;
-	}
-	/* MIPS has cache coherency issues, this is a no-op everywhere else */
-	CACHEFLUSH(env->me_map + off, len, DCACHE);
-done:
-	/* Memory ordering issues are irrelevant; since the entire writer
-	 * is wrapped by wmutex, all of these changes will become visible
-	 * after the wmutex is unlocked. Since the DB is multi-version,
-	 * readers will get consistent data regardless of how fresh or
-	 * how stale their view of these values is.
-	 */
-	if (env->me_txns)
-		env->me_txns->mti_txnid = txn->mt_txnid;
-
-	return MDB_SUCCESS;
-}
-
-/** Check both meta pages to see which one is newer.
- * @param[in] env the environment handle
- * @return meta toggle (0 or 1).
- */
-static int
-mdb_env_pick_meta(const MDB_env *env)
-{
-	return (env->me_metas[0]->mm_txnid < env->me_metas[1]->mm_txnid);
-}
-
-int ESECT
-mdb_env_create(MDB_env **env)
-{
-	MDB_env *e;
-
-	e = calloc(1, sizeof(MDB_env));
-	if (!e)
-		return ENOMEM;
-
-	e->me_maxreaders = DEFAULT_READERS;
-	e->me_maxdbs = e->me_numdbs = 2;
-	e->me_fd = INVALID_HANDLE_VALUE;
-	e->me_lfd = INVALID_HANDLE_VALUE;
-	e->me_mfd = INVALID_HANDLE_VALUE;
-#ifdef MDB_USE_POSIX_SEM
-	e->me_rmutex = SEM_FAILED;
-	e->me_wmutex = SEM_FAILED;
-#endif
-	e->me_pid = getpid();
-	GET_PAGESIZE(e->me_os_psize);
-	VGMEMP_CREATE(e,0,0);
-	*env = e;
-	return MDB_SUCCESS;
-}
-
-static int ESECT
-mdb_env_map(MDB_env *env, void *addr)
-{
-	MDB_page *p;
-	unsigned int flags = env->me_flags;
-#ifdef _WIN32
-	int rc;
-	HANDLE mh;
-	LONG sizelo, sizehi;
-	size_t msize;
-
-	if (flags & MDB_RDONLY) {
-		/* Don't set explicit map size, use whatever exists */
-		msize = 0;
-		sizelo = 0;
-		sizehi = 0;
-	} else {
-		msize = env->me_mapsize;
-		sizelo = msize & 0xffffffff;
-		sizehi = msize >> 16 >> 16; /* only needed on Win64 */
-
-		/* Windows won't create mappings for zero length files.
-		 * and won't map more than the file size.
-		 * Just set the maxsize right now.
-		 */
-		if (SetFilePointer(env->me_fd, sizelo, &sizehi, 0) != (DWORD)sizelo
-			|| !SetEndOfFile(env->me_fd)
-			|| SetFilePointer(env->me_fd, 0, NULL, 0) != 0)
-			return ErrCode();
-	}
-
-	mh = CreateFileMapping(env->me_fd, NULL, flags & MDB_WRITEMAP ?
-		PAGE_READWRITE : PAGE_READONLY,
-		sizehi, sizelo, NULL);
-	if (!mh)
-		return ErrCode();
-	env->me_map = MapViewOfFileEx(mh, flags & MDB_WRITEMAP ?
-		FILE_MAP_WRITE : FILE_MAP_READ,
-		0, 0, msize, addr);
-	rc = env->me_map ? 0 : ErrCode();
-	CloseHandle(mh);
-	if (rc)
-		return rc;
-#else
-	int prot = PROT_READ;
-	if (flags & MDB_WRITEMAP) {
-		prot |= PROT_WRITE;
-		if (ftruncate(env->me_fd, env->me_mapsize) < 0)
-			return ErrCode();
-	}
-	env->me_map = mmap(addr, env->me_mapsize, prot, MAP_SHARED,
-		env->me_fd, 0);
-	if (env->me_map == MAP_FAILED) {
-		env->me_map = NULL;
-		return ErrCode();
-	}
-
-	if (flags & MDB_NORDAHEAD) {
-		/* Turn off readahead. It's harmful when the DB is larger than RAM. */
-#ifdef MADV_RANDOM
-		madvise(env->me_map, env->me_mapsize, MADV_RANDOM);
-#else
-#ifdef POSIX_MADV_RANDOM
-		posix_madvise(env->me_map, env->me_mapsize, POSIX_MADV_RANDOM);
-#endif /* POSIX_MADV_RANDOM */
-#endif /* MADV_RANDOM */
-	}
-#endif /* _WIN32 */
-
-	/* Can happen because the address argument to mmap() is just a
-	 * hint.  mmap() can pick another, e.g. if the range is in use.
-	 * The MAP_FIXED flag would prevent that, but then mmap could
-	 * instead unmap existing pages to make room for the new map.
-	 */
-	if (addr && env->me_map != addr)
-		return EBUSY;	/* TODO: Make a new MDB_* error code? */
-
-	p = (MDB_page *)env->me_map;
-	env->me_metas[0] = METADATA(p);
-	env->me_metas[1] = (MDB_meta *)((char *)env->me_metas[0] + env->me_psize);
-
-	return MDB_SUCCESS;
-}
-
-int ESECT
-mdb_env_set_mapsize(MDB_env *env, size_t size)
-{
-	/* If env is already open, caller is responsible for making
-	 * sure there are no active txns.
-	 */
-	if (env->me_map) {
-		int rc;
-		void *old;
-		if (env->me_txn)
-			return EINVAL;
-		if (!size)
-			size = env->me_metas[mdb_env_pick_meta(env)]->mm_mapsize;
-		else if (size < env->me_mapsize) {
-			/* If the configured size is smaller, make sure it's
-			 * still big enough. Silently round up to minimum if not.
-			 */
-			size_t minsize = (env->me_metas[mdb_env_pick_meta(env)]->mm_last_pg + 1) * env->me_psize;
-			if (size < minsize)
-				size = minsize;
-		}
-		munmap(env->me_map, env->me_mapsize);
-		env->me_mapsize = size;
-		old = (env->me_flags & MDB_FIXEDMAP) ? env->me_map : NULL;
-		rc = mdb_env_map(env, old);
-		if (rc)
-			return rc;
-	}
-	env->me_mapsize = size;
-	if (env->me_psize)
-		env->me_maxpg = env->me_mapsize / env->me_psize;
-	return MDB_SUCCESS;
-}
-
-int ESECT
-mdb_env_set_maxdbs(MDB_env *env, MDB_dbi dbs)
-{
-	if (env->me_map)
-		return EINVAL;
-	env->me_maxdbs = dbs + 2; /* Named databases + main and free DB */
-	return MDB_SUCCESS;
-}
-
-int ESECT
-mdb_env_set_maxreaders(MDB_env *env, unsigned int readers)
-{
-	if (env->me_map || readers < 1)
-		return EINVAL;
-	env->me_maxreaders = readers;
-	return MDB_SUCCESS;
-}
-
-int ESECT
-mdb_env_get_maxreaders(MDB_env *env, unsigned int *readers)
-{
-	if (!env || !readers)
-		return EINVAL;
-	*readers = env->me_maxreaders;
-	return MDB_SUCCESS;
-}
-
-static int ESECT
-mdb_fsize(HANDLE fd, size_t *size)
-{
-#ifdef _WIN32
-	LARGE_INTEGER fsize;
-
-	if (!GetFileSizeEx(fd, &fsize))
-		return ErrCode();
-
-	*size = fsize.QuadPart;
-#else
-	struct stat st;
-
-	if (fstat(fd, &st))
-		return ErrCode();
-
-	*size = st.st_size;
-#endif
-	return MDB_SUCCESS;
-}
-
-#ifdef BROKEN_FDATASYNC
-#include <sys/utsname.h>
-#include <sys/vfs.h>
-#endif
-
-/** Further setup required for opening an LMDB environment
- */
-static int ESECT
-mdb_env_open2(MDB_env *env)
-{
-	unsigned int flags = env->me_flags;
-	int i, newenv = 0, rc;
-	MDB_meta meta;
-
-#ifdef _WIN32
-	/* See if we should use QueryLimited */
-	rc = GetVersion();
-	if ((rc & 0xff) > 5)
-		env->me_pidquery = MDB_PROCESS_QUERY_LIMITED_INFORMATION;
-	else
-		env->me_pidquery = PROCESS_QUERY_INFORMATION;
-#endif /* _WIN32 */
-#ifdef BROKEN_FDATASYNC
-	/* ext3/ext4 fdatasync is broken on some older Linux kernels.
-	 * https://lkml.org/lkml/2012/9/3/83
-	 * Kernels after 3.6-rc6 are known good.
-	 * https://lkml.org/lkml/2012/9/10/556
-	 * See if the DB is on ext3/ext4, then check for new enough kernel
-	 * Kernels 2.6.32.60, 2.6.34.15, 3.2.30, and 3.5.4 are also known
-	 * to be patched.
-	 */
-	{
-		struct statfs st;
-		fstatfs(env->me_fd, &st);
-		while (st.f_type == 0xEF53) {
-			struct utsname uts;
-			int i;
-			uname(&uts);
-			if (uts.release[0] < '3') {
-				if (!strncmp(uts.release, "2.6.32.", 7)) {
-					i = atoi(uts.release+7);
-					if (i >= 60)
-						break;	/* 2.6.32.60 and newer is OK */
-				} else if (!strncmp(uts.release, "2.6.34.", 7)) {
-					i = atoi(uts.release+7);
-					if (i >= 15)
-						break;	/* 2.6.34.15 and newer is OK */
-				}
-			} else if (uts.release[0] == '3') {
-				i = atoi(uts.release+2);
-				if (i > 5)
-					break;	/* 3.6 and newer is OK */
-				if (i == 5) {
-					i = atoi(uts.release+4);
-					if (i >= 4)
-						break;	/* 3.5.4 and newer is OK */
-				} else if (i == 2) {
-					i = atoi(uts.release+4);
-					if (i >= 30)
-						break;	/* 3.2.30 and newer is OK */
-				}
-			} else {	/* 4.x and newer is OK */
-				break;
-			}
-			env->me_flags |= MDB_FSYNCONLY;
-			break;
-		}
-	}
-#endif
-
-	memset(&meta, 0, sizeof(meta));
-
-	if ((i = mdb_env_read_header(env, &meta)) != 0) {
-		if (i != ENOENT)
-			return i;
-		DPUTS("new mdbenv");
-		newenv = 1;
-		env->me_psize = env->me_os_psize;
-		if (env->me_psize > MAX_PAGESIZE)
-			env->me_psize = MAX_PAGESIZE;
-	} else {
-		env->me_psize = meta.mm_psize;
-	}
-
-	/* Was a mapsize configured? */
-	if (!env->me_mapsize) {
-		/* If this is a new environment, take the default,
-		 * else use the size recorded in the existing env.
-		 */
-		env->me_mapsize = newenv ? DEFAULT_MAPSIZE : meta.mm_mapsize;
-	} else if (env->me_mapsize < meta.mm_mapsize) {
-		/* If the configured size is smaller, make sure it's
-		 * still big enough. Silently round up to minimum if not.
-		 */
-		size_t minsize = (meta.mm_last_pg + 1) * meta.mm_psize;
-		if (env->me_mapsize < minsize)
-			env->me_mapsize = minsize;
-	}
-
-	rc = mdb_env_map(env, (flags & MDB_FIXEDMAP) ? meta.mm_address : NULL);
-	if (rc)
-		return rc;
-
-	if (newenv) {
-		if (flags & MDB_FIXEDMAP)
-			meta.mm_address = env->me_map;
-		i = mdb_env_init_meta(env, &meta);
-		if (i != MDB_SUCCESS) {
-			return i;
-		}
-	}
-
-	env->me_maxfree_1pg = (env->me_psize - PAGEHDRSZ) / sizeof(pgno_t) - 1;
-	env->me_nodemax = (((env->me_psize - PAGEHDRSZ) / MDB_MINKEYS) & -2)
-		- sizeof(indx_t);
-#if !(MDB_MAXKEYSIZE)
-	env->me_maxkey = env->me_nodemax - (NODESIZE + sizeof(MDB_db));
-#endif
-	env->me_maxpg = env->me_mapsize / env->me_psize;
-
-#if MDB_DEBUG
-	{
-		int toggle = mdb_env_pick_meta(env);
-		MDB_db *db = &env->me_metas[toggle]->mm_dbs[MAIN_DBI];
-
-		DPRINTF(("opened database version %u, pagesize %u",
-			env->me_metas[0]->mm_version, env->me_psize));
-		DPRINTF(("using meta page %d",    toggle));
-		DPRINTF(("depth: %u",             db->md_depth));
-		DPRINTF(("entries: %"Z"u",        db->md_entries));
-		DPRINTF(("branch pages: %"Z"u",   db->md_branch_pages));
-		DPRINTF(("leaf pages: %"Z"u",     db->md_leaf_pages));
-		DPRINTF(("overflow pages: %"Z"u", db->md_overflow_pages));
-		DPRINTF(("root: %"Z"u",           db->md_root));
-	}
-#endif
-
-	return MDB_SUCCESS;
-}
-
-
-/** Release a reader thread's slot in the reader lock table.
- *	This function is called automatically when a thread exits.
- * @param[in] ptr This points to the slot in the reader lock table.
- */
-static void
-mdb_env_reader_dest(void *ptr)
-{
-	MDB_reader *reader = ptr;
-
-	reader->mr_pid = 0;
-}
-
-#ifdef _WIN32
-/** Junk for arranging thread-specific callbacks on Windows. This is
- *	necessarily platform and compiler-specific. Windows supports up
- *	to 1088 keys. Let's assume nobody opens more than 64 environments
- *	in a single process, for now. They can override this if needed.
- */
-#ifndef MAX_TLS_KEYS
-#define MAX_TLS_KEYS	64
-#endif
-static pthread_key_t mdb_tls_keys[MAX_TLS_KEYS];
-static int mdb_tls_nkeys;
-
-static void NTAPI mdb_tls_callback(PVOID module, DWORD reason, PVOID ptr)
-{
-	int i;
-	switch(reason) {
-	case DLL_PROCESS_ATTACH: break;
-	case DLL_THREAD_ATTACH: break;
-	case DLL_THREAD_DETACH:
-		for (i=0; i<mdb_tls_nkeys; i++) {
-			MDB_reader *r = pthread_getspecific(mdb_tls_keys[i]);
-			if (r) {
-				mdb_env_reader_dest(r);
-			}
-		}
-		break;
-	case DLL_PROCESS_DETACH: break;
-	}
-}
-#ifdef __GNUC__
-#ifdef _WIN64
-const PIMAGE_TLS_CALLBACK mdb_tls_cbp __attribute__((section (".CRT$XLB"))) = mdb_tls_callback;
-#else
-PIMAGE_TLS_CALLBACK mdb_tls_cbp __attribute__((section (".CRT$XLB"))) = mdb_tls_callback;
-#endif
-#else
-#ifdef _WIN64
-/* Force some symbol references.
- *	_tls_used forces the linker to create the TLS directory if not already done
- *	mdb_tls_cbp prevents whole-program-optimizer from dropping the symbol.
- */
-#pragma comment(linker, "/INCLUDE:_tls_used")
-#pragma comment(linker, "/INCLUDE:mdb_tls_cbp")
-#pragma const_seg(".CRT$XLB")
-extern const PIMAGE_TLS_CALLBACK mdb_tls_cbp;
-const PIMAGE_TLS_CALLBACK mdb_tls_cbp = mdb_tls_callback;
-#pragma const_seg()
-#else	/* _WIN32 */
-#pragma comment(linker, "/INCLUDE:__tls_used")
-#pragma comment(linker, "/INCLUDE:_mdb_tls_cbp")
-#pragma data_seg(".CRT$XLB")
-PIMAGE_TLS_CALLBACK mdb_tls_cbp = mdb_tls_callback;
-#pragma data_seg()
-#endif	/* WIN 32/64 */
-#endif	/* !__GNUC__ */
-#endif
-
-/** Downgrade the exclusive lock on the region back to shared */
-static int ESECT
-mdb_env_share_locks(MDB_env *env, int *excl)
-{
-	int rc = 0, toggle = mdb_env_pick_meta(env);
-
-	env->me_txns->mti_txnid = env->me_metas[toggle]->mm_txnid;
-
-#ifdef _WIN32
-	{
-		OVERLAPPED ov;
-		/* First acquire a shared lock. The Unlock will
-		 * then release the existing exclusive lock.
-		 */
-		memset(&ov, 0, sizeof(ov));
-		if (!LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {
-			rc = ErrCode();
-		} else {
-			UnlockFile(env->me_lfd, 0, 0, 1, 0);
-			*excl = 0;
-		}
-	}
-#else
-	{
-		struct flock lock_info;
-		/* The shared lock replaces the existing lock */
-		memset((void *)&lock_info, 0, sizeof(lock_info));
-		lock_info.l_type = F_RDLCK;
-		lock_info.l_whence = SEEK_SET;
-		lock_info.l_start = 0;
-		lock_info.l_len = 1;
-		while ((rc = fcntl(env->me_lfd, F_SETLK, &lock_info)) &&
-				(rc = ErrCode()) == EINTR) ;
-		*excl = rc ? -1 : 0;	/* error may mean we lost the lock */
-	}
-#endif
-
-	return rc;
-}
-
-/** Try to get exclusive lock, otherwise shared.
- *	Maintain *excl = -1: no/unknown lock, 0: shared, 1: exclusive.
- */
-static int ESECT
-mdb_env_excl_lock(MDB_env *env, int *excl)
-{
-	int rc = 0;
-#ifdef _WIN32
-	if (LockFile(env->me_lfd, 0, 0, 1, 0)) {
-		*excl = 1;
-	} else {
-		OVERLAPPED ov;
-		memset(&ov, 0, sizeof(ov));
-		if (LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {
-			*excl = 0;
-		} else {
-			rc = ErrCode();
-		}
-	}
-#else
-	struct flock lock_info;
-	memset((void *)&lock_info, 0, sizeof(lock_info));
-	lock_info.l_type = F_WRLCK;
-	lock_info.l_whence = SEEK_SET;
-	lock_info.l_start = 0;
-	lock_info.l_len = 1;
-	while ((rc = fcntl(env->me_lfd, F_SETLK, &lock_info)) &&
-			(rc = ErrCode()) == EINTR) ;
-	if (!rc) {
-		*excl = 1;
-	} else
-# ifdef MDB_USE_POSIX_SEM
-	if (*excl < 0) /* always true when !MDB_USE_POSIX_SEM */
-# endif
-	{
-		lock_info.l_type = F_RDLCK;
-		while ((rc = fcntl(env->me_lfd, F_SETLKW, &lock_info)) &&
-				(rc = ErrCode()) == EINTR) ;
-		if (rc == 0)
-			*excl = 0;
-	}
-#endif
-	return rc;
-}
-
-#ifdef MDB_USE_HASH
-/*
- * hash_64 - 64 bit Fowler/Noll/Vo-0 FNV-1a hash code
- *
- * @(#) $Revision: 5.1 $
- * @(#) $Id: hash_64a.c,v 5.1 2009/06/30 09:01:38 chongo Exp $
- * @(#) $Source: /usr/local/src/cmd/fnv/RCS/hash_64a.c,v $
- *
- *	  http://www.isthe.com/chongo/tech/comp/fnv/index.html
- *
- ***
- *
- * Please do not copyright this code.  This code is in the public domain.
- *
- * LANDON CURT NOLL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
- * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO
- * EVENT SHALL LANDON CURT NOLL BE LIABLE FOR ANY SPECIAL, INDIRECT OR
- * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
- * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
- * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
- * PERFORMANCE OF THIS SOFTWARE.
- *
- * By:
- *	chongo <Landon Curt Noll> /\oo/\
- *	  http://www.isthe.com/chongo/
- *
- * Share and Enjoy!	:-)
- */
-
-typedef unsigned long long	mdb_hash_t;
-#define MDB_HASH_INIT ((mdb_hash_t)0xcbf29ce484222325ULL)
-
-/** perform a 64 bit Fowler/Noll/Vo FNV-1a hash on a buffer
- * @param[in] val	value to hash
- * @param[in] hval	initial value for hash
- * @return 64 bit hash
- *
- * NOTE: To use the recommended 64 bit FNV-1a hash, use MDB_HASH_INIT as the
- * 	 hval arg on the first call.
- */
-static mdb_hash_t
-mdb_hash_val(MDB_val *val, mdb_hash_t hval)
-{
-	unsigned char *s = (unsigned char *)val->mv_data;	/* unsigned string */
-	unsigned char *end = s + val->mv_size;
-	/*
-	 * FNV-1a hash each octet of the string
-	 */
-	while (s < end) {
-		/* xor the bottom with the current octet */
-		hval ^= (mdb_hash_t)*s++;
-
-		/* multiply by the 64 bit FNV magic prime mod 2^64 */
-		hval += (hval << 1) + (hval << 4) + (hval << 5) +
-			(hval << 7) + (hval << 8) + (hval << 40);
-	}
-	/* return our new hash value */
-	return hval;
-}
-
-/** Hash the string and output the encoded hash.
- * This uses modified RFC1924 Ascii85 encoding to accommodate systems with
- * very short name limits. We don't care about the encoding being reversible,
- * we just want to preserve as many bits of the input as possible in a
- * small printable string.
- * @param[in] str string to hash
- * @param[out] encbuf an array of 11 chars to hold the hash
- */
-static const char mdb_a85[]= "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz!#$%&()*+-;<=>?@^_`{|}~";
-
-static void
-mdb_pack85(unsigned long l, char *out)
-{
-	int i;
-
-	for (i=0; i<5; i++) {
-		*out++ = mdb_a85[l % 85];
-		l /= 85;
-	}
-}
-
-static void
-mdb_hash_enc(MDB_val *val, char *encbuf)
-{
-	mdb_hash_t h = mdb_hash_val(val, MDB_HASH_INIT);
-
-	mdb_pack85(h, encbuf);
-	mdb_pack85(h>>32, encbuf+5);
-	encbuf[10] = '\0';
-}
-#endif
-
-/** Open and/or initialize the lock region for the environment.
- * @param[in] env The LMDB environment.
- * @param[in] lpath The pathname of the file used for the lock region.
- * @param[in] mode The Unix permissions for the file, if we create it.
- * @param[in,out] excl In -1, out lock type: -1 none, 0 shared, 1 exclusive
- * @return 0 on success, non-zero on failure.
- */
-static int ESECT
-mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
-{
-#ifdef _WIN32
-#	define MDB_ERRCODE_ROFS	ERROR_WRITE_PROTECT
-#else
-#	define MDB_ERRCODE_ROFS	EROFS
-#ifdef O_CLOEXEC	/* Linux: Open file and set FD_CLOEXEC atomically */
-#	define MDB_CLOEXEC		O_CLOEXEC
-#else
-	int fdflags;
-#	define MDB_CLOEXEC		0
-#endif
-#endif
-	int rc;
-	off_t size, rsize;
-
-#ifdef _WIN32
-	env->me_lfd = CreateFile(lpath, GENERIC_READ|GENERIC_WRITE,
-		FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_ALWAYS,
-		FILE_ATTRIBUTE_NORMAL, NULL);
-#else
-	env->me_lfd = open(lpath, O_RDWR|O_CREAT|MDB_CLOEXEC, mode);
-#endif
-	if (env->me_lfd == INVALID_HANDLE_VALUE) {
-		rc = ErrCode();
-		if (rc == MDB_ERRCODE_ROFS && (env->me_flags & MDB_RDONLY)) {
-			return MDB_SUCCESS;
-		}
-		goto fail_errno;
-	}
-#if ! ((MDB_CLOEXEC) || defined(_WIN32))
-	/* Lose record locks when exec*() */
-	if ((fdflags = fcntl(env->me_lfd, F_GETFD) | FD_CLOEXEC) >= 0)
-			fcntl(env->me_lfd, F_SETFD, fdflags);
-#endif
-
-	if (!(env->me_flags & MDB_NOTLS)) {
-		rc = pthread_key_create(&env->me_txkey, mdb_env_reader_dest);
-		if (rc)
-			goto fail;
-		env->me_flags |= MDB_ENV_TXKEY;
-#ifdef _WIN32
-		/* Windows TLS callbacks need help finding their TLS info. */
-		if (mdb_tls_nkeys >= MAX_TLS_KEYS) {
-			rc = MDB_TLS_FULL;
-			goto fail;
-		}
-		mdb_tls_keys[mdb_tls_nkeys++] = env->me_txkey;
-#endif
-	}
-
-	/* Try to get exclusive lock. If we succeed, then
-	 * nobody is using the lock region and we should initialize it.
-	 */
-	if ((rc = mdb_env_excl_lock(env, excl))) goto fail;
-
-#ifdef _WIN32
-	size = GetFileSize(env->me_lfd, NULL);
-#else
-	size = lseek(env->me_lfd, 0, SEEK_END);
-	if (size == -1) goto fail_errno;
-#endif
-	rsize = (env->me_maxreaders-1) * sizeof(MDB_reader) + sizeof(MDB_txninfo);
-	if (size < rsize && *excl > 0) {
-#ifdef _WIN32
-		if (SetFilePointer(env->me_lfd, rsize, NULL, FILE_BEGIN) != (DWORD)rsize
-			|| !SetEndOfFile(env->me_lfd))
-			goto fail_errno;
-#else
-		if (ftruncate(env->me_lfd, rsize) != 0) goto fail_errno;
-#endif
-	} else {
-		rsize = size;
-		size = rsize - sizeof(MDB_txninfo);
-		env->me_maxreaders = size/sizeof(MDB_reader) + 1;
-	}
-	{
-#ifdef _WIN32
-		HANDLE mh;
-		mh = CreateFileMapping(env->me_lfd, NULL, PAGE_READWRITE,
-			0, 0, NULL);
-		if (!mh) goto fail_errno;
-		env->me_txns = MapViewOfFileEx(mh, FILE_MAP_WRITE, 0, 0, rsize, NULL);
-		CloseHandle(mh);
-		if (!env->me_txns) goto fail_errno;
-#else
-		void *m = mmap(NULL, rsize, PROT_READ|PROT_WRITE, MAP_SHARED,
-			env->me_lfd, 0);
-		if (m == MAP_FAILED) goto fail_errno;
-		env->me_txns = m;
-#endif
-	}
-	if (*excl > 0) {
-#ifdef _WIN32
-		BY_HANDLE_FILE_INFORMATION stbuf;
-		struct {
-			DWORD volume;
-			DWORD nhigh;
-			DWORD nlow;
-		} idbuf;
-		MDB_val val;
-		char encbuf[11];
-
-		if (!mdb_sec_inited) {
-			InitializeSecurityDescriptor(&mdb_null_sd,
-				SECURITY_DESCRIPTOR_REVISION);
-			SetSecurityDescriptorDacl(&mdb_null_sd, TRUE, 0, FALSE);
-			mdb_all_sa.nLength = sizeof(SECURITY_ATTRIBUTES);
-			mdb_all_sa.bInheritHandle = FALSE;
-			mdb_all_sa.lpSecurityDescriptor = &mdb_null_sd;
-			mdb_sec_inited = 1;
-		}
-		if (!GetFileInformationByHandle(env->me_lfd, &stbuf)) goto fail_errno;
-		idbuf.volume = stbuf.dwVolumeSerialNumber;
-		idbuf.nhigh  = stbuf.nFileIndexHigh;
-		idbuf.nlow   = stbuf.nFileIndexLow;
-		val.mv_data = &idbuf;
-		val.mv_size = sizeof(idbuf);
-		mdb_hash_enc(&val, encbuf);
-		sprintf(env->me_txns->mti_rmname, "Global\\MDBr%s", encbuf);
-		sprintf(env->me_txns->mti_wmname, "Global\\MDBw%s", encbuf);
-		env->me_rmutex = CreateMutex(&mdb_all_sa, FALSE, env->me_txns->mti_rmname);
-		if (!env->me_rmutex) goto fail_errno;
-		env->me_wmutex = CreateMutex(&mdb_all_sa, FALSE, env->me_txns->mti_wmname);
-		if (!env->me_wmutex) goto fail_errno;
-#elif defined(MDB_USE_POSIX_SEM)
-		struct stat stbuf;
-		struct {
-			dev_t dev;
-			ino_t ino;
-		} idbuf;
-		MDB_val val;
-		char encbuf[11];
-
-#if defined(__NetBSD__)
-#define	MDB_SHORT_SEMNAMES	1	/* limited to 14 chars */
-#endif
-		if (fstat(env->me_lfd, &stbuf)) goto fail_errno;
-		idbuf.dev = stbuf.st_dev;
-		idbuf.ino = stbuf.st_ino;
-		val.mv_data = &idbuf;
-		val.mv_size = sizeof(idbuf);
-		mdb_hash_enc(&val, encbuf);
-#ifdef MDB_SHORT_SEMNAMES
-		encbuf[9] = '\0';	/* drop name from 15 chars to 14 chars */
-#endif
-		sprintf(env->me_txns->mti_rmname, "/MDBr%s", encbuf);
-		sprintf(env->me_txns->mti_wmname, "/MDBw%s", encbuf);
-		/* Clean up after a previous run, if needed:  Try to
-		 * remove both semaphores before doing anything else.
-		 */
-		sem_unlink(env->me_txns->mti_rmname);
-		sem_unlink(env->me_txns->mti_wmname);
-		env->me_rmutex = sem_open(env->me_txns->mti_rmname,
-			O_CREAT|O_EXCL, mode, 1);
-		if (env->me_rmutex == SEM_FAILED) goto fail_errno;
-		env->me_wmutex = sem_open(env->me_txns->mti_wmname,
-			O_CREAT|O_EXCL, mode, 1);
-		if (env->me_wmutex == SEM_FAILED) goto fail_errno;
-#else	/* MDB_USE_POSIX_SEM */
-		pthread_mutexattr_t mattr;
-
-		if ((rc = pthread_mutexattr_init(&mattr))
-			|| (rc = pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED))
-			|| (rc = pthread_mutex_init(&env->me_txns->mti_mutex, &mattr))
-			|| (rc = pthread_mutex_init(&env->me_txns->mti_wmutex, &mattr)))
-			goto fail;
-		pthread_mutexattr_destroy(&mattr);
-#endif	/* _WIN32 || MDB_USE_POSIX_SEM */
-
-		env->me_txns->mti_magic = MDB_MAGIC;
-		env->me_txns->mti_format = MDB_LOCK_FORMAT;
-		env->me_txns->mti_txnid = 0;
-		env->me_txns->mti_numreaders = 0;
-
-	} else {
-		if (env->me_txns->mti_magic != MDB_MAGIC) {
-			DPUTS("lock region has invalid magic");
-			rc = MDB_INVALID;
-			goto fail;
-		}
-		if (env->me_txns->mti_format != MDB_LOCK_FORMAT) {
-			DPRINTF(("lock region has format+version 0x%x, expected 0x%x",
-				env->me_txns->mti_format, MDB_LOCK_FORMAT));
-			rc = MDB_VERSION_MISMATCH;
-			goto fail;
-		}
-		rc = ErrCode();
-		if (rc && rc != EACCES && rc != EAGAIN) {
-			goto fail;
-		}
-#ifdef _WIN32
-		env->me_rmutex = OpenMutex(SYNCHRONIZE, FALSE, env->me_txns->mti_rmname);
-		if (!env->me_rmutex) goto fail_errno;
-		env->me_wmutex = OpenMutex(SYNCHRONIZE, FALSE, env->me_txns->mti_wmname);
-		if (!env->me_wmutex) goto fail_errno;
-#elif defined(MDB_USE_POSIX_SEM)
-		env->me_rmutex = sem_open(env->me_txns->mti_rmname, 0);
-		if (env->me_rmutex == SEM_FAILED) goto fail_errno;
-		env->me_wmutex = sem_open(env->me_txns->mti_wmname, 0);
-		if (env->me_wmutex == SEM_FAILED) goto fail_errno;
-#endif
-	}
-	return MDB_SUCCESS;
-
-fail_errno:
-	rc = ErrCode();
-fail:
-	return rc;
-}
-
-	/** The name of the lock file in the DB environment */
-#define LOCKNAME	"/lock.mdb"
-	/** The name of the data file in the DB environment */
-#define DATANAME	"/data.mdb"
-	/** The suffix of the lock file when no subdir is used */
-#define LOCKSUFF	"-lock"
-	/** Only a subset of the @ref mdb_env flags can be changed
-	 *	at runtime. Changing other flags requires closing the
-	 *	environment and re-opening it with the new flags.
-	 */
-#define	CHANGEABLE	(MDB_NOSYNC|MDB_NOMETASYNC|MDB_MAPASYNC|MDB_NOMEMINIT)
-#define	CHANGELESS	(MDB_FIXEDMAP|MDB_NOSUBDIR|MDB_RDONLY|MDB_WRITEMAP| \
-	MDB_NOTLS|MDB_NOLOCK|MDB_NORDAHEAD)
-
-#if VALID_FLAGS & PERSISTENT_FLAGS & (CHANGEABLE|CHANGELESS)
-# error "Persistent DB flags & env flags overlap, but both go in mm_flags"
-#endif
-
-int ESECT
-mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mdb_mode_t mode)
-{
-	int		oflags, rc, len, excl = -1;
-	char *lpath, *dpath;
-
-	if (env->me_fd!=INVALID_HANDLE_VALUE || (flags & ~(CHANGEABLE|CHANGELESS)))
-		return EINVAL;
-
-	len = strlen(path);
-	if (flags & MDB_NOSUBDIR) {
-		rc = len + sizeof(LOCKSUFF) + len + 1;
-	} else {
-		rc = len + sizeof(LOCKNAME) + len + sizeof(DATANAME);
-	}
-	lpath = malloc(rc);
-	if (!lpath)
-		return ENOMEM;
-	if (flags & MDB_NOSUBDIR) {
-		dpath = lpath + len + sizeof(LOCKSUFF);
-		sprintf(lpath, "%s" LOCKSUFF, path);
-		strcpy(dpath, path);
-	} else {
-		dpath = lpath + len + sizeof(LOCKNAME);
-		sprintf(lpath, "%s" LOCKNAME, path);
-		sprintf(dpath, "%s" DATANAME, path);
-	}
-
-	rc = MDB_SUCCESS;
-	flags |= env->me_flags;
-	if (flags & MDB_RDONLY) {
-		/* silently ignore WRITEMAP when we're only getting read access */
-		flags &= ~MDB_WRITEMAP;
-	} else {
-		if (!((env->me_free_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX)) &&
-			  (env->me_dirty_list = calloc(MDB_IDL_UM_SIZE, sizeof(MDB_ID2)))))
-			rc = ENOMEM;
-	}
-	env->me_flags = flags |= MDB_ENV_ACTIVE;
-	if (rc)
-		goto leave;
-
-	env->me_path = strdup(path);
-	env->me_dbxs = calloc(env->me_maxdbs, sizeof(MDB_dbx));
-	env->me_dbflags = calloc(env->me_maxdbs, sizeof(uint16_t));
-	env->me_dbiseqs = calloc(env->me_maxdbs, sizeof(unsigned int));
-	if (!(env->me_dbxs && env->me_path && env->me_dbflags && env->me_dbiseqs)) {
-		rc = ENOMEM;
-		goto leave;
-	}
-
-	/* For RDONLY, get lockfile after we know datafile exists */
-	if (!(flags & (MDB_RDONLY|MDB_NOLOCK))) {
-		rc = mdb_env_setup_locks(env, lpath, mode, &excl);
-		if (rc)
-			goto leave;
-	}
-
-#ifdef _WIN32
-	if (F_ISSET(flags, MDB_RDONLY)) {
-		oflags = GENERIC_READ;
-		len = OPEN_EXISTING;
-	} else {
-		oflags = GENERIC_READ|GENERIC_WRITE;
-		len = OPEN_ALWAYS;
-	}
-	mode = FILE_ATTRIBUTE_NORMAL;
-	env->me_fd = CreateFile(dpath, oflags, FILE_SHARE_READ|FILE_SHARE_WRITE,
-		NULL, len, mode, NULL);
-#else
-	if (F_ISSET(flags, MDB_RDONLY))
-		oflags = O_RDONLY;
-	else
-		oflags = O_RDWR | O_CREAT;
-
-	env->me_fd = open(dpath, oflags, mode);
-#endif
-	if (env->me_fd == INVALID_HANDLE_VALUE) {
-		rc = ErrCode();
-		goto leave;
-	}
-
-	if ((flags & (MDB_RDONLY|MDB_NOLOCK)) == MDB_RDONLY) {
-		rc = mdb_env_setup_locks(env, lpath, mode, &excl);
-		if (rc)
-			goto leave;
-	}
-
-	if ((rc = mdb_env_open2(env)) == MDB_SUCCESS) {
-		if (flags & (MDB_RDONLY|MDB_WRITEMAP)) {
-			env->me_mfd = env->me_fd;
-		} else {
-			/* Synchronous fd for meta writes. Needed even with
-			 * MDB_NOSYNC/MDB_NOMETASYNC, in case these get reset.
