Reduce state that push rules pull from DB

5 files changed, 22 insertions, 1 deletions

diff --git a/synapse/push/bulk_push_rule_evaluator.py b/synapse/push/bulk_push_rule_evaluator.py
index 90436a043e..6b7aa6b74d 100644
--- a/synapse/push/bulk_push_rule_evaluator.py
+++ b/synapse/push/bulk_push_rule_evaluator.py
@@ -211,13 +211,17 @@ class BulkPushRuleEvaluator:
 
         room_members = await self.store.get_joined_users_from_context(event, context)
 
+        room_member_count = await self.store.get_number_joined_users_in_room(
+            event.room_id
+        )
+
         (
             power_levels,
             sender_power_level,
         ) = await self._get_power_levels_and_sender_level(event, context)
 
         evaluator = PushRuleEvaluatorForEvent(
-            event, len(room_members), sender_power_level, power_levels
+            event, room_member_count, sender_power_level, power_levels
         )
 
         # If the event is not a state event check if any users ignore the sender.
diff --git a/synapse/storage/_base.py b/synapse/storage/_base.py
index 8df80664a2..f2a40b9308 100644
--- a/synapse/storage/_base.py
+++ b/synapse/storage/_base.py
@@ -74,6 +74,9 @@ class SQLBaseStore(metaclass=ABCMeta):
             self._attempt_to_invalidate_cache(
                 "get_users_in_room_with_profiles", (room_id,)
             )
+            self._attempt_to_invalidate_cache(
+                "get_number_joined_users_in_room.invalidate", (room_id,)
+            )
 
         # Purge other caches based on room state.
         self._attempt_to_invalidate_cache("get_room_summary", (room_id,))
diff --git a/synapse/storage/databases/main/cache.py b/synapse/storage/databases/main/cache.py
index a07d48f66c..17f7bf66bf 100644
--- a/synapse/storage/databases/main/cache.py
+++ b/synapse/storage/databases/main/cache.py
@@ -218,6 +218,7 @@ class CacheInvalidationWorkerStore(SQLBaseStore):
             self._membership_stream_cache.entity_has_changed(state_key, stream_ordering)
             self.get_invited_rooms_for_local_user.invalidate((state_key,))
             self.get_local_users_in_room.invalidate((room_id,))
+            self.get_number_joined_users_in_room((room_id,))
 
         if relates_to:
             self.get_relations_for_event.invalidate((relates_to,))
diff --git a/synapse/storage/databases/main/events.py b/synapse/storage/databases/main/events.py
index 28190bf6f5..b533b944bc 100644
--- a/synapse/storage/databases/main/events.py
+++ b/synapse/storage/databases/main/events.py
@@ -1770,6 +1770,10 @@ class PersistEventsStore:
                 self.store.get_local_users_in_room.invalidate,
                 (event.room_id,),
             )
+            txn.call_after(
+                self.store.get_number_joined_users_in_room.invalidate,
+                (event.room_id,),
+            )
 
             # The `_get_membership_from_event_id` is immutable, except for the
             # case where we look up an event *before* persisting it.
diff --git a/synapse/storage/databases/main/roommember.py b/synapse/storage/databases/main/roommember.py
index 70a30e75b0..72202b1373 100644
--- a/synapse/storage/databases/main/roommember.py
+++ b/synapse/storage/databases/main/roommember.py
@@ -338,6 +338,15 @@ class RoomMemberWorkerStore(EventsWorkerStore):
         )
 
     @cached()
+    async def get_number_joined_users_in_room(self, room_id: str) -> int:
+        return await self.db_pool.simple_select_one_onecol(
+            table="current_state_events",
+            keyvalues={"room_id": room_id, "membership": Membership.JOIN},
+            retcol="COUNT(*)",
+            desc="get_number_joined_users_in_room",
+        )
+
+    @cached()
     async def get_invited_rooms_for_local_user(
         self, user_id: str
     ) -> List[RoomsForUser]: