diff --git a/changelog.d/5752.misc b/changelog.d/5752.misc
new file mode 100644
index 0000000000..5e15dfd5fa
--- /dev/null
+++ b/changelog.d/5752.misc
@@ -0,0 +1 @@
+Reduce database IO usage by optimising queries for current membership.
diff --git a/synapse/storage/roommember.py b/synapse/storage/roommember.py
index a1b9fd8199..a4936022e7 100644
--- a/synapse/storage/roommember.py
+++ b/synapse/storage/roommember.py
@@ -179,19 +179,27 @@ class RoomMemberWorkerStore(EventsWorkerStore):
# we order by membership and then fairly arbitrarily by event_id so
# heroes are consistent
- sql = """
- SELECT m.user_id, m.membership, m.event_id
- FROM room_memberships as m
- INNER JOIN current_state_events as c
- ON m.event_id = c.event_id
- AND m.room_id = c.room_id
- AND m.user_id = c.state_key
- WHERE c.type = 'm.room.member' AND c.room_id = ?
- ORDER BY
- CASE m.membership WHEN ? THEN 1 WHEN ? THEN 2 ELSE 3 END ASC,
- m.event_id ASC
- LIMIT ?
- """
+ if self._current_state_events_membership_up_to_date:
+ sql = """
+ SELECT state_key, membership, event_id
+ FROM current_state_events
+ WHERE type = 'm.room.member' AND room_id = ?
+ ORDER BY
+ CASE membership WHEN ? THEN 1 WHEN ? THEN 2 ELSE 3 END ASC,
+ event_id ASC
+ LIMIT ?
+ """
+ else:
+ sql = """
+ SELECT c.state_key, m.membership, c.event_id
+ FROM room_memberships as m
+ INNER JOIN current_state_events as c USING (room_id, event_id)
+ WHERE c.type = 'm.room.member' AND c.room_id = ?
+ ORDER BY
+ CASE m.membership WHEN ? THEN 1 WHEN ? THEN 2 ELSE 3 END ASC,
+ c.event_id ASC
+ LIMIT ?
+ """
# 6 is 5 (number of heroes) plus 1, in case one of them is the calling user.
txn.execute(sql, (room_id, Membership.JOIN, Membership.INVITE, 6))
@@ -256,28 +264,35 @@ class RoomMemberWorkerStore(EventsWorkerStore):
return invite
return None
+ @defer.inlineCallbacks
def get_rooms_for_user_where_membership_is(self, user_id, membership_list):
""" Get all the rooms for this user where the membership for this user
matches one in the membership list.
+ Filters out forgotten rooms.
+
Args:
user_id (str): The user ID.
membership_list (list): A list of synapse.api.constants.Membership
values which the user must be in.
+
Returns:
- A list of dictionary objects, with room_id, membership and sender
- defined.
+ Deferred[list[RoomsForUser]]
"""
if not membership_list:
return defer.succeed(None)
- return self.runInteraction(
+ rooms = yield self.runInteraction(
"get_rooms_for_user_where_membership_is",
self._get_rooms_for_user_where_membership_is_txn,
user_id,
membership_list,
)
+ # Now we filter out forgotten rooms
+ forgotten_rooms = yield self.get_forgotten_rooms_for_user(user_id)
+ return [room for room in rooms if room.room_id not in forgotten_rooms]
+
def _get_rooms_for_user_where_membership_is_txn(
self, txn, user_id, membership_list
):
@@ -287,26 +302,33 @@ class RoomMemberWorkerStore(EventsWorkerStore):
results = []
if membership_list:
- where_clause = "user_id = ? AND (%s) AND forgotten = 0" % (
- " OR ".join(["m.membership = ?" for _ in membership_list]),
- )
-
- args = [user_id]
- args.extend(membership_list)
+ if self._current_state_events_membership_up_to_date:
+ sql = """
+ SELECT room_id, e.sender, c.membership, event_id, 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 state_key = ?
+ AND c.membership IN (%s)
+ """ % (
+ ",".join("?" * len(membership_list))
+ )
+ else:
+ sql = """
+ SELECT room_id, e.sender, m.membership, event_id, e.stream_ordering
+ FROM current_state_events AS c
+ INNER JOIN room_memberships AS m USING (room_id, event_id)
+ INNER JOIN events AS e USING (room_id, event_id)
+ WHERE
+ c.type = 'm.room.member'
+ AND state_key = ?
