Refactor sync APIs to reuse pagination API

The sync API often returns events in a topological rather than stream
ordering, e.g. when the user joined the room or on initial sync. When
this happens we can reuse existing pagination storage functions.

1 files changed, 13 insertions, 6 deletions

diff --git a/synapse/handlers/sync.py b/synapse/handlers/sync.py
index c25a76d215..b75daa340d 100644
--- a/synapse/handlers/sync.py
+++ b/synapse/handlers/sync.py
@@ -354,12 +354,19 @@ class SyncHandler(object):
                 since_key = since_token.room_key
 
             while limited and len(recents) < timeline_limit and max_repeat:
-                events, end_key = yield self.store.get_room_events_stream_for_room(
-                    room_id,
-                    limit=load_limit + 1,
-                    from_key=since_key,
-                    to_key=end_key,
-                )
+                if since_key:
+                    events, end_key = yield self.store.get_room_events_stream_for_room(
+                        room_id,
+                        limit=load_limit + 1,
+                        from_key=since_key,
+                        to_key=end_key,
+                    )
+                else:
+                    events, end_key = yield self.store.get_recent_events_for_room(
+                        room_id,
+                        limit=load_limit + 1,
+                        end_token=end_key,
+                    )
                 loaded_recents = sync_config.filter_collection.filter_room_timeline(
                     events
                 )