diff --git a/synapse/storage/roommember.py b/synapse/storage/roommember.py
index b3c002b9eb..bc77705e97 100644
--- a/synapse/storage/roommember.py
+++ b/synapse/storage/roommember.py
@@ -639,6 +639,39 @@ class RoomMemberWorkerStore(EventsWorkerStore):
count = yield self.runInteraction("did_forget_membership", f)
defer.returnValue(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.
+ 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.
@@ -670,6 +703,13 @@ 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.
@@ -771,6 +811,9 @@ 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..fc0b498843
--- /dev/null
+++ b/synapse/storage/schema/delta/56/room_membership_idx.sql
@@ -0,0 +1,25 @@
+/* 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.
+ */
+
+-- We add membership to current state so that we don't need to join against
+-- room_memberships, which can be surprisingly costly (we do such queries
+-- very frequently).
+-- This will be null for non-membership events and the content.membership key
+-- for membership events. (Will also be null for membership events until the
+-- background update job has finished).
+
+-- 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', '{}');
|
