Add a cache on get_rooms_for_local_user_where_membership_is (#17460)

As it gets used in sliding sync.

We basically invalidate it in all the same places as
`get_rooms_for_user`. Most of the changes are due to needing the
arguments you pass in to be hashable (which lists aren't)

changelog.d/17460.misc

@@ -0,0 +1 @@
+Add cache to `get_rooms_for_local_user_where_membership_is` to speed up sliding sync.

synapse/api/constants.py

@@ -50,7 +50,7 @@ class Membership:
  KNOCK: Final = "knock"
  LEAVE: Final = "leave"
  BAN: Final = "ban"
- LIST: Final = {INVITE, JOIN, KNOCK, LEAVE, BAN}
+ LIST: Final = frozenset((INVITE, JOIN, KNOCK, LEAVE, BAN))
 
 
 class PresenceState:

synapse/storage/_base.py

@@ -120,6 +120,9 @@ def _invalidate_state_caches(
  "get_user_in_room_with_profile", (room_id, user_id)
  )
  self._attempt_to_invalidate_cache("get_rooms_for_user", (user_id,))
+ self._attempt_to_invalidate_cache(
+ "_get_rooms_for_local_user_where_membership_is_inner", (user_id,)
+ )
 
  # Purge other caches based on room state.
  self._attempt_to_invalidate_cache("get_room_summary", (room_id,))
@@ -146,6 +149,9 @@ def _invalidate_state_caches_all(self, room_id: str) -> None:
  self._attempt_to_invalidate_cache("does_pair_of_users_share_a_room", None)
  self._attempt_to_invalidate_cache("get_user_in_room_with_profile", None)
  self._attempt_to_invalidate_cache("get_rooms_for_user", None)
+ self._attempt_to_invalidate_cache(
+ "_get_rooms_for_local_user_where_membership_is_inner", None
+ )
  self._attempt_to_invalidate_cache("get_room_summary", (room_id,))
 
  def _attempt_to_invalidate_cache(

synapse/storage/databases/main/cache.py

@@ -331,6 +331,9 @@ def _invalidate_caches_for_event(
  "get_invited_rooms_for_local_user", (state_key,)
  )
  self._attempt_to_invalidate_cache("get_rooms_for_user", (state_key,))
+ self._attempt_to_invalidate_cache(
+ "_get_rooms_for_local_user_where_membership_is_inner", (state_key,)
+ )
 
  self._attempt_to_invalidate_cache(
  "did_forget",
@@ -393,6 +396,9 @@ def _invalidate_caches_for_room_events(self, room_id: str) -> None:
  self._attempt_to_invalidate_cache("get_thread_id_for_receipts", None)
  self._attempt_to_invalidate_cache("get_invited_rooms_for_local_user", None)
  self._attempt_to_invalidate_cache("get_rooms_for_user", None)
+ self._attempt_to_invalidate_cache(
+ "_get_rooms_for_local_user_where_membership_is_inner", None
+ )
  self._attempt_to_invalidate_cache("did_forget", None)
  self._attempt_to_invalidate_cache("get_forgotten_rooms_for_user", None)
  self._attempt_to_invalidate_cache("get_references_for_event", None)

synapse/storage/databases/main/roommember.py

@@ -445,9 +445,11 @@ async def get_rooms_for_local_user_where_membership_is(
  if not membership_list:
  return []
 
- rooms = await self.db_pool.runInteraction(
- "get_rooms_for_local_user_where_membership_is",
- self._get_rooms_for_local_user_where_membership_is_txn,
+ # Convert membership list to frozen set as a) it needs to be hashable,
+ # and b) we don't care about the order.
+ membership_list = frozenset(membership_list)
+
+ rooms = await self._get_rooms_for_local_user_where_membership_is_inner(
  user_id,
  membership_list,
  )
@@ -466,6 +468,24 @@ async def get_rooms_for_local_user_where_membership_is(
 
  return [room for room in rooms if room.room_id not in rooms_to_exclude]
 
+ @cached(max_entries=1000, tree=True)
+ async def _get_rooms_for_local_user_where_membership_is_inner(
+ self,
+ user_id: str,
+ membership_list: Collection[str],
+ ) -> Sequence[RoomsForUser]:
+ if not membership_list:
+ return []
+
+ rooms = await self.db_pool.runInteraction(
+ "get_rooms_for_local_user_where_membership_is",
+ self._get_rooms_for_local_user_where_membership_is_txn,
+ user_id,
+ membership_list,
+ )
+
+ return rooms
+
  def _get_rooms_for_local_user_where_membership_is_txn(
  self,
  txn: LoggingTransaction,

tests/handlers/test_sync.py

@@ -211,6 +211,7 @@ def test_unknown_room_version(self) -> None:
 
  # Blow away caches (supported room versions can only change due to a restart).
  self.store.get_rooms_for_user.invalidate_all()
+ self.store._get_rooms_for_local_user_where_membership_is_inner.invalidate_all()
  self.store._get_event_cache.clear()
  self.store._event_ref.clear()