Adding classes, functions, and utilities for common LMDB operations.

1 files changed, 98 insertions, 0 deletions

diff --git a/src/lmdb/error.cpp b/src/lmdb/error.cpp
new file mode 100644
index 000000000..359677064
--- /dev/null
+++ b/src/lmdb/error.cpp
@@ -0,0 +1,98 @@
+// Copyright (c) 2014-2018, The Monero Project
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+//
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+//
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include "error.h"
+
+#include <lmdb.h>
+#include <string>
+
+namespace {
+    struct category final : std::error_category
+    {
+        virtual const char* name() const noexcept override final
+        {
+            return "lmdb::error_category()";
+        }
+
+        virtual std::string message(int value) const override final
+        {
+            char const* const msg = mdb_strerror(value);
+            if (msg)
+                return msg;
+            return "Unknown lmdb::error_category() value";
+        }
+
+        virtual std::error_condition default_error_condition(int value) const noexcept override final
+        {
+            switch (value)
+            {
+                case MDB_KEYEXIST:
+                case MDB_NOTFOUND:
+                    break; // map to nothing generic
+                case MDB_PAGE_NOTFOUND:
+                case MDB_CORRUPTED:
+                    return std::errc::state_not_recoverable;
+                case MDB_PANIC:
+                case MDB_VERSION_MISMATCH:
+                case MDB_INVALID:
+                    break; // map to nothing generic
+                case MDB_MAP_FULL:
+                    return std::errc::no_buffer_space;
+                case MDB_DBS_FULL:
+                    break; // map to nothing generic
+                case MDB_READERS_FULL:
+                case MDB_TLS_FULL:
+                    return std::errc::no_lock_available;
+                case MDB_TXN_FULL:
+                case MDB_CURSOR_FULL:
+                case MDB_PAGE_FULL:
+                case MDB_MAP_RESIZED:
+                    break; // map to nothing generic
+                case MDB_INCOMPATIBLE:
+                    return std::errc::invalid_argument;
+                case MDB_BAD_RSLOT:
+                case MDB_BAD_TXN:
+                case MDB_BAD_VALSIZE:
+                case MDB_BAD_DBI:
+                    return std::errc::invalid_argument;
+                default:
+                    return std::error_condition{value, std::generic_category()};
+            }
+            return std::error_condition{value, *this};
+        }
+    };
+}
+
+namespace lmdb
+{
+    std::error_category const& error_category() noexcept
+    {
+        static const category instance{};
+        return instance;
+    }
+}
+