Commit acbff5b1 authored by Howard Chu's avatar Howard Chu
Browse files

Add mdb_cursor_renew()

Allow cursors on read-only txns to be reused with later txns.
parent 076b2b36
......@@ -5285,6 +5285,19 @@ mdb_cursor_open(MDB_txn *txn, MDB_dbi dbi, MDB_cursor **ret)
return MDB_SUCCESS;
}
int
mdb_cursor_renew(MDB_txn *txn, MDB_cursor *mc)
{
if (txn == NULL || mc == NULL || mc->mc_dbi >= txn->mt_numdbs)
return EINVAL;
if (txn->mt_cursors)
return EINVAL;
mdb_cursor_init(mc, txn, mc->mc_dbi, mc->mc_xcursor);
return MDB_SUCCESS;
}
/* Return the count of duplicate data items for the current key */
int
mdb_cursor_count(MDB_cursor *mc, size_t *countp)
......
......@@ -904,6 +904,23 @@ int mdb_cursor_open(MDB_txn *txn, MDB_dbi dbi, MDB_cursor **cursor);
*/
void mdb_cursor_close(MDB_cursor *cursor);
/** @brief Renew a cursor handle.
*
* Cursors are associated with a specific transaction and database and
* may not span threads. Cursors that are only used in read-only
* transactions may be re-used, to avoid unnecessary malloc/free overhead.
* The cursor may be associated with a new read-only transaction, and
* referencing the same database handle as it was created with.
* @param[in] txn A transaction handle returned by #mdb_txn_begin()
* @param[in] cursor A cursor handle returned by #mdb_cursor_open()
* @return A non-zero error value on failure and 0 on success. Some possible
* errors are:
* <ul>
* <li>EINVAL - an invalid parameter was specified.
* </ul>
*/
int mdb_cursor_renew(MDB_txn *txn, MDB_cursor *cursor);
/** @brief Return the cursor's transaction handle.
*
* @param[in] cursor A cursor handle returned by #mdb_cursor_open()
......
Supports Markdown
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment