lmdb.c File Reference

Lightning Memory-Mapped Database (LMDB) backend for the key/value Store. More...

#include "config.h"
#include <stddef.h>
#include <lmdb.h>
#include "mutt/lib.h"
#include "lib.h"

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Data Structures
struct	StoreLmdbCtx
	LMDB context. More...

Enumerations
enum	MdbTxnMode { TXN_UNINITIALIZED, TXN_READ, TXN_WRITE }
	LMDB transaction state. More...

Functions
static int	mdb_get_r_txn (struct StoreLmdbCtx *ctx)
	Get an LMDB read transaction. More...
static int	mdb_get_w_txn (struct StoreLmdbCtx *ctx)
	Get an LMDB write transaction. More...
static void *	store_lmdb_open (const char *path)
	Implements StoreOps::open() -. More...
static void *	store_lmdb_fetch (void *store, const char *key, size_t klen, size_t *vlen)
	Implements StoreOps::fetch() -. More...
static void	store_lmdb_free (void *store, void **ptr)
	Implements StoreOps::free() -. More...
static int	store_lmdb_store (void *store, const char *key, size_t klen, void *value, size_t vlen)
	Implements StoreOps::store() -. More...
static int	store_lmdb_delete_record (void *store, const char *key, size_t klen)
	Implements StoreOps::delete_record() -. More...
static void	store_lmdb_close (void **ptr)
	Implements StoreOps::close() -. More...
static const char *	store_lmdb_version (void)
	Implements StoreOps::version() -. More...

Variables
const size_t	LMDB_DB_SIZE = 2147483648
	The maximum size of the database file (2GiB). More...

Detailed Description

Lightning Memory-Mapped Database (LMDB) backend for the key/value Store.

Authors

• Thomas Glanzmann
• Tobias Werth
• Brian Fundakowski Feldman
• Pietro Cerutti

Copyright

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.

Definition in file lmdb.c.

Enumeration Type Documentation

MdbTxnMode

enum MdbTxnMode

LMDB transaction state.

Enumerator
TXN_UNINITIALIZED	Transaction is uninitialised.
TXN_READ	Read transaction in progress.
TXN_WRITE	Write transaction in progress.

Definition at line 46 of file lmdb.c.

{
  TXN_UNINITIALIZED, 
  TXN_READ,          
  TXN_WRITE,         
};

Function Documentation

mdb_get_r_txn()

static int mdb_get_r_txn ( struct StoreLmdbCtx *  ctx )

static

Get an LMDB read transaction.

Parameters

ctx	LMDB context

Return values

num	LMDB return code, e.g. MDB_SUCCESS

Definition at line 69 of file lmdb.c.

{
  int rc;

  if (ctx->txn && ((ctx->txn_mode == TXN_READ) || (ctx->txn_mode == TXN_WRITE)))
    return MDB_SUCCESS;

  if (ctx->txn)
    rc = mdb_txn_renew(ctx->txn);
  else
    rc = mdb_txn_begin(ctx->env, NULL, MDB_RDONLY, &ctx->txn);

  if (rc == MDB_SUCCESS)
    ctx->txn_mode = TXN_READ;
  else
  {
    mutt_debug(LL_DEBUG2, "%s: %s\n",
               ctx->txn ? "mdb_txn_renew" : "mdb_txn_begin", mdb_strerror(rc));
  }

  return rc;
}

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mdb_get_w_txn()

static int mdb_get_w_txn ( struct StoreLmdbCtx *  ctx )

static

Get an LMDB write transaction.

Parameters

ctx	LMDB context

Return values

num	LMDB return code, e.g. MDB_SUCCESS

Definition at line 97 of file lmdb.c.

{
  int rc;

  if (ctx->txn)
  {
    if (ctx->txn_mode == TXN_WRITE)
      return MDB_SUCCESS;

    /* Free up the memory for readonly or reset transactions */
    mdb_txn_abort(ctx->txn);
  }

  rc = mdb_txn_begin(ctx->env, NULL, 0, &ctx->txn);
  if (rc == MDB_SUCCESS)
    ctx->txn_mode = TXN_WRITE;
  else
    mutt_debug(LL_DEBUG2, "mdb_txn_begin: %s\n", mdb_strerror(rc));

  return rc;
}

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Variable Documentation

LMDB_DB_SIZE

const size_t LMDB_DB_SIZE = 2147483648

The maximum size of the database file (2GiB).

The file is mmap(2)'d into memory.

Definition at line 41 of file lmdb.c.