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,
|