-			 */
-#ifdef _WIN32
-			len = OPEN_EXISTING;
-			env->me_mfd = CreateFile(dpath, oflags,
-				FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, len,
-				mode | FILE_FLAG_WRITE_THROUGH, NULL);
-#else
-			oflags &= ~O_CREAT;
-			env->me_mfd = open(dpath, oflags | MDB_DSYNC, mode);
-#endif
-			if (env->me_mfd == INVALID_HANDLE_VALUE) {
-				rc = ErrCode();
-				goto leave;
-			}
-		}
-		DPRINTF(("opened dbenv %p", (void *) env));
-		if (excl > 0) {
-			rc = mdb_env_share_locks(env, &excl);
-			if (rc)
-				goto leave;
-		}
-		if (!((flags & MDB_RDONLY) ||
-			  (env->me_pbuf = calloc(1, env->me_psize))))
-			rc = ENOMEM;
-		if (!(flags & MDB_RDONLY)) {
-			MDB_txn *txn;
-			int tsize = sizeof(MDB_txn), size = tsize + env->me_maxdbs *
-				(sizeof(MDB_db)+sizeof(MDB_cursor *)+sizeof(unsigned int)+1);
-			txn = calloc(1, size);
-			if (txn) {
-				txn->mt_dbs = (MDB_db *)((char *)txn + tsize);
-				txn->mt_cursors = (MDB_cursor **)(txn->mt_dbs + env->me_maxdbs);
-				txn->mt_dbiseqs = (unsigned int *)(txn->mt_cursors + env->me_maxdbs);
-				txn->mt_dbflags = (unsigned char *)(txn->mt_dbiseqs + env->me_maxdbs);
-				txn->mt_env = env;
-				txn->mt_dbxs = env->me_dbxs;
-				env->me_txn0 = txn;
-			} else {
-				rc = ENOMEM;
-			}
-		}
-	}
-
-leave:
-	if (rc) {
-		mdb_env_close0(env, excl);
-	}
-	free(lpath);
-	return rc;
-}
-
-/** Destroy resources from mdb_env_open(), clear our readers & DBIs */
-static void ESECT
-mdb_env_close0(MDB_env *env, int excl)
-{
-	int i;
-
-	if (!(env->me_flags & MDB_ENV_ACTIVE))
-		return;
-
-	/* Doing this here since me_dbxs may not exist during mdb_env_close */
-	if (env->me_dbxs) {
-		for (i = env->me_maxdbs; --i > MAIN_DBI; )
-			free(env->me_dbxs[i].md_name.mv_data);
-		free(env->me_dbxs);
-	}
-
-	free(env->me_pbuf);
-	free(env->me_dbiseqs);
-	free(env->me_dbflags);
-	free(env->me_path);
-	free(env->me_dirty_list);
-	free(env->me_txn0);
-	mdb_midl_free(env->me_free_pgs);
-
-	if (env->me_flags & MDB_ENV_TXKEY) {
-		pthread_key_delete(env->me_txkey);
-#ifdef _WIN32
-		/* Delete our key from the global list */
-		for (i=0; i<mdb_tls_nkeys; i++)
-			if (mdb_tls_keys[i] == env->me_txkey) {
-				mdb_tls_keys[i] = mdb_tls_keys[mdb_tls_nkeys-1];
-				mdb_tls_nkeys--;
-				break;
-			}
-#endif
-	}
-
-	if (env->me_map) {
-		munmap(env->me_map, env->me_mapsize);
-	}
-	if (env->me_mfd != env->me_fd && env->me_mfd != INVALID_HANDLE_VALUE)
-		(void) close(env->me_mfd);
-	if (env->me_fd != INVALID_HANDLE_VALUE)
-		(void) close(env->me_fd);
-	if (env->me_txns) {
-		MDB_PID_T pid = env->me_pid;
-		/* Clearing readers is done in this function because
-		 * me_txkey with its destructor must be disabled first.
-		 */
-		for (i = env->me_numreaders; --i >= 0; )
-			if (env->me_txns->mti_readers[i].mr_pid == pid)
-				env->me_txns->mti_readers[i].mr_pid = 0;
-#ifdef _WIN32
-		if (env->me_rmutex) {
-			CloseHandle(env->me_rmutex);
-			if (env->me_wmutex) CloseHandle(env->me_wmutex);
-		}
-		/* Windows automatically destroys the mutexes when
-		 * the last handle closes.
-		 */
-#elif defined(MDB_USE_POSIX_SEM)
-		if (env->me_rmutex != SEM_FAILED) {
-			sem_close(env->me_rmutex);
-			if (env->me_wmutex != SEM_FAILED)
-				sem_close(env->me_wmutex);
-			/* If we have the filelock:  If we are the
-			 * only remaining user, clean up semaphores.
-			 */
-			if (excl == 0)
-				mdb_env_excl_lock(env, &excl);
-			if (excl > 0) {
-				sem_unlink(env->me_txns->mti_rmname);
-				sem_unlink(env->me_txns->mti_wmname);
-			}
-		}
-#endif
-		munmap((void *)env->me_txns, (env->me_maxreaders-1)*sizeof(MDB_reader)+sizeof(MDB_txninfo));
-	}
-	if (env->me_lfd != INVALID_HANDLE_VALUE) {
-#ifdef _WIN32
-		if (excl >= 0) {
-			/* Unlock the lockfile.  Windows would have unlocked it
-			 * after closing anyway, but not necessarily at once.
-			 */
-			UnlockFile(env->me_lfd, 0, 0, 1, 0);
-		}
-#endif
-		(void) close(env->me_lfd);
-	}
-
-	env->me_flags &= ~(MDB_ENV_ACTIVE|MDB_ENV_TXKEY);
-}
-
-
-void ESECT
-mdb_env_close(MDB_env *env)
-{
-	MDB_page *dp;
-
-	if (env == NULL)
-		return;
-
-	VGMEMP_DESTROY(env);
-	while ((dp = env->me_dpages) != NULL) {
-		VGMEMP_DEFINED(&dp->mp_next, sizeof(dp->mp_next));
-		env->me_dpages = dp->mp_next;
-		free(dp);
-	}
-
-	mdb_env_close0(env, 0);
-	free(env);
-}
-
-/** Compare two items pointing at aligned size_t's */
-static int
-mdb_cmp_long(const MDB_val *a, const MDB_val *b)
-{
-	return (*(size_t *)a->mv_data < *(size_t *)b->mv_data) ? -1 :
-		*(size_t *)a->mv_data > *(size_t *)b->mv_data;
-}
-
-/** Compare two items pointing at aligned unsigned int's.
- *
- *	This is also set as #MDB_INTEGERDUP|#MDB_DUPFIXED's #MDB_dbx.%md_dcmp,
- *	but #mdb_cmp_clong() is called instead if the data type is size_t.
- */
-static int
-mdb_cmp_int(const MDB_val *a, const MDB_val *b)
-{
-	return (*(unsigned int *)a->mv_data < *(unsigned int *)b->mv_data) ? -1 :
-		*(unsigned int *)a->mv_data > *(unsigned int *)b->mv_data;
-}
-
-/** Compare two items pointing at unsigned ints of unknown alignment.
- *	Nodes and keys are guaranteed to be 2-byte aligned.
- */
-static int
-mdb_cmp_cint(const MDB_val *a, const MDB_val *b)
-{
-#if BYTE_ORDER == LITTLE_ENDIAN
-	unsigned short *u, *c;
-	int x;
-
-	u = (unsigned short *) ((char *) a->mv_data + a->mv_size);
-	c = (unsigned short *) ((char *) b->mv_data + a->mv_size);
-	do {
-		x = *--u - *--c;
-	} while(!x && u > (unsigned short *)a->mv_data);
-	return x;
-#else
-	unsigned short *u, *c, *end;
-	int x;
-
-	end = (unsigned short *) ((char *) a->mv_data + a->mv_size);
-	u = (unsigned short *)a->mv_data;
-	c = (unsigned short *)b->mv_data;
-	do {
-		x = *u++ - *c++;
-	} while(!x && u < end);
-	return x;
-#endif
-}
-
-/** Compare two items lexically */
-static int
-mdb_cmp_memn(const MDB_val *a, const MDB_val *b)
-{
-	int diff;
-	ssize_t len_diff;
-	unsigned int len;
-
-	len = a->mv_size;
-	len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size;
-	if (len_diff > 0) {
-		len = b->mv_size;
-		len_diff = 1;
-	}
-
-	diff = memcmp(a->mv_data, b->mv_data, len);
-	return diff ? diff : len_diff<0 ? -1 : len_diff;
-}
-
-/** Compare two items in reverse byte order */
-static int
-mdb_cmp_memnr(const MDB_val *a, const MDB_val *b)
-{
-	const unsigned char	*p1, *p2, *p1_lim;
-	ssize_t len_diff;
-	int diff;
-
-	p1_lim = (const unsigned char *)a->mv_data;
-	p1 = (const unsigned char *)a->mv_data + a->mv_size;
-	p2 = (const unsigned char *)b->mv_data + b->mv_size;
-
-	len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size;
-	if (len_diff > 0) {
-		p1_lim += len_diff;
-		len_diff = 1;
-	}
-
-	while (p1 > p1_lim) {
-		diff = *--p1 - *--p2;
-		if (diff)
-			return diff;
-	}
-	return len_diff<0 ? -1 : len_diff;
-}
-
-/** Search for key within a page, using binary search.
- * Returns the smallest entry larger or equal to the key.
- * If exactp is non-null, stores whether the found entry was an exact match
- * in *exactp (1 or 0).
- * Updates the cursor index with the index of the found entry.
- * If no entry larger or equal to the key is found, returns NULL.
- */
-static MDB_node *
-mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp)
-{
-	unsigned int	 i = 0, nkeys;
-	int		 low, high;
-	int		 rc = 0;
-	MDB_page *mp = mc->mc_pg[mc->mc_top];
-	MDB_node	*node = NULL;
-	MDB_val	 nodekey;
-	MDB_cmp_func *cmp;
-	DKBUF;
-
-	nkeys = NUMKEYS(mp);
-
-	DPRINTF(("searching %u keys in %s %spage %"Z"u",
-	    nkeys, IS_LEAF(mp) ? "leaf" : "branch", IS_SUBP(mp) ? "sub-" : "",
-	    mdb_dbg_pgno(mp)));
-
-	low = IS_LEAF(mp) ? 0 : 1;
-	high = nkeys - 1;
-	cmp = mc->mc_dbx->md_cmp;
-
-	/* Branch pages have no data, so if using integer keys,
-	 * alignment is guaranteed. Use faster mdb_cmp_int.
-	 */
-	if (cmp == mdb_cmp_cint && IS_BRANCH(mp)) {
-		if (NODEPTR(mp, 1)->mn_ksize == sizeof(size_t))
-			cmp = mdb_cmp_long;
-		else
-			cmp = mdb_cmp_int;
-	}
-
-	if (IS_LEAF2(mp)) {
-		nodekey.mv_size = mc->mc_db->md_pad;
-		node = NODEPTR(mp, 0);	/* fake */
-		while (low <= high) {
-			i = (low + high) >> 1;
-			nodekey.mv_data = LEAF2KEY(mp, i, nodekey.mv_size);
-			rc = cmp(key, &nodekey);
-			DPRINTF(("found leaf index %u [%s], rc = %i",
-			    i, DKEY(&nodekey), rc));
-			if (rc == 0)
-				break;
-			if (rc > 0)
-				low = i + 1;
-			else
-				high = i - 1;
-		}
-	} else {
-		while (low <= high) {
-			i = (low + high) >> 1;
-
-			node = NODEPTR(mp, i);
-			nodekey.mv_size = NODEKSZ(node);
-			nodekey.mv_data = NODEKEY(node);
-
-			rc = cmp(key, &nodekey);
-#if MDB_DEBUG
-			if (IS_LEAF(mp))
-				DPRINTF(("found leaf index %u [%s], rc = %i",
-				    i, DKEY(&nodekey), rc));
-			else
-				DPRINTF(("found branch index %u [%s -> %"Z"u], rc = %i",
-				    i, DKEY(&nodekey), NODEPGNO(node), rc));
-#endif
-			if (rc == 0)
-				break;
-			if (rc > 0)
-				low = i + 1;
-			else
-				high = i - 1;
-		}
-	}
-
-	if (rc > 0) {	/* Found entry is less than the key. */
-		i++;	/* Skip to get the smallest entry larger than key. */
-		if (!IS_LEAF2(mp))
-			node = NODEPTR(mp, i);
-	}
-	if (exactp)
-		*exactp = (rc == 0 && nkeys > 0);
-	/* store the key index */
-	mc->mc_ki[mc->mc_top] = i;
-	if (i >= nkeys)
-		/* There is no entry larger or equal to the key. */
-		return NULL;
-
-	/* nodeptr is fake for LEAF2 */
-	return node;
-}
-
-#if 0
-static void
-mdb_cursor_adjust(MDB_cursor *mc, func)
-{
-	MDB_cursor *m2;
-
-	for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
-		if (m2->mc_pg[m2->mc_top] == mc->mc_pg[mc->mc_top]) {
-			func(mc, m2);
-		}
-	}
-}
-#endif
-
-/** Pop a page off the top of the cursor's stack. */
-static void
-mdb_cursor_pop(MDB_cursor *mc)
-{
-	if (mc->mc_snum) {
-#if MDB_DEBUG
-		MDB_page	*top = mc->mc_pg[mc->mc_top];
-#endif
-		mc->mc_snum--;
-		if (mc->mc_snum)
-			mc->mc_top--;
-
-		DPRINTF(("popped page %"Z"u off db %d cursor %p", top->mp_pgno,
-			DDBI(mc), (void *) mc));
-	}
-}
-
-/** Push a page onto the top of the cursor's stack. */
-static int
-mdb_cursor_push(MDB_cursor *mc, MDB_page *mp)
-{
-	DPRINTF(("pushing page %"Z"u on db %d cursor %p", mp->mp_pgno,
-		DDBI(mc), (void *) mc));
-
-	if (mc->mc_snum >= CURSOR_STACK) {
-		mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
-		return MDB_CURSOR_FULL;
-	}
-
-	mc->mc_top = mc->mc_snum++;
-	mc->mc_pg[mc->mc_top] = mp;
-	mc->mc_ki[mc->mc_top] = 0;
-
-	return MDB_SUCCESS;
-}
-
-/** Find the address of the page corresponding to a given page number.
- * @param[in] txn the transaction for this access.
- * @param[in] pgno the page number for the page to retrieve.
- * @param[out] ret address of a pointer where the page's address will be stored.
- * @param[out] lvl dirty_list inheritance level of found page. 1=current txn, 0=mapped page.
- * @return 0 on success, non-zero on failure.
- */
-static int
-mdb_page_get(MDB_txn *txn, pgno_t pgno, MDB_page **ret, int *lvl)
-{
-	MDB_env *env = txn->mt_env;
-	MDB_page *p = NULL;
-	int level;
-
-	if (!((txn->mt_flags & MDB_TXN_RDONLY) | (env->me_flags & MDB_WRITEMAP))) {
-		MDB_txn *tx2 = txn;
-		level = 1;
-		do {
-			MDB_ID2L dl = tx2->mt_u.dirty_list;
-			unsigned x;
-			/* Spilled pages were dirtied in this txn and flushed
-			 * because the dirty list got full. Bring this page
-			 * back in from the map (but don't unspill it here,
-			 * leave that unless page_touch happens again).
-			 */
-			if (tx2->mt_spill_pgs) {
-				MDB_ID pn = pgno << 1;
-				x = mdb_midl_search(tx2->mt_spill_pgs, pn);
-				if (x <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[x] == pn) {
-					p = (MDB_page *)(env->me_map + env->me_psize * pgno);
-					goto done;
-				}
-			}
-			if (dl[0].mid) {
-				unsigned x = mdb_mid2l_search(dl, pgno);
-				if (x <= dl[0].mid && dl[x].mid == pgno) {
-					p = dl[x].mptr;
-					goto done;
-				}
-			}
-			level++;
-		} while ((tx2 = tx2->mt_parent) != NULL);
-	}
-
-	if (pgno < txn->mt_next_pgno) {
-		level = 0;
-		p = (MDB_page *)(env->me_map + env->me_psize * pgno);
-	} else {
-		DPRINTF(("page %"Z"u not found", pgno));
-		txn->mt_flags |= MDB_TXN_ERROR;
-		return MDB_PAGE_NOTFOUND;
-	}
-
-done:
-	*ret = p;
-	if (lvl)
-		*lvl = level;
-	return MDB_SUCCESS;
-}
-
-/** Finish #mdb_page_search() / #mdb_page_search_lowest().
- *	The cursor is at the root page, set up the rest of it.
- */
-static int
-mdb_page_search_root(MDB_cursor *mc, MDB_val *key, int flags)
-{
-	MDB_page	*mp = mc->mc_pg[mc->mc_top];
-	int rc;
-	DKBUF;
-
-	while (IS_BRANCH(mp)) {
-		MDB_node	*node;
-		indx_t		i;
-
-		DPRINTF(("branch page %"Z"u has %u keys", mp->mp_pgno, NUMKEYS(mp)));
-		mdb_cassert(mc, NUMKEYS(mp) > 1);
-		DPRINTF(("found index 0 to page %"Z"u", NODEPGNO(NODEPTR(mp, 0))));
-
-		if (flags & (MDB_PS_FIRST|MDB_PS_LAST)) {
-			i = 0;
-			if (flags & MDB_PS_LAST)
-				i = NUMKEYS(mp) - 1;
-		} else {
-			int	 exact;
-			node = mdb_node_search(mc, key, &exact);
-			if (node == NULL)
-				i = NUMKEYS(mp) - 1;
-			else {
-				i = mc->mc_ki[mc->mc_top];
-				if (!exact) {
-					mdb_cassert(mc, i > 0);
-					i--;
-				}
-			}
-			DPRINTF(("following index %u for key [%s]", i, DKEY(key)));
-		}
-
-		mdb_cassert(mc, i < NUMKEYS(mp));
-		node = NODEPTR(mp, i);
-
-		if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mp, NULL)) != 0)
-			return rc;
-
-		mc->mc_ki[mc->mc_top] = i;
-		if ((rc = mdb_cursor_push(mc, mp)))
-			return rc;
-
-		if (flags & MDB_PS_MODIFY) {
-			if ((rc = mdb_page_touch(mc)) != 0)
-				return rc;
-			mp = mc->mc_pg[mc->mc_top];
-		}
-	}
-
-	if (!IS_LEAF(mp)) {
-		DPRINTF(("internal error, index points to a %02X page!?",
-		    mp->mp_flags));
-		mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
-		return MDB_CORRUPTED;
-	}
-
-	DPRINTF(("found leaf page %"Z"u for key [%s]", mp->mp_pgno,
-	    key ? DKEY(key) : "null"));
-	mc->mc_flags |= C_INITIALIZED;
-	mc->mc_flags &= ~C_EOF;
-
-	return MDB_SUCCESS;
-}
-
-/** Search for the lowest key under the current branch page.
- * This just bypasses a NUMKEYS check in the current page
- * before calling mdb_page_search_root(), because the callers
- * are all in situations where the current page is known to
- * be underfilled.
- */
-static int
-mdb_page_search_lowest(MDB_cursor *mc)
-{
-	MDB_page	*mp = mc->mc_pg[mc->mc_top];
-	MDB_node	*node = NODEPTR(mp, 0);
-	int rc;
-
-	if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mp, NULL)) != 0)
-		return rc;
-
-	mc->mc_ki[mc->mc_top] = 0;
-	if ((rc = mdb_cursor_push(mc, mp)))
-		return rc;
-	return mdb_page_search_root(mc, NULL, MDB_PS_FIRST);
-}
-
-/** Search for the page a given key should be in.
- * Push it and its parent pages on the cursor stack.
- * @param[in,out] mc the cursor for this operation.
- * @param[in] key the key to search for, or NULL for first/last page.
- * @param[in] flags If MDB_PS_MODIFY is set, visited pages in the DB
- *   are touched (updated with new page numbers).
- *   If MDB_PS_FIRST or MDB_PS_LAST is set, find first or last leaf.
- *   This is used by #mdb_cursor_first() and #mdb_cursor_last().
- *   If MDB_PS_ROOTONLY set, just fetch root node, no further lookups.
- * @return 0 on success, non-zero on failure.
- */
-static int
-mdb_page_search(MDB_cursor *mc, MDB_val *key, int flags)
-{
-	int		 rc;
-	pgno_t		 root;
-
-	/* Make sure the txn is still viable, then find the root from
-	 * the txn's db table and set it as the root of the cursor's stack.
-	 */
-	if (F_ISSET(mc->mc_txn->mt_flags, MDB_TXN_ERROR)) {
-		DPUTS("transaction has failed, must abort");
-		return MDB_BAD_TXN;
-	} else {
-		/* Make sure we're using an up-to-date root */
-		if (*mc->mc_dbflag & DB_STALE) {
-				MDB_cursor mc2;
-				if (TXN_DBI_CHANGED(mc->mc_txn, mc->mc_dbi))
-					return MDB_BAD_DBI;
-				mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, NULL);
-				rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, 0);
-				if (rc)
-					return rc;
-				{
-					MDB_val data;
-					int exact = 0;
-					uint16_t flags;
-					MDB_node *leaf = mdb_node_search(&mc2,
-						&mc->mc_dbx->md_name, &exact);
-					if (!exact)
-						return MDB_NOTFOUND;
-					rc = mdb_node_read(mc->mc_txn, leaf, &data);
-					if (rc)
-						return rc;
-					memcpy(&flags, ((char *) data.mv_data + offsetof(MDB_db, md_flags)),
-						sizeof(uint16_t));
-					/* The txn may not know this DBI, or another process may
-					 * have dropped and recreated the DB with other flags.
-					 */
-					if ((mc->mc_db->md_flags & PERSISTENT_FLAGS) != flags)
-						return MDB_INCOMPATIBLE;
-					memcpy(mc->mc_db, data.mv_data, sizeof(MDB_db));
-				}
-				*mc->mc_dbflag &= ~DB_STALE;
-		}
-		root = mc->mc_db->md_root;
-
-		if (root == P_INVALID) {		/* Tree is empty. */
-			DPUTS("tree is empty");
-			return MDB_NOTFOUND;
-		}
-	}
-
-	mdb_cassert(mc, root > 1);
-	if (!mc->mc_pg[0] || mc->mc_pg[0]->mp_pgno != root)
-		if ((rc = mdb_page_get(mc->mc_txn, root, &mc->mc_pg[0], NULL)) != 0)
-			return rc;
-
-	mc->mc_snum = 1;
-	mc->mc_top = 0;
-
-	DPRINTF(("db %d root page %"Z"u has flags 0x%X",
-		DDBI(mc), root, mc->mc_pg[0]->mp_flags));
-
-	if (flags & MDB_PS_MODIFY) {
-		if ((rc = mdb_page_touch(mc)))
-			return rc;
-	}
-
-	if (flags & MDB_PS_ROOTONLY)
-		return MDB_SUCCESS;
-
-	return mdb_page_search_root(mc, key, flags);
-}
-
-static int
-mdb_ovpage_free(MDB_cursor *mc, MDB_page *mp)
-{
-	MDB_txn *txn = mc->mc_txn;
-	pgno_t pg = mp->mp_pgno;
-	unsigned x = 0, ovpages = mp->mp_pages;
-	MDB_env *env = txn->mt_env;
-	MDB_IDL sl = txn->mt_spill_pgs;
-	MDB_ID pn = pg << 1;
-	int rc;
-
-	DPRINTF(("free ov page %"Z"u (%d)", pg, ovpages));
-	/* If the page is dirty or on the spill list we just acquired it,
-	 * so we should give it back to our current free list, if any.
-	 * Otherwise put it onto the list of pages we freed in this txn.
-	 *
-	 * Won't create me_pghead: me_pglast must be inited along with it.
-	 * Unsupported in nested txns: They would need to hide the page
-	 * range in ancestor txns' dirty and spilled lists.
-	 */
-	if (env->me_pghead &&
-		!txn->mt_parent &&
-		((mp->mp_flags & P_DIRTY) ||
-		 (sl && (x = mdb_midl_search(sl, pn)) <= sl[0] && sl[x] == pn)))
-	{
-		unsigned i, j;
-		pgno_t *mop;
-		MDB_ID2 *dl, ix, iy;
-		rc = mdb_midl_need(&env->me_pghead, ovpages);
-		if (rc)
-			return rc;
-		if (!(mp->mp_flags & P_DIRTY)) {
-			/* This page is no longer spilled */
-			if (x == sl[0])
-				sl[0]--;
-			else
-				sl[x] |= 1;
-			goto release;
-		}
-		/* Remove from dirty list */
-		dl = txn->mt_u.dirty_list;
-		x = dl[0].mid--;
-		for (ix = dl[x]; ix.mptr != mp; ix = iy) {
-			if (x > 1) {
-				x--;
-				iy = dl[x];
-				dl[x] = ix;
-			} else {
-				mdb_cassert(mc, x > 1);
-				j = ++(dl[0].mid);
-				dl[j] = ix;		/* Unsorted. OK when MDB_TXN_ERROR. */
-				txn->mt_flags |= MDB_TXN_ERROR;
-				return MDB_CORRUPTED;
-			}
-		}
-		if (!(env->me_flags & MDB_WRITEMAP))
-			mdb_dpage_free(env, mp);
-release:
-		/* Insert in me_pghead */
-		mop = env->me_pghead;
-		j = mop[0] + ovpages;
-		for (i = mop[0]; i && mop[i] < pg; i--)
-			mop[j--] = mop[i];
-		while (j>i)
-			mop[j--] = pg++;
-		mop[0] += ovpages;
-	} else {
-		rc = mdb_midl_append_range(&txn->mt_free_pgs, pg, ovpages);
-		if (rc)
-			return rc;
-	}
-	mc->mc_db->md_overflow_pages -= ovpages;
-	return 0;
-}
-
-/** Return the data associated with a given node.
- * @param[in] txn The transaction for this operation.
- * @param[in] leaf The node being read.
- * @param[out] data Updated to point to the node's data.
- * @return 0 on success, non-zero on failure.
- */
-static int
-mdb_node_read(MDB_txn *txn, MDB_node *leaf, MDB_val *data)
-{
-	MDB_page	*omp;		/* overflow page */
-	pgno_t		 pgno;
-	int rc;
-
-	if (!F_ISSET(leaf->mn_flags, F_BIGDATA)) {
-		data->mv_size = NODEDSZ(leaf);
-		data->mv_data = NODEDATA(leaf);
-		return MDB_SUCCESS;
-	}
-
-	/* Read overflow data.
-	 */
-	data->mv_size = NODEDSZ(leaf);
-	memcpy(&pgno, NODEDATA(leaf), sizeof(pgno));
-	if ((rc = mdb_page_get(txn, pgno, &omp, NULL)) != 0) {
-		DPRINTF(("read overflow page %"Z"u failed", pgno));
-		return rc;
-	}
-	data->mv_data = METADATA(omp);
-
-	return MDB_SUCCESS;
-}
-
-int
-mdb_get(MDB_txn *txn, MDB_dbi dbi,
-    MDB_val *key, MDB_val *data)
-{
-	MDB_cursor	mc;
-	MDB_xcursor	mx;
-	int exact = 0;
-	DKBUF;
-
-	DPRINTF(("===> get db %u key [%s]", dbi, DKEY(key)));
-
-	if (!key || !data || dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
-		return EINVAL;
-
-	if (txn->mt_flags & MDB_TXN_ERROR)
-		return MDB_BAD_TXN;
-
-	mdb_cursor_init(&mc, txn, dbi, &mx);
-	return mdb_cursor_set(&mc, key, data, MDB_SET, &exact);
-}
-
-/** Find a sibling for a page.
- * Replaces the page at the top of the cursor's stack with the
- * specified sibling, if one exists.
- * @param[in] mc The cursor for this operation.
- * @param[in] move_right Non-zero if the right sibling is requested,
- * otherwise the left sibling.
- * @return 0 on success, non-zero on failure.
- */
-static int
-mdb_cursor_sibling(MDB_cursor *mc, int move_right)
-{
-	int		 rc;
-	MDB_node	*indx;
-	MDB_page	*mp;
-
-	if (mc->mc_snum < 2) {
-		return MDB_NOTFOUND;		/* root has no siblings */
-	}
-
-	mdb_cursor_pop(mc);
-	DPRINTF(("parent page is page %"Z"u, index %u",
-		mc->mc_pg[mc->mc_top]->mp_pgno, mc->mc_ki[mc->mc_top]));
-
-	if (move_right ? (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mc->mc_pg[mc->mc_top]))
-		       : (mc->mc_ki[mc->mc_top] == 0)) {
-		DPRINTF(("no more keys left, moving to %s sibling",
-		    move_right ? "right" : "left"));
-		if ((rc = mdb_cursor_sibling(mc, move_right)) != MDB_SUCCESS) {
-			/* undo cursor_pop before returning */
-			mc->mc_top++;
-			mc->mc_snum++;
-			return rc;
-		}
-	} else {
-		if (move_right)
-			mc->mc_ki[mc->mc_top]++;
-		else
-			mc->mc_ki[mc->mc_top]--;
-		DPRINTF(("just moving to %s index key %u",
-		    move_right ? "right" : "left", mc->mc_ki[mc->mc_top]));
-	}
-	mdb_cassert(mc, IS_BRANCH(mc->mc_pg[mc->mc_top]));
-
-	indx = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
-	if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(indx), &mp, NULL)) != 0) {
-		/* mc will be inconsistent if caller does mc_snum++ as above */
-		mc->mc_flags &= ~(C_INITIALIZED|C_EOF);
-		return rc;
-	}
-
-	mdb_cursor_push(mc, mp);
-	if (!move_right)
-		mc->mc_ki[mc->mc_top] = NUMKEYS(mp)-1;
-
-	return MDB_SUCCESS;
-}
-
-/** Move the cursor to the next data item. */
-static int
-mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
-{
-	MDB_page	*mp;
-	MDB_node	*leaf;
-	int rc;
-
-	if (mc->mc_flags & C_EOF) {
-		return MDB_NOTFOUND;
-	}
-
-	mdb_cassert(mc, mc->mc_flags & C_INITIALIZED);
-
-	mp = mc->mc_pg[mc->mc_top];
-
-	if (mc->mc_db->md_flags & MDB_DUPSORT) {
-		leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
-		if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
-			if (op == MDB_NEXT || op == MDB_NEXT_DUP) {
-				rc = mdb_cursor_next(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_NEXT);
-				if (op != MDB_NEXT || rc != MDB_NOTFOUND) {
-					if (rc == MDB_SUCCESS)
-						MDB_GET_KEY(leaf, key);
-					return rc;
-				}
-			}
-		} else {
-			mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
-			if (op == MDB_NEXT_DUP)
-				return MDB_NOTFOUND;
-		}
-	}
-
-	DPRINTF(("cursor_next: top page is %"Z"u in cursor %p",
-		mdb_dbg_pgno(mp), (void *) mc));
-	if (mc->mc_flags & C_DEL)
-		goto skip;
-
-	if (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mp)) {
-		DPUTS("=====> move to next sibling page");
-		if ((rc = mdb_cursor_sibling(mc, 1)) != MDB_SUCCESS) {
-			mc->mc_flags |= C_EOF;
-			return rc;
-		}
-		mp = mc->mc_pg[mc->mc_top];
-		DPRINTF(("next page is %"Z"u, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]));
-	} else
-		mc->mc_ki[mc->mc_top]++;
-
-skip:
-	DPRINTF(("==> cursor points to page %"Z"u with %u keys, key index %u",
-	    mdb_dbg_pgno(mp), NUMKEYS(mp), mc->mc_ki[mc->mc_top]));
-
-	if (IS_LEAF2(mp)) {
-		key->mv_size = mc->mc_db->md_pad;
-		key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
-		return MDB_SUCCESS;
-	}
-
-	mdb_cassert(mc, IS_LEAF(mp));
-	leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
-
-	if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
-		mdb_xcursor_init1(mc, leaf);
-	}
-	if (data) {
-		if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
-			return rc;
-
-		if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
-			rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
-			if (rc != MDB_SUCCESS)
-				return rc;
-		}
-	}
-
-	MDB_GET_KEY(leaf, key);
-	return MDB_SUCCESS;
-}
-
-/** Move the cursor to the previous data item. */
-static int
-mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
-{
-	MDB_page	*mp;
-	MDB_node	*leaf;
-	int rc;
-
-	mdb_cassert(mc, mc->mc_flags & C_INITIALIZED);
-
-	mp = mc->mc_pg[mc->mc_top];
-
-	if (mc->mc_db->md_flags & MDB_DUPSORT) {
-		leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
-		if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
-			if (op == MDB_PREV || op == MDB_PREV_DUP) {
-				rc = mdb_cursor_prev(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_PREV);
-				if (op != MDB_PREV || rc != MDB_NOTFOUND) {
-					if (rc == MDB_SUCCESS) {
-						MDB_GET_KEY(leaf, key);
-						mc->mc_flags &= ~C_EOF;
-					}
-					return rc;
-				}
-			}
-		} else {
-			mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
-			if (op == MDB_PREV_DUP)
-				return MDB_NOTFOUND;
-		}
-	}
-
-	DPRINTF(("cursor_prev: top page is %"Z"u in cursor %p",
-		mdb_dbg_pgno(mp), (void *) mc));
-
-	if (mc->mc_ki[mc->mc_top] == 0)  {
-		DPUTS("=====> move to prev sibling page");
-		if ((rc = mdb_cursor_sibling(mc, 0)) != MDB_SUCCESS) {
-			return rc;
-		}
-		mp = mc->mc_pg[mc->mc_top];
-		mc->mc_ki[mc->mc_top] = NUMKEYS(mp) - 1;
-		DPRINTF(("prev page is %"Z"u, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]));
-	} else
-		mc->mc_ki[mc->mc_top]--;
-
-	mc->mc_flags &= ~C_EOF;
-
-	DPRINTF(("==> cursor points to page %"Z"u with %u keys, key index %u",
-	    mdb_dbg_pgno(mp), NUMKEYS(mp), mc->mc_ki[mc->mc_top]));
-
-	if (IS_LEAF2(mp)) {
-		key->mv_size = mc->mc_db->md_pad;
-		key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
-		return MDB_SUCCESS;
-	}
-
-	mdb_cassert(mc, IS_LEAF(mp));
-	leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
-
-	if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
-		mdb_xcursor_init1(mc, leaf);
-	}
-	if (data) {
-		if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
-			return rc;
-
-		if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
-			rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);
-			if (rc != MDB_SUCCESS)
-				return rc;
-		}
-	}
-
-	MDB_GET_KEY(leaf, key);
-	return MDB_SUCCESS;
-}
-
-/** Set the cursor on a specific data item. */
-static int
-mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data,
-    MDB_cursor_op op, int *exactp)
-{
-	int		 rc;
-	MDB_page	*mp;
-	MDB_node	*leaf = NULL;
-	DKBUF;
-
-	if (key->mv_size == 0)
-		return MDB_BAD_VALSIZE;
-
-	if (mc->mc_xcursor)
-		mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
-
-	/* See if we're already on the right page */
-	if (mc->mc_flags & C_INITIALIZED) {
-		MDB_val nodekey;
-
-		mp = mc->mc_pg[mc->mc_top];
-		if (!NUMKEYS(mp)) {
-			mc->mc_ki[mc->mc_top] = 0;
-			return MDB_NOTFOUND;
-		}
-		if (mp->mp_flags & P_LEAF2) {
-			nodekey.mv_size = mc->mc_db->md_pad;
-			nodekey.mv_data = LEAF2KEY(mp, 0, nodekey.mv_size);
-		} else {
-			leaf = NODEPTR(mp, 0);
-			MDB_GET_KEY2(leaf, nodekey);
-		}
-		rc = mc->mc_dbx->md_cmp(key, &nodekey);
-		if (rc == 0) {
-			/* Probably happens rarely, but first node on the page
-			 * was the one we wanted.
-			 */
-			mc->mc_ki[mc->mc_top] = 0;
-			if (exactp)
-				*exactp = 1;
-			goto set1;
-		}
-		if (rc > 0) {
-			unsigned int i;
-			unsigned int nkeys = NUMKEYS(mp);
-			if (nkeys > 1) {
-				if (mp->mp_flags & P_LEAF2) {
-					nodekey.mv_data = LEAF2KEY(mp,
-						 nkeys-1, nodekey.mv_size);
-				} else {
-					leaf = NODEPTR(mp, nkeys-1);
-					MDB_GET_KEY2(leaf, nodekey);
-				}
-				rc = mc->mc_dbx->md_cmp(key, &nodekey);
-				if (rc == 0) {
-					/* last node was the one we wanted */
-					mc->mc_ki[mc->mc_top] = nkeys-1;
-					if (exactp)
-						*exactp = 1;
-					goto set1;
-				}
-				if (rc < 0) {
-					if (mc->mc_ki[mc->mc_top] < NUMKEYS(mp)) {
-						/* This is definitely the right page, skip search_page */
-						if (mp->mp_flags & P_LEAF2) {
-							nodekey.mv_data = LEAF2KEY(mp,
-								 mc->mc_ki[mc->mc_top], nodekey.mv_size);
-						} else {
-							leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
-							MDB_GET_KEY2(leaf, nodekey);
-						}
-						rc = mc->mc_dbx->md_cmp(key, &nodekey);
-						if (rc == 0) {
-							/* current node was the one we wanted */
-							if (exactp)
-								*exactp = 1;
-							goto set1;
-						}
-					}
-					rc = 0;
-					goto set2;
-				}
-			}
-			/* If any parents have right-sibs, search.
-			 * Otherwise, there's nothing further.
