Wait for lazy join to complete when getting current state (#12872)

1 files changed, 18 insertions, 0 deletions

diff --git a/synapse/storage/databases/main/room.py b/synapse/storage/databases/main/room.py
index cfd8ce1624..68d4fc2e64 100644
--- a/synapse/storage/databases/main/room.py
+++ b/synapse/storage/databases/main/room.py
@@ -1139,6 +1139,24 @@ class RoomWorkerStore(CacheInvalidationWorkerStore):
             keyvalues={"room_id": room_id},
         )
 
+    async def is_partial_state_room(self, room_id: str) -> bool:
+        """Checks if this room has partial state.
+
+        Returns true if this is a "partial-state" room, which means that the state
+        at events in the room, and `current_state_events`, may not yet be
+        complete.
+        """
+
+        entry = await self.db_pool.simple_select_one_onecol(
+            table="partial_state_rooms",
+            keyvalues={"room_id": room_id},
+            retcol="room_id",
+            allow_none=True,
+            desc="is_partial_state_room",
+        )
+
+        return entry is not None
+
 
 class _BackgroundUpdates:
     REMOVE_TOMESTONED_ROOMS_BG_UPDATE = "remove_tombstoned_rooms_from_directory"