Faster joins: add issue links to the TODOs (#13004)

... to help us keep track of these things

synapse/storage/controllers/persist_events.py

@@ -388,10 +388,13 @@ class EventsPersistenceStorageController:
 
         # TODO(faster_joins): get a real stream ordering, to make this work correctly
         #    across workers.
+        #    https://github.com/matrix-org/synapse/issues/12994
         #
         # TODO(faster_joins): this can race against event persistence, in which case we
         #    will end up with incorrect state. Perhaps we should make this a job we
-        #    farm out to the event persister, somehow.
+        #    farm out to the event persister thread, somehow.
+        #    https://github.com/matrix-org/synapse/issues/13007
+        #
         stream_id = self.main_store.get_room_max_stream_ordering()
         await self.persist_events_store.update_current_state(room_id, delta, stream_id)
 

synapse/storage/controllers/state.py

@@ -452,6 +452,9 @@ class StateStorageController:
                  up to date.
         """
         # FIXME(faster_joins): what do we do here?
+        #   https://github.com/matrix-org/synapse/issues/12814
+        #   https://github.com/matrix-org/synapse/issues/12815
+        #   https://github.com/matrix-org/synapse/issues/13008
 
         return await self.stores.main.get_partial_current_state_deltas(
             prev_stream_id, max_stream_id

synapse/storage/databases/main/room.py

@@ -1112,6 +1112,7 @@ class RoomWorkerStore(CacheInvalidationWorkerStore):
         # this can race with incoming events, so we watch out for FK errors.
         # TODO(faster_joins): this still doesn't completely fix the race, since the persist process
         #   is not atomic. I fear we need an application-level lock.
+        #   https://github.com/matrix-org/synapse/issues/12988
         try:
             await self.db_pool.runInteraction(
                 "clear_partial_state_room", self._clear_partial_state_room_txn, room_id
@@ -1119,6 +1120,7 @@ class RoomWorkerStore(CacheInvalidationWorkerStore):
             return True
         except self.db_pool.engine.module.DatabaseError as e:
             # TODO(faster_joins): how do we distinguish between FK errors and other errors?
+            #   https://github.com/matrix-org/synapse/issues/12988
             logger.warning(
                 "Exception while clearing lazy partial-state-room %s, retrying: %s",
                 room_id,

synapse/storage/databases/main/state.py

@@ -435,6 +435,7 @@ class StateGroupWorkerStore(EventsWorkerStore, SQLBaseStore):
         )
 
         # TODO(faster_joins): need to do something about workers here
+        #   https://github.com/matrix-org/synapse/issues/12994
         txn.call_after(self.is_partial_state_event.invalidate, (event.event_id,))
         txn.call_after(
             self._get_state_group_for_event.prefill,

synapse/storage/state.py

@@ -546,6 +546,7 @@ class StateFilter:
         #  the sender of a piece of state wasn't actually in the room, then clearly that
         #  state shouldn't have been returned.
         #  We should at least add some tests around this to see what happens.
+        #  https://github.com/matrix-org/synapse/issues/13006
 
         # if we haven't requested membership events, then it depends on the value of
         # 'include_others'