-			 */
-			for (i=0; i<mc->mc_top; i++)
-				if (mc->mc_ki[i] <
-					NUMKEYS(mc->mc_pg[i])-1)
-					break;
-			if (i == mc->mc_top) {
-				/* There are no other pages */
-				mc->mc_ki[mc->mc_top] = nkeys;
-				return MDB_NOTFOUND;
-			}
-		}
-		if (!mc->mc_top) {
-			/* There are no other pages */
-			mc->mc_ki[mc->mc_top] = 0;
-			if (op == MDB_SET_RANGE && !exactp) {
-				rc = 0;
-				goto set1;
-			} else
-				return MDB_NOTFOUND;
-		}
-	}
-
-	rc = mdb_page_search(mc, key, 0);
-	if (rc != MDB_SUCCESS)
-		return rc;
-
-	mp = mc->mc_pg[mc->mc_top];
-	mdb_cassert(mc, IS_LEAF(mp));
-
-set2:
-	leaf = mdb_node_search(mc, key, exactp);
-	if (exactp != NULL && !*exactp) {
-		/* MDB_SET specified and not an exact match. */
-		return MDB_NOTFOUND;
-	}
-
-	if (leaf == NULL) {
-		DPUTS("===> inexact leaf not found, goto sibling");
-		if ((rc = mdb_cursor_sibling(mc, 1)) != MDB_SUCCESS)
-			return rc;		/* no entries matched */
-		mp = mc->mc_pg[mc->mc_top];
-		mdb_cassert(mc, IS_LEAF(mp));
-		leaf = NODEPTR(mp, 0);
-	}
-
-set1:
-	mc->mc_flags |= C_INITIALIZED;
-	mc->mc_flags &= ~C_EOF;
-
-	if (IS_LEAF2(mp)) {
-		if (op == MDB_SET_RANGE || op == MDB_SET_KEY) {
-			key->mv_size = mc->mc_db->md_pad;
-			key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
-		}
-		return MDB_SUCCESS;
-	}
-
-	if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
-		mdb_xcursor_init1(mc, leaf);
-	}
-	if (data) {
-		if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
-			if (op == MDB_SET || op == MDB_SET_KEY || op == MDB_SET_RANGE) {
-				rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
-			} else {
-				int ex2, *ex2p;
-				if (op == MDB_GET_BOTH) {
-					ex2p = &ex2;
-					ex2 = 0;
-				} else {
-					ex2p = NULL;
-				}
-				rc = mdb_cursor_set(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_SET_RANGE, ex2p);
-				if (rc != MDB_SUCCESS)
-					return rc;
-			}
-		} else if (op == MDB_GET_BOTH || op == MDB_GET_BOTH_RANGE) {
-			MDB_val olddata;
-			MDB_cmp_func *dcmp;
-			if ((rc = mdb_node_read(mc->mc_txn, leaf, &olddata)) != MDB_SUCCESS)
-				return rc;
-			dcmp = mc->mc_dbx->md_dcmp;
-#if UINT_MAX < SIZE_MAX
-			if (dcmp == mdb_cmp_int && olddata.mv_size == sizeof(size_t))
-				dcmp = mdb_cmp_clong;
-#endif
-			rc = dcmp(data, &olddata);
-			if (rc) {
-				if (op == MDB_GET_BOTH || rc > 0)
-					return MDB_NOTFOUND;
-				rc = 0;
-				*data = olddata;
-			}
-
-		} else {
-			if (mc->mc_xcursor)
-				mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
-			if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
-				return rc;
-		}
-	}
-
-	/* The key already matches in all other cases */
-	if (op == MDB_SET_RANGE || op == MDB_SET_KEY)
-		MDB_GET_KEY(leaf, key);
-	DPRINTF(("==> cursor placed on key [%s]", DKEY(key)));
-
-	return rc;
-}
-
-/** Move the cursor to the first item in the database. */
-static int
-mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data)
-{
-	int		 rc;
-	MDB_node	*leaf;
-
-	if (mc->mc_xcursor)
-		mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
-
-	if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) {
-		rc = mdb_page_search(mc, NULL, MDB_PS_FIRST);
-		if (rc != MDB_SUCCESS)
-			return rc;
-	}
-	mdb_cassert(mc, IS_LEAF(mc->mc_pg[mc->mc_top]));
-
-	leaf = NODEPTR(mc->mc_pg[mc->mc_top], 0);
-	mc->mc_flags |= C_INITIALIZED;
-	mc->mc_flags &= ~C_EOF;
-
-	mc->mc_ki[mc->mc_top] = 0;
-
-	if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
-		key->mv_size = mc->mc_db->md_pad;
-		key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], 0, key->mv_size);
-		return MDB_SUCCESS;
-	}
-
-	if (data) {
-		if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
-			mdb_xcursor_init1(mc, leaf);
-			rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
-			if (rc)
-				return rc;
-		} else {
-			if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
-				return rc;
-		}
-	}
-	MDB_GET_KEY(leaf, key);
-	return MDB_SUCCESS;
-}
-
-/** Move the cursor to the last item in the database. */
-static int
-mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data)
-{
-	int		 rc;
-	MDB_node	*leaf;
-
-	if (mc->mc_xcursor)
-		mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
-
-	if (!(mc->mc_flags & C_EOF)) {
-
-		if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) {
-			rc = mdb_page_search(mc, NULL, MDB_PS_LAST);
-			if (rc != MDB_SUCCESS)
-				return rc;
-		}
-		mdb_cassert(mc, IS_LEAF(mc->mc_pg[mc->mc_top]));
-
-	}
-	mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]) - 1;
-	mc->mc_flags |= C_INITIALIZED|C_EOF;
-	leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
-
-	if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
-		key->mv_size = mc->mc_db->md_pad;
-		key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], key->mv_size);
-		return MDB_SUCCESS;
-	}
-
-	if (data) {
-		if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
-			mdb_xcursor_init1(mc, leaf);
-			rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);
-			if (rc)
-				return rc;
-		} else {
-			if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS)
-				return rc;
-		}
-	}
-
-	MDB_GET_KEY(leaf, key);
-	return MDB_SUCCESS;
-}
-
-int
-mdb_cursor_get(MDB_cursor *mc, MDB_val *key, MDB_val *data,
-    MDB_cursor_op op)
-{
-	int		 rc;
-	int		 exact = 0;
-	int		 (*mfunc)(MDB_cursor *mc, MDB_val *key, MDB_val *data);
-
-	if (mc == NULL)
-		return EINVAL;
-
-	if (mc->mc_txn->mt_flags & MDB_TXN_ERROR)
-		return MDB_BAD_TXN;
-
-	switch (op) {
-	case MDB_GET_CURRENT:
-		if (!(mc->mc_flags & C_INITIALIZED)) {
-			rc = EINVAL;
-		} else {
-			MDB_page *mp = mc->mc_pg[mc->mc_top];
-			int nkeys = NUMKEYS(mp);
-			if (!nkeys || mc->mc_ki[mc->mc_top] >= nkeys) {
-				mc->mc_ki[mc->mc_top] = nkeys;
-				rc = MDB_NOTFOUND;
-				break;
-			}
-			rc = MDB_SUCCESS;
-			if (IS_LEAF2(mp)) {
-				key->mv_size = mc->mc_db->md_pad;
-				key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
-			} else {
-				MDB_node *leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
-				MDB_GET_KEY(leaf, key);
-				if (data) {
-					if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
-						if (mc->mc_flags & C_DEL)
-							mdb_xcursor_init1(mc, leaf);
-						rc = mdb_cursor_get(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_GET_CURRENT);
-					} else {
-						rc = mdb_node_read(mc->mc_txn, leaf, data);
-					}
-				}
-			}
-		}
-		break;
-	case MDB_GET_BOTH:
-	case MDB_GET_BOTH_RANGE:
-		if (data == NULL) {
-			rc = EINVAL;
-			break;
-		}
-		if (mc->mc_xcursor == NULL) {
-			rc = MDB_INCOMPATIBLE;
-			break;
-		}
-		/* FALLTHRU */
-	case MDB_SET:
-	case MDB_SET_KEY:
-	case MDB_SET_RANGE:
-		if (key == NULL) {
-			rc = EINVAL;
-		} else {
-			rc = mdb_cursor_set(mc, key, data, op,
-				op == MDB_SET_RANGE ? NULL : &exact);
-		}
-		break;
-	case MDB_GET_MULTIPLE:
-		if (data == NULL || !(mc->mc_flags & C_INITIALIZED)) {
-			rc = EINVAL;
-			break;
-		}
-		if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {
-			rc = MDB_INCOMPATIBLE;
-			break;
-		}
-		rc = MDB_SUCCESS;
-		if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) ||
-			(mc->mc_xcursor->mx_cursor.mc_flags & C_EOF))
-			break;
-		goto fetchm;
-	case MDB_NEXT_MULTIPLE:
-		if (data == NULL) {
-			rc = EINVAL;
-			break;
-		}
-		if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {
-			rc = MDB_INCOMPATIBLE;
-			break;
-		}
-		if (!(mc->mc_flags & C_INITIALIZED))
-			rc = mdb_cursor_first(mc, key, data);
-		else
-			rc = mdb_cursor_next(mc, key, data, MDB_NEXT_DUP);
-		if (rc == MDB_SUCCESS) {
-			if (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) {
-				MDB_cursor *mx;
-fetchm:
-				mx = &mc->mc_xcursor->mx_cursor;
-				data->mv_size = NUMKEYS(mx->mc_pg[mx->mc_top]) *
-					mx->mc_db->md_pad;
-				data->mv_data = METADATA(mx->mc_pg[mx->mc_top]);
-				mx->mc_ki[mx->mc_top] = NUMKEYS(mx->mc_pg[mx->mc_top])-1;
-			} else {
-				rc = MDB_NOTFOUND;
-			}
-		}
-		break;
-	case MDB_NEXT:
-	case MDB_NEXT_DUP:
-	case MDB_NEXT_NODUP:
-		if (!(mc->mc_flags & C_INITIALIZED))
-			rc = mdb_cursor_first(mc, key, data);
-		else
-			rc = mdb_cursor_next(mc, key, data, op);
-		break;
-	case MDB_PREV:
-	case MDB_PREV_DUP:
-	case MDB_PREV_NODUP:
-		if (!(mc->mc_flags & C_INITIALIZED)) {
-			rc = mdb_cursor_last(mc, key, data);
-			if (rc)
-				break;
-			mc->mc_flags |= C_INITIALIZED;
-			mc->mc_ki[mc->mc_top]++;
-		}
-		rc = mdb_cursor_prev(mc, key, data, op);
-		break;
-	case MDB_FIRST:
-		rc = mdb_cursor_first(mc, key, data);
-		break;
-	case MDB_FIRST_DUP:
-		mfunc = mdb_cursor_first;
-	mmove:
-		if (data == NULL || !(mc->mc_flags & C_INITIALIZED)) {
-			rc = EINVAL;
-			break;
-		}
-		if (mc->mc_xcursor == NULL) {
-			rc = MDB_INCOMPATIBLE;
-			break;
-		}
-		{
-			MDB_node *leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
-			if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
-				MDB_GET_KEY(leaf, key);
-				rc = mdb_node_read(mc->mc_txn, leaf, data);
-				break;
-			}
-		}
-		if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {
-			rc = EINVAL;
-			break;
-		}
-		rc = mfunc(&mc->mc_xcursor->mx_cursor, data, NULL);
-		break;
-	case MDB_LAST:
-		rc = mdb_cursor_last(mc, key, data);
-		break;
-	case MDB_LAST_DUP:
-		mfunc = mdb_cursor_last;
-		goto mmove;
-	default:
-		DPRINTF(("unhandled/unimplemented cursor operation %u", op));
-		rc = EINVAL;
-		break;
-	}
-
-	if (mc->mc_flags & C_DEL)
-		mc->mc_flags ^= C_DEL;
-
-	return rc;
-}
-
-/** Touch all the pages in the cursor stack. Set mc_top.
- *	Makes sure all the pages are writable, before attempting a write operation.
- * @param[in] mc The cursor to operate on.
- */
-static int
-mdb_cursor_touch(MDB_cursor *mc)
-{
-	int rc = MDB_SUCCESS;
-
-	if (mc->mc_dbi > MAIN_DBI && !(*mc->mc_dbflag & DB_DIRTY)) {
-		MDB_cursor mc2;
-		MDB_xcursor mcx;
-		if (TXN_DBI_CHANGED(mc->mc_txn, mc->mc_dbi))
-			return MDB_BAD_DBI;
-		mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, &mcx);
-		rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, MDB_PS_MODIFY);
-		if (rc)
-			 return rc;
-		*mc->mc_dbflag |= DB_DIRTY;
-	}
-	mc->mc_top = 0;
-	if (mc->mc_snum) {
-		do {
-			rc = mdb_page_touch(mc);
-		} while (!rc && ++(mc->mc_top) < mc->mc_snum);
-		mc->mc_top = mc->mc_snum-1;
-	}
-	return rc;
-}
-
-/** Do not spill pages to disk if txn is getting full, may fail instead */
-#define MDB_NOSPILL	0x8000
-
-int
-mdb_cursor_put(MDB_cursor *mc, MDB_val *key, MDB_val *data,
-    unsigned int flags)
-{
-	enum { MDB_NO_ROOT = MDB_LAST_ERRCODE+10 }; /* internal code */
-	MDB_env		*env;
-	MDB_node	*leaf = NULL;
-	MDB_page	*fp, *mp;
-	uint16_t	fp_flags;
-	MDB_val		xdata, *rdata, dkey, olddata;
-	MDB_db dummy;
-	int do_sub = 0, insert_key, insert_data;
-	unsigned int mcount = 0, dcount = 0, nospill;
-	size_t nsize;
-	int rc, rc2;
-	unsigned int nflags;
-	DKBUF;
-
-	if (mc == NULL || key == NULL)
-		return EINVAL;
-
-	env = mc->mc_txn->mt_env;
-
-	/* Check this first so counter will always be zero on any
-	 * early failures.
-	 */
-	if (flags & MDB_MULTIPLE) {
-		dcount = data[1].mv_size;
-		data[1].mv_size = 0;
-		if (!F_ISSET(mc->mc_db->md_flags, MDB_DUPFIXED))
-			return MDB_INCOMPATIBLE;
-	}
-
-	nospill = flags & MDB_NOSPILL;
-	flags &= ~MDB_NOSPILL;
-
-	if (mc->mc_txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_ERROR))
-		return (mc->mc_txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
-
-	if (key->mv_size-1 >= ENV_MAXKEY(env))
-		return MDB_BAD_VALSIZE;
-
-#if SIZE_MAX > MAXDATASIZE
-	if (data->mv_size > ((mc->mc_db->md_flags & MDB_DUPSORT) ? ENV_MAXKEY(env) : MAXDATASIZE))
-		return MDB_BAD_VALSIZE;
-#else
-	if ((mc->mc_db->md_flags & MDB_DUPSORT) && data->mv_size > ENV_MAXKEY(env))
-		return MDB_BAD_VALSIZE;
-#endif
-
-	DPRINTF(("==> put db %d key [%s], size %"Z"u, data size %"Z"u",
-		DDBI(mc), DKEY(key), key ? key->mv_size : 0, data->mv_size));
-
-	dkey.mv_size = 0;
-
-	if (flags == MDB_CURRENT) {
-		if (!(mc->mc_flags & C_INITIALIZED))
-			return EINVAL;
-		rc = MDB_SUCCESS;
-	} else if (mc->mc_db->md_root == P_INVALID) {
-		/* new database, cursor has nothing to point to */
-		mc->mc_snum = 0;
-		mc->mc_top = 0;
-		mc->mc_flags &= ~C_INITIALIZED;
-		rc = MDB_NO_ROOT;
-	} else {
-		int exact = 0;
-		MDB_val d2;
-		if (flags & MDB_APPEND) {
-			MDB_val k2;
-			rc = mdb_cursor_last(mc, &k2, &d2);
-			if (rc == 0) {
-				rc = mc->mc_dbx->md_cmp(key, &k2);
-				if (rc > 0) {
-					rc = MDB_NOTFOUND;
-					mc->mc_ki[mc->mc_top]++;
-				} else {
-					/* new key is <= last key */
-					rc = MDB_KEYEXIST;
-				}
-			}
-		} else {
-			rc = mdb_cursor_set(mc, key, &d2, MDB_SET, &exact);
-		}
-		if ((flags & MDB_NOOVERWRITE) && rc == 0) {
-			DPRINTF(("duplicate key [%s]", DKEY(key)));
-			*data = d2;
-			return MDB_KEYEXIST;
-		}
-		if (rc && rc != MDB_NOTFOUND)
-			return rc;
-	}
-
-	if (mc->mc_flags & C_DEL)
-		mc->mc_flags ^= C_DEL;
-
-	/* Cursor is positioned, check for room in the dirty list */
-	if (!nospill) {
-		if (flags & MDB_MULTIPLE) {
-			rdata = &xdata;
-			xdata.mv_size = data->mv_size * dcount;
-		} else {
-			rdata = data;
-		}
-		if ((rc2 = mdb_page_spill(mc, key, rdata)))
-			return rc2;
-	}
-
-	if (rc == MDB_NO_ROOT) {
-		MDB_page *np;
-		/* new database, write a root leaf page */
-		DPUTS("allocating new root leaf page");
-		if ((rc2 = mdb_page_new(mc, P_LEAF, 1, &np))) {
-			return rc2;
-		}
-		mdb_cursor_push(mc, np);
-		mc->mc_db->md_root = np->mp_pgno;
-		mc->mc_db->md_depth++;
-		*mc->mc_dbflag |= DB_DIRTY;
-		if ((mc->mc_db->md_flags & (MDB_DUPSORT|MDB_DUPFIXED))
-			== MDB_DUPFIXED)
-			np->mp_flags |= P_LEAF2;
-		mc->mc_flags |= C_INITIALIZED;
-	} else {
-		/* make sure all cursor pages are writable */
-		rc2 = mdb_cursor_touch(mc);
-		if (rc2)
-			return rc2;
-	}
-
-	insert_key = insert_data = rc;
-	if (insert_key) {
-		/* The key does not exist */
-		DPRINTF(("inserting key at index %i", mc->mc_ki[mc->mc_top]));
-		if ((mc->mc_db->md_flags & MDB_DUPSORT) &&
-			LEAFSIZE(key, data) > env->me_nodemax)
-		{
-			/* Too big for a node, insert in sub-DB.  Set up an empty
-			 * "old sub-page" for prep_subDB to expand to a full page.
-			 */
-			fp_flags = P_LEAF|P_DIRTY;
-			fp = env->me_pbuf;
-			fp->mp_pad = data->mv_size; /* used if MDB_DUPFIXED */
-			fp->mp_lower = fp->mp_upper = (PAGEHDRSZ-PAGEBASE);
-			olddata.mv_size = PAGEHDRSZ;
-			goto prep_subDB;
-		}
-	} else {
-		/* there's only a key anyway, so this is a no-op */
-		if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
-			char *ptr;
-			unsigned int ksize = mc->mc_db->md_pad;
-			if (key->mv_size != ksize)
-				return MDB_BAD_VALSIZE;
-			ptr = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], ksize);
-			memcpy(ptr, key->mv_data, ksize);
-fix_parent:
-			/* if overwriting slot 0 of leaf, need to
-			 * update branch key if there is a parent page
-			 */
-			if (mc->mc_top && !mc->mc_ki[mc->mc_top]) {
-				unsigned short top = mc->mc_top;
-				mc->mc_top--;
-				/* slot 0 is always an empty key, find real slot */
-				while (mc->mc_top && !mc->mc_ki[mc->mc_top])
-					mc->mc_top--;
-				if (mc->mc_ki[mc->mc_top])
-					rc2 = mdb_update_key(mc, key);
-				else
-					rc2 = MDB_SUCCESS;
-				mc->mc_top = top;
-				if (rc2)
-					return rc2;
-			}
-			return MDB_SUCCESS;
-		}
-
-more:
-		leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
-		olddata.mv_size = NODEDSZ(leaf);
-		olddata.mv_data = NODEDATA(leaf);
-
-		/* DB has dups? */
-		if (F_ISSET(mc->mc_db->md_flags, MDB_DUPSORT)) {
-			/* Prepare (sub-)page/sub-DB to accept the new item,
-			 * if needed.  fp: old sub-page or a header faking
-			 * it.  mp: new (sub-)page.  offset: growth in page
-			 * size.  xdata: node data with new page or DB.
-			 */
-			unsigned	i, offset = 0;
-			mp = fp = xdata.mv_data = env->me_pbuf;
-			mp->mp_pgno = mc->mc_pg[mc->mc_top]->mp_pgno;
-
-			/* Was a single item before, must convert now */
-			if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
-				MDB_cmp_func *dcmp;
-				/* Just overwrite the current item */
-				if (flags == MDB_CURRENT)
-					goto current;
-				dcmp = mc->mc_dbx->md_dcmp;
-#if UINT_MAX < SIZE_MAX
-				if (dcmp == mdb_cmp_int && olddata.mv_size == sizeof(size_t))
-					dcmp = mdb_cmp_clong;
-#endif
-				/* does data match? */
-				if (!dcmp(data, &olddata)) {
-					if (flags & MDB_NODUPDATA)
-						return MDB_KEYEXIST;
-					/* overwrite it */
-					goto current;
-				}
-
-				/* Back up original data item */
-				dkey.mv_size = olddata.mv_size;
-				dkey.mv_data = memcpy(fp+1, olddata.mv_data, olddata.mv_size);
-
-				/* Make sub-page header for the dup items, with dummy body */
-				fp->mp_flags = P_LEAF|P_DIRTY|P_SUBP;
-				fp->mp_lower = (PAGEHDRSZ-PAGEBASE);
-				xdata.mv_size = PAGEHDRSZ + dkey.mv_size + data->mv_size;
-				if (mc->mc_db->md_flags & MDB_DUPFIXED) {
-					fp->mp_flags |= P_LEAF2;
-					fp->mp_pad = data->mv_size;
-					xdata.mv_size += 2 * data->mv_size;	/* leave space for 2 more */
-				} else {
-					xdata.mv_size += 2 * (sizeof(indx_t) + NODESIZE) +
-						(dkey.mv_size & 1) + (data->mv_size & 1);
-				}
-				fp->mp_upper = xdata.mv_size - PAGEBASE;
-				olddata.mv_size = xdata.mv_size; /* pretend olddata is fp */
-			} else if (leaf->mn_flags & F_SUBDATA) {
-				/* Data is on sub-DB, just store it */
-				flags |= F_DUPDATA|F_SUBDATA;
-				goto put_sub;
-			} else {
-				/* Data is on sub-page */
-				fp = olddata.mv_data;
-				switch (flags) {
-				default:
-					if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {
-						offset = EVEN(NODESIZE + sizeof(indx_t) +
-							data->mv_size);
-						break;
-					}
-					offset = fp->mp_pad;
-					if (SIZELEFT(fp) < offset) {
-						offset *= 4; /* space for 4 more */
-						break;
-					}
-					/* FALLTHRU: Big enough MDB_DUPFIXED sub-page */
-				case MDB_CURRENT:
-					fp->mp_flags |= P_DIRTY;
-					COPY_PGNO(fp->mp_pgno, mp->mp_pgno);
-					mc->mc_xcursor->mx_cursor.mc_pg[0] = fp;
-					flags |= F_DUPDATA;
-					goto put_sub;
-				}
-				xdata.mv_size = olddata.mv_size + offset;
-			}
-
-			fp_flags = fp->mp_flags;
-			if (NODESIZE + NODEKSZ(leaf) + xdata.mv_size > env->me_nodemax) {
-					/* Too big for a sub-page, convert to sub-DB */
-					fp_flags &= ~P_SUBP;
-prep_subDB:
-					if (mc->mc_db->md_flags & MDB_DUPFIXED) {
-						fp_flags |= P_LEAF2;
-						dummy.md_pad = fp->mp_pad;
-						dummy.md_flags = MDB_DUPFIXED;
-						if (mc->mc_db->md_flags & MDB_INTEGERDUP)
-							dummy.md_flags |= MDB_INTEGERKEY;
-					} else {
-						dummy.md_pad = 0;
-						dummy.md_flags = 0;
-					}
-					dummy.md_depth = 1;
-					dummy.md_branch_pages = 0;
-					dummy.md_leaf_pages = 1;
-					dummy.md_overflow_pages = 0;
-					dummy.md_entries = NUMKEYS(fp);
-					xdata.mv_size = sizeof(MDB_db);
-					xdata.mv_data = &dummy;
-					if ((rc = mdb_page_alloc(mc, 1, &mp)))
-						return rc;
-					offset = env->me_psize - olddata.mv_size;
-					flags |= F_DUPDATA|F_SUBDATA;
-					dummy.md_root = mp->mp_pgno;
-			}
-			if (mp != fp) {
-				mp->mp_flags = fp_flags | P_DIRTY;
-				mp->mp_pad   = fp->mp_pad;
-				mp->mp_lower = fp->mp_lower;
-				mp->mp_upper = fp->mp_upper + offset;
-				if (fp_flags & P_LEAF2) {
-					memcpy(METADATA(mp), METADATA(fp), NUMKEYS(fp) * fp->mp_pad);
-				} else {
-					memcpy((char *)mp + mp->mp_upper + PAGEBASE, (char *)fp + fp->mp_upper + PAGEBASE,
-						olddata.mv_size - fp->mp_upper - PAGEBASE);
-					for (i=0; i<NUMKEYS(fp); i++)
-						mp->mp_ptrs[i] = fp->mp_ptrs[i] + offset;
-				}
-			}
-
-			rdata = &xdata;
-			flags |= F_DUPDATA;
-			do_sub = 1;
-			if (!insert_key)
-				mdb_node_del(mc, 0);
-			goto new_sub;
-		}
-current:
-		/* overflow page overwrites need special handling */
-		if (F_ISSET(leaf->mn_flags, F_BIGDATA)) {
-			MDB_page *omp;
-			pgno_t pg;
-			int level, ovpages, dpages = OVPAGES(data->mv_size, env->me_psize);
-
-			memcpy(&pg, olddata.mv_data, sizeof(pg));
-			if ((rc2 = mdb_page_get(mc->mc_txn, pg, &omp, &level)) != 0)
-				return rc2;
-			ovpages = omp->mp_pages;
-
-			/* Is the ov page large enough? */
-			if (ovpages >= dpages) {
-			  if (!(omp->mp_flags & P_DIRTY) &&
-				  (level || (env->me_flags & MDB_WRITEMAP)))
-			  {
-				rc = mdb_page_unspill(mc->mc_txn, omp, &omp);
-				if (rc)
-					return rc;
-				level = 0;		/* dirty in this txn or clean */
-			  }
-			  /* Is it dirty? */
-			  if (omp->mp_flags & P_DIRTY) {
-				/* yes, overwrite it. Note in this case we don't
-				 * bother to try shrinking the page if the new data
-				 * is smaller than the overflow threshold.
-				 */
-				if (level > 1) {
-					/* It is writable only in a parent txn */
-					size_t sz = (size_t) env->me_psize * ovpages, off;
-					MDB_page *np = mdb_page_malloc(mc->mc_txn, ovpages);
-					MDB_ID2 id2;
-					if (!np)
-						return ENOMEM;
-					id2.mid = pg;
-					id2.mptr = np;
-					rc2 = mdb_mid2l_insert(mc->mc_txn->mt_u.dirty_list, &id2);
-					mdb_cassert(mc, rc2 == 0);
-					if (!(flags & MDB_RESERVE)) {
-						/* Copy end of page, adjusting alignment so
-						 * compiler may copy words instead of bytes.
-						 */
-						off = (PAGEHDRSZ + data->mv_size) & -sizeof(size_t);
-						memcpy((size_t *)((char *)np + off),
-							(size_t *)((char *)omp + off), sz - off);
-						sz = PAGEHDRSZ;
-					}
-					memcpy(np, omp, sz); /* Copy beginning of page */
-					omp = np;
-				}
-				SETDSZ(leaf, data->mv_size);
-				if (F_ISSET(flags, MDB_RESERVE))
-					data->mv_data = METADATA(omp);
-				else
-					memcpy(METADATA(omp), data->mv_data, data->mv_size);
-				return MDB_SUCCESS;
-			  }
-			}
-			if ((rc2 = mdb_ovpage_free(mc, omp)) != MDB_SUCCESS)
-				return rc2;
-		} else if (data->mv_size == olddata.mv_size) {
-			/* same size, just replace it. Note that we could
-			 * also reuse this node if the new data is smaller,
-			 * but instead we opt to shrink the node in that case.
-			 */
-			if (F_ISSET(flags, MDB_RESERVE))
-				data->mv_data = olddata.mv_data;
-			else if (!(mc->mc_flags & C_SUB))
-				memcpy(olddata.mv_data, data->mv_data, data->mv_size);
-			else {
-				memcpy(NODEKEY(leaf), key->mv_data, key->mv_size);
-				goto fix_parent;
-			}
-			return MDB_SUCCESS;
-		}
-		mdb_node_del(mc, 0);
-	}
-
-	rdata = data;
-
-new_sub:
-	nflags = flags & NODE_ADD_FLAGS;
-	nsize = IS_LEAF2(mc->mc_pg[mc->mc_top]) ? key->mv_size : mdb_leaf_size(env, key, rdata);
-	if (SIZELEFT(mc->mc_pg[mc->mc_top]) < nsize) {
-		if (( flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA )
-			nflags &= ~MDB_APPEND; /* sub-page may need room to grow */
-		if (!insert_key)
-			nflags |= MDB_SPLIT_REPLACE;
-		rc = mdb_page_split(mc, key, rdata, P_INVALID, nflags);
-	} else {
-		/* There is room already in this leaf page. */
-		rc = mdb_node_add(mc, mc->mc_ki[mc->mc_top], key, rdata, 0, nflags);
-		if (rc == 0 && insert_key) {
-			/* Adjust other cursors pointing to mp */
-			MDB_cursor *m2, *m3;
-			MDB_dbi dbi = mc->mc_dbi;
-			unsigned i = mc->mc_top;
-			MDB_page *mp = mc->mc_pg[i];
-
-			for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
-				if (mc->mc_flags & C_SUB)
-					m3 = &m2->mc_xcursor->mx_cursor;
-				else
-					m3 = m2;
-				if (m3 == mc || m3->mc_snum < mc->mc_snum) continue;
-				if (m3->mc_pg[i] == mp && m3->mc_ki[i] >= mc->mc_ki[i]) {
-					m3->mc_ki[i]++;
-				}
-			}
-		}
-	}
-
-	if (rc == MDB_SUCCESS) {
-		/* Now store the actual data in the child DB. Note that we're
-		 * storing the user data in the keys field, so there are strict
-		 * size limits on dupdata. The actual data fields of the child
-		 * DB are all zero size.
-		 */
-		if (do_sub) {
-			int xflags;
-			size_t ecount;
-put_sub:
-			xdata.mv_size = 0;
-			xdata.mv_data = "";
-			leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
-			if (flags & MDB_CURRENT) {
-				xflags = MDB_CURRENT|MDB_NOSPILL;
-			} else {
-				mdb_xcursor_init1(mc, leaf);
-				xflags = (flags & MDB_NODUPDATA) ?
-					MDB_NOOVERWRITE|MDB_NOSPILL : MDB_NOSPILL;
-			}
-			/* converted, write the original data first */
-			if (dkey.mv_size) {
-				rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, &dkey, &xdata, xflags);
-				if (rc)
-					goto bad_sub;
-				{
-					/* Adjust other cursors pointing to mp */
-					MDB_cursor *m2;
-					unsigned i = mc->mc_top;
-					MDB_page *mp = mc->mc_pg[i];
-
-					for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
-						if (m2 == mc || m2->mc_snum < mc->mc_snum) continue;
-						if (!(m2->mc_flags & C_INITIALIZED)) continue;
-						if (m2->mc_pg[i] == mp && m2->mc_ki[i] == mc->mc_ki[i]) {
-							mdb_xcursor_init1(m2, leaf);
-						}
-					}
-				}
-				/* we've done our job */
-				dkey.mv_size = 0;
-			}
-			ecount = mc->mc_xcursor->mx_db.md_entries;
-			if (flags & MDB_APPENDDUP)
-				xflags |= MDB_APPEND;
-			rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, data, &xdata, xflags);
-			if (flags & F_SUBDATA) {
-				void *db = NODEDATA(leaf);
-				memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db));
-			}
-			insert_data = mc->mc_xcursor->mx_db.md_entries - ecount;
-		}
-		/* Increment count unless we just replaced an existing item. */
-		if (insert_data)
-			mc->mc_db->md_entries++;
-		if (insert_key) {
-			/* Invalidate txn if we created an empty sub-DB */
-			if (rc)
-				goto bad_sub;
-			/* If we succeeded and the key didn't exist before,
-			 * make sure the cursor is marked valid.
-			 */
-			mc->mc_flags |= C_INITIALIZED;
-		}
-		if (flags & MDB_MULTIPLE) {
-			if (!rc) {
-				mcount++;
-				/* let caller know how many succeeded, if any */
-				data[1].mv_size = mcount;
-				if (mcount < dcount) {
-					data[0].mv_data = (char *)data[0].mv_data + data[0].mv_size;
-					insert_key = insert_data = 0;
-					goto more;
-				}
-			}
-		}
-		return rc;
-bad_sub:
-		if (rc == MDB_KEYEXIST)	/* should not happen, we deleted that item */
-			rc = MDB_CORRUPTED;
-	}
-	mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
-	return rc;
-}
-
-int
-mdb_cursor_del(MDB_cursor *mc, unsigned int flags)
-{
-	MDB_node	*leaf;
-	MDB_page	*mp;
-	int rc;
-
-	if (mc->mc_txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_ERROR))
-		return (mc->mc_txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
-
-	if (!(mc->mc_flags & C_INITIALIZED))
-		return EINVAL;
-
-	if (mc->mc_ki[mc->mc_top] >= NUMKEYS(mc->mc_pg[mc->mc_top]))
-		return MDB_NOTFOUND;
-
-	if (!(flags & MDB_NOSPILL) && (rc = mdb_page_spill(mc, NULL, NULL)))
-		return rc;
-
-	rc = mdb_cursor_touch(mc);
-	if (rc)
-		return rc;
-
-	mp = mc->mc_pg[mc->mc_top];
-	if (IS_LEAF2(mp))
-		goto del_key;
-	leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
-
-	if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
-		if (flags & MDB_NODUPDATA) {
-			/* mdb_cursor_del0() will subtract the final entry */
-			mc->mc_db->md_entries -= mc->mc_xcursor->mx_db.md_entries - 1;
-		} else {
-			if (!F_ISSET(leaf->mn_flags, F_SUBDATA)) {
-				mc->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
-			}
-			rc = mdb_cursor_del(&mc->mc_xcursor->mx_cursor, MDB_NOSPILL);
-			if (rc)
-				return rc;
-			/* If sub-DB still has entries, we're done */
-			if (mc->mc_xcursor->mx_db.md_entries) {
-				if (leaf->mn_flags & F_SUBDATA) {
-					/* update subDB info */
-					void *db = NODEDATA(leaf);
-					memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db));
-				} else {
-					MDB_cursor *m2;
-					/* shrink fake page */
-					mdb_node_shrink(mp, mc->mc_ki[mc->mc_top]);
-					leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
-					mc->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
-					/* fix other sub-DB cursors pointed at this fake page */
-					for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
-						if (m2 == mc || m2->mc_snum < mc->mc_snum) continue;
-						if (m2->mc_pg[mc->mc_top] == mp &&
-							m2->mc_ki[mc->mc_top] == mc->mc_ki[mc->mc_top])
-							m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
-					}
-				}
-				mc->mc_db->md_entries--;
-				mc->mc_flags |= C_DEL;
-				return rc;
-			}
-			/* otherwise fall thru and delete the sub-DB */
-		}
-
-		if (leaf->mn_flags & F_SUBDATA) {
-			/* add all the child DB's pages to the free list */
-			rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0);
-			if (rc)
-				goto fail;
-		}
-	}
-
-	/* add overflow pages to free list */
-	if (F_ISSET(leaf->mn_flags, F_BIGDATA)) {
-		MDB_page *omp;
-		pgno_t pg;
-
-		memcpy(&pg, NODEDATA(leaf), sizeof(pg));
-		if ((rc = mdb_page_get(mc->mc_txn, pg, &omp, NULL)) ||
-			(rc = mdb_ovpage_free(mc, omp)))
-			goto fail;
-	}
-
-del_key:
-	return mdb_cursor_del0(mc);
-
-fail:
-	mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
-	return rc;
-}
-
-/** Allocate and initialize new pages for a database.
- * @param[in] mc a cursor on the database being added to.
- * @param[in] flags flags defining what type of page is being allocated.
- * @param[in] num the number of pages to allocate. This is usually 1,
- * unless allocating overflow pages for a large record.
- * @param[out] mp Address of a page, or NULL on failure.
- * @return 0 on success, non-zero on failure.
- */
-static int
-mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp)
-{
-	MDB_page	*np;
-	int rc;
-
-	if ((rc = mdb_page_alloc(mc, num, &np)))
-		return rc;
-	DPRINTF(("allocated new mpage %"Z"u, page size %u",
-	    np->mp_pgno, mc->mc_txn->mt_env->me_psize));
-	np->mp_flags = flags | P_DIRTY;
-	np->mp_lower = (PAGEHDRSZ-PAGEBASE);
-	np->mp_upper = mc->mc_txn->mt_env->me_psize - PAGEBASE;
-
-	if (IS_BRANCH(np))
-		mc->mc_db->md_branch_pages++;
-	else if (IS_LEAF(np))
-		mc->mc_db->md_leaf_pages++;
-	else if (IS_OVERFLOW(np)) {
-		mc->mc_db->md_overflow_pages += num;
-		np->mp_pages = num;
-	}
-	*mp = np;
-
-	return 0;
-}
-
-/** Calculate the size of a leaf node.
- * The size depends on the environment's page size; if a data item
- * is too large it will be put onto an overflow page and the node
- * size will only include the key and not the data. Sizes are always
- * rounded up to an even number of bytes, to guarantee 2-byte alignment
- * of the #MDB_node headers.
- * @param[in] env The environment handle.
- * @param[in] key The key for the node.
- * @param[in] data The data for the node.
- * @return The number of bytes needed to store the node.
- */
-static size_t
-mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data)
-{
-	size_t		 sz;
-
-	sz = LEAFSIZE(key, data);
-	if (sz > env->me_nodemax) {
-		/* put on overflow page */
-		sz -= data->mv_size - sizeof(pgno_t);
-	}
-
-	return EVEN(sz + sizeof(indx_t));
-}
-
-/** Calculate the size of a branch node.
