s/MDB_NORDLOCK/MDB_NOLOCK/

[openldap] / libraries / liblmdb / lmdb.h

diff --git a/libraries/liblmdb/lmdb.h b/libraries/liblmdb/lmdb.h
index 1d2e0ddc5e92e3bca07df8862684d618d28d5d9f..8cdac26b062296fc19de1a96b524bb0b715c5162 100644 (file)
--- a/libraries/liblmdb/lmdb.h
+++ b/libraries/liblmdb/lmdb.h
@@ -170,7 +170,7 @@ typedef int mdb_filehandle_t;
 /** Library minor version */
 #define MDB_VERSION_MINOR      9
 /** Library patch version */
-#define MDB_VERSION_PATCH      7
+#define MDB_VERSION_PATCH      8
 
 /** Combine args a,b,c into a single integer for easy version comparisons */
 #define MDB_VERINT(a,b,c)      (((a) << 24) | ((b) << 16) | (c))
@@ -180,7 +180,7 @@ typedef int mdb_filehandle_t;
        MDB_VERINT(MDB_VERSION_MAJOR,MDB_VERSION_MINOR,MDB_VERSION_PATCH)
 
 /** The release date of this library version */
-#define MDB_VERSION_DATE       "January 10, 2013"
+#define MDB_VERSION_DATE       "September 9, 2013"
 
 /** A stringifier for the version info */
 #define MDB_VERSTR(a,b,c,d)    "MDB " #a "." #b "." #c ": (" d ")"
@@ -216,13 +216,13 @@ typedef struct MDB_cursor MDB_cursor;
 /** @brief Generic structure used for passing keys and data in and out
  * of the database.
  *
- * Key sizes must be between 1 and the liblmdb build-time constant
- * #MDB_MAXKEYSIZE inclusive. This currently defaults to 511. The
- * same applies to data sizes in databases with the #MDB_DUPSORT flag.
- * Other data items can in theory be from 0 to 0xffffffff bytes long.
- *
  * Values returned from the database are valid only until a subsequent
- * update operation, or the end of the transaction.
+ * update operation, or the end of the transaction. Do not modify or
+ * free them, they commonly point into the database itself.
+ *
+ * Key sizes must be between 1 and #mdb_env_get_maxkeysize() inclusive.
+ * The same applies to data sizes in databases with the #MDB_DUPSORT flag.
+ * Other data items can in theory be from 0 to 0xffffffff bytes long.
  */
 typedef struct MDB_val {
        size_t           mv_size;       /**< size of the data item */
@@ -265,10 +265,12 @@ typedef void (MDB_rel_func)(MDB_val *item, void *oldptr, void *newptr, void *rel
 #define MDB_NOMETASYNC         0x40000
        /** use writable mmap */
 #define MDB_WRITEMAP           0x80000
-       /** use asynchronous msync when MDB_WRITEMAP is used */
+       /** use asynchronous msync when #MDB_WRITEMAP is used */
 #define MDB_MAPASYNC           0x100000
        /** tie reader locktable slots to #MDB_txn objects instead of to threads */
 #define MDB_NOTLS              0x200000
+       /** don't do any locking, caller must manage their own locks */
+#define MDB_NOLOCK             0x400000
 /** @} */
 
 /**    @defgroup       mdb_dbi_open    Database Flags
@@ -486,6 +488,8 @@ int  mdb_env_create(MDB_env **env);
         *              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. 
         *      <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,
@@ -523,6 +527,13 @@ int  mdb_env_create(MDB_env **env);
         *              user threads over individual OS threads need this option. Such an
         *              application must also serialize the write transactions in an OS
         *              thread, since MDB's write locking is unaware of the user threads.
+        *      <li>#MDB_NOLOCK
+        *              Don't do any locking. If concurrent access is anticipated, the
+        *              caller must manage all concurrency itself. For proper operation
+        *              the caller must enforce single-writer semantics, and must ensure
+        *              that no readers are using old transactions while a writer is
+        *              active. The simplest approach is to use an exclusive lock so that
+        *              no readers may be active at all when a writer begins.
         * </ul>
         * @param[in] mode The UNIX permissions to set on created files. This parameter
         * is ignored on Windows.
@@ -733,8 +744,10 @@ int  mdb_env_set_maxdbs(MDB_env *env, MDB_dbi dbs);
 
        /** @brief Get the maximum size of a key for the environment.
         *
+        * This is the compile-time constant #MDB_MAXKEYSIZE, default 511.
+        * See @ref MDB_val.
         * @param[in] env An environment handle returned by #mdb_env_create()
-        * @return The maximum size of a key. (#MDB_MAXKEYSIZE)
+        * @return The maximum size of a key
         */
 int  mdb_env_get_maxkeysize(MDB_env *env);