diff --git a/changelog.d/6936.misc b/changelog.d/6936.misc
new file mode 100644
index 0000000000..9400725017
--- /dev/null
+++ b/changelog.d/6936.misc
@@ -0,0 +1 @@
+Increase DB/CPU perf of `_is_server_still_joined` check.
diff --git a/synapse/storage/data_stores/main/roommember.py b/synapse/storage/data_stores/main/roommember.py
index 042289f0e0..d5ced05701 100644
--- a/synapse/storage/data_stores/main/roommember.py
+++ b/synapse/storage/data_stores/main/roommember.py
@@ -868,6 +868,37 @@ class RoomMemberWorkerStore(EventsWorkerStore):
desc="get_membership_from_event_ids",
)
+ async def is_local_host_in_room_ignoring_users(
+ self, room_id: str, ignore_users: Collection[str]
+ ) -> bool:
+ """Check if there are any local users, excluding those in the given
+ list, in the room.
+ """
+
+ clause, args = make_in_list_sql_clause(
+ self.database_engine, "user_id", ignore_users
+ )
+
+ sql = """
+ SELECT 1 FROM local_current_membership
+ WHERE
+ room_id = ? AND membership = ?
+ AND NOT (%s)
+ LIMIT 1
+ """ % (
+ clause,
+ )
+
+ def _is_local_host_in_room_ignoring_users_txn(txn):
+ txn.execute(sql, (room_id, Membership.JOIN, *args))
+
+ return bool(txn.fetchone())
+
+ return await self.db.runInteraction(
+ "is_local_host_in_room_ignoring_users",
+ _is_local_host_in_room_ignoring_users_txn,
+ )
+
class RoomMemberBackgroundUpdateStore(SQLBaseStore):
def __init__(self, database: Database, db_conn, hs):
diff --git a/synapse/storage/persist_events.py b/synapse/storage/persist_events.py
index a5370ed527..b950550f23 100644
--- a/synapse/storage/persist_events.py
+++ b/synapse/storage/persist_events.py
@@ -727,6 +727,7 @@ class EventsPersistenceStorage(object):
# Check if any of the given events are a local join that appear in the
# current state
+ events_to_check = [] # Event IDs that aren't an event we're persisting
for (typ, state_key), event_id in delta.to_insert.items():
if typ != EventTypes.Member or not self.is_mine_id(state_key):
continue
@@ -736,8 +737,33 @@ class EventsPersistenceStorage(object):
if event.membership == Membership.JOIN:
return True
- # There's been a change of membership but we don't have a local join
- # event in the new events, so we need to check the full state.
+ # The event is not in `ev_ctx_rm`, so we need to pull it out of
+ # the DB.
+ events_to_check.append(event_id)
+
+ # Check if any of the changes that we don't have events for are joins.
+ if events_to_check:
+ rows = await self.main_store.get_membership_from_event_ids(events_to_check)
+ is_still_joined = any(row["membership"] == Membership.JOIN for row in rows)
+ if is_still_joined:
+ return True
+
+ # None of the new state events are local joins, so we check the database
+ # to see if there are any other local users in the room. We ignore users
+ # whose state has changed as we've already their new state above.
+ users_to_ignore = [
+ state_key
+ for _, state_key in itertools.chain(delta.to_insert, delta.to_delete)
+ if self.is_mine_id(state_key)
+ ]
+
+ if await self.main_store.is_local_host_in_room_ignoring_users(
+ room_id, users_to_ignore
+ ):
+ return True
+
+ # The server will leave the room, so we go and find out which remote
+ # users will still be joined when we leave.
if current_state is None:
current_state = await self.main_store.get_current_state_ids(room_id)
current_state = dict(current_state)
@@ -746,19 +772,6 @@ class EventsPersistenceStorage(object):
current_state.update(delta.to_insert)
- event_ids = [
- event_id
- for (typ, state_key,), event_id in current_state.items()
- if typ == EventTypes.Member and self.is_mine_id(state_key)
- ]
-
- rows = await self.main_store.get_membership_from_event_ids(event_ids)
- is_still_joined = any(row["membership"] == Membership.JOIN for row in rows)
- if is_still_joined:
- return True
-
- # The server will leave the room, so we go and find out which remote
- # users will still be joined when we leave.
remote_event_ids = [
event_id
for (typ, state_key,), event_id in current_state.items()
|
