diff options
| -rw-r--r-- | changelog.d/14962.feature | 1 | ||||
| -rw-r--r-- | synapse/storage/databases/main/roommember.py | 46 |
2 files changed, 45 insertions, 2 deletions
diff --git a/changelog.d/14962.feature b/changelog.d/14962.feature new file mode 100644 index 0000000000..38f26012f2 --- /dev/null +++ b/changelog.d/14962.feature @@ -0,0 +1 @@ +Improve performance when joining or sending an event large rooms. diff --git a/synapse/storage/databases/main/roommember.py b/synapse/storage/databases/main/roommember.py index 8e2ba7b7b4..ea6a5e2f34 100644 --- a/synapse/storage/databases/main/roommember.py +++ b/synapse/storage/databases/main/roommember.py @@ -13,6 +13,7 @@ # See the License for the specific language governing permissions and # limitations under the License. import logging +from itertools import chain from typing import ( TYPE_CHECKING, AbstractSet, @@ -1131,12 +1132,33 @@ class RoomMemberWorkerStore(EventsWorkerStore): else: # The cache doesn't match the state group or prev state group, # so we calculate the result from first principles. + # + # We need to fetch all hosts joined to the room according to `state` by + # inspecting all join memberships in `state`. However, if the `state` is + # relatively recent then many of its events are likely to be held in + # the current state of the room, which is easily available and likely + # cached. + # + # We therefore compute the set of `state` events not in the + # current state and only fetch those. + current_memberships = ( + await self._get_approximate_current_memberships_in_room(room_id) + ) + unknown_state_events = {} + joined_users_in_current_state = [] + + for (type, state_key), event_id in state.items(): + if event_id not in current_memberships: + unknown_state_events[type, state_key] = event_id + elif current_memberships[event_id] == Membership.JOIN: + joined_users_in_current_state.append(state_key) + joined_user_ids = await self.get_joined_user_ids_from_state( - room_id, state + room_id, unknown_state_events ) cache.hosts_to_joined_users = {} - for user_id in joined_user_ids: + for user_id in chain(joined_user_ids, joined_users_in_current_state): host = intern_string(get_domain_from_id(user_id)) cache.hosts_to_joined_users.setdefault(host, set()).add(user_id) @@ -1147,6 +1169,26 @@ class RoomMemberWorkerStore(EventsWorkerStore): return frozenset(cache.hosts_to_joined_users) + async def _get_approximate_current_memberships_in_room( + self, room_id: str + ) -> Mapping[str, Optional[str]]: + """Build a map from event id to membership, for all events in the current state. + + The event ids of non-memberships events (e.g. `m.room.power_levels`) are present + in the result, mapped to values of `None`. + + The result is approximate for partially-joined rooms. It is fully accurate + for fully-joined rooms. + """ + + rows = await self.db_pool.simple_select_list( + "current_state_events", + keyvalues={"room_id": room_id}, + retcols=("event_id", "membership"), + desc="has_completed_background_updates", + ) + return {row["event_id"]: row["membership"] for row in rows} + @cached(max_entries=10000) def _get_joined_hosts_cache(self, room_id: str) -> "_JoinedHostsCache": return _JoinedHostsCache() |