- * The size should depend on the environment's page size but since
- * we currently don't support spilling large keys onto overflow
- * pages, it's simply the size of the #MDB_node header plus the
- * size of the key. Sizes are always rounded up to an even number
- * of bytes, to guarantee 2-byte alignment of the #MDB_node headers.
- * @param[in] env The environment handle.
- * @param[in] key The key for the node.
- * @return The number of bytes needed to store the node.
- */
-static size_t
-mdb_branch_size(MDB_env *env, MDB_val *key)
-{
-	size_t		 sz;
-
-	sz = INDXSIZE(key);
-	if (sz > env->me_nodemax) {
-		/* put on overflow page */
-		/* not implemented */
-		/* sz -= key->size - sizeof(pgno_t); */
-	}
-
-	return sz + sizeof(indx_t);
-}
-
-/** Add a node to the page pointed to by the cursor.
- * @param[in] mc The cursor for this operation.
- * @param[in] indx The index on the page where the new node should be added.
- * @param[in] key The key for the new node.
- * @param[in] data The data for the new node, if any.
- * @param[in] pgno The page number, if adding a branch node.
- * @param[in] flags Flags for the node.
- * @return 0 on success, non-zero on failure. Possible errors are:
- * <ul>
- *	<li>ENOMEM - failed to allocate overflow pages for the node.
- *	<li>MDB_PAGE_FULL - there is insufficient room in the page. This error
- *	should never happen since all callers already calculate the
- *	page's free space before calling this function.
- * </ul>
- */
-static int
-mdb_node_add(MDB_cursor *mc, indx_t indx,
-    MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags)
-{
-	unsigned int	 i;
-	size_t		 node_size = NODESIZE;
-	ssize_t		 room;
-	indx_t		 ofs;
-	MDB_node	*node;
-	MDB_page	*mp = mc->mc_pg[mc->mc_top];
-	MDB_page	*ofp = NULL;		/* overflow page */
-	DKBUF;
-
-	mdb_cassert(mc, mp->mp_upper >= mp->mp_lower);
-
-	DPRINTF(("add to %s %spage %"Z"u index %i, data size %"Z"u key size %"Z"u [%s]",
-	    IS_LEAF(mp) ? "leaf" : "branch",
-		IS_SUBP(mp) ? "sub-" : "",
-		mdb_dbg_pgno(mp), indx, data ? data->mv_size : 0,
-		key ? key->mv_size : 0, key ? DKEY(key) : "null"));
-
-	if (IS_LEAF2(mp)) {
-		/* Move higher keys up one slot. */
-		int ksize = mc->mc_db->md_pad, dif;
-		char *ptr = LEAF2KEY(mp, indx, ksize);
-		dif = NUMKEYS(mp) - indx;
-		if (dif > 0)
-			memmove(ptr+ksize, ptr, dif*ksize);
-		/* insert new key */
-		memcpy(ptr, key->mv_data, ksize);
-
-		/* Just using these for counting */
-		mp->mp_lower += sizeof(indx_t);
-		mp->mp_upper -= ksize - sizeof(indx_t);
-		return MDB_SUCCESS;
-	}
-
-	room = (ssize_t)SIZELEFT(mp) - (ssize_t)sizeof(indx_t);
-	if (key != NULL)
-		node_size += key->mv_size;
-	if (IS_LEAF(mp)) {
-		mdb_cassert(mc, data);
-		if (F_ISSET(flags, F_BIGDATA)) {
-			/* Data already on overflow page. */
-			node_size += sizeof(pgno_t);
-		} else if (node_size + data->mv_size > mc->mc_txn->mt_env->me_nodemax) {
-			int ovpages = OVPAGES(data->mv_size, mc->mc_txn->mt_env->me_psize);
-			int rc;
-			/* Put data on overflow page. */
-			DPRINTF(("data size is %"Z"u, node would be %"Z"u, put data on overflow page",
-			    data->mv_size, node_size+data->mv_size));
-			node_size = EVEN(node_size + sizeof(pgno_t));
-			if ((ssize_t)node_size > room)
-				goto full;
-			if ((rc = mdb_page_new(mc, P_OVERFLOW, ovpages, &ofp)))
-				return rc;
-			DPRINTF(("allocated overflow page %"Z"u", ofp->mp_pgno));
-			flags |= F_BIGDATA;
-			goto update;
-		} else {
-			node_size += data->mv_size;
-		}
-	}
-	node_size = EVEN(node_size);
-	if ((ssize_t)node_size > room)
-		goto full;
-
-update:
-	/* Move higher pointers up one slot. */
-	for (i = NUMKEYS(mp); i > indx; i--)
-		mp->mp_ptrs[i] = mp->mp_ptrs[i - 1];
-
-	/* Adjust free space offsets. */
-	ofs = mp->mp_upper - node_size;
-	mdb_cassert(mc, ofs >= mp->mp_lower + sizeof(indx_t));
-	mp->mp_ptrs[indx] = ofs;
-	mp->mp_upper = ofs;
-	mp->mp_lower += sizeof(indx_t);
-
-	/* Write the node data. */
-	node = NODEPTR(mp, indx);
-	node->mn_ksize = (key == NULL) ? 0 : key->mv_size;
-	node->mn_flags = flags;
-	if (IS_LEAF(mp))
-		SETDSZ(node,data->mv_size);
-	else
-		SETPGNO(node,pgno);
-
-	if (key)
-		memcpy(NODEKEY(node), key->mv_data, key->mv_size);
-
-	if (IS_LEAF(mp)) {
-		mdb_cassert(mc, key);
-		if (ofp == NULL) {
-			if (F_ISSET(flags, F_BIGDATA))
-				memcpy(node->mn_data + key->mv_size, data->mv_data,
-				    sizeof(pgno_t));
-			else if (F_ISSET(flags, MDB_RESERVE))
-				data->mv_data = node->mn_data + key->mv_size;
-			else
-				memcpy(node->mn_data + key->mv_size, data->mv_data,
-				    data->mv_size);
-		} else {
-			memcpy(node->mn_data + key->mv_size, &ofp->mp_pgno,
-			    sizeof(pgno_t));
-			if (F_ISSET(flags, MDB_RESERVE))
-				data->mv_data = METADATA(ofp);
-			else
-				memcpy(METADATA(ofp), data->mv_data, data->mv_size);
-		}
-	}
-
-	return MDB_SUCCESS;
-
-full:
-	DPRINTF(("not enough room in page %"Z"u, got %u ptrs",
-		mdb_dbg_pgno(mp), NUMKEYS(mp)));
-	DPRINTF(("upper-lower = %u - %u = %"Z"d", mp->mp_upper,mp->mp_lower,room));
-	DPRINTF(("node size = %"Z"u", node_size));
-	mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
-	return MDB_PAGE_FULL;
-}
-
-/** Delete the specified node from a page.
- * @param[in] mc Cursor pointing to the node to delete.
- * @param[in] ksize The size of a node. Only used if the page is
- * part of a #MDB_DUPFIXED database.
- */
-static void
-mdb_node_del(MDB_cursor *mc, int ksize)
-{
-	MDB_page *mp = mc->mc_pg[mc->mc_top];
-	indx_t	indx = mc->mc_ki[mc->mc_top];
-	unsigned int	 sz;
-	indx_t		 i, j, numkeys, ptr;
-	MDB_node	*node;
-	char		*base;
-
-	DPRINTF(("delete node %u on %s page %"Z"u", indx,
-	    IS_LEAF(mp) ? "leaf" : "branch", mdb_dbg_pgno(mp)));
-	numkeys = NUMKEYS(mp);
-	mdb_cassert(mc, indx < numkeys);
-
-	if (IS_LEAF2(mp)) {
-		int x = numkeys - 1 - indx;
-		base = LEAF2KEY(mp, indx, ksize);
-		if (x)
-			memmove(base, base + ksize, x * ksize);
-		mp->mp_lower -= sizeof(indx_t);
-		mp->mp_upper += ksize - sizeof(indx_t);
-		return;
-	}
-
-	node = NODEPTR(mp, indx);
-	sz = NODESIZE + node->mn_ksize;
-	if (IS_LEAF(mp)) {
-		if (F_ISSET(node->mn_flags, F_BIGDATA))
-			sz += sizeof(pgno_t);
-		else
-			sz += NODEDSZ(node);
-	}
-	sz = EVEN(sz);
-
-	ptr = mp->mp_ptrs[indx];
-	for (i = j = 0; i < numkeys; i++) {
-		if (i != indx) {
-			mp->mp_ptrs[j] = mp->mp_ptrs[i];
-			if (mp->mp_ptrs[i] < ptr)
-				mp->mp_ptrs[j] += sz;
-			j++;
-		}
-	}
-
-	base = (char *)mp + mp->mp_upper + PAGEBASE;
-	memmove(base + sz, base, ptr - mp->mp_upper);
-
-	mp->mp_lower -= sizeof(indx_t);
-	mp->mp_upper += sz;
-}
-
-/** Compact the main page after deleting a node on a subpage.
- * @param[in] mp The main page to operate on.
- * @param[in] indx The index of the subpage on the main page.
- */
-static void
-mdb_node_shrink(MDB_page *mp, indx_t indx)
-{
-	MDB_node *node;
-	MDB_page *sp, *xp;
-	char *base;
-	int nsize, delta;
-	indx_t		 i, numkeys, ptr;
-
-	node = NODEPTR(mp, indx);
-	sp = (MDB_page *)NODEDATA(node);
-	delta = SIZELEFT(sp);
-	xp = (MDB_page *)((char *)sp + delta);
-
-	/* shift subpage upward */
-	if (IS_LEAF2(sp)) {
-		nsize = NUMKEYS(sp) * sp->mp_pad;
-		if (nsize & 1)
-			return;		/* do not make the node uneven-sized */
-		memmove(METADATA(xp), METADATA(sp), nsize);
-	} else {
-		int i;
-		numkeys = NUMKEYS(sp);
-		for (i=numkeys-1; i>=0; i--)
-			xp->mp_ptrs[i] = sp->mp_ptrs[i] - delta;
-	}
-	xp->mp_upper = sp->mp_lower;
-	xp->mp_lower = sp->mp_lower;
-	xp->mp_flags = sp->mp_flags;
-	xp->mp_pad = sp->mp_pad;
-	COPY_PGNO(xp->mp_pgno, mp->mp_pgno);
-
-	nsize = NODEDSZ(node) - delta;
-	SETDSZ(node, nsize);
-
-	/* shift lower nodes upward */
-	ptr = mp->mp_ptrs[indx];
-	numkeys = NUMKEYS(mp);
-	for (i = 0; i < numkeys; i++) {
-		if (mp->mp_ptrs[i] <= ptr)
-			mp->mp_ptrs[i] += delta;
-	}
-
-	base = (char *)mp + mp->mp_upper + PAGEBASE;
-	memmove(base + delta, base, ptr - mp->mp_upper + NODESIZE + NODEKSZ(node));
-	mp->mp_upper += delta;
-}
-
-/** Initial setup of a sorted-dups cursor.
- * Sorted duplicates are implemented as a sub-database for the given key.
- * The duplicate data items are actually keys of the sub-database.
- * Operations on the duplicate data items are performed using a sub-cursor
- * initialized when the sub-database is first accessed. This function does
- * the preliminary setup of the sub-cursor, filling in the fields that
- * depend only on the parent DB.
- * @param[in] mc The main cursor whose sorted-dups cursor is to be initialized.
- */
-static void
-mdb_xcursor_init0(MDB_cursor *mc)
-{
-	MDB_xcursor *mx = mc->mc_xcursor;
-
-	mx->mx_cursor.mc_xcursor = NULL;
-	mx->mx_cursor.mc_txn = mc->mc_txn;
-	mx->mx_cursor.mc_db = &mx->mx_db;
-	mx->mx_cursor.mc_dbx = &mx->mx_dbx;
-	mx->mx_cursor.mc_dbi = mc->mc_dbi;
-	mx->mx_cursor.mc_dbflag = &mx->mx_dbflag;
-	mx->mx_cursor.mc_snum = 0;
-	mx->mx_cursor.mc_top = 0;
-	mx->mx_cursor.mc_flags = C_SUB;
-	mx->mx_dbx.md_name.mv_size = 0;
-	mx->mx_dbx.md_name.mv_data = NULL;
-	mx->mx_dbx.md_cmp = mc->mc_dbx->md_dcmp;
-	mx->mx_dbx.md_dcmp = NULL;
-	mx->mx_dbx.md_rel = mc->mc_dbx->md_rel;
-}
-
-/** Final setup of a sorted-dups cursor.
- *	Sets up the fields that depend on the data from the main cursor.
- * @param[in] mc The main cursor whose sorted-dups cursor is to be initialized.
- * @param[in] node The data containing the #MDB_db record for the
- * sorted-dup database.
- */
-static void
-mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node)
-{
-	MDB_xcursor *mx = mc->mc_xcursor;
-
-	if (node->mn_flags & F_SUBDATA) {
-		memcpy(&mx->mx_db, NODEDATA(node), sizeof(MDB_db));
-		mx->mx_cursor.mc_pg[0] = 0;
-		mx->mx_cursor.mc_snum = 0;
-		mx->mx_cursor.mc_top = 0;
-		mx->mx_cursor.mc_flags = C_SUB;
-	} else {
-		MDB_page *fp = NODEDATA(node);
-		mx->mx_db.md_pad = mc->mc_pg[mc->mc_top]->mp_pad;
-		mx->mx_db.md_flags = 0;
-		mx->mx_db.md_depth = 1;
-		mx->mx_db.md_branch_pages = 0;
-		mx->mx_db.md_leaf_pages = 1;
-		mx->mx_db.md_overflow_pages = 0;
-		mx->mx_db.md_entries = NUMKEYS(fp);
-		COPY_PGNO(mx->mx_db.md_root, fp->mp_pgno);
-		mx->mx_cursor.mc_snum = 1;
-		mx->mx_cursor.mc_top = 0;
-		mx->mx_cursor.mc_flags = C_INITIALIZED|C_SUB;
-		mx->mx_cursor.mc_pg[0] = fp;
-		mx->mx_cursor.mc_ki[0] = 0;
-		if (mc->mc_db->md_flags & MDB_DUPFIXED) {
-			mx->mx_db.md_flags = MDB_DUPFIXED;
-			mx->mx_db.md_pad = fp->mp_pad;
-			if (mc->mc_db->md_flags & MDB_INTEGERDUP)
-				mx->mx_db.md_flags |= MDB_INTEGERKEY;
-		}
-	}
-	DPRINTF(("Sub-db -%u root page %"Z"u", mx->mx_cursor.mc_dbi,
-		mx->mx_db.md_root));
-	mx->mx_dbflag = DB_VALID|DB_DIRTY; /* DB_DIRTY guides mdb_cursor_touch */
-#if UINT_MAX < SIZE_MAX
-	if (mx->mx_dbx.md_cmp == mdb_cmp_int && mx->mx_db.md_pad == sizeof(size_t))
-		mx->mx_dbx.md_cmp = mdb_cmp_clong;
-#endif
-}
-
-/** Initialize a cursor for a given transaction and database. */
-static void
-mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx)
-{
-	mc->mc_next = NULL;
-	mc->mc_backup = NULL;
-	mc->mc_dbi = dbi;
-	mc->mc_txn = txn;
-	mc->mc_db = &txn->mt_dbs[dbi];
-	mc->mc_dbx = &txn->mt_dbxs[dbi];
-	mc->mc_dbflag = &txn->mt_dbflags[dbi];
-	mc->mc_snum = 0;
-	mc->mc_top = 0;
-	mc->mc_pg[0] = 0;
-	mc->mc_ki[0] = 0;
-	mc->mc_flags = 0;
-	if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) {
-		mdb_tassert(txn, mx != NULL);
-		mc->mc_xcursor = mx;
-		mdb_xcursor_init0(mc);
-	} else {
-		mc->mc_xcursor = NULL;
-	}
-	if (*mc->mc_dbflag & DB_STALE) {
-		mdb_page_search(mc, NULL, MDB_PS_ROOTONLY);
-	}
-}
-
-int
-mdb_cursor_open(MDB_txn *txn, MDB_dbi dbi, MDB_cursor **ret)
-{
-	MDB_cursor	*mc;
-	size_t size = sizeof(MDB_cursor);
-
-	if (!ret || !TXN_DBI_EXIST(txn, dbi))
-		return EINVAL;
-
-	if (txn->mt_flags & MDB_TXN_ERROR)
-		return MDB_BAD_TXN;
-
-	/* Allow read access to the freelist */
-	if (!dbi && !F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))
-		return EINVAL;
-
-	if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT)
-		size += sizeof(MDB_xcursor);
-
-	if ((mc = malloc(size)) != NULL) {
-		mdb_cursor_init(mc, txn, dbi, (MDB_xcursor *)(mc + 1));
-		if (txn->mt_cursors) {
-			mc->mc_next = txn->mt_cursors[dbi];
-			txn->mt_cursors[dbi] = mc;
-			mc->mc_flags |= C_UNTRACK;
-		}
-	} else {
-		return ENOMEM;
-	}
-
-	*ret = mc;
-
-	return MDB_SUCCESS;
-}
-
-int
-mdb_cursor_renew(MDB_txn *txn, MDB_cursor *mc)
-{
-	if (!mc || !TXN_DBI_EXIST(txn, mc->mc_dbi))
-		return EINVAL;
-
-	if ((mc->mc_flags & C_UNTRACK) || txn->mt_cursors)
-		return EINVAL;
-
-	if (txn->mt_flags & MDB_TXN_ERROR)
-		return MDB_BAD_TXN;
-
-	mdb_cursor_init(mc, txn, mc->mc_dbi, mc->mc_xcursor);
-	return MDB_SUCCESS;
-}
-
-/* Return the count of duplicate data items for the current key */
-int
-mdb_cursor_count(MDB_cursor *mc, size_t *countp)
-{
-	MDB_node	*leaf;
-
-	if (mc == NULL || countp == NULL)
-		return EINVAL;
-
-	if (mc->mc_xcursor == NULL)
-		return MDB_INCOMPATIBLE;
-
-	if (mc->mc_txn->mt_flags & MDB_TXN_ERROR)
-		return MDB_BAD_TXN;
-
-	if (!(mc->mc_flags & C_INITIALIZED))
-		return EINVAL;
-
-	if (!mc->mc_snum || (mc->mc_flags & C_EOF))
-		return MDB_NOTFOUND;
-
-	leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
-	if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
-		*countp = 1;
-	} else {
-		if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED))
-			return EINVAL;
-
-		*countp = mc->mc_xcursor->mx_db.md_entries;
-	}
-	return MDB_SUCCESS;
-}
-
-void
-mdb_cursor_close(MDB_cursor *mc)
-{
-	if (mc && !mc->mc_backup) {
-		/* remove from txn, if tracked */
-		if ((mc->mc_flags & C_UNTRACK) && mc->mc_txn->mt_cursors) {
-			MDB_cursor **prev = &mc->mc_txn->mt_cursors[mc->mc_dbi];
-			while (*prev && *prev != mc) prev = &(*prev)->mc_next;
-			if (*prev == mc)
-				*prev = mc->mc_next;
-		}
-		free(mc);
-	}
-}
-
-MDB_txn *
-mdb_cursor_txn(MDB_cursor *mc)
-{
-	if (!mc) return NULL;
-	return mc->mc_txn;
-}
-
-MDB_dbi
-mdb_cursor_dbi(MDB_cursor *mc)
-{
-	return mc->mc_dbi;
-}
-
-/** Replace the key for a branch node with a new key.
- * @param[in] mc Cursor pointing to the node to operate on.
- * @param[in] key The new key to use.
- * @return 0 on success, non-zero on failure.
- */
-static int
-mdb_update_key(MDB_cursor *mc, MDB_val *key)
-{
-	MDB_page		*mp;
-	MDB_node		*node;
-	char			*base;
-	size_t			 len;
-	int				 delta, ksize, oksize;
-	indx_t			 ptr, i, numkeys, indx;
-	DKBUF;
-
-	indx = mc->mc_ki[mc->mc_top];
-	mp = mc->mc_pg[mc->mc_top];
-	node = NODEPTR(mp, indx);
-	ptr = mp->mp_ptrs[indx];
-#if MDB_DEBUG
-	{
-		MDB_val	k2;
-		char kbuf2[DKBUF_MAXKEYSIZE*2+1];
-		k2.mv_data = NODEKEY(node);
-		k2.mv_size = node->mn_ksize;
-		DPRINTF(("update key %u (ofs %u) [%s] to [%s] on page %"Z"u",
-			indx, ptr,
-			mdb_dkey(&k2, kbuf2),
-			DKEY(key),
-			mp->mp_pgno));
-	}
-#endif
-
-	/* Sizes must be 2-byte aligned. */
-	ksize = EVEN(key->mv_size);
-	oksize = EVEN(node->mn_ksize);
-	delta = ksize - oksize;
-
-	/* Shift node contents if EVEN(key length) changed. */
-	if (delta) {
-		if (delta > 0 && SIZELEFT(mp) < delta) {
-			pgno_t pgno;
-			/* not enough space left, do a delete and split */
-			DPRINTF(("Not enough room, delta = %d, splitting...", delta));
-			pgno = NODEPGNO(node);
-			mdb_node_del(mc, 0);
-			return mdb_page_split(mc, key, NULL, pgno, MDB_SPLIT_REPLACE);
-		}
-
-		numkeys = NUMKEYS(mp);
-		for (i = 0; i < numkeys; i++) {
-			if (mp->mp_ptrs[i] <= ptr)
-				mp->mp_ptrs[i] -= delta;
-		}
-
-		base = (char *)mp + mp->mp_upper + PAGEBASE;
-		len = ptr - mp->mp_upper + NODESIZE;
-		memmove(base - delta, base, len);
-		mp->mp_upper -= delta;
-
-		node = NODEPTR(mp, indx);
-	}
-
-	/* But even if no shift was needed, update ksize */
-	if (node->mn_ksize != key->mv_size)
-		node->mn_ksize = key->mv_size;
-
-	if (key->mv_size)
-		memcpy(NODEKEY(node), key->mv_data, key->mv_size);
-
-	return MDB_SUCCESS;
-}
-
-static void
-mdb_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst);
-
-/** Move a node from csrc to cdst.
- */
-static int
-mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst)
-{
-	MDB_node		*srcnode;
-	MDB_val		 key, data;
-	pgno_t	srcpg;
-	MDB_cursor mn;
-	int			 rc;
-	unsigned short flags;
-
-	DKBUF;
-
-	/* Mark src and dst as dirty. */
-	if ((rc = mdb_page_touch(csrc)) ||
-	    (rc = mdb_page_touch(cdst)))
-		return rc;
-
-	if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
-		key.mv_size = csrc->mc_db->md_pad;
-		key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top], key.mv_size);
-		data.mv_size = 0;
-		data.mv_data = NULL;
-		srcpg = 0;
-		flags = 0;
-	} else {
-		srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top]);
-		mdb_cassert(csrc, !((size_t)srcnode & 1));
-		srcpg = NODEPGNO(srcnode);
-		flags = srcnode->mn_flags;
-		if (csrc->mc_ki[csrc->mc_top] == 0 && IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {
-			unsigned int snum = csrc->mc_snum;
-			MDB_node *s2;
-			/* must find the lowest key below src */
-			rc = mdb_page_search_lowest(csrc);
-			if (rc)
-				return rc;
-			if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
-				key.mv_size = csrc->mc_db->md_pad;
-				key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);
-			} else {
-				s2 = NODEPTR(csrc->mc_pg[csrc->mc_top], 0);
-				key.mv_size = NODEKSZ(s2);
-				key.mv_data = NODEKEY(s2);
-			}
-			csrc->mc_snum = snum--;
-			csrc->mc_top = snum;
-		} else {
-			key.mv_size = NODEKSZ(srcnode);
-			key.mv_data = NODEKEY(srcnode);
-		}
-		data.mv_size = NODEDSZ(srcnode);
-		data.mv_data = NODEDATA(srcnode);
-	}
-	if (IS_BRANCH(cdst->mc_pg[cdst->mc_top]) && cdst->mc_ki[cdst->mc_top] == 0) {
-		unsigned int snum = cdst->mc_snum;
-		MDB_node *s2;
-		MDB_val bkey;
-		/* must find the lowest key below dst */
-		mdb_cursor_copy(cdst, &mn);
-		rc = mdb_page_search_lowest(&mn);
-		if (rc)
-			return rc;
-		if (IS_LEAF2(mn.mc_pg[mn.mc_top])) {
-			bkey.mv_size = mn.mc_db->md_pad;
-			bkey.mv_data = LEAF2KEY(mn.mc_pg[mn.mc_top], 0, bkey.mv_size);
-		} else {
-			s2 = NODEPTR(mn.mc_pg[mn.mc_top], 0);
-			bkey.mv_size = NODEKSZ(s2);
-			bkey.mv_data = NODEKEY(s2);
-		}
-		mn.mc_snum = snum--;
-		mn.mc_top = snum;
-		mn.mc_ki[snum] = 0;
-		rc = mdb_update_key(&mn, &bkey);
-		if (rc)
-			return rc;
-	}
-
-	DPRINTF(("moving %s node %u [%s] on page %"Z"u to node %u on page %"Z"u",
-	    IS_LEAF(csrc->mc_pg[csrc->mc_top]) ? "leaf" : "branch",
-	    csrc->mc_ki[csrc->mc_top],
-		DKEY(&key),
-	    csrc->mc_pg[csrc->mc_top]->mp_pgno,
-	    cdst->mc_ki[cdst->mc_top], cdst->mc_pg[cdst->mc_top]->mp_pgno));
-
-	/* Add the node to the destination page.
-	 */
-	rc = mdb_node_add(cdst, cdst->mc_ki[cdst->mc_top], &key, &data, srcpg, flags);
-	if (rc != MDB_SUCCESS)
-		return rc;
-
-	/* Delete the node from the source page.
-	 */
-	mdb_node_del(csrc, key.mv_size);
-
-	{
-		/* Adjust other cursors pointing to mp */
-		MDB_cursor *m2, *m3;
-		MDB_dbi dbi = csrc->mc_dbi;
-		MDB_page *mp = csrc->mc_pg[csrc->mc_top];
-
-		for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
-			if (csrc->mc_flags & C_SUB)
-				m3 = &m2->mc_xcursor->mx_cursor;
-			else
-				m3 = m2;
-			if (m3 == csrc) continue;
-			if (m3->mc_pg[csrc->mc_top] == mp && m3->mc_ki[csrc->mc_top] ==
-				csrc->mc_ki[csrc->mc_top]) {
-				m3->mc_pg[csrc->mc_top] = cdst->mc_pg[cdst->mc_top];
-				m3->mc_ki[csrc->mc_top] = cdst->mc_ki[cdst->mc_top];
-			}
-		}
-	}
-
-	/* Update the parent separators.
-	 */
-	if (csrc->mc_ki[csrc->mc_top] == 0) {
-		if (csrc->mc_ki[csrc->mc_top-1] != 0) {
-			if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
-				key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);
-			} else {
-				srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], 0);
-				key.mv_size = NODEKSZ(srcnode);
-				key.mv_data = NODEKEY(srcnode);
-			}
-			DPRINTF(("update separator for source page %"Z"u to [%s]",
-				csrc->mc_pg[csrc->mc_top]->mp_pgno, DKEY(&key)));
-			mdb_cursor_copy(csrc, &mn);
-			mn.mc_snum--;
-			mn.mc_top--;
-			if ((rc = mdb_update_key(&mn, &key)) != MDB_SUCCESS)
-				return rc;
-		}
-		if (IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {
-			MDB_val	 nullkey;
-			indx_t	ix = csrc->mc_ki[csrc->mc_top];
-			nullkey.mv_size = 0;
-			csrc->mc_ki[csrc->mc_top] = 0;
-			rc = mdb_update_key(csrc, &nullkey);
-			csrc->mc_ki[csrc->mc_top] = ix;
-			mdb_cassert(csrc, rc == MDB_SUCCESS);
-		}
-	}
-
-	if (cdst->mc_ki[cdst->mc_top] == 0) {
-		if (cdst->mc_ki[cdst->mc_top-1] != 0) {
-			if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
-				key.mv_data = LEAF2KEY(cdst->mc_pg[cdst->mc_top], 0, key.mv_size);
-			} else {
-				srcnode = NODEPTR(cdst->mc_pg[cdst->mc_top], 0);
-				key.mv_size = NODEKSZ(srcnode);
-				key.mv_data = NODEKEY(srcnode);
-			}
-			DPRINTF(("update separator for destination page %"Z"u to [%s]",
-				cdst->mc_pg[cdst->mc_top]->mp_pgno, DKEY(&key)));
-			mdb_cursor_copy(cdst, &mn);
-			mn.mc_snum--;
-			mn.mc_top--;
-			if ((rc = mdb_update_key(&mn, &key)) != MDB_SUCCESS)
-				return rc;
-		}
-		if (IS_BRANCH(cdst->mc_pg[cdst->mc_top])) {
-			MDB_val	 nullkey;
-			indx_t	ix = cdst->mc_ki[cdst->mc_top];
-			nullkey.mv_size = 0;
-			cdst->mc_ki[cdst->mc_top] = 0;
-			rc = mdb_update_key(cdst, &nullkey);
-			cdst->mc_ki[cdst->mc_top] = ix;
-			mdb_cassert(cdst, rc == MDB_SUCCESS);
-		}
-	}
-
-	return MDB_SUCCESS;
-}
-
-/** Merge one page into another.
- *  The nodes from the page pointed to by \b csrc will
- *	be copied to the page pointed to by \b cdst and then
- *	the \b csrc page will be freed.
- * @param[in] csrc Cursor pointing to the source page.
- * @param[in] cdst Cursor pointing to the destination page.
- * @return 0 on success, non-zero on failure.
- */
-static int
-mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst)
-{
-	MDB_page	*psrc, *pdst;
-	MDB_node	*srcnode;
-	MDB_val		 key, data;
-	unsigned	 nkeys;
-	int			 rc;
-	indx_t		 i, j;
-
-	psrc = csrc->mc_pg[csrc->mc_top];
-	pdst = cdst->mc_pg[cdst->mc_top];
-
-	DPRINTF(("merging page %"Z"u into %"Z"u", psrc->mp_pgno, pdst->mp_pgno));
-
-	mdb_cassert(csrc, csrc->mc_snum > 1);	/* can't merge root page */
-	mdb_cassert(csrc, cdst->mc_snum > 1);
-
-	/* Mark dst as dirty. */
-	if ((rc = mdb_page_touch(cdst)))
-		return rc;
-
-	/* Move all nodes from src to dst.
-	 */
-	j = nkeys = NUMKEYS(pdst);
-	if (IS_LEAF2(psrc)) {
-		key.mv_size = csrc->mc_db->md_pad;
-		key.mv_data = METADATA(psrc);
-		for (i = 0; i < NUMKEYS(psrc); i++, j++) {
-			rc = mdb_node_add(cdst, j, &key, NULL, 0, 0);
-			if (rc != MDB_SUCCESS)
-				return rc;
-			key.mv_data = (char *)key.mv_data + key.mv_size;
-		}
-	} else {
-		for (i = 0; i < NUMKEYS(psrc); i++, j++) {
-			srcnode = NODEPTR(psrc, i);
-			if (i == 0 && IS_BRANCH(psrc)) {
-				MDB_cursor mn;
-				MDB_node *s2;
-				mdb_cursor_copy(csrc, &mn);
-				/* must find the lowest key below src */
-				rc = mdb_page_search_lowest(&mn);
-				if (rc)
-					return rc;
-				if (IS_LEAF2(mn.mc_pg[mn.mc_top])) {
-					key.mv_size = mn.mc_db->md_pad;
-					key.mv_data = LEAF2KEY(mn.mc_pg[mn.mc_top], 0, key.mv_size);
-				} else {
-					s2 = NODEPTR(mn.mc_pg[mn.mc_top], 0);
-					key.mv_size = NODEKSZ(s2);
-					key.mv_data = NODEKEY(s2);
-				}
-			} else {
-				key.mv_size = srcnode->mn_ksize;
-				key.mv_data = NODEKEY(srcnode);
-			}
-
-			data.mv_size = NODEDSZ(srcnode);
-			data.mv_data = NODEDATA(srcnode);
-			rc = mdb_node_add(cdst, j, &key, &data, NODEPGNO(srcnode), srcnode->mn_flags);
-			if (rc != MDB_SUCCESS)
-				return rc;
-		}
-	}
-
-	DPRINTF(("dst page %"Z"u now has %u keys (%.1f%% filled)",
-	    pdst->mp_pgno, NUMKEYS(pdst),
-		(float)PAGEFILL(cdst->mc_txn->mt_env, pdst) / 10));
-
-	/* Unlink the src page from parent and add to free list.
-	 */
-	csrc->mc_top--;
-	mdb_node_del(csrc, 0);
-	if (csrc->mc_ki[csrc->mc_top] == 0) {
-		key.mv_size = 0;
-		rc = mdb_update_key(csrc, &key);
-		if (rc) {
-			csrc->mc_top++;
-			return rc;
-		}
-	}
-	csrc->mc_top++;
-
-	psrc = csrc->mc_pg[csrc->mc_top];
-	/* If not operating on FreeDB, allow this page to be reused
-	 * in this txn. Otherwise just add to free list.
-	 */
-	rc = mdb_page_loose(csrc, psrc);
-	if (rc)
-		return rc;
-	if (IS_LEAF(psrc))
-		csrc->mc_db->md_leaf_pages--;
-	else
-		csrc->mc_db->md_branch_pages--;
-	{
-		/* Adjust other cursors pointing to mp */
-		MDB_cursor *m2, *m3;
-		MDB_dbi dbi = csrc->mc_dbi;
-
-		for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
-			if (csrc->mc_flags & C_SUB)
-				m3 = &m2->mc_xcursor->mx_cursor;
-			else
-				m3 = m2;
-			if (m3 == csrc) continue;
-			if (m3->mc_snum < csrc->mc_snum) continue;
-			if (m3->mc_pg[csrc->mc_top] == psrc) {
-				m3->mc_pg[csrc->mc_top] = pdst;
-				m3->mc_ki[csrc->mc_top] += nkeys;
-			}
-		}
-	}
-	{
-		unsigned int snum = cdst->mc_snum;
-		uint16_t depth = cdst->mc_db->md_depth;
-		mdb_cursor_pop(cdst);
-		rc = mdb_rebalance(cdst);
-		/* Did the tree shrink? */
-		if (depth > cdst->mc_db->md_depth)
-			snum--;
-		cdst->mc_snum = snum;
-		cdst->mc_top = snum-1;
-	}
-	return rc;
-}
-
-/** Copy the contents of a cursor.
- * @param[in] csrc The cursor to copy from.
- * @param[out] cdst The cursor to copy to.
- */
-static void
-mdb_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst)
-{
-	unsigned int i;
-
-	cdst->mc_txn = csrc->mc_txn;
-	cdst->mc_dbi = csrc->mc_dbi;
-	cdst->mc_db  = csrc->mc_db;
-	cdst->mc_dbx = csrc->mc_dbx;
-	cdst->mc_snum = csrc->mc_snum;
-	cdst->mc_top = csrc->mc_top;
-	cdst->mc_flags = csrc->mc_flags;
-
-	for (i=0; i<csrc->mc_snum; i++) {
-		cdst->mc_pg[i] = csrc->mc_pg[i];
-		cdst->mc_ki[i] = csrc->mc_ki[i];
-	}
-}
-
-/** Rebalance the tree after a delete operation.
- * @param[in] mc Cursor pointing to the page where rebalancing
- * should begin.
- * @return 0 on success, non-zero on failure.
- */
-static int
-mdb_rebalance(MDB_cursor *mc)
-{
-	MDB_node	*node;
-	int rc;
-	unsigned int ptop, minkeys;
-	MDB_cursor	mn;
-	indx_t oldki;
-
-	minkeys = 1 + (IS_BRANCH(mc->mc_pg[mc->mc_top]));
-	DPRINTF(("rebalancing %s page %"Z"u (has %u keys, %.1f%% full)",
-	    IS_LEAF(mc->mc_pg[mc->mc_top]) ? "leaf" : "branch",
-	    mdb_dbg_pgno(mc->mc_pg[mc->mc_top]), NUMKEYS(mc->mc_pg[mc->mc_top]),
-		(float)PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) / 10));
-
-	if (PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) >= FILL_THRESHOLD &&
-		NUMKEYS(mc->mc_pg[mc->mc_top]) >= minkeys) {
-		DPRINTF(("no need to rebalance page %"Z"u, above fill threshold",
-		    mdb_dbg_pgno(mc->mc_pg[mc->mc_top])));
-		return MDB_SUCCESS;
-	}
-
-	if (mc->mc_snum < 2) {
-		MDB_page *mp = mc->mc_pg[0];
-		if (IS_SUBP(mp)) {
-			DPUTS("Can't rebalance a subpage, ignoring");
-			return MDB_SUCCESS;
-		}
-		if (NUMKEYS(mp) == 0) {
-			DPUTS("tree is completely empty");
-			mc->mc_db->md_root = P_INVALID;
-			mc->mc_db->md_depth = 0;
-			mc->mc_db->md_leaf_pages = 0;
-			rc = mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno);
-			if (rc)
-				return rc;
-			/* Adjust cursors pointing to mp */
-			mc->mc_snum = 0;
-			mc->mc_top = 0;
-			mc->mc_flags &= ~C_INITIALIZED;
-			{
-				MDB_cursor *m2, *m3;
-				MDB_dbi dbi = mc->mc_dbi;
-
-				for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
-					if (mc->mc_flags & C_SUB)
-						m3 = &m2->mc_xcursor->mx_cursor;
-					else
-						m3 = m2;
-					if (m3->mc_snum < mc->mc_snum) continue;
-					if (m3->mc_pg[0] == mp) {
-						m3->mc_snum = 0;
-						m3->mc_top = 0;
-						m3->mc_flags &= ~C_INITIALIZED;
-					}
-				}
-			}
-		} else if (IS_BRANCH(mp) && NUMKEYS(mp) == 1) {
-			int i;
-			DPUTS("collapsing root page!");
-			rc = mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno);
-			if (rc)
-				return rc;
-			mc->mc_db->md_root = NODEPGNO(NODEPTR(mp, 0));
-			rc = mdb_page_get(mc->mc_txn,mc->mc_db->md_root,&mc->mc_pg[0],NULL);
-			if (rc)
-				return rc;
-			mc->mc_db->md_depth--;
-			mc->mc_db->md_branch_pages--;
-			mc->mc_ki[0] = mc->mc_ki[1];
-			for (i = 1; i<mc->mc_db->md_depth; i++) {
-				mc->mc_pg[i] = mc->mc_pg[i+1];
-				mc->mc_ki[i] = mc->mc_ki[i+1];
-			}
-			{
-				/* Adjust other cursors pointing to mp */
-				MDB_cursor *m2, *m3;
-				MDB_dbi dbi = mc->mc_dbi;
-
-				for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
-					if (mc->mc_flags & C_SUB)
-						m3 = &m2->mc_xcursor->mx_cursor;
-					else
-						m3 = m2;
-					if (m3 == mc || m3->mc_snum < mc->mc_snum) continue;
-					if (m3->mc_pg[0] == mp) {
-						for (i=0; i<m3->mc_snum; i++) {
-							m3->mc_pg[i] = m3->mc_pg[i+1];
-							m3->mc_ki[i] = m3->mc_ki[i+1];
-						}
-						m3->mc_snum--;
-						m3->mc_top--;
-					}
-				}
-			}
-		} else
-			DPUTS("root page doesn't need rebalancing");
-		return MDB_SUCCESS;
-	}
-
-	/* The parent (branch page) must have at least 2 pointers,
-	 * otherwise the tree is invalid.
