Fix cache call signature to accept on_invalidate. (#8684)

Cached functions accept an `on_invalidate` function, which we failed to add to the type signature. It's rarely used in the files that we have typed, which is why we haven't noticed it before.

synapse/handlers/presence.py

@@ -48,7 +48,7 @@ from synapse.util.wheel_timer import WheelTimer
 
 MYPY = False
 if MYPY:
-    import synapse.server
+    from synapse.server import HomeServer
 
 logger = logging.getLogger(__name__)
 
@@ -101,7 +101,7 @@ assert LAST_ACTIVE_GRANULARITY < IDLE_TIMER
 class BasePresenceHandler(abc.ABC):
     """Parts of the PresenceHandler that are shared between workers and master"""
 
-    def __init__(self, hs: "synapse.server.HomeServer"):
+    def __init__(self, hs: "HomeServer"):
         self.clock = hs.get_clock()
         self.store = hs.get_datastore()
 
@@ -199,7 +199,7 @@ class BasePresenceHandler(abc.ABC):
 
 
 class PresenceHandler(BasePresenceHandler):
-    def __init__(self, hs: "synapse.server.HomeServer"):
+    def __init__(self, hs: "HomeServer"):
         super().__init__(hs)
         self.hs = hs
         self.is_mine_id = hs.is_mine_id
@@ -1011,7 +1011,7 @@ def format_user_presence_state(state, now, include_user_id=True):
 
 
 class PresenceEventSource:
-    def __init__(self, hs):
+    def __init__(self, hs: "HomeServer"):
         # We can't call get_presence_handler here because there's a cycle:
         #
         #   Presence -> Notifier -> PresenceEventSource -> Presence
@@ -1071,12 +1071,14 @@ class PresenceEventSource:
 
             users_interested_in = await self._get_interested_in(user, explicit_room_id)
 
-            user_ids_changed = set()
+            user_ids_changed = set()  # type: Collection[str]
             changed = None
             if from_key:
                 changed = stream_change_cache.get_all_entities_changed(from_key)
 
             if changed is not None and len(changed) < 500:
+                assert isinstance(user_ids_changed, set)
+
                 # For small deltas, its quicker to get all changes and then
                 # work out if we share a room or they're in our presence list
                 get_updates_counter.labels("stream").inc()