Faster room joins: Avoid blocking `/keys/changes` (#13888)

Part of the work for #12993.

Once #12993 is fully resolved, we expect `/keys/changes` to behave
sensibly when joined to a room with partial state.

Signed-off-by: Sean Quah <seanq@matrix.org>

1 files changed, 5 insertions, 2 deletions

diff --git a/synapse/handlers/device.py b/synapse/handlers/device.py

index 6566b3bf3d..bad262731c 100644
--- a/synapse/handlers/device.py
+++ b/synapse/handlers/device.py
@@ -195,7 +195,9 @@ class DeviceWorkerHandler:
         possibly_changed = set(changed)
         possibly_left = set()
         for room_id in rooms_changed:
-            current_state_ids = await self._state_storage.get_current_state_ids(room_id)
+            current_state_ids = await self._state_storage.get_current_state_ids(
+                room_id, await_full_state=False
+            )
 
             # The user may have left the room
             # TODO: Check if they actually did or if we were just invited.
@@ -234,7 +236,8 @@ class DeviceWorkerHandler:
 
             # mapping from event_id -> state_dict
             prev_state_ids = await self._state_storage.get_state_ids_for_events(
-                event_ids
+                event_ids,
+                await_full_state=False,
             )
 
             # Check if we've joined the room? If so we just blindly add all the users to