Add mdb_dbi_flags()

Retrieve the flags from a DB handle.

libraries/liblmdb/lmdb.h

@@ -889,6 +889,15 @@ int  mdb_dbi_open(MDB_txn *txn, const char *name, unsigned int flags, MDB_dbi *d
 	 */
 int  mdb_stat(MDB_txn *txn, MDB_dbi dbi, MDB_stat *stat);
 
+	/** @brief Retrieve the DB flags for a database handle.
+	 *
+	 * @param[in] env An environment handle returned by #mdb_env_create()
+	 * @param[in] dbi A database handle returned by #mdb_dbi_open()
+	 * @param[out] flags Address where the flags will be returned.
+	 * @return A non-zero error value on failure and 0 on success.
+	 */
+int mdb_dbi_flags(MDB_env *env, MDB_dbi dbi, unsigned int *flags);
+
 	/** @brief Close a database handle.
 	 *
 	 * This call is not mutex protected. Handles should only be closed by

libraries/liblmdb/mdb.c

@@ -7743,6 +7743,15 @@ void mdb_dbi_close(MDB_env *env, MDB_dbi dbi)
 	free(ptr);
 }
 
+int mdb_dbi_flags(MDB_env *env, MDB_dbi dbi, unsigned int *flags)
+{
+	/* We could return the flags for the FREE_DBI too but what's the point? */
+	if (dbi <= MAIN_DBI || dbi >= env->me_numdbs)
+		return EINVAL;
+	*flags = env->me_dbflags[dbi];
+	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.