Fix bug in sliding sync when using old DB. (#17398)

We don't necessarily have `instance_name` for old events (before we
support multiple event persisters). We treat those as if the
`instance_name` was "master".

---------

Co-authored-by: Eric Eastwood <eric.eastwood@beta.gouv.fr>

1 files changed, 6 insertions, 61 deletions

diff --git a/synapse/storage/databases/main/roommember.py b/synapse/storage/databases/main/roommember.py
index d8b54dc4e3..5d2fd08495 100644
--- a/synapse/storage/databases/main/roommember.py
+++ b/synapse/storage/databases/main/roommember.py
@@ -50,12 +50,7 @@ from synapse.storage.database import (
 from synapse.storage.databases.main.cache import CacheInvalidationWorkerStore
 from synapse.storage.databases.main.events_worker import EventsWorkerStore
 from synapse.storage.engines import Sqlite3Engine
-from synapse.storage.roommember import (
-    GetRoomsForUserWithStreamOrdering,
-    MemberSummary,
-    ProfileInfo,
-    RoomsForUser,
-)
+from synapse.storage.roommember import MemberSummary, ProfileInfo, RoomsForUser
 from synapse.types import (
     JsonDict,
     PersistedEventPosition,
@@ -494,7 +489,11 @@ class RoomMemberWorkerStore(EventsWorkerStore, CacheInvalidationWorkerStore):
                 sender=sender,
                 membership=membership,
                 event_id=event_id,
-                event_pos=PersistedEventPosition(instance_name, stream_ordering),
+                event_pos=PersistedEventPosition(
+                    # If instance_name is null we default to "master"
+                    instance_name or "master",
+                    stream_ordering,
+                ),
                 room_version_id=room_version,
             )
             for room_id, sender, membership, event_id, instance_name, stream_ordering, room_version in txn
@@ -606,53 +605,6 @@ class RoomMemberWorkerStore(EventsWorkerStore, CacheInvalidationWorkerStore):
 
         return results
 
-    @cached(max_entries=500000, iterable=True)
-    async def get_rooms_for_user_with_stream_ordering(
-        self, user_id: str
-    ) -> FrozenSet[GetRoomsForUserWithStreamOrdering]:
-        """Returns a set of room_ids the user is currently joined to.
-
-        If a remote user only returns rooms this server is currently
-        participating in.
-
-        Args:
-            user_id
-
-        Returns:
-            Returns the rooms the user is in currently, along with the stream
-            ordering of the most recent join for that user and room, along with
-            the room version of the room.
-        """
-        return await self.db_pool.runInteraction(
-            "get_rooms_for_user_with_stream_ordering",
-            self._get_rooms_for_user_with_stream_ordering_txn,
-            user_id,
-        )
-
-    def _get_rooms_for_user_with_stream_ordering_txn(
-        self, txn: LoggingTransaction, user_id: str
-    ) -> FrozenSet[GetRoomsForUserWithStreamOrdering]:
-        # We use `current_state_events` here and not `local_current_membership`
-        # as a) this gets called with remote users and b) this only gets called
-        # for rooms the server is participating in.
-        sql = """
-            SELECT room_id, e.instance_name, e.stream_ordering
-            FROM current_state_events AS c
-            INNER JOIN events AS e USING (room_id, event_id)
-            WHERE
-                c.type = 'm.room.member'
-                AND c.state_key = ?
-                AND c.membership = ?
-        """
-
-        txn.execute(sql, (user_id, Membership.JOIN))
-        return frozenset(
-            GetRoomsForUserWithStreamOrdering(
-                room_id, PersistedEventPosition(instance, stream_id)
-            )
-            for room_id, instance, stream_id in txn
-        )
-
     async def get_users_server_still_shares_room_with(
         self, user_ids: Collection[str]
     ) -> Set[str]:
@@ -701,13 +653,6 @@ class RoomMemberWorkerStore(EventsWorkerStore, CacheInvalidationWorkerStore):
         If a remote user only returns rooms this server is currently
         participating in.
         """
-        rooms = self.get_rooms_for_user_with_stream_ordering.cache.get_immediate(
-            (user_id,),
-            None,
-            update_metrics=False,
-        )
-        if rooms:
-            return frozenset(r.room_id for r in rooms)
 
         room_ids = await self.db_pool.simple_select_onecol(
             table="current_state_events",