diff options
Diffstat (limited to 'synapse/storage/util/id_generators.py')
-rw-r--r-- | synapse/storage/util/id_generators.py | 30 |
1 files changed, 15 insertions, 15 deletions
diff --git a/synapse/storage/util/id_generators.py b/synapse/storage/util/id_generators.py index 03f2aa6a5c..310b7dc6ee 100644 --- a/synapse/storage/util/id_generators.py +++ b/synapse/storage/util/id_generators.py @@ -29,16 +29,16 @@ class IdGenerator(object): return self._next_id -def _load_current_id(db_conn, table, column, direction=1): +def _load_current_id(db_conn, table, column, step=1): cur = db_conn.cursor() - if direction == 1: + if step == 1: cur.execute("SELECT MAX(%s) FROM %s" % (column, table,)) else: cur.execute("SELECT MIN(%s) FROM %s" % (column, table,)) val, = cur.fetchone() cur.close() - current_id = int(val) if val else direction - return (max if direction == 1 else min)(current_id, direction) + current_id = int(val) if val else step + return (max if step > 0 else min)(current_id, step) class StreamIdGenerator(object): @@ -58,21 +58,21 @@ class StreamIdGenerator(object): :param list extra_tables: List of pairs of database tables and columns to use to source the initial value of the generator from. The value with the largest magnitude is used. - :param int direction: which direction the stream ids grow in. +1 to grow + :param int step: which direction the stream ids grow in. +1 to grow upwards, -1 to grow downwards. Usage: with stream_id_gen.get_next() as stream_id: # ... persist event ... """ - def __init__(self, db_conn, table, column, extra_tables=[], direction=1): + def __init__(self, db_conn, table, column, extra_tables=[], step=1): self._lock = threading.Lock() - self._direction = direction - self._current = _load_current_id(db_conn, table, column, direction) + self._step = step + self._current = _load_current_id(db_conn, table, column, step) for table, column in extra_tables: - self._current = (max if direction > 0 else min)( + self._current = (max if step > 0 else min)( self._current, - _load_current_id(db_conn, table, column, direction) + _load_current_id(db_conn, table, column, step) ) self._unfinished_ids = deque() @@ -83,7 +83,7 @@ class StreamIdGenerator(object): # ... persist event ... """ with self._lock: - self._current += self._direction + self._current += self._step next_id = self._current self._unfinished_ids.append(next_id) @@ -106,9 +106,9 @@ class StreamIdGenerator(object): """ with self._lock: next_ids = range( - self._current + self._direction, - self._current + self._direction * (n + 1), - self._direction + self._current + self._step, + self._current + self._step * (n + 1), + self._step ) self._current += n @@ -132,7 +132,7 @@ class StreamIdGenerator(object): """ with self._lock: if self._unfinished_ids: - return self._unfinished_ids[0] - self._direction + return self._unfinished_ids[0] - self._step return self._current |