-	 */
-	ptop = mc->mc_top-1;
-	mdb_cassert(mc, NUMKEYS(mc->mc_pg[ptop]) > 1);
-
-	/* Leaf page fill factor is below the threshold.
-	 * Try to move keys from left or right neighbor, or
-	 * merge with a neighbor page.
-	 */
-
-	/* Find neighbors.
-	 */
-	mdb_cursor_copy(mc, &mn);
-	mn.mc_xcursor = NULL;
-
-	oldki = mc->mc_ki[mc->mc_top];
-	if (mc->mc_ki[ptop] == 0) {
-		/* We're the leftmost leaf in our parent.
-		 */
-		DPUTS("reading right neighbor");
-		mn.mc_ki[ptop]++;
-		node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]);
-		rc = mdb_page_get(mc->mc_txn,NODEPGNO(node),&mn.mc_pg[mn.mc_top],NULL);
-		if (rc)
-			return rc;
-		mn.mc_ki[mn.mc_top] = 0;
-		mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]);
-	} else {
-		/* There is at least one neighbor to the left.
-		 */
-		DPUTS("reading left neighbor");
-		mn.mc_ki[ptop]--;
-		node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]);
-		rc = mdb_page_get(mc->mc_txn,NODEPGNO(node),&mn.mc_pg[mn.mc_top],NULL);
-		if (rc)
-			return rc;
-		mn.mc_ki[mn.mc_top] = NUMKEYS(mn.mc_pg[mn.mc_top]) - 1;
-		mc->mc_ki[mc->mc_top] = 0;
-	}
-
-	DPRINTF(("found neighbor page %"Z"u (%u keys, %.1f%% full)",
-	    mn.mc_pg[mn.mc_top]->mp_pgno, NUMKEYS(mn.mc_pg[mn.mc_top]),
-		(float)PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) / 10));
-
-	/* If the neighbor page is above threshold and has enough keys,
-	 * move one key from it. Otherwise we should try to merge them.
-	 * (A branch page must never have less than 2 keys.)
-	 */
-	minkeys = 1 + (IS_BRANCH(mn.mc_pg[mn.mc_top]));
-	if (PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) >= FILL_THRESHOLD && NUMKEYS(mn.mc_pg[mn.mc_top]) > minkeys) {
-		rc = mdb_node_move(&mn, mc);
-		if (mc->mc_ki[ptop]) {
-			oldki++;
-		}
-	} else {
-		if (mc->mc_ki[ptop] == 0) {
-			rc = mdb_page_merge(&mn, mc);
-		} else {
-			MDB_cursor dummy;
-			oldki += NUMKEYS(mn.mc_pg[mn.mc_top]);
-			mn.mc_ki[mn.mc_top] += mc->mc_ki[mn.mc_top] + 1;
-			/* We want mdb_rebalance to find mn when doing fixups */
-			if (mc->mc_flags & C_SUB) {
-				dummy.mc_next = mc->mc_txn->mt_cursors[mc->mc_dbi];
-				mc->mc_txn->mt_cursors[mc->mc_dbi] = &dummy;
-				dummy.mc_xcursor = (MDB_xcursor *)&mn;
-			} else {
-				mn.mc_next = mc->mc_txn->mt_cursors[mc->mc_dbi];
-				mc->mc_txn->mt_cursors[mc->mc_dbi] = &mn;
-			}
-			rc = mdb_page_merge(mc, &mn);
-			if (mc->mc_flags & C_SUB)
-				mc->mc_txn->mt_cursors[mc->mc_dbi] = dummy.mc_next;
-			else
-				mc->mc_txn->mt_cursors[mc->mc_dbi] = mn.mc_next;
-			mdb_cursor_copy(&mn, mc);
-		}
-		mc->mc_flags &= ~C_EOF;
-	}
-	mc->mc_ki[mc->mc_top] = oldki;
-	return rc;
-}
-
-/** Complete a delete operation started by #mdb_cursor_del(). */
-static int
-mdb_cursor_del0(MDB_cursor *mc)
-{
-	int rc;
-	MDB_page *mp;
-	indx_t ki;
-	unsigned int nkeys;
-
-	ki = mc->mc_ki[mc->mc_top];
-	mdb_node_del(mc, mc->mc_db->md_pad);
-	mc->mc_db->md_entries--;
-	rc = mdb_rebalance(mc);
-
-	if (rc == MDB_SUCCESS) {
-		MDB_cursor *m2, *m3;
-		MDB_dbi dbi = mc->mc_dbi;
-
-		/* DB is totally empty now, just bail out.
-		 * Other cursors adjustments were already done
-		 * by mdb_rebalance and aren't needed here.
-		 */
-		if (!mc->mc_snum)
-			return rc;
-
-		mp = mc->mc_pg[mc->mc_top];
-		nkeys = NUMKEYS(mp);
-
-		/* if mc points past last node in page, find next sibling */
-		if (mc->mc_ki[mc->mc_top] >= nkeys) {
-			rc = mdb_cursor_sibling(mc, 1);
-			if (rc == MDB_NOTFOUND) {
-				mc->mc_flags |= C_EOF;
-				rc = MDB_SUCCESS;
-			}
-		}
-
-		/* Adjust other cursors pointing to mp */
-		for (m2 = mc->mc_txn->mt_cursors[dbi]; !rc && m2; m2=m2->mc_next) {
-			m3 = (mc->mc_flags & C_SUB) ? &m2->mc_xcursor->mx_cursor : m2;
-			if (! (m2->mc_flags & m3->mc_flags & C_INITIALIZED))
-				continue;
-			if (m3 == mc || m3->mc_snum < mc->mc_snum)
-				continue;
-			if (m3->mc_pg[mc->mc_top] == mp) {
-				if (m3->mc_ki[mc->mc_top] >= ki) {
-					m3->mc_flags |= C_DEL;
-					if (m3->mc_ki[mc->mc_top] > ki)
-						m3->mc_ki[mc->mc_top]--;
-					else if (mc->mc_db->md_flags & MDB_DUPSORT)
-						m3->mc_xcursor->mx_cursor.mc_flags |= C_EOF;
-				}
-				if (m3->mc_ki[mc->mc_top] >= nkeys) {
-					rc = mdb_cursor_sibling(m3, 1);
-					if (rc == MDB_NOTFOUND) {
-						m3->mc_flags |= C_EOF;
-						rc = MDB_SUCCESS;
-					}
-				}
-			}
-		}
-		mc->mc_flags |= C_DEL;
-	}
-
-	if (rc)
-		mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
-	return rc;
-}
-
-int
-mdb_del(MDB_txn *txn, MDB_dbi dbi,
-    MDB_val *key, MDB_val *data)
-{
-	if (!key || dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
-		return EINVAL;
-
-	if (txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_ERROR))
-		return (txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
-
-	if (!F_ISSET(txn->mt_dbs[dbi].md_flags, MDB_DUPSORT)) {
-		/* must ignore any data */
-		data = NULL;
-	}
-
-	return mdb_del0(txn, dbi, key, data, 0);
-}
-
-static int
-mdb_del0(MDB_txn *txn, MDB_dbi dbi,
-	MDB_val *key, MDB_val *data, unsigned flags)
-{
-	MDB_cursor mc;
-	MDB_xcursor mx;
-	MDB_cursor_op op;
-	MDB_val rdata, *xdata;
-	int		 rc, exact = 0;
-	DKBUF;
-
-	DPRINTF(("====> delete db %u key [%s]", dbi, DKEY(key)));
-
-	mdb_cursor_init(&mc, txn, dbi, &mx);
-
-	if (data) {
-		op = MDB_GET_BOTH;
-		rdata = *data;
-		xdata = &rdata;
-	} else {
-		op = MDB_SET;
-		xdata = NULL;
-		flags |= MDB_NODUPDATA;
-	}
-	rc = mdb_cursor_set(&mc, key, xdata, op, &exact);
-	if (rc == 0) {
-		/* let mdb_page_split know about this cursor if needed:
-		 * delete will trigger a rebalance; if it needs to move
-		 * a node from one page to another, it will have to
-		 * update the parent's separator key(s). If the new sepkey
-		 * is larger than the current one, the parent page may
-		 * run out of space, triggering a split. We need this
-		 * cursor to be consistent until the end of the rebalance.
-		 */
-		mc.mc_flags |= C_UNTRACK;
-		mc.mc_next = txn->mt_cursors[dbi];
-		txn->mt_cursors[dbi] = &mc;
-		rc = mdb_cursor_del(&mc, flags);
-		txn->mt_cursors[dbi] = mc.mc_next;
-	}
-	return rc;
-}
-
-/** Split a page and insert a new node.
- * @param[in,out] mc Cursor pointing to the page and desired insertion index.
- * The cursor will be updated to point to the actual page and index where
- * the node got inserted after the split.
- * @param[in] newkey The key for the newly inserted node.
- * @param[in] newdata The data for the newly inserted node.
- * @param[in] newpgno The page number, if the new node is a branch node.
- * @param[in] nflags The #NODE_ADD_FLAGS for the new node.
- * @return 0 on success, non-zero on failure.
- */
-static int
-mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno,
-	unsigned int nflags)
-{
-	unsigned int flags;
-	int		 rc = MDB_SUCCESS, new_root = 0, did_split = 0;
-	indx_t		 newindx;
-	pgno_t		 pgno = 0;
-	int	 i, j, split_indx, nkeys, pmax;
-	MDB_env 	*env = mc->mc_txn->mt_env;
-	MDB_node	*node;
-	MDB_val	 sepkey, rkey, xdata, *rdata = &xdata;
-	MDB_page	*copy = NULL;
-	MDB_page	*mp, *rp, *pp;
-	int ptop;
-	MDB_cursor	mn;
-	DKBUF;
-
-	mp = mc->mc_pg[mc->mc_top];
-	newindx = mc->mc_ki[mc->mc_top];
-	nkeys = NUMKEYS(mp);
-
-	DPRINTF(("-----> splitting %s page %"Z"u and adding [%s] at index %i/%i",
-	    IS_LEAF(mp) ? "leaf" : "branch", mp->mp_pgno,
-	    DKEY(newkey), mc->mc_ki[mc->mc_top], nkeys));
-
-	/* Create a right sibling. */
-	if ((rc = mdb_page_new(mc, mp->mp_flags, 1, &rp)))
-		return rc;
-	DPRINTF(("new right sibling: page %"Z"u", rp->mp_pgno));
-
-	if (mc->mc_snum < 2) {
-		if ((rc = mdb_page_new(mc, P_BRANCH, 1, &pp)))
-			goto done;
-		/* shift current top to make room for new parent */
-		mc->mc_pg[1] = mc->mc_pg[0];
-		mc->mc_ki[1] = mc->mc_ki[0];
-		mc->mc_pg[0] = pp;
-		mc->mc_ki[0] = 0;
-		mc->mc_db->md_root = pp->mp_pgno;
-		DPRINTF(("root split! new root = %"Z"u", pp->mp_pgno));
-		mc->mc_db->md_depth++;
-		new_root = 1;
-
-		/* Add left (implicit) pointer. */
-		if ((rc = mdb_node_add(mc, 0, NULL, NULL, mp->mp_pgno, 0)) != MDB_SUCCESS) {
-			/* undo the pre-push */
-			mc->mc_pg[0] = mc->mc_pg[1];
-			mc->mc_ki[0] = mc->mc_ki[1];
-			mc->mc_db->md_root = mp->mp_pgno;
-			mc->mc_db->md_depth--;
-			goto done;
-		}
-		mc->mc_snum = 2;
-		mc->mc_top = 1;
-		ptop = 0;
-	} else {
-		ptop = mc->mc_top-1;
-		DPRINTF(("parent branch page is %"Z"u", mc->mc_pg[ptop]->mp_pgno));
-	}
-
-	mc->mc_flags |= C_SPLITTING;
-	mdb_cursor_copy(mc, &mn);
-	mn.mc_pg[mn.mc_top] = rp;
-	mn.mc_ki[ptop] = mc->mc_ki[ptop]+1;
-
-	if (nflags & MDB_APPEND) {
-		mn.mc_ki[mn.mc_top] = 0;
-		sepkey = *newkey;
-		split_indx = newindx;
-		nkeys = 0;
-	} else {
-
-		split_indx = (nkeys+1) / 2;
-
-		if (IS_LEAF2(rp)) {
-			char *split, *ins;
-			int x;
-			unsigned int lsize, rsize, ksize;
-			/* Move half of the keys to the right sibling */
-			x = mc->mc_ki[mc->mc_top] - split_indx;
-			ksize = mc->mc_db->md_pad;
-			split = LEAF2KEY(mp, split_indx, ksize);
-			rsize = (nkeys - split_indx) * ksize;
-			lsize = (nkeys - split_indx) * sizeof(indx_t);
-			mp->mp_lower -= lsize;
-			rp->mp_lower += lsize;
-			mp->mp_upper += rsize - lsize;
-			rp->mp_upper -= rsize - lsize;
-			sepkey.mv_size = ksize;
-			if (newindx == split_indx) {
-				sepkey.mv_data = newkey->mv_data;
-			} else {
-				sepkey.mv_data = split;
-			}
-			if (x<0) {
-				ins = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], ksize);
-				memcpy(rp->mp_ptrs, split, rsize);
-				sepkey.mv_data = rp->mp_ptrs;
-				memmove(ins+ksize, ins, (split_indx - mc->mc_ki[mc->mc_top]) * ksize);
-				memcpy(ins, newkey->mv_data, ksize);
-				mp->mp_lower += sizeof(indx_t);
-				mp->mp_upper -= ksize - sizeof(indx_t);
-			} else {
-				if (x)
-					memcpy(rp->mp_ptrs, split, x * ksize);
-				ins = LEAF2KEY(rp, x, ksize);
-				memcpy(ins, newkey->mv_data, ksize);
-				memcpy(ins+ksize, split + x * ksize, rsize - x * ksize);
-				rp->mp_lower += sizeof(indx_t);
-				rp->mp_upper -= ksize - sizeof(indx_t);
-				mc->mc_ki[mc->mc_top] = x;
-				mc->mc_pg[mc->mc_top] = rp;
-			}
-		} else {
-			int psize, nsize, k;
-			/* Maximum free space in an empty page */
-			pmax = env->me_psize - PAGEHDRSZ;
-			if (IS_LEAF(mp))
-				nsize = mdb_leaf_size(env, newkey, newdata);
-			else
-				nsize = mdb_branch_size(env, newkey);
-			nsize = EVEN(nsize);
-
-			/* grab a page to hold a temporary copy */
-			copy = mdb_page_malloc(mc->mc_txn, 1);
-			if (copy == NULL) {
-				rc = ENOMEM;
-				goto done;
-			}
-			copy->mp_pgno  = mp->mp_pgno;
-			copy->mp_flags = mp->mp_flags;
-			copy->mp_lower = (PAGEHDRSZ-PAGEBASE);
-			copy->mp_upper = env->me_psize - PAGEBASE;
-
-			/* prepare to insert */
-			for (i=0, j=0; i<nkeys; i++) {
-				if (i == newindx) {
-					copy->mp_ptrs[j++] = 0;
-				}
-				copy->mp_ptrs[j++] = mp->mp_ptrs[i];
-			}
-
-			/* When items are relatively large the split point needs
-			 * to be checked, because being off-by-one will make the
-			 * difference between success or failure in mdb_node_add.
-			 *
-			 * It's also relevant if a page happens to be laid out
-			 * such that one half of its nodes are all "small" and
-			 * the other half of its nodes are "large." If the new
-			 * item is also "large" and falls on the half with
-			 * "large" nodes, it also may not fit.
-			 *
-			 * As a final tweak, if the new item goes on the last
-			 * spot on the page (and thus, onto the new page), bias
-			 * the split so the new page is emptier than the old page.
-			 * This yields better packing during sequential inserts.
-			 */
-			if (nkeys < 20 || nsize > pmax/16 || newindx >= nkeys) {
-				/* Find split point */
-				psize = 0;
-				if (newindx <= split_indx || newindx >= nkeys) {
-					i = 0; j = 1;
-					k = newindx >= nkeys ? nkeys : split_indx+2;
-				} else {
-					i = nkeys; j = -1;
-					k = split_indx-1;
-				}
-				for (; i!=k; i+=j) {
-					if (i == newindx) {
-						psize += nsize;
-						node = NULL;
-					} else {
-						node = (MDB_node *)((char *)mp + copy->mp_ptrs[i] + PAGEBASE);
-						psize += NODESIZE + NODEKSZ(node) + sizeof(indx_t);
-						if (IS_LEAF(mp)) {
-							if (F_ISSET(node->mn_flags, F_BIGDATA))
-								psize += sizeof(pgno_t);
-							else
-								psize += NODEDSZ(node);
-						}
-						psize = EVEN(psize);
-					}
-					if (psize > pmax || i == k-j) {
-						split_indx = i + (j<0);
-						break;
-					}
-				}
-			}
-			if (split_indx == newindx) {
-				sepkey.mv_size = newkey->mv_size;
-				sepkey.mv_data = newkey->mv_data;
-			} else {
-				node = (MDB_node *)((char *)mp + copy->mp_ptrs[split_indx] + PAGEBASE);
-				sepkey.mv_size = node->mn_ksize;
-				sepkey.mv_data = NODEKEY(node);
-			}
-		}
-	}
-
-	DPRINTF(("separator is %d [%s]", split_indx, DKEY(&sepkey)));
-
-	/* Copy separator key to the parent.
-	 */
-	if (SIZELEFT(mn.mc_pg[ptop]) < mdb_branch_size(env, &sepkey)) {
-		mn.mc_snum--;
-		mn.mc_top--;
-		did_split = 1;
-		rc = mdb_page_split(&mn, &sepkey, NULL, rp->mp_pgno, 0);
-		if (rc)
-			goto done;
-
-		/* root split? */
-		if (mn.mc_snum == mc->mc_snum) {
-			mc->mc_pg[mc->mc_snum] = mc->mc_pg[mc->mc_top];
-			mc->mc_ki[mc->mc_snum] = mc->mc_ki[mc->mc_top];
-			mc->mc_pg[mc->mc_top] = mc->mc_pg[ptop];
-			mc->mc_ki[mc->mc_top] = mc->mc_ki[ptop];
-			mc->mc_snum++;
-			mc->mc_top++;
-			ptop++;
-		}
-		/* Right page might now have changed parent.
-		 * Check if left page also changed parent.
-		 */
-		if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&
-		    mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) {
-			for (i=0; i<ptop; i++) {
-				mc->mc_pg[i] = mn.mc_pg[i];
-				mc->mc_ki[i] = mn.mc_ki[i];
-			}
-			mc->mc_pg[ptop] = mn.mc_pg[ptop];
-			if (mn.mc_ki[ptop]) {
-				mc->mc_ki[ptop] = mn.mc_ki[ptop] - 1;
-			} else {
-				/* find right page's left sibling */
-				mc->mc_ki[ptop] = mn.mc_ki[ptop];
-				mdb_cursor_sibling(mc, 0);
-			}
-		}
-	} else {
-		mn.mc_top--;
-		rc = mdb_node_add(&mn, mn.mc_ki[ptop], &sepkey, NULL, rp->mp_pgno, 0);
-		mn.mc_top++;
-	}
-	mc->mc_flags ^= C_SPLITTING;
-	if (rc != MDB_SUCCESS) {
-		goto done;
-	}
-	if (nflags & MDB_APPEND) {
-		mc->mc_pg[mc->mc_top] = rp;
-		mc->mc_ki[mc->mc_top] = 0;
-		rc = mdb_node_add(mc, 0, newkey, newdata, newpgno, nflags);
-		if (rc)
-			goto done;
-		for (i=0; i<mc->mc_top; i++)
-			mc->mc_ki[i] = mn.mc_ki[i];
-	} else if (!IS_LEAF2(mp)) {
-		/* Move nodes */
-		mc->mc_pg[mc->mc_top] = rp;
-		i = split_indx;
-		j = 0;
-		do {
-			if (i == newindx) {
-				rkey.mv_data = newkey->mv_data;
-				rkey.mv_size = newkey->mv_size;
-				if (IS_LEAF(mp)) {
-					rdata = newdata;
-				} else
-					pgno = newpgno;
-				flags = nflags;
-				/* Update index for the new key. */
-				mc->mc_ki[mc->mc_top] = j;
-			} else {
-				node = (MDB_node *)((char *)mp + copy->mp_ptrs[i] + PAGEBASE);
-				rkey.mv_data = NODEKEY(node);
-				rkey.mv_size = node->mn_ksize;
-				if (IS_LEAF(mp)) {
-					xdata.mv_data = NODEDATA(node);
-					xdata.mv_size = NODEDSZ(node);
-					rdata = &xdata;
-				} else
-					pgno = NODEPGNO(node);
-				flags = node->mn_flags;
-			}
-
-			if (!IS_LEAF(mp) && j == 0) {
-				/* First branch index doesn't need key data. */
-				rkey.mv_size = 0;
-			}
-
-			rc = mdb_node_add(mc, j, &rkey, rdata, pgno, flags);
-			if (rc)
-				goto done;
-			if (i == nkeys) {
-				i = 0;
-				j = 0;
-				mc->mc_pg[mc->mc_top] = copy;
-			} else {
-				i++;
-				j++;
-			}
-		} while (i != split_indx);
-
-		nkeys = NUMKEYS(copy);
-		for (i=0; i<nkeys; i++)
-			mp->mp_ptrs[i] = copy->mp_ptrs[i];
-		mp->mp_lower = copy->mp_lower;
-		mp->mp_upper = copy->mp_upper;
-		memcpy(NODEPTR(mp, nkeys-1), NODEPTR(copy, nkeys-1),
-			env->me_psize - copy->mp_upper - PAGEBASE);
-
-		/* reset back to original page */
-		if (newindx < split_indx) {
-			mc->mc_pg[mc->mc_top] = mp;
-			if (nflags & MDB_RESERVE) {
-				node = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
-				if (!(node->mn_flags & F_BIGDATA))
-					newdata->mv_data = NODEDATA(node);
-			}
-		} else {
-			mc->mc_pg[mc->mc_top] = rp;
-			mc->mc_ki[ptop]++;
-			/* Make sure mc_ki is still valid.
-			 */
-			if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&
-				mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) {
-				for (i=0; i<=ptop; i++) {
-					mc->mc_pg[i] = mn.mc_pg[i];
-					mc->mc_ki[i] = mn.mc_ki[i];
-				}
-			}
-		}
-	}
-
-	{
-		/* Adjust other cursors pointing to mp */
-		MDB_cursor *m2, *m3;
-		MDB_dbi dbi = mc->mc_dbi;
-		int fixup = NUMKEYS(mp);
-
-		for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
-			if (mc->mc_flags & C_SUB)
-				m3 = &m2->mc_xcursor->mx_cursor;
-			else
-				m3 = m2;
-			if (m3 == mc)
-				continue;
-			if (!(m2->mc_flags & m3->mc_flags & C_INITIALIZED))
-				continue;
-			if (m3->mc_flags & C_SPLITTING)
-				continue;
-			if (new_root) {
-				int k;
-				/* root split */
-				for (k=m3->mc_top; k>=0; k--) {
-					m3->mc_ki[k+1] = m3->mc_ki[k];
-					m3->mc_pg[k+1] = m3->mc_pg[k];
-				}
-				if (m3->mc_ki[0] >= split_indx) {
-					m3->mc_ki[0] = 1;
-				} else {
-					m3->mc_ki[0] = 0;
-				}
-				m3->mc_pg[0] = mc->mc_pg[0];
-				m3->mc_snum++;
-				m3->mc_top++;
-			}
-			if (m3->mc_top >= mc->mc_top && m3->mc_pg[mc->mc_top] == mp) {
-				if (m3->mc_ki[mc->mc_top] >= newindx && !(nflags & MDB_SPLIT_REPLACE))
-					m3->mc_ki[mc->mc_top]++;
-				if (m3->mc_ki[mc->mc_top] >= fixup) {
-					m3->mc_pg[mc->mc_top] = rp;
-					m3->mc_ki[mc->mc_top] -= fixup;
-					m3->mc_ki[ptop] = mn.mc_ki[ptop];
-				}
-			} else if (!did_split && m3->mc_top >= ptop && m3->mc_pg[ptop] == mc->mc_pg[ptop] &&
-				m3->mc_ki[ptop] >= mc->mc_ki[ptop]) {
-				m3->mc_ki[ptop]++;
-			}
-		}
-	}
-	DPRINTF(("mp left: %d, rp left: %d", SIZELEFT(mp), SIZELEFT(rp)));
-
-done:
-	if (copy)					/* tmp page */
-		mdb_page_free(env, copy);
-	if (rc)
-		mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
-	return rc;
-}
-
-int
-mdb_put(MDB_txn *txn, MDB_dbi dbi,
-    MDB_val *key, MDB_val *data, unsigned int flags)
-{
-	MDB_cursor mc;
-	MDB_xcursor mx;
-
-	if (!key || !data || dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
-		return EINVAL;
-
-	if ((flags & (MDB_NOOVERWRITE|MDB_NODUPDATA|MDB_RESERVE|MDB_APPEND|MDB_APPENDDUP)) != flags)
-		return EINVAL;
-
-	mdb_cursor_init(&mc, txn, dbi, &mx);
-	return mdb_cursor_put(&mc, key, data, flags);
-}
-
-#ifndef MDB_WBUF
-#define MDB_WBUF	(1024*1024)
-#endif
-
-	/** State needed for a compacting copy. */
-typedef struct mdb_copy {
-	pthread_mutex_t mc_mutex;
-	pthread_cond_t mc_cond;
-	char *mc_wbuf[2];
-	char *mc_over[2];
-	MDB_env *mc_env;
-	MDB_txn *mc_txn;
-	int mc_wlen[2];
-	int mc_olen[2];
-	pgno_t mc_next_pgno;
-	HANDLE mc_fd;
-	int mc_status;
-	volatile int mc_new;
-	int mc_toggle;
-
-} mdb_copy;
-
-	/** Dedicated writer thread for compacting copy. */
-static THREAD_RET ESECT
-mdb_env_copythr(void *arg)
-{
-	mdb_copy *my = arg;
-	char *ptr;
-	int toggle = 0, wsize, rc;
-#ifdef _WIN32
-	DWORD len;
-#define DO_WRITE(rc, fd, ptr, w2, len)	rc = WriteFile(fd, ptr, w2, &len, NULL)
-#else
-	int len;
-#define DO_WRITE(rc, fd, ptr, w2, len)	len = write(fd, ptr, w2); rc = (len >= 0)
-#endif
-
-	pthread_mutex_lock(&my->mc_mutex);
-	my->mc_new = 0;
-	pthread_cond_signal(&my->mc_cond);
-	for(;;) {
-		while (!my->mc_new)
-			pthread_cond_wait(&my->mc_cond, &my->mc_mutex);
-		if (my->mc_new < 0) {
-			my->mc_new = 0;
-			break;
-		}
-		my->mc_new = 0;
-		wsize = my->mc_wlen[toggle];
-		ptr = my->mc_wbuf[toggle];
-again:
-		while (wsize > 0) {
-			DO_WRITE(rc, my->mc_fd, ptr, wsize, len);
-			if (!rc) {
-				rc = ErrCode();
-				break;
-			} else if (len > 0) {
-				rc = MDB_SUCCESS;
-				ptr += len;
-				wsize -= len;
-				continue;
-			} else {
-				rc = EIO;
-				break;
-			}
-		}
-		if (rc) {
-			my->mc_status = rc;
-			break;
-		}
-		/* If there's an overflow page tail, write it too */
-		if (my->mc_olen[toggle]) {
-			wsize = my->mc_olen[toggle];
-			ptr = my->mc_over[toggle];
-			my->mc_olen[toggle] = 0;
-			goto again;
-		}
-		my->mc_wlen[toggle] = 0;
-		toggle ^= 1;
-		pthread_cond_signal(&my->mc_cond);
-	}
-	pthread_cond_signal(&my->mc_cond);
-	pthread_mutex_unlock(&my->mc_mutex);
-	return (THREAD_RET)0;
-#undef DO_WRITE
-}
-
-	/** Tell the writer thread there's a buffer ready to write */
-static int ESECT
-mdb_env_cthr_toggle(mdb_copy *my, int st)
-{
-	int toggle = my->mc_toggle ^ 1;
-	pthread_mutex_lock(&my->mc_mutex);
-	if (my->mc_status) {
-		pthread_mutex_unlock(&my->mc_mutex);
-		return my->mc_status;
-	}
-	while (my->mc_new == 1)
-		pthread_cond_wait(&my->mc_cond, &my->mc_mutex);
-	my->mc_new = st;
-	my->mc_toggle = toggle;
-	pthread_cond_signal(&my->mc_cond);
-	pthread_mutex_unlock(&my->mc_mutex);
-	return 0;
-}
-
-	/** Depth-first tree traversal for compacting copy. */
-static int ESECT
-mdb_env_cwalk(mdb_copy *my, pgno_t *pg, int flags)
-{
-	MDB_cursor mc;
-	MDB_txn *txn = my->mc_txn;
-	MDB_node *ni;
-	MDB_page *mo, *mp, *leaf;
-	char *buf, *ptr;
-	int rc, toggle;
-	unsigned int i;
-
-	/* Empty DB, nothing to do */
-	if (*pg == P_INVALID)
-		return MDB_SUCCESS;
-
-	mc.mc_snum = 1;
-	mc.mc_top = 0;
-	mc.mc_txn = txn;
-
-	rc = mdb_page_get(my->mc_txn, *pg, &mc.mc_pg[0], NULL);
-	if (rc)
-		return rc;
-	rc = mdb_page_search_root(&mc, NULL, MDB_PS_FIRST);
-	if (rc)
-		return rc;
-
-	/* Make cursor pages writable */
-	buf = ptr = malloc(my->mc_env->me_psize * mc.mc_snum);
-	if (buf == NULL)
-		return ENOMEM;
-
-	for (i=0; i<mc.mc_top; i++) {
-		mdb_page_copy((MDB_page *)ptr, mc.mc_pg[i], my->mc_env->me_psize);
-		mc.mc_pg[i] = (MDB_page *)ptr;
-		ptr += my->mc_env->me_psize;
-	}
-
-	/* This is writable space for a leaf page. Usually not needed. */
-	leaf = (MDB_page *)ptr;
-
-	toggle = my->mc_toggle;
-	while (mc.mc_snum > 0) {
-		unsigned n;
-		mp = mc.mc_pg[mc.mc_top];
-		n = NUMKEYS(mp);
-
-		if (IS_LEAF(mp)) {
-			if (!IS_LEAF2(mp) && !(flags & F_DUPDATA)) {
-				for (i=0; i<n; i++) {
-					ni = NODEPTR(mp, i);
-					if (ni->mn_flags & F_BIGDATA) {
-						MDB_page *omp;
-						pgno_t pg;
-
-						/* Need writable leaf */
-						if (mp != leaf) {
-							mc.mc_pg[mc.mc_top] = leaf;
-							mdb_page_copy(leaf, mp, my->mc_env->me_psize);
-							mp = leaf;
-							ni = NODEPTR(mp, i);
-						}
-
-						memcpy(&pg, NODEDATA(ni), sizeof(pg));
-						rc = mdb_page_get(txn, pg, &omp, NULL);
-						if (rc)
-							goto done;
-						if (my->mc_wlen[toggle] >= MDB_WBUF) {
-							rc = mdb_env_cthr_toggle(my, 1);
-							if (rc)
-								goto done;
-							toggle = my->mc_toggle;
-						}
-						mo = (MDB_page *)(my->mc_wbuf[toggle] + my->mc_wlen[toggle]);
-						memcpy(mo, omp, my->mc_env->me_psize);
-						mo->mp_pgno = my->mc_next_pgno;
-						my->mc_next_pgno += omp->mp_pages;
-						my->mc_wlen[toggle] += my->mc_env->me_psize;
-						if (omp->mp_pages > 1) {
-							my->mc_olen[toggle] = my->mc_env->me_psize * (omp->mp_pages - 1);
-							my->mc_over[toggle] = (char *)omp + my->mc_env->me_psize;
-							rc = mdb_env_cthr_toggle(my, 1);
-							if (rc)
-								goto done;
-							toggle = my->mc_toggle;
-						}
-						memcpy(NODEDATA(ni), &mo->mp_pgno, sizeof(pgno_t));
-					} else if (ni->mn_flags & F_SUBDATA) {
-						MDB_db db;
-
-						/* Need writable leaf */
-						if (mp != leaf) {
-							mc.mc_pg[mc.mc_top] = leaf;
-							mdb_page_copy(leaf, mp, my->mc_env->me_psize);
-							mp = leaf;
-							ni = NODEPTR(mp, i);
-						}
-
-						memcpy(&db, NODEDATA(ni), sizeof(db));
-						my->mc_toggle = toggle;
-						rc = mdb_env_cwalk(my, &db.md_root, ni->mn_flags & F_DUPDATA);
-						if (rc)
-							goto done;
-						toggle = my->mc_toggle;
-						memcpy(NODEDATA(ni), &db, sizeof(db));
-					}
-				}
-			}
-		} else {
-			mc.mc_ki[mc.mc_top]++;
-			if (mc.mc_ki[mc.mc_top] < n) {
-				pgno_t pg;
-again:
-				ni = NODEPTR(mp, mc.mc_ki[mc.mc_top]);
-				pg = NODEPGNO(ni);
-				rc = mdb_page_get(txn, pg, &mp, NULL);
-				if (rc)
-					goto done;
-				mc.mc_top++;
-				mc.mc_snum++;
-				mc.mc_ki[mc.mc_top] = 0;
-				if (IS_BRANCH(mp)) {
-					/* Whenever we advance to a sibling branch page,
-					 * we must proceed all the way down to its first leaf.
