From 696f5324539b014a5a9613c3a534abb2b3725dac Mon Sep 17 00:00:00 2001 From: Erik Johnston Date: Tue, 8 May 2018 16:19:33 +0100 Subject: Reuse existing pagination code for context API --- synapse/storage/stream.py | 90 ++++++++--------------------------------------- 1 file changed, 15 insertions(+), 75 deletions(-) diff --git a/synapse/storage/stream.py b/synapse/storage/stream.py index ce98587608..938a8809dc 100644 --- a/synapse/storage/stream.py +++ b/synapse/storage/stream.py @@ -42,7 +42,7 @@ from synapse.util.caches.descriptors import cached from synapse.types import RoomStreamToken from synapse.util.caches.stream_change_cache import StreamChangeCache from synapse.util.logcontext import make_deferred_yieldable, run_in_background -from synapse.storage.engines import PostgresEngine, Sqlite3Engine +from synapse.storage.engines import PostgresEngine import abc import logging @@ -595,88 +595,28 @@ class StreamWorkerStore(EventsWorkerStore, SQLBaseStore): retcols=["stream_ordering", "topological_ordering"], ) - token = RoomStreamToken( - results["topological_ordering"], + # Paginating backwards includes the event at the token, but paginating + # forward doesn't. + before_token = RoomStreamToken( + results["topological_ordering"] - 1, results["stream_ordering"], ) - if isinstance(self.database_engine, Sqlite3Engine): - # SQLite3 doesn't optimise ``(x < a) OR (x = a AND y < b)`` - # So we give pass it to SQLite3 as the UNION ALL of the two queries. - - query_before = ( - "SELECT topological_ordering, stream_ordering, event_id FROM events" - " WHERE room_id = ? AND topological_ordering < ?" - " UNION ALL" - " SELECT topological_ordering, stream_ordering, event_id FROM events" - " WHERE room_id = ? AND topological_ordering = ? AND stream_ordering < ?" - " ORDER BY topological_ordering DESC, stream_ordering DESC LIMIT ?" - ) - before_args = ( - room_id, token.topological, - room_id, token.topological, token.stream, - before_limit, - ) - - query_after = ( - "SELECT topological_ordering, stream_ordering, event_id FROM events" - " WHERE room_id = ? AND topological_ordering > ?" - " UNION ALL" - " SELECT topological_ordering, stream_ordering, event_id FROM events" - " WHERE room_id = ? AND topological_ordering = ? AND stream_ordering > ?" - " ORDER BY topological_ordering ASC, stream_ordering ASC LIMIT ?" - ) - after_args = ( - room_id, token.topological, - room_id, token.topological, token.stream, - after_limit, - ) - else: - query_before = ( - "SELECT topological_ordering, stream_ordering, event_id FROM events" - " WHERE room_id = ? AND %s" - " ORDER BY topological_ordering DESC, stream_ordering DESC LIMIT ?" - ) % (upper_bound(token, self.database_engine, inclusive=False),) - - before_args = (room_id, before_limit) - - query_after = ( - "SELECT topological_ordering, stream_ordering, event_id FROM events" - " WHERE room_id = ? AND %s" - " ORDER BY topological_ordering ASC, stream_ordering ASC LIMIT ?" - ) % (lower_bound(token, self.database_engine, inclusive=False),) - - after_args = (room_id, after_limit) - - txn.execute(query_before, before_args) + after_token = RoomStreamToken( + results["topological_ordering"], + results["stream_ordering"], + ) - rows = self.cursor_to_dict(txn) + rows, start_token = self.paginate_room_events_txn( + txn, room_id, before_token, direction='b', limit=before_limit, + ) events_before = [r["event_id"] for r in rows] - if rows: - start_token = str(RoomStreamToken( - rows[0]["topological_ordering"], - rows[0]["stream_ordering"] - 1, - )) - else: - start_token = str(RoomStreamToken( - token.topological, - token.stream - 1, - )) - - txn.execute(query_after, after_args) - - rows = self.cursor_to_dict(txn) + rows, end_token = self.paginate_room_events_txn( + txn, room_id, after_token, direction='f', limit=after_limit, + ) events_after = [r["event_id"] for r in rows] - if rows: - end_token = str(RoomStreamToken( - rows[-1]["topological_ordering"], - rows[-1]["stream_ordering"], - )) - else: - end_token = str(token) - return { "before": { "event_ids": events_before, -- cgit 1.4.1