From 3b3da8648325615ba2893a7b85bda14cc6684838 Mon Sep 17 00:00:00 2001
From: Riccardo Spagni <ric@spagni.net>
Date: Mon, 2 Mar 2015 17:10:16 +0200
Subject: moved 32-bit/64-bit detection into main CMakeLists
---
db_drivers/liblmdb64/mdb.c | 9665 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 9665 insertions(+)
create mode 100644 db_drivers/liblmdb64/mdb.c
(limited to 'db_drivers/liblmdb64/mdb.c')
diff --git a/db_drivers/liblmdb64/mdb.c b/db_drivers/liblmdb64/mdb.c
new file mode 100644
index 000000000..c4dc26903
--- /dev/null
+++ b/db_drivers/liblmdb64/mdb.c
@@ -0,0 +1,9665 @@
+/** @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 2011-2014 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_SYSV_SEM 1
+# define MDB_FDATASYNC fsync
+#elif defined(ANDROID)
+# define MDB_FDATASYNC fsync
+#endif
+
+#ifndef _WIN32
+#include <pthread.h>
+#ifdef 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 */
+#endif /* MDB_USE_SYSV_SEM */
+#endif /* !_WIN32 */
+
+#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
+
+#if defined(_WIN32) || defined(MDB_USE_SYSV_SEM) || defined(EOWNERDEAD)
+#define MDB_ROBUST_SUPPORTED 1
+#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
+
+/* 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)
+#else
+#define MDB_OWNERDEAD EOWNERDEAD
+#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
+typedef HANDLE mdb_mutex_t;
+#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 MDB_MUTEX(env, rw) ((env)->me_##rw##mutex)
+#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))
+#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_SYSV_SEM
+
+typedef struct mdb_mutex {
+ int semid;
+ int semnum;
+ int *locked;
+} mdb_mutex_t;
+
+#define MDB_MUTEX(env, rw) (&(env)->me_##rw##mutex)
+#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_mutex_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
+ /** Pointer/HANDLE type of shared mutex/semaphore.
+ */
+typedef pthread_mutex_t mdb_mutex_t;
+ /** Mutex for the reader table (rw = r) or write transaction (rw = w).
+ */
+#define MDB_MUTEX(env, rw) (&(env)->me_txns->mti_##rw##mutex)
+ /** Lock the reader or writer mutex.
+ * Returns 0 or a code to give #mdb_mutex_failed(), as in #LOCK_MUTEX().
+ */
+#define LOCK_MUTEX0(mutex) pthread_mutex_lock(mutex)
+ /** Unlock the reader or writer mutex.
+ */
+#define UNLOCK_MUTEX(mutex) pthread_mutex_unlock(mutex)
+ /** Mark mutex-protected data as repaired, after death of previous owner.
+ */
+#define mdb_mutex_consistent(mutex) pthread_mutex_consistent(mutex)
+#endif /* MDB_USE_SYSV_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)
+#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_mutex_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;
+ * 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 ((MDB_DEVEL) ? 999 : 1)
+
+ /** @brief The max size of a key we can write, or 0 for dynamic max.
+ *
+ * Define this as 0 to compute the max from the page size. 511
+ * is default for backwards compat: liblmdb <= 0.9.10 can break
+ * when modifying a DB with keys/dupsort data bigger than its max.
+ * #MDB_DEVEL sets the default to 0.
+ *
+ * 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)
+ 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 #MDB_MUTEX(env,r) reader table lock.
+ */
+ pthread_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
+ * 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_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)
+ 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;
+#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 */ \
+ + (SYSV_SEM_FLAG << 18) \
+ + (((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 */
+#endif
+#if defined(_WIN32) || defined(MDB_USE_SYSV_SEM)
+ /* Windows mutexes/SysV semaphores do not reside in shared mem */
+ mdb_mutex_t me_rmutex;
+ mdb_mutex_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_SYSV_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);
+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;
+/** @endcond */
+
+#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 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",
+ "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)
+{
+ return txn->mt_dbxs[dbi].md_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;
+ uint16_t x;
+ int rc, new_notls = 0;
+
+ if (txn->mt_flags & MDB_TXN_RDONLY) {
+ /* Setup db info */
+ txn->mt_numdbs = env->me_numdbs;
+ txn->mt_dbxs = env->me_dbxs; /* mostly static anyway */
+ 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();
+ mdb_mutex_t *rmutex = MDB_MUTEX(env, r);
+
+ if (!env->me_live_reader) {
+ rc = mdb_reader_pid(env, Pidset, pid);
+ if (rc)
+ return rc;
+ env->me_live_reader = 1;
+ }
+
+ 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(rmutex);
+ return MDB_READERS_FULL;
+ }
+ r = &ti->mti_readers[i];
+ r->mr_txnid = (txnid_t)-1;
+ r->mr_tid = tid;
+ r->mr_pid = pid; /* should be written last, see ITS#7971. */
+ if (i == nr)
+ ti->mti_numreaders = ++nr;
+ /* Save numreaders for un-mutexed mdb_env_close() */
+ env->me_numreaders = nr;
+ UNLOCK_MUTEX(rmutex);
+
+ 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];
+ }
+ } else {
+ if (ti) {
+ if (LOCK_MUTEX(rc, env, MDB_MUTEX(env, w)))
+ 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) ];
+ txn->mt_txnid = meta->mm_txnid;
+ }
+ /* Setup db info */
+ txn->mt_numdbs = env->me_numdbs;
+ txn->mt_txnid++;
+#if MDB_DEBUG
+ if (txn->mt_txnid == mdb_debug_start)
+ mdb_debug = 1;
+#endif
+ txn->mt_flags = 0;
+ 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;
+
+ 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;
+}
+
+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)
+{
+ 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(MDB_MUTEX(env, w));
+ } 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) {
+ /* 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 {