-					 */
-					mdb_page_copy(mc.mc_pg[mc.mc_top], mp, my->mc_env->me_psize);
-					goto again;
-				} else
-					mc.mc_pg[mc.mc_top] = mp;
-				continue;
-			}
-		}
-		if (my->mc_wlen[toggle] >= MDB_WBUF) {
-			rc = mdb_env_cthr_toggle(my, 1);
-			if (rc)
-				goto done;
-			toggle = my->mc_toggle;
-		}
-		mo = (MDB_page *)(my->mc_wbuf[toggle] + my->mc_wlen[toggle]);
-		mdb_page_copy(mo, mp, my->mc_env->me_psize);
-		mo->mp_pgno = my->mc_next_pgno++;
-		my->mc_wlen[toggle] += my->mc_env->me_psize;
-		if (mc.mc_top) {
-			/* Update parent if there is one */
-			ni = NODEPTR(mc.mc_pg[mc.mc_top-1], mc.mc_ki[mc.mc_top-1]);
-			SETPGNO(ni, mo->mp_pgno);
-			mdb_cursor_pop(&mc);
-		} else {
-			/* Otherwise we're done */
-			*pg = mo->mp_pgno;
-			break;
-		}
-	}
-done:
-	free(buf);
-	return rc;
-}
-
-	/** Copy environment with compaction. */
-static int ESECT
-mdb_env_copyfd1(MDB_env *env, HANDLE fd)
-{
-	MDB_meta *mm;
-	MDB_page *mp;
-	mdb_copy my;
-	MDB_txn *txn = NULL;
-	pthread_t thr;
-	int rc;
-
-#ifdef _WIN32
-	my.mc_mutex = CreateMutex(NULL, FALSE, NULL);
-	my.mc_cond = CreateEvent(NULL, FALSE, FALSE, NULL);
-	my.mc_wbuf[0] = _aligned_malloc(MDB_WBUF*2, env->me_os_psize);
-	if (my.mc_wbuf[0] == NULL)
-		return errno;
-#else
-	pthread_mutex_init(&my.mc_mutex, NULL);
-	pthread_cond_init(&my.mc_cond, NULL);
-#ifdef HAVE_MEMALIGN
-	my.mc_wbuf[0] = memalign(env->me_os_psize, MDB_WBUF*2);
-	if (my.mc_wbuf[0] == NULL)
-		return errno;
-#else
-	rc = posix_memalign((void **)&my.mc_wbuf[0], env->me_os_psize, MDB_WBUF*2);
-	if (rc)
-		return rc;
-#endif
-#endif
-	memset(my.mc_wbuf[0], 0, MDB_WBUF*2);
-	my.mc_wbuf[1] = my.mc_wbuf[0] + MDB_WBUF;
-	my.mc_wlen[0] = 0;
-	my.mc_wlen[1] = 0;
-	my.mc_olen[0] = 0;
-	my.mc_olen[1] = 0;
-	my.mc_next_pgno = 2;
-	my.mc_status = 0;
-	my.mc_new = 1;
-	my.mc_toggle = 0;
-	my.mc_env = env;
-	my.mc_fd = fd;
-	THREAD_CREATE(thr, mdb_env_copythr, &my);
-
-	rc = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
-	if (rc)
-		return rc;
-
-	mp = (MDB_page *)my.mc_wbuf[0];
-	memset(mp, 0, 2*env->me_psize);
-	mp->mp_pgno = 0;
-	mp->mp_flags = P_META;
-	mm = (MDB_meta *)METADATA(mp);
-	mdb_env_init_meta0(env, mm);
-	mm->mm_address = env->me_metas[0]->mm_address;
-
-	mp = (MDB_page *)(my.mc_wbuf[0] + env->me_psize);
-	mp->mp_pgno = 1;
-	mp->mp_flags = P_META;
-	*(MDB_meta *)METADATA(mp) = *mm;
-	mm = (MDB_meta *)METADATA(mp);
-
-	/* Count the number of free pages, subtract from lastpg to find
-	 * number of active pages
-	 */
-	{
-		MDB_ID freecount = 0;
-		MDB_cursor mc;
-		MDB_val key, data;
-		mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
-		while ((rc = mdb_cursor_get(&mc, &key, &data, MDB_NEXT)) == 0)
-			freecount += *(MDB_ID *)data.mv_data;
-		freecount += txn->mt_dbs[0].md_branch_pages +
-			txn->mt_dbs[0].md_leaf_pages +
-			txn->mt_dbs[0].md_overflow_pages;
-
-		/* Set metapage 1 */
-		mm->mm_last_pg = txn->mt_next_pgno - freecount - 1;
-		mm->mm_dbs[1] = txn->mt_dbs[1];
-		if (mm->mm_last_pg > 1) {
-			mm->mm_dbs[1].md_root = mm->mm_last_pg;
-			mm->mm_txnid = 1;
-		} else {
-			mm->mm_dbs[1].md_root = P_INVALID;
-		}
-	}
-	my.mc_wlen[0] = env->me_psize * 2;
-	my.mc_txn = txn;
-	pthread_mutex_lock(&my.mc_mutex);
-	while(my.mc_new)
-		pthread_cond_wait(&my.mc_cond, &my.mc_mutex);
-	pthread_mutex_unlock(&my.mc_mutex);
-	rc = mdb_env_cwalk(&my, &txn->mt_dbs[1].md_root, 0);
-	if (rc == MDB_SUCCESS && my.mc_wlen[my.mc_toggle])
-		rc = mdb_env_cthr_toggle(&my, 1);
-	mdb_env_cthr_toggle(&my, -1);
-	pthread_mutex_lock(&my.mc_mutex);
-	while(my.mc_new)
-		pthread_cond_wait(&my.mc_cond, &my.mc_mutex);
-	pthread_mutex_unlock(&my.mc_mutex);
-	THREAD_FINISH(thr);
-
-	mdb_txn_abort(txn);
-#ifdef _WIN32
-	CloseHandle(my.mc_cond);
-	CloseHandle(my.mc_mutex);
-	_aligned_free(my.mc_wbuf[0]);
-#else
-	pthread_cond_destroy(&my.mc_cond);
-	pthread_mutex_destroy(&my.mc_mutex);
-	free(my.mc_wbuf[0]);
-#endif
-	return rc;
-}
-
-	/** Copy environment as-is. */
-static int ESECT
-mdb_env_copyfd0(MDB_env *env, HANDLE fd)
-{
-	MDB_txn *txn = NULL;
-	int rc;
-	size_t wsize;
-	char *ptr;
-#ifdef _WIN32
-	DWORD len, w2;
-#define DO_WRITE(rc, fd, ptr, w2, len)	rc = WriteFile(fd, ptr, w2, &len, NULL)
-#else
-	ssize_t len;
-	size_t w2;
-#define DO_WRITE(rc, fd, ptr, w2, len)	len = write(fd, ptr, w2); rc = (len >= 0)
-#endif
-
-	/* Do the lock/unlock of the reader mutex before starting the
-	 * write txn.  Otherwise other read txns could block writers.
-	 */
-	rc = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
-	if (rc)
-		return rc;
-
-	if (env->me_txns) {
-		/* We must start the actual read txn after blocking writers */
-		mdb_txn_reset0(txn, "reset-stage1");
-
-		/* Temporarily block writers until we snapshot the meta pages */
-		LOCK_MUTEX_W(env);
-
-		rc = mdb_txn_renew0(txn);
-		if (rc) {
-			UNLOCK_MUTEX_W(env);
-			goto leave;
-		}
-	}
-
-	wsize = env->me_psize * 2;
-	ptr = env->me_map;
-	w2 = wsize;
-	while (w2 > 0) {
-		DO_WRITE(rc, fd, ptr, w2, len);
-		if (!rc) {
-			rc = ErrCode();
-			break;
-		} else if (len > 0) {
-			rc = MDB_SUCCESS;
-			ptr += len;
-			w2 -= len;
-			continue;
-		} else {
-			/* Non-blocking or async handles are not supported */
-			rc = EIO;
-			break;
-		}
-	}
-	if (env->me_txns)
-		UNLOCK_MUTEX_W(env);
-
-	if (rc)
-		goto leave;
-
-	w2 = txn->mt_next_pgno * env->me_psize;
-	{
-		size_t fsize = 0;
-		if ((rc = mdb_fsize(env->me_fd, &fsize)))
-			goto leave;
-		if (w2 > fsize)
-			w2 = fsize;
-	}
-	wsize = w2 - wsize;
-	while (wsize > 0) {
-		if (wsize > MAX_WRITE)
-			w2 = MAX_WRITE;
-		else
-			w2 = wsize;
-		DO_WRITE(rc, fd, ptr, w2, len);
-		if (!rc) {
-			rc = ErrCode();
-			break;
-		} else if (len > 0) {
-			rc = MDB_SUCCESS;
-			ptr += len;
-			wsize -= len;
-			continue;
-		} else {
-			rc = EIO;
-			break;
-		}
-	}
-
-leave:
-	mdb_txn_abort(txn);
-	return rc;
-}
-
-int ESECT
-mdb_env_copyfd2(MDB_env *env, HANDLE fd, unsigned int flags)
-{
-	if (flags & MDB_CP_COMPACT)
-		return mdb_env_copyfd1(env, fd);
-	else
-		return mdb_env_copyfd0(env, fd);
-}
-
-int ESECT
-mdb_env_copyfd(MDB_env *env, HANDLE fd)
-{
-	return mdb_env_copyfd2(env, fd, 0);
-}
-
-int ESECT
-mdb_env_copy2(MDB_env *env, const char *path, unsigned int flags)
-{
-	int rc, len;
-	char *lpath;
-	HANDLE newfd = INVALID_HANDLE_VALUE;
-
-	if (env->me_flags & MDB_NOSUBDIR) {
-		lpath = (char *)path;
-	} else {
-		len = strlen(path);
-		len += sizeof(DATANAME);
-		lpath = malloc(len);
-		if (!lpath)
-			return ENOMEM;
-		sprintf(lpath, "%s" DATANAME, path);
-	}
-
-	/* The destination path must exist, but the destination file must not.
-	 * We don't want the OS to cache the writes, since the source data is
-	 * already in the OS cache.
-	 */
-#ifdef _WIN32
-	newfd = CreateFile(lpath, GENERIC_WRITE, 0, NULL, CREATE_NEW,
-				FILE_FLAG_NO_BUFFERING|FILE_FLAG_WRITE_THROUGH, NULL);
-#else
-	newfd = open(lpath, O_WRONLY|O_CREAT|O_EXCL, 0666);
-#endif
-	if (newfd == INVALID_HANDLE_VALUE) {
-		rc = ErrCode();
-		goto leave;
-	}
-
-	if (env->me_psize >= env->me_os_psize) {
-#ifdef O_DIRECT
-	/* Set O_DIRECT if the file system supports it */
-	if ((rc = fcntl(newfd, F_GETFL)) != -1)
-		(void) fcntl(newfd, F_SETFL, rc | O_DIRECT);
-#endif
-#ifdef F_NOCACHE	/* __APPLE__ */
-	rc = fcntl(newfd, F_NOCACHE, 1);
-	if (rc) {
-		rc = ErrCode();
-		goto leave;
-	}
-#endif
-	}
-
-	rc = mdb_env_copyfd2(env, newfd, flags);
-
-leave:
-	if (!(env->me_flags & MDB_NOSUBDIR))
-		free(lpath);
-	if (newfd != INVALID_HANDLE_VALUE)
-		if (close(newfd) < 0 && rc == MDB_SUCCESS)
-			rc = ErrCode();
-
-	return rc;
-}
-
-int ESECT
-mdb_env_copy(MDB_env *env, const char *path)
-{
-	return mdb_env_copy2(env, path, 0);
-}
-
-int ESECT
-mdb_env_set_flags(MDB_env *env, unsigned int flag, int onoff)
-{
-	if ((flag & CHANGEABLE) != flag)
-		return EINVAL;
-	if (onoff)
-		env->me_flags |= flag;
-	else
-		env->me_flags &= ~flag;
-	return MDB_SUCCESS;
-}
-
-int ESECT
-mdb_env_get_flags(MDB_env *env, unsigned int *arg)
-{
-	if (!env || !arg)
-		return EINVAL;
-
-	*arg = env->me_flags;
-	return MDB_SUCCESS;
-}
-
-int ESECT
-mdb_env_set_userctx(MDB_env *env, void *ctx)
-{
-	if (!env)
-		return EINVAL;
-	env->me_userctx = ctx;
-	return MDB_SUCCESS;
-}
-
-void * ESECT
-mdb_env_get_userctx(MDB_env *env)
-{
-	return env ? env->me_userctx : NULL;
-}
-
-int ESECT
-mdb_env_set_assert(MDB_env *env, MDB_assert_func *func)
-{
-	if (!env)
-		return EINVAL;
-#ifndef NDEBUG
-	env->me_assert_func = func;
-#endif
-	return MDB_SUCCESS;
-}
-
-int ESECT
-mdb_env_get_path(MDB_env *env, const char **arg)
-{
-	if (!env || !arg)
-		return EINVAL;
-
-	*arg = env->me_path;
-	return MDB_SUCCESS;
-}
-
-int ESECT
-mdb_env_get_fd(MDB_env *env, mdb_filehandle_t *arg)
-{
-	if (!env || !arg)
-		return EINVAL;
-
-	*arg = env->me_fd;
-	return MDB_SUCCESS;
-}
-
-/** Common code for #mdb_stat() and #mdb_env_stat().
- * @param[in] env the environment to operate in.
- * @param[in] db the #MDB_db record containing the stats to return.
- * @param[out] arg the address of an #MDB_stat structure to receive the stats.
- * @return 0, this function always succeeds.
- */
-static int ESECT
-mdb_stat0(MDB_env *env, MDB_db *db, MDB_stat *arg)
-{
-	arg->ms_psize = env->me_psize;
-	arg->ms_depth = db->md_depth;
-	arg->ms_branch_pages = db->md_branch_pages;
-	arg->ms_leaf_pages = db->md_leaf_pages;
-	arg->ms_overflow_pages = db->md_overflow_pages;
-	arg->ms_entries = db->md_entries;
-
-	return MDB_SUCCESS;
-}
-
-int ESECT
-mdb_env_stat(MDB_env *env, MDB_stat *arg)
-{
-	int toggle;
-
-	if (env == NULL || arg == NULL)
-		return EINVAL;
-
-	toggle = mdb_env_pick_meta(env);
-
-	return mdb_stat0(env, &env->me_metas[toggle]->mm_dbs[MAIN_DBI], arg);
-}
-
-int ESECT
-mdb_env_info(MDB_env *env, MDB_envinfo *arg)
-{
-	int toggle;
-
-	if (env == NULL || arg == NULL)
-		return EINVAL;
-
-	toggle = mdb_env_pick_meta(env);
-	arg->me_mapaddr = env->me_metas[toggle]->mm_address;
-	arg->me_mapsize = env->me_mapsize;
-	arg->me_maxreaders = env->me_maxreaders;
-
-	/* me_numreaders may be zero if this process never used any readers. Use
-	 * the shared numreader count if it exists.
-	 */
-	arg->me_numreaders = env->me_txns ? env->me_txns->mti_numreaders : env->me_numreaders;
-
-	arg->me_last_pgno = env->me_metas[toggle]->mm_last_pg;
-	arg->me_last_txnid = env->me_metas[toggle]->mm_txnid;
-	return MDB_SUCCESS;
-}
-
-/** Set the default comparison functions for a database.
- * Called immediately after a database is opened to set the defaults.
- * The user can then override them with #mdb_set_compare() or
- * #mdb_set_dupsort().
- * @param[in] txn A transaction handle returned by #mdb_txn_begin()
- * @param[in] dbi A database handle returned by #mdb_dbi_open()
- */
-static void
-mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi)
-{
-	uint16_t f = txn->mt_dbs[dbi].md_flags;
-
-	txn->mt_dbxs[dbi].md_cmp =
-		(f & MDB_REVERSEKEY) ? mdb_cmp_memnr :
-		(f & MDB_INTEGERKEY) ? mdb_cmp_cint  : mdb_cmp_memn;
-
-	txn->mt_dbxs[dbi].md_dcmp =
-		!(f & MDB_DUPSORT) ? 0 :
-		((f & MDB_INTEGERDUP)
-		 ? ((f & MDB_DUPFIXED)   ? mdb_cmp_int   : mdb_cmp_cint)
-		 : ((f & MDB_REVERSEDUP) ? mdb_cmp_memnr : mdb_cmp_memn));
-}
-
-int mdb_dbi_open(MDB_txn *txn, const char *name, unsigned int flags, MDB_dbi *dbi)
-{
-	MDB_val key, data;
-	MDB_dbi i;
-	MDB_cursor mc;
-	MDB_db dummy;
-	int rc, dbflag, exact;
-	unsigned int unused = 0, seq;
-	size_t len;
-
-	if (txn->mt_dbxs[FREE_DBI].md_cmp == NULL) {
-		mdb_default_cmp(txn, FREE_DBI);
-	}
-
-	if ((flags & VALID_FLAGS) != flags)
-		return EINVAL;
-	if (txn->mt_flags & MDB_TXN_ERROR)
-		return MDB_BAD_TXN;
-
-	/* main DB? */
-	if (!name) {
-		*dbi = MAIN_DBI;
-		if (flags & PERSISTENT_FLAGS) {
-			uint16_t f2 = flags & PERSISTENT_FLAGS;
-			/* make sure flag changes get committed */
-			if ((txn->mt_dbs[MAIN_DBI].md_flags | f2) != txn->mt_dbs[MAIN_DBI].md_flags) {
-				txn->mt_dbs[MAIN_DBI].md_flags |= f2;
-				txn->mt_flags |= MDB_TXN_DIRTY;
-			}
-		}
-		mdb_default_cmp(txn, MAIN_DBI);
-		return MDB_SUCCESS;
-	}
-
-	if (txn->mt_dbxs[MAIN_DBI].md_cmp == NULL) {
-		mdb_default_cmp(txn, MAIN_DBI);
-	}
-
-	/* Is the DB already open? */
-	len = strlen(name);
-	for (i=2; i<txn->mt_numdbs; i++) {
-		if (!txn->mt_dbxs[i].md_name.mv_size) {
-			/* Remember this free slot */
-			if (!unused) unused = i;
-			continue;
-		}
-		if (len == txn->mt_dbxs[i].md_name.mv_size &&
-			!strncmp(name, txn->mt_dbxs[i].md_name.mv_data, len)) {
-			*dbi = i;
-			return MDB_SUCCESS;
-		}
-	}
-
-	/* If no free slot and max hit, fail */
-	if (!unused && txn->mt_numdbs >= txn->mt_env->me_maxdbs)
-		return MDB_DBS_FULL;
-
-	/* Cannot mix named databases with some mainDB flags */
-	if (txn->mt_dbs[MAIN_DBI].md_flags & (MDB_DUPSORT|MDB_INTEGERKEY))
-		return (flags & MDB_CREATE) ? MDB_INCOMPATIBLE : MDB_NOTFOUND;
-
-	/* Find the DB info */
-	dbflag = DB_NEW|DB_VALID;
-	exact = 0;
-	key.mv_size = len;
-	key.mv_data = (void *)name;
-	mdb_cursor_init(&mc, txn, MAIN_DBI, NULL);
-	rc = mdb_cursor_set(&mc, &key, &data, MDB_SET, &exact);
-	if (rc == MDB_SUCCESS) {
-		/* make sure this is actually a DB */
-		MDB_node *node = NODEPTR(mc.mc_pg[mc.mc_top], mc.mc_ki[mc.mc_top]);
-		if (!(node->mn_flags & F_SUBDATA))
-			return MDB_INCOMPATIBLE;
-	} else if (rc == MDB_NOTFOUND && (flags & MDB_CREATE)) {
-		/* Create if requested */
-		data.mv_size = sizeof(MDB_db);
-		data.mv_data = &dummy;
-		memset(&dummy, 0, sizeof(dummy));
-		dummy.md_root = P_INVALID;
-		dummy.md_flags = flags & PERSISTENT_FLAGS;
-		rc = mdb_cursor_put(&mc, &key, &data, F_SUBDATA);
-		dbflag |= DB_DIRTY;
-	}
-
-	/* OK, got info, add to table */
-	if (rc == MDB_SUCCESS) {
-		unsigned int slot = unused ? unused : txn->mt_numdbs;
-		txn->mt_dbxs[slot].md_name.mv_data = strdup(name);
-		txn->mt_dbxs[slot].md_name.mv_size = len;
-		txn->mt_dbxs[slot].md_rel = NULL;
-		txn->mt_dbflags[slot] = dbflag;
-		/* txn-> and env-> are the same in read txns, use
-		 * tmp variable to avoid undefined assignment
-		 */
-		seq = ++txn->mt_env->me_dbiseqs[slot];
-		txn->mt_dbiseqs[slot] = seq;
-
-		memcpy(&txn->mt_dbs[slot], data.mv_data, sizeof(MDB_db));
-		*dbi = slot;
-		mdb_default_cmp(txn, slot);
-		if (!unused) {
-			txn->mt_numdbs++;
-		}
-	}
-
-	return rc;
-}
-
-int mdb_stat(MDB_txn *txn, MDB_dbi dbi, MDB_stat *arg)
-{
-	if (!arg || !TXN_DBI_EXIST(txn, dbi))
-		return EINVAL;
-
-	if (txn->mt_flags & MDB_TXN_ERROR)
-		return MDB_BAD_TXN;
-
-	if (txn->mt_dbflags[dbi] & DB_STALE) {
-		MDB_cursor mc;
-		MDB_xcursor mx;
-		/* Stale, must read the DB's root. cursor_init does it for us. */
-		mdb_cursor_init(&mc, txn, dbi, &mx);
-	}
-	return mdb_stat0(txn->mt_env, &txn->mt_dbs[dbi], arg);
-}
-
-void mdb_dbi_close(MDB_env *env, MDB_dbi dbi)
-{
-	char *ptr;
-	if (dbi <= MAIN_DBI || dbi >= env->me_maxdbs)
-		return;
-	ptr = env->me_dbxs[dbi].md_name.mv_data;
-	/* If there was no name, this was already closed */
-	if (ptr) {
-		env->me_dbxs[dbi].md_name.mv_data = NULL;
-		env->me_dbxs[dbi].md_name.mv_size = 0;
-		env->me_dbflags[dbi] = 0;
-		env->me_dbiseqs[dbi]++;
-		free(ptr);
-	}
-}
-
-int mdb_dbi_flags(MDB_txn *txn, MDB_dbi dbi, unsigned int *flags)
-{
-	/* We could return the flags for the FREE_DBI too but what's the point? */
-	if (dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
-		return EINVAL;
-	*flags = txn->mt_dbs[dbi].md_flags & PERSISTENT_FLAGS;
-	return MDB_SUCCESS;
-}
-
-/** Add all the DB's pages to the free list.
- * @param[in] mc Cursor on the DB to free.
- * @param[in] subs non-Zero to check for sub-DBs in this DB.
- * @return 0 on success, non-zero on failure.
- */
-static int
-mdb_drop0(MDB_cursor *mc, int subs)
-{
-	int rc;
-
-	rc = mdb_page_search(mc, NULL, MDB_PS_FIRST);
-	if (rc == MDB_SUCCESS) {
-		MDB_txn *txn = mc->mc_txn;
-		MDB_node *ni;
-		MDB_cursor mx;
-		unsigned int i;
-
-		/* LEAF2 pages have no nodes, cannot have sub-DBs */
-		if (IS_LEAF2(mc->mc_pg[mc->mc_top]))
-			mdb_cursor_pop(mc);
-
-		mdb_cursor_copy(mc, &mx);
-		while (mc->mc_snum > 0) {
-			MDB_page *mp = mc->mc_pg[mc->mc_top];
-			unsigned n = NUMKEYS(mp);
-			if (IS_LEAF(mp)) {
-				for (i=0; i<n; i++) {
-					ni = NODEPTR(mp, i);
-					if (ni->mn_flags & F_BIGDATA) {
-						MDB_page *omp;
-						pgno_t pg;
-						memcpy(&pg, NODEDATA(ni), sizeof(pg));
-						rc = mdb_page_get(txn, pg, &omp, NULL);
-						if (rc != 0)
-							goto done;
-						mdb_cassert(mc, IS_OVERFLOW(omp));
-						rc = mdb_midl_append_range(&txn->mt_free_pgs,
-							pg, omp->mp_pages);
-						if (rc)
-							goto done;
-					} else if (subs && (ni->mn_flags & F_SUBDATA)) {
-						mdb_xcursor_init1(mc, ni);
-						rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0);
-						if (rc)
-							goto done;
-					}
-				}
-			} else {
-				if ((rc = mdb_midl_need(&txn->mt_free_pgs, n)) != 0)
-					goto done;
-				for (i=0; i<n; i++) {
-					pgno_t pg;
-					ni = NODEPTR(mp, i);
-					pg = NODEPGNO(ni);
-					/* free it */
-					mdb_midl_xappend(txn->mt_free_pgs, pg);
-				}
-			}
-			if (!mc->mc_top)
-				break;
-			mc->mc_ki[mc->mc_top] = i;
-			rc = mdb_cursor_sibling(mc, 1);
-			if (rc) {
-				if (rc != MDB_NOTFOUND)
-					goto done;
-				/* no more siblings, go back to beginning
-				 * of previous level.
-				 */
-				mdb_cursor_pop(mc);
-				mc->mc_ki[0] = 0;
-				for (i=1; i<mc->mc_snum; i++) {
-					mc->mc_ki[i] = 0;
-					mc->mc_pg[i] = mx.mc_pg[i];
-				}
-			}
-		}
-		/* free it */
-		rc = mdb_midl_append(&txn->mt_free_pgs, mc->mc_db->md_root);
-done:
-		if (rc)
-			txn->mt_flags |= MDB_TXN_ERROR;
-	} else if (rc == MDB_NOTFOUND) {
-		rc = MDB_SUCCESS;
-	}
-	return rc;
-}
-
-int mdb_drop(MDB_txn *txn, MDB_dbi dbi, int del)
-{
-	MDB_cursor *mc, *m2;
-	int rc;
-
-	if ((unsigned)del > 1 || dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
-		return EINVAL;
-
-	if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))
-		return EACCES;
-
-	if (dbi > MAIN_DBI && TXN_DBI_CHANGED(txn, dbi))
-		return MDB_BAD_DBI;
-
-	rc = mdb_cursor_open(txn, dbi, &mc);
-	if (rc)
-		return rc;
-
-	rc = mdb_drop0(mc, mc->mc_db->md_flags & MDB_DUPSORT);
-	/* Invalidate the dropped DB's cursors */
-	for (m2 = txn->mt_cursors[dbi]; m2; m2 = m2->mc_next)
-		m2->mc_flags &= ~(C_INITIALIZED|C_EOF);
-	if (rc)
-		goto leave;
-
-	/* Can't delete the main DB */
-	if (del && dbi > MAIN_DBI) {
-		rc = mdb_del0(txn, MAIN_DBI, &mc->mc_dbx->md_name, NULL, 0);
-		if (!rc) {
-			txn->mt_dbflags[dbi] = DB_STALE;
-			mdb_dbi_close(txn->mt_env, dbi);
-		} else {
-			txn->mt_flags |= MDB_TXN_ERROR;
-		}
-	} else {
-		/* reset the DB record, mark it dirty */
-		txn->mt_dbflags[dbi] |= DB_DIRTY;
-		txn->mt_dbs[dbi].md_depth = 0;
-		txn->mt_dbs[dbi].md_branch_pages = 0;
-		txn->mt_dbs[dbi].md_leaf_pages = 0;
-		txn->mt_dbs[dbi].md_overflow_pages = 0;
-		txn->mt_dbs[dbi].md_entries = 0;
-		txn->mt_dbs[dbi].md_root = P_INVALID;
-
-		txn->mt_flags |= MDB_TXN_DIRTY;
-	}
-leave:
-	mdb_cursor_close(mc);
-	return rc;
-}
-
-int mdb_set_compare(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)
-{
-	if (dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
-		return EINVAL;
-
-	txn->mt_dbxs[dbi].md_cmp = cmp;
-	return MDB_SUCCESS;
-}
-
-int mdb_set_dupsort(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)
-{
-	if (dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
-		return EINVAL;
-
-	txn->mt_dbxs[dbi].md_dcmp = cmp;
-	return MDB_SUCCESS;
-}
-
-int mdb_set_relfunc(MDB_txn *txn, MDB_dbi dbi, MDB_rel_func *rel)
-{
-	if (dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
-		return EINVAL;
-
-	txn->mt_dbxs[dbi].md_rel = rel;
-	return MDB_SUCCESS;
-}
-
-int mdb_set_relctx(MDB_txn *txn, MDB_dbi dbi, void *ctx)
-{
-	if (dbi == FREE_DBI || !TXN_DBI_EXIST(txn, dbi))
-		return EINVAL;
-
-	txn->mt_dbxs[dbi].md_relctx = ctx;
-	return MDB_SUCCESS;
-}
-
-int ESECT
-mdb_env_get_maxkeysize(MDB_env *env)
-{
-	return ENV_MAXKEY(env);
-}
-
-int ESECT
-mdb_reader_list(MDB_env *env, MDB_msg_func *func, void *ctx)
-{
-	unsigned int i, rdrs;
-	MDB_reader *mr;
-	char buf[64];
-	int rc = 0, first = 1;
-
-	if (!env || !func)
-		return -1;
-	if (!env->me_txns) {
-		return func("(no reader locks)\n", ctx);
-	}
-	rdrs = env->me_txns->mti_numreaders;
-	mr = env->me_txns->mti_readers;
-	for (i=0; i<rdrs; i++) {
-		if (mr[i].mr_pid) {
-			txnid_t	txnid = mr[i].mr_txnid;
-			sprintf(buf, txnid == (txnid_t)-1 ?
-				"%10d %"Z"x -\n" : "%10d %"Z"x %"Z"u\n",
-				(int)mr[i].mr_pid, (size_t)mr[i].mr_tid, txnid);
-			if (first) {
-				first = 0;
-				rc = func("    pid     thread     txnid\n", ctx);
-				if (rc < 0)
-					break;
-			}
-			rc = func(buf, ctx);
-			if (rc < 0)
-				break;
-		}
-	}
-	if (first) {
-		rc = func("(no active readers)\n", ctx);
-	}
-	return rc;
-}
-
-/** Insert pid into list if not already present.
- * return -1 if already present.
- */
-static int ESECT
-mdb_pid_insert(MDB_PID_T *ids, MDB_PID_T pid)
-{
-	/* binary search of pid in list */
-	unsigned base = 0;
-	unsigned cursor = 1;
-	int val = 0;
-	unsigned n = ids[0];
-
-	while( 0 < n ) {
-		unsigned pivot = n >> 1;
-		cursor = base + pivot + 1;
-		val = pid - ids[cursor];
-
-		if( val < 0 ) {
-			n = pivot;
-
-		} else if ( val > 0 ) {
-			base = cursor;
-			n -= pivot + 1;
-
-		} else {
-			/* found, so it's a duplicate */
-			return -1;
-		}
-	}
-
-	if( val > 0 ) {
-		++cursor;
-	}
-	ids[0]++;
-	for (n = ids[0]; n > cursor; n--)
-		ids[n] = ids[n-1];
-	ids[n] = pid;
-	return 0;
-}
-
-int ESECT
-mdb_reader_check(MDB_env *env, int *dead)
-{
-	unsigned int i, j, rdrs;
-	MDB_reader *mr;
-	MDB_PID_T *pids, pid;
-	int count = 0;
-
-	if (!env)
-		return EINVAL;
-	if (dead)
-		*dead = 0;
-	if (!env->me_txns)
-		return MDB_SUCCESS;
-	rdrs = env->me_txns->mti_numreaders;
-	pids = malloc((rdrs+1) * sizeof(MDB_PID_T));
-	if (!pids)
-		return ENOMEM;
-	pids[0] = 0;
-	mr = env->me_txns->mti_readers;
-	for (i=0; i<rdrs; i++) {
-		if (mr[i].mr_pid && mr[i].mr_pid != env->me_pid) {
-			pid = mr[i].mr_pid;
-			if (mdb_pid_insert(pids, pid) == 0) {
-				if (!mdb_reader_pid(env, Pidcheck, pid)) {
-					LOCK_MUTEX_R(env);
-					/* Recheck, a new process may have reused pid */
-					if (!mdb_reader_pid(env, Pidcheck, pid)) {
-						for (j=i; j<rdrs; j++)
-							if (mr[j].mr_pid == pid) {
-								DPRINTF(("clear stale reader pid %u txn %"Z"d",
-									(unsigned) pid, mr[j].mr_txnid));
-								mr[j].mr_pid = 0;
-								count++;
-							}
-					}
-					UNLOCK_MUTEX_R(env);
-				}
-			}
-		}
-	}
-	free(pids);
-	if (dead)
-		*dead = count;
-	return MDB_SUCCESS;
-}
-/** @} */
diff --git a/external/db_drivers/liblmdb64/mdb_copy.1 b/external/db_drivers/liblmdb64/mdb_copy.1
deleted file mode 100644
index 1e2a97694..000000000
--- a/external/db_drivers/liblmdb64/mdb_copy.1
+++ /dev/null
@@ -1,54 +0,0 @@
-.TH MDB_COPY 1 "2014/06/20" "LMDB 0.9.14"
-.\" Copyright 2012-2015 Howard Chu, Symas Corp. All Rights Reserved.
-.\" Copying restrictions apply.  See COPYRIGHT/LICENSE.
-.SH NAME
-mdb_copy \- LMDB environment copy tool
-.SH SYNOPSIS
-.B mdb_copy
-[\c
-.BR \-V ]
-[\c
-.BR \-c ]
-[\c
-.BR \-n ]
-.B srcpath
-[\c
-.BR dstpath ]
-.SH DESCRIPTION
-The
-.B mdb_copy
-utility copies an LMDB environment. The environment can
-be copied regardless of whether it is currently in use.
-No lockfile is created, since it gets recreated at need.
-
-If
-.I dstpath
-is specified it must be the path of an empty directory
-for storing the backup. Otherwise, the backup will be
-written to stdout.
-
-.SH OPTIONS
-.TP
-.BR \-V
-Write the library version number to the standard output, and exit.
-.TP
-.BR \-c
-Compact while copying. Only current data pages will be copied; freed
-or unused pages will be omitted from the copy. This option will
-slow down the backup process as it is more CPU-intensive.
-.TP
-.BR \-n
-Open LDMB environment(s) which do not use subdirectories.
-
-.SH DIAGNOSTICS
-Exit status is zero if no errors occur.
-Errors result in a non-zero exit status and
-a diagnostic message being written to standard error.
-.SH CAVEATS
-This utility can trigger significant file size growth if run
-in parallel with write transactions, because pages which they
-free during copying cannot be reused until the copy is done.
-.SH "SEE ALSO"
-.BR mdb_stat (1)
-.SH AUTHOR
-Howard Chu of Symas Corporation <http://www.symas.com>
diff --git a/external/db_drivers/liblmdb64/mdb_copy.c b/external/db_drivers/liblmdb64/mdb_copy.c
deleted file mode 100644
index f37ccbcc2..000000000
--- a/external/db_drivers/liblmdb64/mdb_copy.c
+++ /dev/null
@@ -1,82 +0,0 @@
-/* mdb_copy.c - memory-mapped database backup tool */
-/*
- * Copyright 2012-2015 Howard Chu, Symas Corp.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted only as authorized by the OpenLDAP
- * Public License.
- *
- * A copy of this license is available in the file LICENSE in the
- * top-level directory of the distribution or, alternatively, at
- * <http://www.OpenLDAP.org/license.html>.
- */
-#ifdef _WIN32
-#include <windows.h>
-#define	MDB_STDOUT	GetStdHandle(STD_OUTPUT_HANDLE)
-#else
-#define	MDB_STDOUT	1
-#endif
-#include <stdio.h>
-#include <stdlib.h>
-#include <signal.h>
-#include "lmdb.h"
-
-static void
-sighandle(int sig)
-{
-}
-
-int main(int argc,char * argv[])
-{
-	int rc;
-	MDB_env *env;
-	const char *progname = argv[0], *act;
-	unsigned flags = MDB_RDONLY;
-	unsigned cpflags = 0;
-
-	for (; argc > 1 && argv[1][0] == '-'; argc--, argv++) {
-		if (argv[1][1] == 'n' && argv[1][2] == '\0')
-			flags |= MDB_NOSUBDIR;
-		else if (argv[1][1] == 'c' && argv[1][2] == '\0')
-			cpflags |= MDB_CP_COMPACT;
-		else if (argv[1][1] == 'V' && argv[1][2] == '\0') {
-			printf("%s\n", MDB_VERSION_STRING);
-			exit(0);
-		} else
-			argc = 0;
-	}
-
-	if (argc<2 || argc>3) {
-		fprintf(stderr, "usage: %s [-V] [-c] [-n] srcpath [dstpath]\n", progname);
-		exit(EXIT_FAILURE);
-	}
-
-#ifdef SIGPIPE
-	signal(SIGPIPE, sighandle);
-#endif
-#ifdef SIGHUP
-	signal(SIGHUP, sighandle);
-#endif
-	signal(SIGINT, sighandle);
-	signal(SIGTERM, sighandle);
-
-	act = "opening environment";
-	rc = mdb_env_create(&env);
-	if (rc == MDB_SUCCESS) {
-		rc = mdb_env_open(env, argv[1], flags, 0600);
-	}
-	if (rc == MDB_SUCCESS) {
-		act = "copying";
-		if (argc == 2)
-			rc = mdb_env_copyfd2(env, MDB_STDOUT, cpflags);
-		else
-			rc = mdb_env_copy2(env, argv[2], cpflags);
-	}
-	if (rc)
-		fprintf(stderr, "%s: %s failed, error %d (%s)\n",
-			progname, act, rc, mdb_strerror(rc));
-	mdb_env_close(env);
-
-	return rc ? EXIT_FAILURE : EXIT_SUCCESS;
-}
diff --git a/external/db_drivers/liblmdb64/mdb_dump.1 b/external/db_drivers/liblmdb64/mdb_dump.1
deleted file mode 100644
index dd545049b..000000000
--- a/external/db_drivers/liblmdb64/mdb_dump.1
+++ /dev/null
@@ -1,75 +0,0 @@
-.TH MDB_DUMP 1 "2014/06/20" "LMDB 0.9.14"
-.\" Copyright 2014-2015 Howard Chu, Symas Corp. All Rights Reserved.
-.\" Copying restrictions apply.  See COPYRIGHT/LICENSE.
-.SH NAME
-mdb_dump \- LMDB environment export tool
-.SH SYNOPSIS
-.B mdb_dump
-.BR \ envpath
-[\c
-.BR \-V ]
-[\c
-.BI \-f \ file\fR]
-[\c
-.BR \-l ]
-[\c
-.BR \-n ]
-[\c
-.BR \-p ]
-[\c
-.BR \-a \ |
-.BI \-s \ subdb\fR]
-.SH DESCRIPTION
-The
-.B mdb_dump
-utility reads a database and writes its contents to the
-standard output using a portable flat-text format
-understood by the
-.BR mdb_load (1)
-utility.
-.SH OPTIONS
-.TP
-.BR \-V
-Write the library version number to the standard output, and exit.
-.TP
-.BR \-f \ file
-Write to the specified file instead of to the standard output.
-.TP
-.BR \-l
-List the databases stored in the environment. Just the
-names will be listed, no data will be output.
-.TP
-.BR \-n
-Dump an LMDB database which does not use subdirectories.
-.TP
-.BR \-p
-If characters in either the key or data items are printing characters (as
-defined by isprint(3)), output them directly. This option permits users to
-use standard text editors and tools to modify the contents of databases.
-
-Note: different systems may have different notions about what characters
-are considered printing characters, and databases dumped in this manner may
-be less portable to external systems. 
-.TP
-.BR \-a
-Dump all of the subdatabases in the environment.
-.TP
-.BR \-s \ subdb
-Dump a specific subdatabase. If no database is specified, only the main database is dumped.
-.SH DIAGNOSTICS
-Exit status is zero if no errors occur.