+ AND m.membership IN (%s)
+ """ % (
+ ",".join("?" * len(membership_list))
+ )
- sql = (
- "SELECT m.room_id, m.sender, m.membership, m.event_id, e.stream_ordering"
- " FROM current_state_events as c"
- " INNER JOIN room_memberships as m"
- " ON m.event_id = c.event_id"
- " INNER JOIN events as e"
- " ON e.event_id = c.event_id"
- " AND m.room_id = c.room_id"
- " AND m.user_id = c.state_key"
- " WHERE c.type = 'm.room.member' AND %s"
- ) % (where_clause,)
-
- txn.execute(sql, args)
+ txn.execute(sql, (user_id, *membership_list))
results = [RoomsForUser(**r) for r in self.cursor_to_dict(txn)]
if do_invite:
@@ -637,6 +659,44 @@ class RoomMemberWorkerStore(EventsWorkerStore):
count = yield self.runInteraction("did_forget_membership", f)
return count == 0
+ @cached()
+ def get_forgotten_rooms_for_user(self, user_id):
+ """Gets all rooms the user has forgotten.
+
+ Args:
+ user_id (str)
+
+ Returns:
+ Deferred[set[str]]
+ """
+
+ def _get_forgotten_rooms_for_user_txn(txn):
+ # This is a slightly convoluted query that first looks up all rooms
+ # that the user has forgotten in the past, then rechecks that list
+ # to see if any have subsequently been updated. This is done so that
+ # we can use a partial index on `forgotten = 1` on the assumption
+ # that few users will actually forget many rooms.
+ #
+ # Note that a room is considered "forgotten" if *all* membership
+ # events for that user and room have the forgotten field set (as
+ # when a user forgets a room we update all rows for that user and
+ # room, not just the current one).
+ sql = """
+ SELECT room_id, (
+ SELECT count(*) FROM room_memberships
+ WHERE room_id = m.room_id AND user_id = m.user_id AND forgotten = 0
+ ) AS count
+ FROM room_memberships AS m
+ WHERE user_id = ? AND forgotten = 1
+ GROUP BY room_id, user_id;
+ """
+ txn.execute(sql, (user_id,))
+ return set(row[0] for row in txn if row[1] == 0)
+
+ return self.runInteraction(
+ "get_forgotten_rooms_for_user", _get_forgotten_rooms_for_user_txn
+ )
+
@defer.inlineCallbacks
def get_rooms_user_has_been_in(self, user_id):
"""Get all rooms that the user has ever been in.
@@ -668,6 +728,13 @@ class RoomMemberStore(RoomMemberWorkerStore):
_CURRENT_STATE_MEMBERSHIP_UPDATE_NAME,
self._background_current_state_membership,
)
+ self.register_background_index_update(
+ "room_membership_forgotten_idx",
+ index_name="room_memberships_user_room_forgotten",
+ table="room_memberships",
+ columns=["user_id", "room_id"],
+ where_clause="forgotten = 1",
+ )
def _store_room_members_txn(self, txn, events, backfilled):
"""Store a room member in the database.
@@ -769,6 +836,9 @@ class RoomMemberStore(RoomMemberWorkerStore):
txn.execute(sql, (user_id, room_id))
self._invalidate_cache_and_stream(txn, self.did_forget, (user_id, room_id))
+ self._invalidate_cache_and_stream(
+ txn, self.get_forgotten_rooms_for_user, (user_id,)
+ )
return self.runInteraction("forget_membership", f)
diff --git a/synapse/storage/schema/delta/56/room_membership_idx.sql b/synapse/storage/schema/delta/56/room_membership_idx.sql
new file mode 100644
index 0000000000..92ab1f5e65
--- /dev/null
+++ b/synapse/storage/schema/delta/56/room_membership_idx.sql
@@ -0,0 +1,18 @@
+/* Copyright 2019 The Matrix.org Foundation C.I.C.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+-- Adds an index on room_memberships for fetching all forgotten rooms for a user
+INSERT INTO background_updates (update_name, progress_json) VALUES
+ ('room_membership_forgotten_idx', '{}');
|
