*
* @author Howard Chu, Symas Corporation.
*
- * @copyright Copyright 2011-2014 Howard Chu, Symas Corp. All rights reserved.
+ * @copyright Copyright 2011-2015 Howard Chu, Symas Corp. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted only as authorized by the OpenLDAP
MDB_VERINT(MDB_VERSION_MAJOR,MDB_VERSION_MINOR,MDB_VERSION_PATCH)
/** The release date of this library version */
-#define MDB_VERSION_DATE "June 20, 2014"
+#define MDB_VERSION_DATE "September 20, 2014"
/** A stringifier for the version info */
#define MDB_VERSTR(a,b,c,d) "LMDB " #a "." #b "." #c ": (" d ")"
#define MDB_MULTIPLE 0x80000
/* @} */
+/** @defgroup mdb_copy Copy Flags
+ * @{
+ */
+/** Compacting copy: Omit free space from copy, and renumber all
+ * pages sequentially.
+ */
+#define MDB_CP_COMPACT 0x01
+/* @} */
+
/** @brief Cursor Get operations.
*
* This is the set of all operations for retrieving data
#define MDB_BAD_TXN (-30782)
/** Unsupported size of key/DB name/data, or wrong DUPFIXED size */
#define MDB_BAD_VALSIZE (-30781)
-#define MDB_LAST_ERRCODE MDB_BAD_VALSIZE
+ /** The specified DBI was changed unexpectedly */
+#define MDB_BAD_DBI (-30780)
+ /** The last defined error code */
+#define MDB_LAST_ERRCODE MDB_BAD_DBI
/** @} */
/** @brief Statistics for a database in the environment */
* and uses fewer mallocs, but loses protection from application bugs
* like wild pointer writes and other bad updates into the database.
* Incompatible with nested transactions.
- * Processes with and without MDB_WRITEMAP on the same environment do
- * not cooperate well.
+ * Do not mix processes with and without MDB_WRITEMAP on the same
+ * environment. This can defeat durability (#mdb_env_sync etc).
* <li>#MDB_NOMETASYNC
* Flush system buffers to disk only once per transaction, omit the
* metadata flush. Defer that until the system flushes files to disk,
*/
int mdb_env_copyfd(MDB_env *env, mdb_filehandle_t fd);
+ /** @brief Copy an LMDB environment to the specified path, with options.
+ *
+ * This function may be used to make a backup of an existing environment.
+ * No lockfile is created, since it gets recreated at need.
+ * @note This call can trigger significant file size growth if run in
+ * parallel with write transactions, because it employs a read-only
+ * transaction. See long-lived transactions under @ref caveats_sec.
+ * @param[in] env An environment handle returned by #mdb_env_create(). It
+ * must have already been opened successfully.
+ * @param[in] path The directory in which the copy will reside. This
+ * directory must already exist and be writable but must otherwise be
+ * empty.
+ * @param[in] flags Special options for this operation. This parameter
+ * must be set to 0 or by bitwise OR'ing together one or more of the
+ * values described here.
+ * <ul>
+ * <li>#MDB_CP_COMPACT - Perform compaction while copying: omit free
+ * pages and sequentially renumber all pages in output. This option
+ * consumes more CPU and runs more slowly than the default.
+ * </ul>
+ * @return A non-zero error value on failure and 0 on success.
+ */
+int mdb_env_copy2(MDB_env *env, const char *path, unsigned int flags);
+
+ /** @brief Copy an LMDB environment to the specified file descriptor,
+ * with options.
+ *
+ * This function may be used to make a backup of an existing environment.
+ * No lockfile is created, since it gets recreated at need. See
+ * #mdb_env_copy2() for further details.
+ * @note This call can trigger significant file size growth if run in
+ * parallel with write transactions, because it employs a read-only
+ * transaction. See long-lived transactions under @ref caveats_sec.