-Errors result in a non-zero exit status and
-a diagnostic message being written to standard error.
-
-Dumping and reloading databases that use user-defined comparison functions
-will result in new databases that use the default comparison functions.
-\fBIn this case it is quite likely that the reloaded database will be
-damaged beyond repair permitting neither record storage nor retrieval.\fP
-
-The only available workaround is to modify the source for the
-.BR mdb_load (1)
-utility to load the database using the correct comparison functions.
-.SH "SEE ALSO"
-.BR mdb_load (1)
-.SH AUTHOR
-Howard Chu of Symas Corporation <http://www.symas.com>
diff --git a/external/db_drivers/liblmdb64/mdb_dump.c b/external/db_drivers/liblmdb64/mdb_dump.c
deleted file mode 100644
index 7202d865b..000000000
--- a/external/db_drivers/liblmdb64/mdb_dump.c
+++ /dev/null
@@ -1,317 +0,0 @@
-/* mdb_dump.c - memory-mapped database dump tool */
-/*
- * Copyright 2011-2015 Howard Chu, Symas Corp.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted only as authorized by the OpenLDAP
- * Public License.
- *
- * A copy of this license is available in the file LICENSE in the
- * top-level directory of the distribution or, alternatively, at
- * <http://www.OpenLDAP.org/license.html>.
- */
-#include <stdio.h>
-#include <errno.h>
-#include <stdlib.h>
-#include <string.h>
-#include <ctype.h>
-#include <unistd.h>
-#include <signal.h>
-#include "lmdb.h"
-
-#ifdef _WIN32
-#define Z	"I"
-#else
-#define Z	"z"
-#endif
-
-#define PRINT	1
-static int mode;
-
-typedef struct flagbit {
-	int bit;
-	char *name;
-} flagbit;
-
-flagbit dbflags[] = {
-	{ MDB_REVERSEKEY, "reversekey" },
-	{ MDB_DUPSORT, "dupsort" },
-	{ MDB_INTEGERKEY, "integerkey" },
-	{ MDB_DUPFIXED, "dupfixed" },
-	{ MDB_INTEGERDUP, "integerdup" },
-	{ MDB_REVERSEDUP, "reversedup" },
-	{ 0, NULL }
-};
-
-static volatile sig_atomic_t gotsig;
-
-static void dumpsig( int sig )
-{
-	gotsig=1;
-}
-
-static const char hexc[] = "0123456789abcdef";
-
-static void hex(unsigned char c)
-{
-	putchar(hexc[c >> 4]);
-	putchar(hexc[c & 0xf]);
-}
-
-static void text(MDB_val *v)
-{
-	unsigned char *c, *end;
-
-	putchar(' ');
-	c = v->mv_data;
-	end = c + v->mv_size;
-	while (c < end) {
-		if (isprint(*c)) {
-			putchar(*c);
-		} else {
-			putchar('\\');
-			hex(*c);
-		}
-		c++;
-	}
-	putchar('\n');
-}
-
-static void byte(MDB_val *v)
-{
-	unsigned char *c, *end;
-
-	putchar(' ');
-	c = v->mv_data;
-	end = c + v->mv_size;
-	while (c < end) {
-		hex(*c++);
-	}
-	putchar('\n');
-}
-
-/* Dump in BDB-compatible format */
-static int dumpit(MDB_txn *txn, MDB_dbi dbi, char *name)
-{
-	MDB_cursor *mc;
-	MDB_stat ms;
-	MDB_val key, data;
-	MDB_envinfo info;
-	unsigned int flags;
-	int rc, i;
-
-	rc = mdb_dbi_flags(txn, dbi, &flags);
-	if (rc) return rc;
-
-	rc = mdb_stat(txn, dbi, &ms);
-	if (rc) return rc;
-
-	rc = mdb_env_info(mdb_txn_env(txn), &info);
-	if (rc) return rc;
-
-	printf("VERSION=3\n");
-	printf("format=%s\n", mode & PRINT ? "print" : "bytevalue");
-	if (name)
-		printf("database=%s\n", name);
-	printf("type=btree\n");
-	printf("mapsize=%" Z "u\n", info.me_mapsize);
-	if (info.me_mapaddr)
-		printf("mapaddr=%p\n", info.me_mapaddr);
-	printf("maxreaders=%u\n", info.me_maxreaders);
-
-	if (flags & MDB_DUPSORT)
-		printf("duplicates=1\n");
-
-	for (i=0; dbflags[i].bit; i++)
-		if (flags & dbflags[i].bit)
-			printf("%s=1\n", dbflags[i].name);
-
-	printf("db_pagesize=%d\n", ms.ms_psize);
-	printf("HEADER=END\n");
-
-	rc = mdb_cursor_open(txn, dbi, &mc);
-	if (rc) return rc;
-
-	while ((rc = mdb_cursor_get(mc, &key, &data, MDB_NEXT) == MDB_SUCCESS)) {
-		if (gotsig) {
-			rc = EINTR;
-			break;
-		}
-		if (mode & PRINT) {
-			text(&key);
-			text(&data);
-		} else {
-			byte(&key);
-			byte(&data);
-		}
-	}
-	printf("DATA=END\n");
-	if (rc == MDB_NOTFOUND)
-		rc = MDB_SUCCESS;
-
-	return rc;
-}
-
-static void usage(char *prog)
-{
-	fprintf(stderr, "usage: %s dbpath [-V] [-f output] [-l] [-n] [-p] [-a|-s subdb]\n", prog);
-	exit(EXIT_FAILURE);
-}
-
-int main(int argc, char *argv[])
-{
-	int i, rc;
-	MDB_env *env;
-	MDB_txn *txn;
-	MDB_dbi dbi;
-	char *prog = argv[0];
-	char *envname;
-	char *subname = NULL;
-	int alldbs = 0, envflags = 0, list = 0;
-
-	if (argc < 2) {
-		usage(prog);
-	}
-
-	/* -a: dump main DB and all subDBs
-	 * -s: dump only the named subDB
-	 * -n: use NOSUBDIR flag on env_open
-	 * -p: use printable characters
-	 * -f: write to file instead of stdout
-	 * -V: print version and exit
-	 * (default) dump only the main DB
-	 */
-	while ((i = getopt(argc, argv, "af:lnps:V")) != EOF) {
-		switch(i) {
-		case 'V':
-			printf("%s\n", MDB_VERSION_STRING);
-			exit(0);
-			break;
-		case 'l':
-			list = 1;
-			/*FALLTHROUGH*/;
-		case 'a':
-			if (subname)
-				usage(prog);
-			alldbs++;
-			break;
-		case 'f':
-			if (freopen(optarg, "w", stdout) == NULL) {
-				fprintf(stderr, "%s: %s: reopen: %s\n",
-					prog, optarg, strerror(errno));
-				exit(EXIT_FAILURE);
-			}
-			break;
-		case 'n':
-			envflags |= MDB_NOSUBDIR;
-			break;
-		case 'p':
-			mode |= PRINT;
-			break;
-		case 's':
-			if (alldbs)
-				usage(prog);
-			subname = optarg;
-			break;
-		default:
-			usage(prog);
-		}
-	}
-
-	if (optind != argc - 1)
-		usage(prog);
-
-#ifdef SIGPIPE
-	signal(SIGPIPE, dumpsig);
-#endif
-#ifdef SIGHUP
-	signal(SIGHUP, dumpsig);
-#endif
-	signal(SIGINT, dumpsig);
-	signal(SIGTERM, dumpsig);
-
-	envname = argv[optind];
-	rc = mdb_env_create(&env);
-	if (rc) {
-		fprintf(stderr, "mdb_env_create failed, error %d %s\n", rc, mdb_strerror(rc));
-		return EXIT_FAILURE;
-	}
-
-	if (alldbs || subname) {
-		mdb_env_set_maxdbs(env, 2);
-	}
-
-	rc = mdb_env_open(env, envname, envflags | MDB_RDONLY, 0664);
-	if (rc) {
-		fprintf(stderr, "mdb_env_open failed, error %d %s\n", rc, mdb_strerror(rc));
-		goto env_close;
-	}
-
-	rc = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
-	if (rc) {
-		fprintf(stderr, "mdb_txn_begin failed, error %d %s\n", rc, mdb_strerror(rc));
-		goto env_close;
-	}
-
-	rc = mdb_open(txn, subname, 0, &dbi);
-	if (rc) {
-		fprintf(stderr, "mdb_open failed, error %d %s\n", rc, mdb_strerror(rc));
-		goto txn_abort;
-	}
-
-	if (alldbs) {
-		MDB_cursor *cursor;
-		MDB_val key;
-		int count = 0;
-
-		rc = mdb_cursor_open(txn, dbi, &cursor);
-		if (rc) {
-			fprintf(stderr, "mdb_cursor_open failed, error %d %s\n", rc, mdb_strerror(rc));
-			goto txn_abort;
-		}
-		while ((rc = mdb_cursor_get(cursor, &key, NULL, MDB_NEXT_NODUP)) == 0) {
-			char *str;
-			MDB_dbi db2;
-			if (memchr(key.mv_data, '\0', key.mv_size))
-				continue;
-			count++;
-			str = malloc(key.mv_size+1);
-			memcpy(str, key.mv_data, key.mv_size);
-			str[key.mv_size] = '\0';
-			rc = mdb_open(txn, str, 0, &db2);
-			if (rc == MDB_SUCCESS) {
-				if (list) {
-					printf("%s\n", str);
-					list++;
-				} else {
-					rc = dumpit(txn, db2, str);
-					if (rc)
-						break;
-				}
-				mdb_close(env, db2);
-			}
-			free(str);
-			if (rc) continue;
-		}
-		mdb_cursor_close(cursor);
-		if (!count) {
-			fprintf(stderr, "%s: %s does not contain multiple databases\n", prog, envname);
-			rc = MDB_NOTFOUND;
-		} else if (rc == MDB_NOTFOUND) {
-			rc = MDB_SUCCESS;
-		}
-	} else {
-		rc = dumpit(txn, dbi, subname);
-	}
-	if (rc && rc != MDB_NOTFOUND)
-		fprintf(stderr, "%s: %s: %s\n", prog, envname, mdb_strerror(rc));
-
-	mdb_close(env, dbi);
-txn_abort:
-	mdb_txn_abort(txn);
-env_close:
-	mdb_env_close(env);
-
-	return rc ? EXIT_FAILURE : EXIT_SUCCESS;
-}
diff --git a/external/db_drivers/liblmdb64/mdb_load.1 b/external/db_drivers/liblmdb64/mdb_load.1
deleted file mode 100644
index 511ec552b..000000000
--- a/external/db_drivers/liblmdb64/mdb_load.1
+++ /dev/null
@@ -1,77 +0,0 @@
-.TH MDB_LOAD 1 "2014/06/20" "LMDB 0.9.14"
-.\" Copyright 2014-2015 Howard Chu, Symas Corp. All Rights Reserved.
-.\" Copying restrictions apply.  See COPYRIGHT/LICENSE.
-.SH NAME
-mdb_load \- LMDB environment import tool
-.SH SYNOPSIS
-.B mdb_load
-.BR \ envpath
-[\c
-.BR \-V ]
-[\c
-.BI \-f \ file\fR]
-[\c
-.BR \-n ]
-[\c
-.BI \-s \ subdb\fR]
-[\c
-.BR \-N ]
-[\c
-.BR \-T ]
-.SH DESCRIPTION
-The
-.B mdb_load
-utility reads from the standard input and loads it into the
-LMDB environment
-.BR envpath .
-
-The input to
-.B mdb_load
-must be in the output format specified by the
-.BR mdb_dump (1)
-utility or as specified by the
-.B -T
-option below.
-.SH OPTIONS
-.TP
-.BR \-V
-Write the library version number to the standard output, and exit.
-.TP
-.BR \-f \ file
-Read from the specified file instead of from the standard input.
-.TP
-.BR \-n
-Load an LMDB database which does not use subdirectories.
-.TP
-.BR \-s \ subdb
-Load a specific subdatabase. If no database is specified, data is loaded into the main database.
-.TP
-.BR \-N
-Don't overwrite existing records when loading into an already existing database; just skip them.
-.TP
-.BR \-T
-Load data from simple text files. The input must be paired lines of text, where the first
-line of the pair is the key item, and the second line of the pair is its corresponding
-data item.
-
-A simple escape mechanism, where newline and backslash (\\) characters are special, is
-applied to the text input. Newline characters are interpreted as record separators.
-Backslash characters in the text will be interpreted in one of two ways: If the backslash
-character precedes another backslash character, the pair will be interpreted as a literal
-backslash. If the backslash character precedes any other character, the two characters
-following the backslash will be interpreted as a hexadecimal specification of a single
-character; for example, \\0a is a newline character in the ASCII character set.
-
-For this reason, any backslash or newline characters that naturally occur in the text
-input must be escaped to avoid misinterpretation by
-.BR mdb_load . 
-
-.SH DIAGNOSTICS
-Exit status is zero if no errors occur.
-Errors result in a non-zero exit status and
-a diagnostic message being written to standard error.
-
-.SH "SEE ALSO"
-.BR mdb_dump (1)
-.SH AUTHOR
-Howard Chu of Symas Corporation <http://www.symas.com>
diff --git a/external/db_drivers/liblmdb64/mdb_load.c b/external/db_drivers/liblmdb64/mdb_load.c
deleted file mode 100644
index 1f6ce0b7e..000000000
--- a/external/db_drivers/liblmdb64/mdb_load.c
+++ /dev/null
@@ -1,454 +0,0 @@
-/* mdb_load.c - memory-mapped database load tool */
-/*
- * Copyright 2011-2015 Howard Chu, Symas Corp.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted only as authorized by the OpenLDAP
- * Public License.
- *
- * A copy of this license is available in the file LICENSE in the
- * top-level directory of the distribution or, alternatively, at
- * <http://www.OpenLDAP.org/license.html>.
- */
-#include <stdio.h>
-#include <stdlib.h>
-#include <errno.h>
-#include <string.h>
-#include <ctype.h>
-#include <unistd.h>
-#include "lmdb.h"
-
-#define PRINT	1
-#define NOHDR	2
-static int mode;
-
-static char *subname = NULL;
-
-static size_t lineno;
-static int version;
-
-static int flags;
-
-static char *prog;
-
-static int Eof;
-
-static MDB_envinfo info;
-
-static MDB_val kbuf, dbuf;
-
-#ifdef _WIN32
-#define Z	"I"
-#else
-#define Z	"z"
-#endif
-
-#define STRLENOF(s)	(sizeof(s)-1)
-
-typedef struct flagbit {
-	int bit;
-	char *name;
-	int len;
-} flagbit;
-
-#define S(s)	s, STRLENOF(s)
-
-flagbit dbflags[] = {
-	{ MDB_REVERSEKEY, S("reversekey") },
-	{ MDB_DUPSORT, S("dupsort") },
-	{ MDB_INTEGERKEY, S("integerkey") },
-	{ MDB_DUPFIXED, S("dupfixed") },
-	{ MDB_INTEGERDUP, S("integerdup") },
-	{ MDB_REVERSEDUP, S("reversedup") },
-	{ 0, NULL, 0 }
-};
-
-static void readhdr(void)
-{
-	char *ptr;
-
-	while (fgets(dbuf.mv_data, dbuf.mv_size, stdin) != NULL) {
-		lineno++;
-		if (!strncmp(dbuf.mv_data, "VERSION=", STRLENOF("VERSION="))) {
-			version=atoi((char *)dbuf.mv_data+STRLENOF("VERSION="));
-			if (version > 3) {
-				fprintf(stderr, "%s: line %" Z "d: unsupported VERSION %d\n",
-					prog, lineno, version);
-				exit(EXIT_FAILURE);
-			}
-		} else if (!strncmp(dbuf.mv_data, "HEADER=END", STRLENOF("HEADER=END"))) {
-			break;
-		} else if (!strncmp(dbuf.mv_data, "format=", STRLENOF("format="))) {
-			if (!strncmp((char *)dbuf.mv_data+STRLENOF("FORMAT="), "print", STRLENOF("print")))
-				mode |= PRINT;
-			else if (strncmp((char *)dbuf.mv_data+STRLENOF("FORMAT="), "bytevalue", STRLENOF("bytevalue"))) {
-				fprintf(stderr, "%s: line %" Z "d: unsupported FORMAT %s\n",
-					prog, lineno, (char *)dbuf.mv_data+STRLENOF("FORMAT="));
-				exit(EXIT_FAILURE);
-			}
-		} else if (!strncmp(dbuf.mv_data, "database=", STRLENOF("database="))) {
-			ptr = memchr(dbuf.mv_data, '\n', dbuf.mv_size);
-			if (ptr) *ptr = '\0';
-			if (subname) free(subname);
-			subname = strdup((char *)dbuf.mv_data+STRLENOF("database="));
-		} else if (!strncmp(dbuf.mv_data, "type=", STRLENOF("type="))) {
-			if (strncmp((char *)dbuf.mv_data+STRLENOF("type="), "btree", STRLENOF("btree")))  {
-				fprintf(stderr, "%s: line %" Z "d: unsupported type %s\n",
-					prog, lineno, (char *)dbuf.mv_data+STRLENOF("type="));
-				exit(EXIT_FAILURE);
-			}
-		} else if (!strncmp(dbuf.mv_data, "mapaddr=", STRLENOF("mapaddr="))) {
-			int i;
-			ptr = memchr(dbuf.mv_data, '\n', dbuf.mv_size);
-			if (ptr) *ptr = '\0';
-			i = sscanf((char *)dbuf.mv_data+STRLENOF("mapaddr="), "%p", &info.me_mapaddr);
-			if (i != 1) {
-				fprintf(stderr, "%s: line %" Z "d: invalid mapaddr %s\n",
-					prog, lineno, (char *)dbuf.mv_data+STRLENOF("mapaddr="));
-				exit(EXIT_FAILURE);
-			}
-		} else if (!strncmp(dbuf.mv_data, "mapsize=", STRLENOF("mapsize="))) {
-			int i;
-			ptr = memchr(dbuf.mv_data, '\n', dbuf.mv_size);
-			if (ptr) *ptr = '\0';
-			i = sscanf((char *)dbuf.mv_data+STRLENOF("mapsize="), "%" Z "u", &info.me_mapsize);
-			if (i != 1) {
-				fprintf(stderr, "%s: line %" Z "d: invalid mapsize %s\n",
-					prog, lineno, (char *)dbuf.mv_data+STRLENOF("mapsize="));
-				exit(EXIT_FAILURE);
-			}
-		} else if (!strncmp(dbuf.mv_data, "maxreaders=", STRLENOF("maxreaders="))) {
-			int i;
-			ptr = memchr(dbuf.mv_data, '\n', dbuf.mv_size);
-			if (ptr) *ptr = '\0';
-			i = sscanf((char *)dbuf.mv_data+STRLENOF("maxreaders="), "%u", &info.me_maxreaders);
-			if (i != 1) {
-				fprintf(stderr, "%s: line %" Z "d: invalid maxreaders %s\n",
-					prog, lineno, (char *)dbuf.mv_data+STRLENOF("maxreaders="));
-				exit(EXIT_FAILURE);
-			}
-		} else {
-			int i;
-			for (i=0; dbflags[i].bit; i++) {
-				if (!strncmp(dbuf.mv_data, dbflags[i].name, dbflags[i].len) &&
-					((char *)dbuf.mv_data)[dbflags[i].len] == '=') {
-					flags |= dbflags[i].bit;
-					break;
-				}
-			}
-			if (!dbflags[i].bit) {
-				ptr = memchr(dbuf.mv_data, '=', dbuf.mv_size);
-				if (!ptr) {
-					fprintf(stderr, "%s: line %" Z "d: unexpected format\n",
-						prog, lineno);
-					exit(EXIT_FAILURE);
-				} else {
-					*ptr = '\0';
-					fprintf(stderr, "%s: line %" Z "d: unrecognized keyword ignored: %s\n",
-						prog, lineno, (char *)dbuf.mv_data);
-				}
-			}
-		}
-	}
-}
-
-static void badend(void)
-{
-	fprintf(stderr, "%s: line %" Z "d: unexpected end of input\n",
-		prog, lineno);
-}
-
-static int unhex(unsigned char *c2)
-{
-	int x, c;
-	x = *c2++ & 0x4f;
-	if (x & 0x40)
-		x -= 55;
-	c = x << 4;
-	x = *c2 & 0x4f;
-	if (x & 0x40)
-		x -= 55;
-	c |= x;
-	return c;
-}
-
-static int readline(MDB_val *out, MDB_val *buf)
-{
-	unsigned char *c1, *c2, *end;
-	size_t len, l2;
-	int c;
-
-	if (!(mode & NOHDR)) {
-		c = fgetc(stdin);
-		if (c == EOF) {
-			Eof = 1;
-			return EOF;
-		}
-		if (c != ' ') {
-			lineno++;
-			if (fgets(buf->mv_data, buf->mv_size, stdin) == NULL) {
-badend:
-				Eof = 1;
-				badend();
-				return EOF;
-			}
-			if (c == 'D' && !strncmp(buf->mv_data, "ATA=END", STRLENOF("ATA=END")))
-				return EOF;
-			goto badend;
-		}
-	}
-	if (fgets(buf->mv_data, buf->mv_size, stdin) == NULL) {
-		Eof = 1;
-		return EOF;
-	}
-	lineno++;
-
-	c1 = buf->mv_data;
-	len = strlen((char *)c1);
-	l2 = len;
-
-	/* Is buffer too short? */
-	while (c1[len-1] != '\n') {
-		buf->mv_data = realloc(buf->mv_data, buf->mv_size*2);
-		if (!buf->mv_data) {
-			Eof = 1;
-			fprintf(stderr, "%s: line %" Z "d: out of memory, line too long\n",
-				prog, lineno);
-			return EOF;
-		}
-		c1 = buf->mv_data;
-		c1 += l2;
-		if (fgets((char *)c1, buf->mv_size+1, stdin) == NULL) {
-			Eof = 1;
-			badend();
-			return EOF;
-		}
-		buf->mv_size *= 2;
-		len = strlen((char *)c1);
-		l2 += len;
-	}
-	c1 = c2 = buf->mv_data;
-	len = l2;
-	c1[--len] = '\0';
-	end = c1 + len;
-
-	if (mode & PRINT) {
-		while (c2 < end) {
-			if (*c2 == '\\') {
-				if (c2[1] == '\\') {
-					c1++; c2 += 2;
-				} else {
-					if (c2+3 > end || !isxdigit(c2[1]) || !isxdigit(c2[2])) {
-						Eof = 1;
-						badend();
-						return EOF;
-					}
-					*c1++ = unhex(++c2);
-					c2 += 2;
-				}
-			} else {
-				c1++; c2++;
-			}
-		}
-	} else {
-		/* odd length not allowed */
-		if (len & 1) {
-			Eof = 1;
-			badend();
-			return EOF;
-		}
-		while (c2 < end) {
-			if (!isxdigit(*c2) || !isxdigit(c2[1])) {
-				Eof = 1;
-				badend();
-				return EOF;
-			}
-			*c1++ = unhex(c2);
-			c2 += 2;
-		}
-	}
-	c2 = out->mv_data = buf->mv_data;
-	out->mv_size = c1 - c2;
-
-	return 0;
-}
-
-static void usage(void)
-{
-	fprintf(stderr, "usage: %s dbpath [-V] [-f input] [-n] [-s name] [-N] [-T]\n", prog);
-	exit(EXIT_FAILURE);
-}
-
-int main(int argc, char *argv[])
-{
-	int i, rc;
-	MDB_env *env;
-	MDB_txn *txn;
-	MDB_cursor *mc;
-	MDB_dbi dbi;
-	char *envname;
-	int envflags = 0, putflags = 0;
-	int dohdr = 0;
-
-	prog = argv[0];
-
-	if (argc < 2) {
-		usage();
-	}
-
-	/* -f: load file instead of stdin
-	 * -n: use NOSUBDIR flag on env_open
-	 * -s: load into named subDB
-	 * -N: use NOOVERWRITE on puts
-	 * -T: read plaintext
-	 * -V: print version and exit
-	 */
-	while ((i = getopt(argc, argv, "f:ns:NTV")) != EOF) {
-		switch(i) {
-		case 'V':
-			printf("%s\n", MDB_VERSION_STRING);
-			exit(0);
-			break;
-		case 'f':
-			if (freopen(optarg, "r", stdin) == NULL) {
-				fprintf(stderr, "%s: %s: reopen: %s\n",
-					prog, optarg, strerror(errno));
-				exit(EXIT_FAILURE);
-			}
-			break;
-		case 'n':
-			envflags |= MDB_NOSUBDIR;
-			break;
-		case 's':
-			subname = strdup(optarg);
-			break;
-		case 'N':
-			putflags = MDB_NOOVERWRITE|MDB_NODUPDATA;
-			break;
-		case 'T':
-			mode |= NOHDR;
-			break;
-		default:
-			usage();
-		}
-	}
-
-	if (optind != argc - 1)
-		usage();
-
-	dbuf.mv_size = 4096;
-	dbuf.mv_data = malloc(dbuf.mv_size);
-
-	if (!(mode & NOHDR))
-		readhdr();
-
-	envname = argv[optind];
-	rc = mdb_env_create(&env);
-	if (rc) {
-		fprintf(stderr, "mdb_env_create failed, error %d %s\n", rc, mdb_strerror(rc));
-		return EXIT_FAILURE;
-	}
-
-	mdb_env_set_maxdbs(env, 2);
-
-	if (info.me_maxreaders)
-		mdb_env_set_maxreaders(env, info.me_maxreaders);
-
-	if (info.me_mapsize)
-		mdb_env_set_mapsize(env, info.me_mapsize);
-
-	if (info.me_mapaddr)
-		envflags |= MDB_FIXEDMAP;
-
-	rc = mdb_env_open(env, envname, envflags, 0664);
-	if (rc) {
-		fprintf(stderr, "mdb_env_open failed, error %d %s\n", rc, mdb_strerror(rc));
-		goto env_close;
-	}
-
-	kbuf.mv_size = mdb_env_get_maxkeysize(env) * 2 + 2;
-	kbuf.mv_data = malloc(kbuf.mv_size);
-
-	while(!Eof) {
-		MDB_val key, data;
-		int batch = 0;
-		flags = 0;
-
-		if (!dohdr) {
-			dohdr = 1;
-		} else if (!(mode & NOHDR))
-			readhdr();
-		
-		rc = mdb_txn_begin(env, NULL, 0, &txn);
-		if (rc) {
-			fprintf(stderr, "mdb_txn_begin failed, error %d %s\n", rc, mdb_strerror(rc));
-			goto env_close;
-		}
-
-		rc = mdb_open(txn, subname, flags|MDB_CREATE, &dbi);
-		if (rc) {
-			fprintf(stderr, "mdb_open failed, error %d %s\n", rc, mdb_strerror(rc));
-			goto txn_abort;
-		}
-
-		rc = mdb_cursor_open(txn, dbi, &mc);
-		if (rc) {
-			fprintf(stderr, "mdb_cursor_open failed, error %d %s\n", rc, mdb_strerror(rc));
-			goto txn_abort;
-		}
-
-		while(1) {
-			rc = readline(&key, &kbuf);
-			if (rc == EOF)
-				break;
-			if (rc)
-				goto txn_abort;
-
-			rc = readline(&data, &dbuf);
-			if (rc)
-				goto txn_abort;
-			
-			rc = mdb_cursor_put(mc, &key, &data, putflags);
-			if (rc == MDB_KEYEXIST && putflags)
-				continue;
-			if (rc)
-				goto txn_abort;
-			batch++;
-			if (batch == 100) {
-				rc = mdb_txn_commit(txn);
-				if (rc) {
-					fprintf(stderr, "%s: line %" Z "d: txn_commit: %s\n",
-						prog, lineno, mdb_strerror(rc));
-					goto env_close;
-				}
-				rc = mdb_txn_begin(env, NULL, 0, &txn);
-				if (rc) {
-					fprintf(stderr, "mdb_txn_begin failed, error %d %s\n", rc, mdb_strerror(rc));
-					goto env_close;
-				}
-				rc = mdb_cursor_open(txn, dbi, &mc);
-				if (rc) {
-					fprintf(stderr, "mdb_cursor_open failed, error %d %s\n", rc, mdb_strerror(rc));
-					goto txn_abort;
-				}
-				batch = 0;
-			}
-		}
-		rc = mdb_txn_commit(txn);
-		txn = NULL;
-		if (rc) {
-			fprintf(stderr, "%s: line %" Z "d: txn_commit: %s\n",
-				prog, lineno, mdb_strerror(rc));
-			goto env_close;
-		}
-		mdb_dbi_close(env, dbi);
-	}
-
-txn_abort:
-	mdb_txn_abort(txn);
-env_close:
-	mdb_env_close(env);
-
-	return rc ? EXIT_FAILURE : EXIT_SUCCESS;
-}
diff --git a/external/db_drivers/liblmdb64/mdb_stat.1 b/external/db_drivers/liblmdb64/mdb_stat.1
deleted file mode 100644
index e6ee5ad58..000000000
--- a/external/db_drivers/liblmdb64/mdb_stat.1
+++ /dev/null
@@ -1,64 +0,0 @@
-.TH MDB_STAT 1 "2014/06/20" "LMDB 0.9.14"
-.\" Copyright 2012-2015 Howard Chu, Symas Corp. All Rights Reserved.
-.\" Copying restrictions apply.  See COPYRIGHT/LICENSE.
-.SH NAME
-mdb_stat \- LMDB environment status tool
-.SH SYNOPSIS
-.B mdb_stat
-.BR \ envpath
-[\c
-.BR \-V ]
-[\c
-.BR \-e ]
-[\c
-.BR \-f [ f [ f ]]]
-[\c
-.BR \-n ]
-[\c
-.BR \-r [ r ]]
-[\c
-.BR \-a \ |
-.BI \-s \ subdb\fR]
-.SH DESCRIPTION
-The
-.B mdb_stat
-utility displays the status of an LMDB environment.
-.SH OPTIONS
-.TP
-.BR \-V
-Write the library version number to the standard output, and exit.
-.TP
-.BR \-e
-Display information about the database environment.
-.TP
-.BR \-f
-Display information about the environment freelist.
-If \fB\-ff\fP is given, summarize each freelist entry.
-If \fB\-fff\fP is given, display the full list of page IDs in the freelist.
-.TP
-.BR \-n
-Display the status of an LMDB database which does not use subdirectories.
-.TP
-.BR \-r
-Display information about the environment reader table.
-Shows the process ID, thread ID, and transaction ID for each active
-reader slot. The process ID and transaction ID are in decimal, the
-thread ID is in hexadecimal. The transaction ID is displayed as "-"
-if the reader does not currently have a read transaction open.
-If \fB\-rr\fP is given, check for stale entries in the reader
-table and clear them. The reader table will be printed again
-after the check is performed.
-.TP
-.BR \-a
-Display the status of all of the subdatabases in the environment.
-.TP
-.BR \-s \ subdb
-Display the status of a specific subdatabase.
-.SH DIAGNOSTICS
-Exit status is zero if no errors occur.
-Errors result in a non-zero exit status and
-a diagnostic message being written to standard error.
-.SH "SEE ALSO"
-.BR mdb_copy (1)
-.SH AUTHOR
-Howard Chu of Symas Corporation <http://www.symas.com>
diff --git a/external/db_drivers/liblmdb64/midl.h b/external/db_drivers/liblmdb64/midl.h
deleted file mode 100644
index 9b041d72d..000000000
--- a/external/db_drivers/liblmdb64/midl.h
+++ /dev/null
@@ -1,186 +0,0 @@
-/**	@file midl.h
- *	@brief LMDB ID List header file.
- *
- *	This file was originally part of back-bdb but has been
- *	modified for use in libmdb. Most of the macros defined
- *	in this file are unused, just left over from the original.
- *
- *	This file is only used internally in libmdb and its definitions
- *	are not exposed publicly.
- */
-/* $OpenLDAP$ */
-/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
- *
- * Copyright 2000-2015 The OpenLDAP Foundation.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted only as authorized by the OpenLDAP
- * Public License.
- *
- * A copy of this license is available in the file LICENSE in the
- * top-level directory of the distribution or, alternatively, at
- * <http://www.OpenLDAP.org/license.html>.
- */
-
-#ifndef _MDB_MIDL_H_
-#define _MDB_MIDL_H_
-
-#include <stddef.h>
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-/** @defgroup internal	LMDB Internals
- *	@{
- */
-
-/** @defgroup idls	ID List Management
- *	@{
- */
-	/** A generic unsigned ID number. These were entryIDs in back-bdb.
-	 *	Preferably it should have the same size as a pointer.
-	 */
-typedef size_t MDB_ID;
-
-	/** An IDL is an ID List, a sorted array of IDs. The first
-	 * element of the array is a counter for how many actual
-	 * IDs are in the list. In the original back-bdb code, IDLs are
-	 * sorted in ascending order. For libmdb IDLs are sorted in
-	 * descending order.
-	 */
-typedef MDB_ID *MDB_IDL;
-
-/* IDL sizes - likely should be even bigger
- *   limiting factors: sizeof(ID), thread stack size
- */
-#define	MDB_IDL_LOGN	16	/* DB_SIZE is 2^16, UM_SIZE is 2^17 */
-#define MDB_IDL_DB_SIZE		(1<<MDB_IDL_LOGN)
-#define MDB_IDL_UM_SIZE		(1<<(MDB_IDL_LOGN+1))
-
-#define MDB_IDL_DB_MAX		(MDB_IDL_DB_SIZE-1)
-#define MDB_IDL_UM_MAX		(MDB_IDL_UM_SIZE-1)
-
-#define MDB_IDL_SIZEOF(ids)		(((ids)[0]+1) * sizeof(MDB_ID))
-#define MDB_IDL_IS_ZERO(ids) ( (ids)[0] == 0 )
-#define MDB_IDL_CPY( dst, src ) (memcpy( dst, src, MDB_IDL_SIZEOF( src ) ))
-#define MDB_IDL_FIRST( ids )	( (ids)[1] )
-#define MDB_IDL_LAST( ids )		( (ids)[(ids)[0]] )
-
-	/** Current max length of an #mdb_midl_alloc()ed IDL */
-#define MDB_IDL_ALLOCLEN( ids )	( (ids)[-1] )
-
-	/** Append ID to IDL. The IDL must be big enough. */
-#define mdb_midl_xappend(idl, id) do { \
-		MDB_ID *xidl = (idl), xlen = ++(xidl[0]); \
-		xidl[xlen] = (id); \
-	} while (0)
-
-	/** Search for an ID in an IDL.
-	 * @param[in] ids	The IDL to search.
-	 * @param[in] id	The ID to search for.
-	 * @return	The index of the first ID greater than or equal to \b id.
-	 */
-unsigned mdb_midl_search( MDB_IDL ids, MDB_ID id );
-
-	/** Allocate an IDL.
-	 * Allocates memory for an IDL of the given size.
-	 * @return	IDL on success, NULL on failure.
-	 */
-MDB_IDL mdb_midl_alloc(int num);
-
-	/** Free an IDL.
-	 * @param[in] ids	The IDL to free.
-	 */
-void mdb_midl_free(MDB_IDL ids);
-
-	/** Shrink an IDL.
-	 * Return the IDL to the default size if it has grown larger.
-	 * @param[in,out] idp	Address of the IDL to shrink.
-	 * @return	0 on no change, non-zero if shrunk.
-	 */
-int mdb_midl_shrink(MDB_IDL *idp);
-
-	/** Make room for num additional elements in an IDL.
-	 * @param[in,out] idp	Address of the IDL.
-	 * @param[in] num	Number of elements to make room for.
-	 * @return	0 on success, ENOMEM on failure.
-	 */
-int mdb_midl_need(MDB_IDL *idp, unsigned num);
-
-	/** Append an ID onto an IDL.
-	 * @param[in,out] idp	Address of the IDL to append to.
-	 * @param[in] id	The ID to append.
-	 * @return	0 on success, ENOMEM if the IDL is too large.
-	 */
-int mdb_midl_append( MDB_IDL *idp, MDB_ID id );
-
-	/** Append an IDL onto an IDL.
-	 * @param[in,out] idp	Address of the IDL to append to.
-	 * @param[in] app	The IDL to append.
-	 * @return	0 on success, ENOMEM if the IDL is too large.
-	 */
-int mdb_midl_append_list( MDB_IDL *idp, MDB_IDL app );
-
-	/** Append an ID range onto an IDL.
-	 * @param[in,out] idp	Address of the IDL to append to.
-	 * @param[in] id	The lowest ID to append.
-	 * @param[in] n		Number of IDs to append.
-	 * @return	0 on success, ENOMEM if the IDL is too large.
-	 */
-int mdb_midl_append_range( MDB_IDL *idp, MDB_ID id, unsigned n );
-
-	/** Merge an IDL onto an IDL. The destination IDL must be big enough.
-	 * @param[in] idl	The IDL to merge into.
-	 * @param[in] merge	The IDL to merge.
-	 */
-void mdb_midl_xmerge( MDB_IDL idl, MDB_IDL merge );
-
-	/** Sort an IDL.
-	 * @param[in,out] ids	The IDL to sort.
-	 */
-void mdb_midl_sort( MDB_IDL ids );
-
-	/** An ID2 is an ID/pointer pair.
-	 */
-typedef struct MDB_ID2 {
-	MDB_ID mid;		/**< The ID */
-	void *mptr;		/**< The pointer */
-} MDB_ID2;
-
-	/** An ID2L is an ID2 List, a sorted array of ID2s.
-	 * The first element's \b mid member is a count of how many actual
-	 * elements are in the array. The \b mptr member of the first element is unused.
-	 * The array is sorted in ascending order by \b mid.
-	 */
-typedef MDB_ID2 *MDB_ID2L;
-
-	/** Search for an ID in an ID2L.
