From d04e2ff3a43cca3f7d393a4770f022c7bf1a372c Mon Sep 17 00:00:00 2001 From: Erik Johnston Date: Mon, 24 Oct 2016 13:35:51 +0100 Subject: Fix incredubly slow back pagination query If a client didn't specify a from token when paginating backwards synapse would attempt to query the (global) maximum topological token. This a) doesn't make much sense since they're room specific and b) there are no indices that lets postgres do this efficiently. --- synapse/storage/stream.py | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) (limited to 'synapse/storage') diff --git a/synapse/storage/stream.py b/synapse/storage/stream.py index 07ea969d4d..888b1cb35d 100644 --- a/synapse/storage/stream.py +++ b/synapse/storage/stream.py @@ -521,13 +521,20 @@ class StreamStore(SQLBaseStore): ) @defer.inlineCallbacks - def get_room_events_max_id(self, direction='f'): + def get_room_events_max_id(self, room_id=None): + """Returns the current token for rooms stream. + + By default, it returns the current global stream token. Specifying a + `room_id` causes it to return the current room specific topological + token. + """ token = yield self._stream_id_gen.get_current_token() - if direction != 'b': + if room_id is None: defer.returnValue("s%d" % (token,)) else: topo = yield self.runInteraction( - "_get_max_topological_txn", self._get_max_topological_txn + "_get_max_topological_txn", self._get_max_topological_txn, + room_id, ) defer.returnValue("t%d-%d" % (topo, token)) @@ -579,11 +586,11 @@ class StreamStore(SQLBaseStore): lambda r: r[0][0] if r else 0 ) - def _get_max_topological_txn(self, txn): + def _get_max_topological_txn(self, txn, room_id): txn.execute( "SELECT MAX(topological_ordering) FROM events" - " WHERE outlier = ?", - (False,) + " WHERE room_id = ?", + (room_id,) ) rows = txn.fetchall() -- cgit 1.5.1