+ * @param[in] env An environment handle returned by #mdb_env_create(). It
+ * must have already been opened successfully.
+ * @param[in] fd The filedescriptor to write the copy to. It must
+ * have already been opened for Write access.
+ * @param[in] flags Special options for this operation.
+ * See #mdb_env_copy2() for options.
+ * @return A non-zero error value on failure and 0 on success.
+ */
+int mdb_env_copyfd2(MDB_env *env, mdb_filehandle_t fd, unsigned int flags);
+
/** @brief Return statistics about the LMDB environment.
*
* @param[in] env An environment handle returned by #mdb_env_create()
* Data is always written to disk when #mdb_txn_commit() is called,
* but the operating system may keep it buffered. LMDB always flushes
* the OS buffers upon commit as well, unless the environment was
- * opened with #MDB_NOSYNC or in part #MDB_NOMETASYNC.
+ * opened with #MDB_NOSYNC or in part #MDB_NOMETASYNC. This call is
+ * not valid if the environment was opened with #MDB_RDONLY.
* @param[in] env An environment handle returned by #mdb_env_create()
* @param[in] force If non-zero, force a synchronous flush. Otherwise
* if the environment has the #MDB_NOSYNC flag set the flushes
* @return A non-zero error value on failure and 0 on success. Some possible
* errors are:
* <ul>
+ * <li>EACCES - the environment is read-only.
* <li>EINVAL - an invalid parameter was specified.
* <li>EIO - an error occurred during synchronization.
* </ul>
* this process. Note that the library does not check for this condition,
* the caller must ensure it explicitly.
*
- * If the mapsize is changed by another process, #mdb_txn_begin() will
+ * The new size takes effect immediately for the current process but
+ * will not be persisted to any others until a write transaction has been
+ * committed by the current process. Also, only mapsize increases are
+ * persisted into the environment.
+ *
+ * If the mapsize is increased by another process, and data has grown
+ * beyond the range of the current mapsize, #mdb_txn_begin() will
* return #MDB_MAP_RESIZED. This function may be called with a size
* of zero to adopt the new size.
*
* After a successful commit the
* handle will reside in the shared environment, and may be used
* by other transactions. This function must not be called from
- * multiple concurrent transactions. A transaction that uses this function
- * must finish (either commit or abort) before any other transaction may
- * use this function.
+ * multiple concurrent transactions in the same process. A transaction
+ * that uses this function must finish (either commit or abort) before
+ * any other transaction in the process may use this function.
*
* To use named databases (with name != NULL), #mdb_env_set_maxdbs()
* must be called before opening the environment. Database names
* LMDB does nothing else with this memory, the caller is expected
* to modify all of the space requested.
* <li>#MDB_APPEND - append the given key/data pair to the end of the
- * database. No key comparisons are performed. This option allows
- * fast bulk loading when keys are already known to be in the
- * correct order. Loading unsorted keys with this flag will cause
- * data corruption.
+ * database. This option allows fast bulk loading when keys are
+ * already known to be in the correct order. Loading unsorted keys
+ * with this flag will cause a #MDB_KEYEXIST error.
* <li>#MDB_APPENDDUP - as above, but for sorted dup data.
* </ul>
* @return A non-zero error value on failure and 0 on success. Some possible
* <ul>
* <li>#MDB_CURRENT - replace the item at the current cursor position.
* The \b key parameter must still be provided, and must match it.
- * So must \b data if using sorted duplicates (#MDB_DUPSORT).
+ * If using sorted duplicates (#MDB_DUPSORT) the data item must still
+ * sort into the same place. This is intended to be used when the
+ * new data is the same size as the old. Otherwise it will simply
+ * perform a delete of the old record followed by an insert.
* <li>#MDB_NODUPDATA - enter the new key/data pair only if it does not
* already appear in the database. This flag may only be specified
* if the database was opened with #MDB_DUPSORT. The function will
projects / openldap / blobdiff