-	 * @param[in] ids	The ID2L to search.
-	 * @param[in] id	The ID to search for.
-	 * @return	The index of the first ID2 whose \b mid member is greater than or equal to \b id.
-	 */
-unsigned mdb_mid2l_search( MDB_ID2L ids, MDB_ID id );
-
-
-	/** Insert an ID2 into a ID2L.
-	 * @param[in,out] ids	The ID2L to insert into.
-	 * @param[in] id	The ID2 to insert.
-	 * @return	0 on success, -1 if the ID was already present in the ID2L.
-	 */
-int mdb_mid2l_insert( MDB_ID2L ids, MDB_ID2 *id );
-
-	/** Append an ID2 into a ID2L.
-	 * @param[in,out] ids	The ID2L to append into.
-	 * @param[in] id	The ID2 to append.
-	 * @return	0 on success, -2 if the ID2L is too big.
-	 */
-int mdb_mid2l_append( MDB_ID2L ids, MDB_ID2 *id );
-
-/** @} */
-/** @} */
-#ifdef __cplusplus
-}
-#endif
-#endif	/* _MDB_MIDL_H_ */
diff --git a/external/db_drivers/liblmdb64/mtest2.c b/external/db_drivers/liblmdb64/mtest2.c
deleted file mode 100644
index eacbe59d5..000000000
--- a/external/db_drivers/liblmdb64/mtest2.c
+++ /dev/null
@@ -1,124 +0,0 @@
-/* mtest2.c - memory-mapped database tester/toy */
-/*
- * Copyright 2011-2015 Howard Chu, Symas Corp.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted only as authorized by the OpenLDAP
- * Public License.
- *
- * A copy of this license is available in the file LICENSE in the
- * top-level directory of the distribution or, alternatively, at
- * <http://www.OpenLDAP.org/license.html>.
- */
-
-/* Just like mtest.c, but using a subDB instead of the main DB */
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <time.h>
-#include "lmdb.h"
-
-#define E(expr) CHECK((rc = (expr)) == MDB_SUCCESS, #expr)
-#define RES(err, expr) ((rc = expr) == (err) || (CHECK(!rc, #expr), 0))
-#define CHECK(test, msg) ((test) ? (void)0 : ((void)fprintf(stderr, \
-	"%s:%d: %s: %s\n", __FILE__, __LINE__, msg, mdb_strerror(rc)), abort()))
-
-int main(int argc,char * argv[])
-{
-	int i = 0, j = 0, rc;
-	MDB_env *env;
-	MDB_dbi dbi;
-	MDB_val key, data;
-	MDB_txn *txn;
-	MDB_stat mst;
-	MDB_cursor *cursor;
-	int count;
-	int *values;
-	char sval[32] = "";
-
-	srand(time(NULL));
-
-	count = (rand()%384) + 64;
-	values = (int *)malloc(count*sizeof(int));
-
-	for(i = 0;i<count;i++) {
-		values[i] = rand()%1024;
-	}
-
-	E(mdb_env_create(&env));
-	E(mdb_env_set_maxreaders(env, 1));
-	E(mdb_env_set_mapsize(env, 10485760));
-	E(mdb_env_set_maxdbs(env, 4));
-	E(mdb_env_open(env, "./testdb", MDB_FIXEDMAP|MDB_NOSYNC, 0664));
-
-	E(mdb_txn_begin(env, NULL, 0, &txn));
-	E(mdb_dbi_open(txn, "id1", MDB_CREATE, &dbi));
-   
-	key.mv_size = sizeof(int);
-	key.mv_data = sval;
-
-	printf("Adding %d values\n", count);
-	for (i=0;i<count;i++) {	
-		sprintf(sval, "%03x %d foo bar", values[i], values[i]);
-		data.mv_size = sizeof(sval);
-		data.mv_data = sval;
-		if (RES(MDB_KEYEXIST, mdb_put(txn, dbi, &key, &data, MDB_NOOVERWRITE)))
-			j++;
-	}
-	if (j) printf("%d duplicates skipped\n", j);
-	E(mdb_txn_commit(txn));
-	E(mdb_env_stat(env, &mst));
-
-	E(mdb_txn_begin(env, NULL, MDB_RDONLY, &txn));
-	E(mdb_cursor_open(txn, dbi, &cursor));
-	while ((rc = mdb_cursor_get(cursor, &key, &data, MDB_NEXT)) == 0) {
-		printf("key: %p %.*s, data: %p %.*s\n",
-			key.mv_data,  (int) key.mv_size,  (char *) key.mv_data,
-			data.mv_data, (int) data.mv_size, (char *) data.mv_data);
-	}
-	CHECK(rc == MDB_NOTFOUND, "mdb_cursor_get");
-	mdb_cursor_close(cursor);
-	mdb_txn_abort(txn);
-
-	j=0;
-	key.mv_data = sval;
-	for (i= count - 1; i > -1; i-= (rand()%5)) {
-		j++;
-		txn=NULL;
-		E(mdb_txn_begin(env, NULL, 0, &txn));
-		sprintf(sval, "%03x ", values[i]);
-		if (RES(MDB_NOTFOUND, mdb_del(txn, dbi, &key, NULL))) {
-			j--;
-			mdb_txn_abort(txn);
-		} else {
-			E(mdb_txn_commit(txn));
-		}
-	}
-	free(values);
-	printf("Deleted %d values\n", j);
-
-	E(mdb_env_stat(env, &mst));
-	E(mdb_txn_begin(env, NULL, MDB_RDONLY, &txn));
-	E(mdb_cursor_open(txn, dbi, &cursor));
-	printf("Cursor next\n");
-	while ((rc = mdb_cursor_get(cursor, &key, &data, MDB_NEXT)) == 0) {
-		printf("key: %.*s, data: %.*s\n",
-			(int) key.mv_size,  (char *) key.mv_data,
-			(int) data.mv_size, (char *) data.mv_data);
-	}
-	CHECK(rc == MDB_NOTFOUND, "mdb_cursor_get");
-	printf("Cursor prev\n");
-	while ((rc = mdb_cursor_get(cursor, &key, &data, MDB_PREV)) == 0) {
-		printf("key: %.*s, data: %.*s\n",
-			(int) key.mv_size,  (char *) key.mv_data,
-			(int) data.mv_size, (char *) data.mv_data);
-	}
-	CHECK(rc == MDB_NOTFOUND, "mdb_cursor_get");
-	mdb_cursor_close(cursor);
-	mdb_txn_abort(txn);
-
-	mdb_dbi_close(env, dbi);
-	mdb_env_close(env);
-	return 0;
-}
diff --git a/external/db_drivers/liblmdb64/mtest3.c b/external/db_drivers/liblmdb64/mtest3.c
deleted file mode 100644
index 9db79e625..000000000
--- a/external/db_drivers/liblmdb64/mtest3.c
+++ /dev/null
@@ -1,133 +0,0 @@
-/* mtest3.c - memory-mapped database tester/toy */
-/*
- * Copyright 2011-2015 Howard Chu, Symas Corp.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted only as authorized by the OpenLDAP
- * Public License.
- *
- * A copy of this license is available in the file LICENSE in the
- * top-level directory of the distribution or, alternatively, at
- * <http://www.OpenLDAP.org/license.html>.
- */
-
-/* Tests for sorted duplicate DBs */
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <time.h>
-#include "lmdb.h"
-
-#define E(expr) CHECK((rc = (expr)) == MDB_SUCCESS, #expr)
-#define RES(err, expr) ((rc = expr) == (err) || (CHECK(!rc, #expr), 0))
-#define CHECK(test, msg) ((test) ? (void)0 : ((void)fprintf(stderr, \
-	"%s:%d: %s: %s\n", __FILE__, __LINE__, msg, mdb_strerror(rc)), abort()))
-
-int main(int argc,char * argv[])
-{
-	int i = 0, j = 0, rc;
-	MDB_env *env;
-	MDB_dbi dbi;
-	MDB_val key, data;
-	MDB_txn *txn;
-	MDB_stat mst;
-	MDB_cursor *cursor;
-	int count;
-	int *values;
-	char sval[32];
-	char kval[sizeof(int)];
-
-	srand(time(NULL));
-
-	memset(sval, 0, sizeof(sval));
-
-	count = (rand()%384) + 64;
-	values = (int *)malloc(count*sizeof(int));
-
-	for(i = 0;i<count;i++) {
-		values[i] = rand()%1024;
-	}
-
-	E(mdb_env_create(&env));
-	E(mdb_env_set_mapsize(env, 10485760));
-	E(mdb_env_set_maxdbs(env, 4));
-	E(mdb_env_open(env, "./testdb", MDB_FIXEDMAP|MDB_NOSYNC, 0664));
-
-	E(mdb_txn_begin(env, NULL, 0, &txn));
-	E(mdb_dbi_open(txn, "id2", MDB_CREATE|MDB_DUPSORT, &dbi));
-
-	key.mv_size = sizeof(int);
-	key.mv_data = kval;
-	data.mv_size = sizeof(sval);
-	data.mv_data = sval;
-
-	printf("Adding %d values\n", count);
-	for (i=0;i<count;i++) {
-		if (!(i & 0x0f))
-			sprintf(kval, "%03x", values[i]);
-		sprintf(sval, "%03x %d foo bar", values[i], values[i]);
-		if (RES(MDB_KEYEXIST, mdb_put(txn, dbi, &key, &data, MDB_NODUPDATA)))
-			j++;
-	}
-	if (j) printf("%d duplicates skipped\n", j);
-	E(mdb_txn_commit(txn));
-	E(mdb_env_stat(env, &mst));
-
-	E(mdb_txn_begin(env, NULL, MDB_RDONLY, &txn));
-	E(mdb_cursor_open(txn, dbi, &cursor));
-	while ((rc = mdb_cursor_get(cursor, &key, &data, MDB_NEXT)) == 0) {
-		printf("key: %p %.*s, data: %p %.*s\n",
-			key.mv_data,  (int) key.mv_size,  (char *) key.mv_data,
-			data.mv_data, (int) data.mv_size, (char *) data.mv_data);
-	}
-	CHECK(rc == MDB_NOTFOUND, "mdb_cursor_get");
-	mdb_cursor_close(cursor);
-	mdb_txn_abort(txn);
-
-	j=0;
-
-	for (i= count - 1; i > -1; i-= (rand()%5)) {
-		j++;
-		txn=NULL;
-		E(mdb_txn_begin(env, NULL, 0, &txn));
-		sprintf(kval, "%03x", values[i & ~0x0f]);
-		sprintf(sval, "%03x %d foo bar", values[i], values[i]);
-		key.mv_size = sizeof(int);
-		key.mv_data = kval;
-		data.mv_size = sizeof(sval);
-		data.mv_data = sval;
-		if (RES(MDB_NOTFOUND, mdb_del(txn, dbi, &key, &data))) {
-			j--;
-			mdb_txn_abort(txn);
-		} else {
-			E(mdb_txn_commit(txn));
-		}
-	}
-	free(values);
-	printf("Deleted %d values\n", j);
-
-	E(mdb_env_stat(env, &mst));
-	E(mdb_txn_begin(env, NULL, MDB_RDONLY, &txn));
-	E(mdb_cursor_open(txn, dbi, &cursor));
-	printf("Cursor next\n");
-	while ((rc = mdb_cursor_get(cursor, &key, &data, MDB_NEXT)) == 0) {
-		printf("key: %.*s, data: %.*s\n",
-			(int) key.mv_size,  (char *) key.mv_data,
-			(int) data.mv_size, (char *) data.mv_data);
-	}
-	CHECK(rc == MDB_NOTFOUND, "mdb_cursor_get");
-	printf("Cursor prev\n");
-	while ((rc = mdb_cursor_get(cursor, &key, &data, MDB_PREV)) == 0) {
-		printf("key: %.*s, data: %.*s\n",
-			(int) key.mv_size,  (char *) key.mv_data,
-			(int) data.mv_size, (char *) data.mv_data);
-	}
-	CHECK(rc == MDB_NOTFOUND, "mdb_cursor_get");
-	mdb_cursor_close(cursor);
-	mdb_txn_abort(txn);
-
-	mdb_dbi_close(env, dbi);
-	mdb_env_close(env);
-	return 0;
-}
diff --git a/external/db_drivers/liblmdb64/mtest4.c b/external/db_drivers/liblmdb64/mtest4.c
deleted file mode 100644
index 6df890e2d..000000000
--- a/external/db_drivers/liblmdb64/mtest4.c
+++ /dev/null
@@ -1,168 +0,0 @@
-/* mtest4.c - memory-mapped database tester/toy */
-/*
- * Copyright 2011-2015 Howard Chu, Symas Corp.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted only as authorized by the OpenLDAP
- * Public License.
- *
- * A copy of this license is available in the file LICENSE in the
- * top-level directory of the distribution or, alternatively, at
- * <http://www.OpenLDAP.org/license.html>.
- */
-
-/* Tests for sorted duplicate DBs with fixed-size keys */
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <time.h>
-#include "lmdb.h"
-
-#define E(expr) CHECK((rc = (expr)) == MDB_SUCCESS, #expr)
-#define RES(err, expr) ((rc = expr) == (err) || (CHECK(!rc, #expr), 0))
-#define CHECK(test, msg) ((test) ? (void)0 : ((void)fprintf(stderr, \
-	"%s:%d: %s: %s\n", __FILE__, __LINE__, msg, mdb_strerror(rc)), abort()))
-
-int main(int argc,char * argv[])
-{
-	int i = 0, j = 0, rc;
-	MDB_env *env;
-	MDB_dbi dbi;
-	MDB_val key, data;
-	MDB_txn *txn;
-	MDB_stat mst;
-	MDB_cursor *cursor;
-	int count;
-	int *values;
-	char sval[8];
-	char kval[sizeof(int)];
-
-	memset(sval, 0, sizeof(sval));
-
-	count = 510;
-	values = (int *)malloc(count*sizeof(int));
-
-	for(i = 0;i<count;i++) {
-		values[i] = i*5;
-	}
-
-	E(mdb_env_create(&env));
-	E(mdb_env_set_mapsize(env, 10485760));
-	E(mdb_env_set_maxdbs(env, 4));
-	E(mdb_env_open(env, "./testdb", MDB_FIXEDMAP|MDB_NOSYNC, 0664));
-
-	E(mdb_txn_begin(env, NULL, 0, &txn));
-	E(mdb_dbi_open(txn, "id4", MDB_CREATE|MDB_DUPSORT|MDB_DUPFIXED, &dbi));
-
-	key.mv_size = sizeof(int);
-	key.mv_data = kval;
-	data.mv_size = sizeof(sval);
-	data.mv_data = sval;
-
-	printf("Adding %d values\n", count);
-	strcpy(kval, "001");
-	for (i=0;i<count;i++) {
-		sprintf(sval, "%07x", values[i]);
-		if (RES(MDB_KEYEXIST, mdb_put(txn, dbi, &key, &data, MDB_NODUPDATA)))
-			j++;
-	}
-	if (j) printf("%d duplicates skipped\n", j);
-	E(mdb_txn_commit(txn));
-	E(mdb_env_stat(env, &mst));
-
-	/* there should be one full page of dups now.
-	 */
-	E(mdb_txn_begin(env, NULL, MDB_RDONLY, &txn));
-	E(mdb_cursor_open(txn, dbi, &cursor));
-	while ((rc = mdb_cursor_get(cursor, &key, &data, MDB_NEXT)) == 0) {
-		printf("key: %p %.*s, data: %p %.*s\n",
-			key.mv_data,  (int) key.mv_size,  (char *) key.mv_data,
-			data.mv_data, (int) data.mv_size, (char *) data.mv_data);
-	}
-	CHECK(rc == MDB_NOTFOUND, "mdb_cursor_get");
-	mdb_cursor_close(cursor);
-	mdb_txn_abort(txn);
-
-	/* test all 3 branches of split code:
-	 * 1: new key in lower half
-	 * 2: new key at split point
-	 * 3: new key in upper half
-	 */
-
-	key.mv_size = sizeof(int);
-	key.mv_data = kval;
-	data.mv_size = sizeof(sval);
-	data.mv_data = sval;
-
-	sprintf(sval, "%07x", values[3]+1);
-	E(mdb_txn_begin(env, NULL, 0, &txn));
-	(void)RES(MDB_KEYEXIST, mdb_put(txn, dbi, &key, &data, MDB_NODUPDATA));
-	mdb_txn_abort(txn);
-
-	sprintf(sval, "%07x", values[255]+1);
-	E(mdb_txn_begin(env, NULL, 0, &txn));
-	(void)RES(MDB_KEYEXIST, mdb_put(txn, dbi, &key, &data, MDB_NODUPDATA));
-	mdb_txn_abort(txn);
-
-	sprintf(sval, "%07x", values[500]+1);
-	E(mdb_txn_begin(env, NULL, 0, &txn));
-	(void)RES(MDB_KEYEXIST, mdb_put(txn, dbi, &key, &data, MDB_NODUPDATA));
-	E(mdb_txn_commit(txn));
-
-	/* Try MDB_NEXT_MULTIPLE */
-	E(mdb_txn_begin(env, NULL, 0, &txn));
-	E(mdb_cursor_open(txn, dbi, &cursor));
-	while ((rc = mdb_cursor_get(cursor, &key, &data, MDB_NEXT_MULTIPLE)) == 0) {
-		printf("key: %.*s, data: %.*s\n",
-			(int) key.mv_size,  (char *) key.mv_data,
-			(int) data.mv_size, (char *) data.mv_data);
-	}
-	CHECK(rc == MDB_NOTFOUND, "mdb_cursor_get");
-	mdb_cursor_close(cursor);
-	mdb_txn_abort(txn);
-	j=0;
-
-	for (i= count - 1; i > -1; i-= (rand()%3)) {
-		j++;
-		txn=NULL;
-		E(mdb_txn_begin(env, NULL, 0, &txn));
-		sprintf(sval, "%07x", values[i]);
-		key.mv_size = sizeof(int);
-		key.mv_data = kval;
-		data.mv_size = sizeof(sval);
-		data.mv_data = sval;
-		if (RES(MDB_NOTFOUND, mdb_del(txn, dbi, &key, &data))) {
-			j--;
-			mdb_txn_abort(txn);
-		} else {
-			E(mdb_txn_commit(txn));
-		}
-	}
-	free(values);
-	printf("Deleted %d values\n", j);
-
-	E(mdb_env_stat(env, &mst));
-	E(mdb_txn_begin(env, NULL, MDB_RDONLY, &txn));
-	E(mdb_cursor_open(txn, dbi, &cursor));
-	printf("Cursor next\n");
-	while ((rc = mdb_cursor_get(cursor, &key, &data, MDB_NEXT)) == 0) {
-		printf("key: %.*s, data: %.*s\n",
-			(int) key.mv_size,  (char *) key.mv_data,
-			(int) data.mv_size, (char *) data.mv_data);
-	}
-	CHECK(rc == MDB_NOTFOUND, "mdb_cursor_get");
-	printf("Cursor prev\n");
-	while ((rc = mdb_cursor_get(cursor, &key, &data, MDB_PREV)) == 0) {
-		printf("key: %.*s, data: %.*s\n",
-			(int) key.mv_size,  (char *) key.mv_data,
-			(int) data.mv_size, (char *) data.mv_data);
-	}
-	CHECK(rc == MDB_NOTFOUND, "mdb_cursor_get");
-	mdb_cursor_close(cursor);
-	mdb_txn_abort(txn);
-
-	mdb_dbi_close(env, dbi);
-	mdb_env_close(env);
-	return 0;
-}
diff --git a/external/db_drivers/liblmdb64/mtest5.c b/external/db_drivers/liblmdb64/mtest5.c
deleted file mode 100644
index 14e3c0da4..000000000
--- a/external/db_drivers/liblmdb64/mtest5.c
+++ /dev/null
@@ -1,135 +0,0 @@
-/* mtest5.c - memory-mapped database tester/toy */
-/*
- * Copyright 2011-2015 Howard Chu, Symas Corp.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted only as authorized by the OpenLDAP
- * Public License.
- *
- * A copy of this license is available in the file LICENSE in the
- * top-level directory of the distribution or, alternatively, at
- * <http://www.OpenLDAP.org/license.html>.
- */
-
-/* Tests for sorted duplicate DBs using cursor_put */
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <time.h>
-#include "lmdb.h"
-
-#define E(expr) CHECK((rc = (expr)) == MDB_SUCCESS, #expr)
-#define RES(err, expr) ((rc = expr) == (err) || (CHECK(!rc, #expr), 0))
-#define CHECK(test, msg) ((test) ? (void)0 : ((void)fprintf(stderr, \
-	"%s:%d: %s: %s\n", __FILE__, __LINE__, msg, mdb_strerror(rc)), abort()))
-
-int main(int argc,char * argv[])
-{
-	int i = 0, j = 0, rc;
-	MDB_env *env;
-	MDB_dbi dbi;
-	MDB_val key, data;
-	MDB_txn *txn;
-	MDB_stat mst;
-	MDB_cursor *cursor;
-	int count;
-	int *values;
-	char sval[32];
-	char kval[sizeof(int)];
-
-	srand(time(NULL));
-
-	memset(sval, 0, sizeof(sval));
-
-	count = (rand()%384) + 64;
-	values = (int *)malloc(count*sizeof(int));
-
-	for(i = 0;i<count;i++) {
-		values[i] = rand()%1024;
-	}
-
-	E(mdb_env_create(&env));
-	E(mdb_env_set_mapsize(env, 10485760));
-	E(mdb_env_set_maxdbs(env, 4));
-	E(mdb_env_open(env, "./testdb", MDB_FIXEDMAP|MDB_NOSYNC, 0664));
-
-	E(mdb_txn_begin(env, NULL, 0, &txn));
-	E(mdb_dbi_open(txn, "id2", MDB_CREATE|MDB_DUPSORT, &dbi));
-	E(mdb_cursor_open(txn, dbi, &cursor));
-
-	key.mv_size = sizeof(int);
-	key.mv_data = kval;
-	data.mv_size = sizeof(sval);
-	data.mv_data = sval;
-
-	printf("Adding %d values\n", count);
-	for (i=0;i<count;i++) {
-		if (!(i & 0x0f))
-			sprintf(kval, "%03x", values[i]);
-		sprintf(sval, "%03x %d foo bar", values[i], values[i]);
-		if (RES(MDB_KEYEXIST, mdb_cursor_put(cursor, &key, &data, MDB_NODUPDATA)))
-			j++;
-	}
-	if (j) printf("%d duplicates skipped\n", j);
-	mdb_cursor_close(cursor);
-	E(mdb_txn_commit(txn));
-	E(mdb_env_stat(env, &mst));
-
-	E(mdb_txn_begin(env, NULL, MDB_RDONLY, &txn));
-	E(mdb_cursor_open(txn, dbi, &cursor));
-	while ((rc = mdb_cursor_get(cursor, &key, &data, MDB_NEXT)) == 0) {
-		printf("key: %p %.*s, data: %p %.*s\n",
-			key.mv_data,  (int) key.mv_size,  (char *) key.mv_data,
-			data.mv_data, (int) data.mv_size, (char *) data.mv_data);
-	}
-	CHECK(rc == MDB_NOTFOUND, "mdb_cursor_get");
-	mdb_cursor_close(cursor);
-	mdb_txn_abort(txn);
-
-	j=0;
-
-	for (i= count - 1; i > -1; i-= (rand()%5)) {
-		j++;
-		txn=NULL;
-		E(mdb_txn_begin(env, NULL, 0, &txn));
-		sprintf(kval, "%03x", values[i & ~0x0f]);
-		sprintf(sval, "%03x %d foo bar", values[i], values[i]);
-		key.mv_size = sizeof(int);
-		key.mv_data = kval;
-		data.mv_size = sizeof(sval);
-		data.mv_data = sval;
-		if (RES(MDB_NOTFOUND, mdb_del(txn, dbi, &key, &data))) {
-			j--;
-			mdb_txn_abort(txn);
-		} else {
-			E(mdb_txn_commit(txn));
-		}
-	}
-	free(values);
-	printf("Deleted %d values\n", j);
-
-	E(mdb_env_stat(env, &mst));
-	E(mdb_txn_begin(env, NULL, MDB_RDONLY, &txn));
-	E(mdb_cursor_open(txn, dbi, &cursor));
-	printf("Cursor next\n");
-	while ((rc = mdb_cursor_get(cursor, &key, &data, MDB_NEXT)) == 0) {
-		printf("key: %.*s, data: %.*s\n",
-			(int) key.mv_size,  (char *) key.mv_data,
-			(int) data.mv_size, (char *) data.mv_data);
-	}
-	CHECK(rc == MDB_NOTFOUND, "mdb_cursor_get");
-	printf("Cursor prev\n");
-	while ((rc = mdb_cursor_get(cursor, &key, &data, MDB_PREV)) == 0) {
-		printf("key: %.*s, data: %.*s\n",
-			(int) key.mv_size,  (char *) key.mv_data,
-			(int) data.mv_size, (char *) data.mv_data);
-	}
-	CHECK(rc == MDB_NOTFOUND, "mdb_cursor_get");
-	mdb_cursor_close(cursor);
-	mdb_txn_abort(txn);
-
-	mdb_dbi_close(env, dbi);
-	mdb_env_close(env);
-	return 0;
-}
diff --git a/external/db_drivers/liblmdb64/mtest6.c b/external/db_drivers/liblmdb64/mtest6.c
deleted file mode 100644
index ae3c7f264..000000000
--- a/external/db_drivers/liblmdb64/mtest6.c
+++ /dev/null
@@ -1,141 +0,0 @@
-/* mtest6.c - memory-mapped database tester/toy */
-/*
- * Copyright 2011-2015 Howard Chu, Symas Corp.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted only as authorized by the OpenLDAP
- * Public License.
- *
- * A copy of this license is available in the file LICENSE in the
- * top-level directory of the distribution or, alternatively, at
- * <http://www.OpenLDAP.org/license.html>.
- */
-
-/* Tests for DB splits and merges */
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <time.h>
-#include "lmdb.h"
-
-#define E(expr) CHECK((rc = (expr)) == MDB_SUCCESS, #expr)
-#define RES(err, expr) ((rc = expr) == (err) || (CHECK(!rc, #expr), 0))
-#define CHECK(test, msg) ((test) ? (void)0 : ((void)fprintf(stderr, \
-	"%s:%d: %s: %s\n", __FILE__, __LINE__, msg, mdb_strerror(rc)), abort()))
-
-char dkbuf[1024];
-
-int main(int argc,char * argv[])
-{
-	int i = 0, j = 0, rc;
-	MDB_env *env;
-	MDB_dbi dbi;
-	MDB_val key, data, sdata;
-	MDB_txn *txn;
-	MDB_stat mst;
-	MDB_cursor *cursor;
-	int count;
-	int *values;
-	long kval;
-	char *sval;
-
-	srand(time(NULL));
-
-	E(mdb_env_create(&env));
-	E(mdb_env_set_mapsize(env, 10485760));
-	E(mdb_env_set_maxdbs(env, 4));
-	E(mdb_env_open(env, "./testdb", MDB_FIXEDMAP|MDB_NOSYNC, 0664));
-
-	E(mdb_txn_begin(env, NULL, 0, &txn));
-	E(mdb_dbi_open(txn, "id6", MDB_CREATE|MDB_INTEGERKEY, &dbi));
-	E(mdb_cursor_open(txn, dbi, &cursor));
-	E(mdb_stat(txn, dbi, &mst));
-
-	sval = calloc(1, mst.ms_psize / 4);
-	key.mv_size = sizeof(long);
-	key.mv_data = &kval;
-	sdata.mv_size = mst.ms_psize / 4 - 30;
-	sdata.mv_data = sval;
-
-	printf("Adding 12 values, should yield 3 splits\n");
-	for (i=0;i<12;i++) {
-		kval = i*5;
-		sprintf(sval, "%08x", kval);
-		data = sdata;
-		(void)RES(MDB_KEYEXIST, mdb_cursor_put(cursor, &key, &data, MDB_NOOVERWRITE));
-	}
-	printf("Adding 12 more values, should yield 3 splits\n");
-	for (i=0;i<12;i++) {
-		kval = i*5+4;
-		sprintf(sval, "%08x", kval);
-		data = sdata;
-		(void)RES(MDB_KEYEXIST, mdb_cursor_put(cursor, &key, &data, MDB_NOOVERWRITE));
-	}
-	printf("Adding 12 more values, should yield 3 splits\n");
-	for (i=0;i<12;i++) {
-		kval = i*5+1;
-		sprintf(sval, "%08x", kval);
-		data = sdata;
-		(void)RES(MDB_KEYEXIST, mdb_cursor_put(cursor, &key, &data, MDB_NOOVERWRITE));
-	}
-	E(mdb_cursor_get(cursor, &key, &data, MDB_FIRST));
-
-	do {
-		printf("key: %p %s, data: %p %.*s\n",
-			key.mv_data,  mdb_dkey(&key, dkbuf),
-			data.mv_data, (int) data.mv_size, (char *) data.mv_data);
-	} while ((rc = mdb_cursor_get(cursor, &key, &data, MDB_NEXT)) == 0);
-	CHECK(rc == MDB_NOTFOUND, "mdb_cursor_get");
-	mdb_cursor_close(cursor);
-	mdb_txn_commit(txn);
-
-#if 0
-	j=0;
-
-	for (i= count - 1; i > -1; i-= (rand()%5)) {
-		j++;
-		txn=NULL;
-		E(mdb_txn_begin(env, NULL, 0, &txn));
-		sprintf(kval, "%03x", values[i & ~0x0f]);
-		sprintf(sval, "%03x %d foo bar", values[i], values[i]);
-		key.mv_size = sizeof(int);
-		key.mv_data = kval;
-		data.mv_size = sizeof(sval);
-		data.mv_data = sval;
-		if (RES(MDB_NOTFOUND, mdb_del(txn, dbi, &key, &data))) {
-			j--;
-			mdb_txn_abort(txn);
-		} else {
-			E(mdb_txn_commit(txn));
-		}
-	}
-	free(values);
-	printf("Deleted %d values\n", j);
-
-	E(mdb_env_stat(env, &mst));
-	E(mdb_txn_begin(env, NULL, MDB_RDONLY, &txn));
-	E(mdb_cursor_open(txn, dbi, &cursor));
-	printf("Cursor next\n");
-	while ((rc = mdb_cursor_get(cursor, &key, &data, MDB_NEXT)) == 0) {
-		printf("key: %.*s, data: %.*s\n",
-			(int) key.mv_size,  (char *) key.mv_data,
-			(int) data.mv_size, (char *) data.mv_data);
-	}
-	CHECK(rc == MDB_NOTFOUND, "mdb_cursor_get");
-	printf("Cursor prev\n");
-	while ((rc = mdb_cursor_get(cursor, &key, &data, MDB_PREV)) == 0) {
-		printf("key: %.*s, data: %.*s\n",
-			(int) key.mv_size,  (char *) key.mv_data,
-			(int) data.mv_size, (char *) data.mv_data);
-	}
-	CHECK(rc == MDB_NOTFOUND, "mdb_cursor_get");
-	mdb_cursor_close(cursor);
-	mdb_txn_abort(txn);
-
-	mdb_dbi_close(env, dbi);
-#endif
-	mdb_env_close(env);
-
-	return 0;
-}
diff --git a/external/db_drivers/liblmdb64/sample-bdb.txt b/external/db_drivers/liblmdb64/sample-bdb.txt
deleted file mode 100644
index 563807a2b..000000000
--- a/external/db_drivers/liblmdb64/sample-bdb.txt
+++ /dev/null
@@ -1,73 +0,0 @@
-/* sample-bdb.txt - BerkeleyDB toy/sample
- *
- * Do a line-by-line comparison of this and sample-mdb.txt
- */
-/*
- * Copyright 2012-2015 Howard Chu, Symas Corp.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted only as authorized by the OpenLDAP
- * Public License.
- *
- * A copy of this license is available in the file LICENSE in the
- * top-level directory of the distribution or, alternatively, at
- * <http://www.OpenLDAP.org/license.html>.
- */
-#include <stdio.h>
-#include <string.h>
-#include <db.h>
-
-int main(int argc,char * argv[])
-{
-	int rc;
-	DB_ENV *env;
-	DB *dbi;
-	DBT key, data;
-	DB_TXN *txn;
-	DBC *cursor;
-	char sval[32], kval[32];
-
-	/* Note: Most error checking omitted for simplicity */
-
-#define FLAGS (DB_INIT_LOCK|DB_INIT_LOG|DB_INIT_TXN|DB_INIT_MPOOL|DB_CREATE|DB_THREAD)
-	rc = db_env_create(&env, 0);
-	rc = env->open(env, "./testdb", FLAGS, 0664);
-	rc = db_create(&dbi, env, 0);
-	rc = env->txn_begin(env, NULL, &txn, 0);
-	rc = dbi->open(dbi, txn, "test.bdb", NULL, DB_BTREE, DB_CREATE, 0664);
-
-	memset(&key, 0, sizeof(DBT));
-	memset(&data, 0, sizeof(DBT));
-	key.size = sizeof(int);
-	key.data = sval;
-	data.size = sizeof(sval);
-	data.data = sval;
-
-	sprintf(sval, "%03x %d foo bar", 32, 3141592);
-	rc = dbi->put(dbi, txn, &key, &data, 0);
-	rc = txn->commit(txn, 0);
-	if (rc) {
-		fprintf(stderr, "txn->commit: (%d) %s\n", rc, db_strerror(rc));
-		goto leave;
-	}
-	rc = env->txn_begin(env, NULL, &txn, 0);
-	rc = dbi->cursor(dbi, txn, &cursor, 0);
-	key.flags = DB_DBT_USERMEM;
-	key.data = kval;
-	key.ulen = sizeof(kval);
-	data.flags = DB_DBT_USERMEM;
-	data.data = sval;
-	data.ulen = sizeof(sval);
-	while ((rc = cursor->c_get(cursor, &key, &data, DB_NEXT)) == 0) {
-		printf("key: %p %.*s, data: %p %.*s\n",
-			key.data,  (int) key.size,  (char *) key.data,
-			data.data, (int) data.size, (char *) data.data);
-	}
-	rc = cursor->c_close(cursor);
-	rc = txn->abort(txn);
-leave:
-	rc = dbi->close(dbi, 0);
-	rc = env->close(env, 0);
-	return rc;
-}
diff --git a/external/db_drivers/liblmdb64/sample-mdb.txt b/external/db_drivers/liblmdb64/sample-mdb.txt
deleted file mode 100644
index 10a256870..000000000
--- a/external/db_drivers/liblmdb64/sample-mdb.txt
+++ /dev/null
@@ -1,62 +0,0 @@
-/* sample-mdb.txt - MDB toy/sample
- *
- * Do a line-by-line comparison of this and sample-bdb.txt
- */
-/*
- * Copyright 2012-2015 Howard Chu, Symas Corp.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted only as authorized by the OpenLDAP
- * Public License.
- *
- * A copy of this license is available in the file LICENSE in the
- * top-level directory of the distribution or, alternatively, at
- * <http://www.OpenLDAP.org/license.html>.
- */
-#include <stdio.h>
-#include "lmdb.h"
-
-int main(int argc,char * argv[])
-{
-	int rc;
-	MDB_env *env;
-	MDB_dbi dbi;
-	MDB_val key, data;
-	MDB_txn *txn;
-	MDB_cursor *cursor;
-	char sval[32];
-
-	/* Note: Most error checking omitted for simplicity */
-
-	rc = mdb_env_create(&env);
-	rc = mdb_env_open(env, "./testdb", 0, 0664);
-	rc = mdb_txn_begin(env, NULL, 0, &txn);
-	rc = mdb_dbi_open(txn, NULL, 0, &dbi);
-
-	key.mv_size = sizeof(int);
-	key.mv_data = sval;
-	data.mv_size = sizeof(sval);
-	data.mv_data = sval;
-
-	sprintf(sval, "%03x %d foo bar", 32, 3141592);
-	rc = mdb_put(txn, dbi, &key, &data, 0);
-	rc = mdb_txn_commit(txn);
-	if (rc) {
-		fprintf(stderr, "mdb_txn_commit: (%d) %s\n", rc, mdb_strerror(rc));
-		goto leave;
-	}
-	rc = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
-	rc = mdb_cursor_open(txn, dbi, &cursor);
-	while ((rc = mdb_cursor_get(cursor, &key, &data, MDB_NEXT)) == 0) {
-		printf("key: %p %.*s, data: %p %.*s\n",
-			key.mv_data,  (int) key.mv_size,  (char *) key.mv_data,
-			data.mv_data, (int) data.mv_size, (char *) data.mv_data);
-	}
-	mdb_cursor_close(cursor);
-	mdb_txn_abort(txn);
-leave:
-	mdb_dbi_close(env, dbi);
-	mdb_env_close(env);
-	return 0;
-}
diff --git a/external/db_drivers/liblmdb64/tooltag b/external/db_drivers/liblmdb64/tooltag
deleted file mode 100644
index 229bf16ba..000000000
--- a/external/db_drivers/liblmdb64/tooltag
+++ /dev/null
@@ -1,22 +0,0 @@
-<tagfile>
-  <compound kind="page">
-    <name>mdb_copy_1</name>
-	<title>mdb_copy - environment copy tool</title>
-	<filename>mdb_copy.1</filename>
-  </compound>
-  <compound kind="page">
-    <name>mdb_dump_1</name>
-	<title>mdb_dump - environment export tool</title>
-	<filename>mdb_dump.1</filename>
-  </compound>
-  <compound kind="page">
-    <name>mdb_load_1</name>
-	<title>mdb_load - environment import tool</title>
-	<filename>mdb_load.1</filename>
-  </compound>
-  <compound kind="page">
-    <name>mdb_stat_1</name>
-	<title>mdb_stat - environment status tool</title>
-	<filename>mdb_stat.1</filename>
-  </compound>
-</tagfile>