+ if (lseek(env->me_fd, wpos, SEEK_SET) == -1) {
+ rc = ErrCode();
+ DPRINTF(("lseek: %s", strerror(rc)));
+ return rc;
+ }
+ wres = writev(env->me_fd, iov, n);
+ }
+#endif
+ if (wres != wsize) {
+ if (wres < 0) {
+ rc = ErrCode();
+ 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(MDB_MUTEX(env, w));
+ 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;
+}
+
+/** 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)
+{
+ 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[in] meta the #MDB_meta to write
+ * @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); \
+ rc = (len >= 0); } while(0)
+#endif
+
+ DPUTS("writing new meta page");
+
+ psize = env->me_psize;
+
+ 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;
+#if !(defined(_MSC_VER) || 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))) {
+ 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;
+#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;
+ 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_SYSV_SEM
+ e->me_rmutex.semid = -1;
+ e->me_wmutex.semid = -1;
+#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;
+ MDB_meta *meta;
+ void *old;
+ if (env->me_txn)
+ return EINVAL;
+ meta = env->me_metas[mdb_env_pick_meta(env)];
+ if (!size)
+ 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;
+ }
+ 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
+
+ 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;
+ 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) {
+ 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;
+ 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;
+ }
+
+ 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_SYSV_SEM
+ if (*excl < 0) /* always true when !MDB_USE_SYSV_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
+#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,
+ 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_SYSV_SEM)
+ unsigned short vals[2] = {1, 1};
+ semid = semget(IPC_PRIVATE, 2, mode);
+ 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_SYSV_SEM */
+ pthread_mutexattr_t mattr;
+
+ if ((rc = pthread_mutexattr_init(&mattr))
+ || (rc = pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED))
+#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_SYSV_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 {
+#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;
+ 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_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
+
+ 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_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));
+ }
+ 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 */
+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 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
+
+/** 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 d2;
+ if ((rc = mdb_node_read(mc->mc_txn, leaf, &d2)) != MDB_SUCCESS)
+ return rc;
+ rc = mc->mc_dbx->md_dcmp(data, &d2);
+ if (rc) {
+ if (op == MDB_GET_BOTH || rc > 0)
+ return MDB_NOTFOUND;
+ rc = 0;
+ *data = d2;
+ }
+
+ } 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)
+{
+ 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)) {
+ /* Just overwrite the current item */
+ if (flags == MDB_CURRENT)
+ goto current;
+
+#if UINT_MAX < SIZE_MAX
+ if (mc->mc_dbx->md_dcmp == mdb_cmp_int && olddata.mv_size == sizeof(size_t))
+ mc->mc_dbx->md_dcmp = mdb_cmp_clong;
+#endif
+ /* does data match? */
+ if (!mc->mc_dbx->md_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_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) {
+ m3->mc_snum--;
+ m3->mc_top--;
+ 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];
+ }
+ }
+ }
+ }
+ } 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 {
+ oldki += NUMKEYS(mn.mc_pg[mn.mc_top]);
+ mn.mc_ki[mn.mc_top] += mc->mc_ki[mn.mc_top] + 1;
+ rc = mdb_page_merge(mc, &mn);
+ 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;
+
+ 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;
+ mdb_mutex_t *wmutex = 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 */
+ wmutex = MDB_MUTEX(env, w);
+ if (LOCK_MUTEX(rc, env, wmutex))
+ goto leave;
+
+ rc = mdb_txn_renew0(txn);
+ if (rc) {
+ UNLOCK_MUTEX(wmutex);
+ 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 (wmutex)
+ UNLOCK_MUTEX(wmutex);
+
+ 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 & (env->me_map ? ~CHANGEABLE : ~(CHANGEABLE|CHANGELESS)))
+ 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)
+{
+ if (!env)
+ return EINVAL;
+ if (dead)
+ *dead = 0;
+ return env->me_txns ? mdb_reader_check0(env, 0, dead) : MDB_SUCCESS;
+}
+
+/** As #mdb_reader_check(). rlocked = <caller locked the reader mutex>. */
+static int mdb_reader_check0(MDB_env *env, int rlocked, int *dead)
+{
+ mdb_mutex_t *rmutex = rlocked ? NULL : MDB_MUTEX(env, r);
+ 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)
+ return ENOMEM;
+ pids[0] = 0;
+ mr = env->me_txns->mti_readers;
+ for (i=0; i<rdrs; i++) {
+ 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)) {
+ /* 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",
+ (unsigned) pid, mr[j].mr_txnid));
+ mr[j].mr_pid = 0;
+ count++;
+ }
+ if (rmutex)
+ UNLOCK_MUTEX(rmutex);
+ }
+ }
+ }
+ }
+ free(pids);
+ if (dead)
+ *dead = count;
+ 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 mdb_mutex_failed(MDB_env *env, mdb_mutex_t *mutex, int rc)
+{
+ int toggle, rlocked, rc2;
+
+ if (rc == MDB_OWNERDEAD) {
+ /* We own the mutex. Clean up after dead previous owner. */
+ rc = MDB_SUCCESS;
+ rlocked = (mutex == MDB_MUTEX(env, r));
+ if (!rlocked) {
+ /* Keep mti_txnid updated, otherwise next writer can
+ * overwrite data which latest meta page refers to.
+ */
+ toggle = mdb_env_pick_meta(env);
+ env->me_txns->mti_txnid = env->me_metas[toggle]->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 */
+/** @} */
--
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