From 03c2bfb7f89d637930da52723161ce74d4f89233 Mon Sep 17 00:00:00 2001 From: Sean Quah <8349537+squahtx@users.noreply.github.com> Date: Fri, 23 Sep 2022 13:44:03 +0100 Subject: [PATCH] Send device list updates out to servers in partially joined rooms (#13874) Use the provided list of servers in the room from the `/send_join` response, since we will not know which users are in the room. This isn't sufficient to ensure that all remote servers receive the right device list updates, since the `/send_join` response may be inaccurate or we may calculate the membership state of new users in the room incorrectly. Signed-off-by: Sean Quah --- changelog.d/13874.misc | 1 + synapse/handlers/device.py | 6 +++- synapse/storage/controllers/state.py | 44 +++++++++++++++++++++++++- synapse/storage/databases/main/room.py | 17 ++++++++++ 4 files changed, 66 insertions(+), 2 deletions(-) create mode 100644 changelog.d/13874.misc diff --git a/changelog.d/13874.misc b/changelog.d/13874.misc new file mode 100644 index 000000000..499e488c3 --- /dev/null +++ b/changelog.d/13874.misc @@ -0,0 +1 @@ +Faster room joins: Send device list updates to most servers in rooms with partial state. diff --git a/synapse/handlers/device.py b/synapse/handlers/device.py index 901e2310b..6566b3bf3 100644 --- a/synapse/handlers/device.py +++ b/synapse/handlers/device.py @@ -688,11 +688,15 @@ class DeviceHandler(DeviceWorkerHandler): # Ignore any users that aren't ours if self.hs.is_mine_id(user_id): hosts = set( - await self._storage_controllers.state.get_current_hosts_in_room( + await self._storage_controllers.state.get_current_hosts_in_room_or_partial_state_approximation( room_id ) ) hosts.discard(self.server_name) + # For rooms with partial state, `hosts` is merely an + # approximation. When we transition to a full state room, we + # will have to send out device list updates to any servers we + # missed. # Check if we've already sent this update to some hosts if current_stream_id == stream_id: diff --git a/synapse/storage/controllers/state.py b/synapse/storage/controllers/state.py index bbe568bf0..b1aa17047 100644 --- a/synapse/storage/controllers/state.py +++ b/synapse/storage/controllers/state.py @@ -23,6 +23,7 @@ from typing import ( List, Mapping, Optional, + Sequence, Tuple, ) @@ -524,12 +525,53 @@ class StateStorageController: return state_map.get(key) async def get_current_hosts_in_room(self, room_id: str) -> List[str]: - """Get current hosts in room based on current state.""" + """Get current hosts in room based on current state. + + Blocks until we have full state for the given room. This only happens for rooms + with partial state. + + Returns: + A list of hosts in the room, sorted by longest in the room first. (aka. + sorted by join with the lowest depth first). + """ await self._partial_state_room_tracker.await_full_state(room_id) return await self.stores.main.get_current_hosts_in_room(room_id) + async def get_current_hosts_in_room_or_partial_state_approximation( + self, room_id: str + ) -> Sequence[str]: + """Get approximation of current hosts in room based on current state. + + For rooms with full state, this is equivalent to `get_current_hosts_in_room`, + with the same order of results. + + For rooms with partial state, no blocking occurs. Instead, the list of hosts + in the room at the time of joining is combined with the list of hosts which + joined the room afterwards. The returned list may include hosts that are not + actually in the room and exclude hosts that are in the room, since we may + calculate state incorrectly during the partial state phase. The order of results + is arbitrary for rooms with partial state. + """ + # We have to read this list first to mitigate races with un-partial stating. + # This will be empty for rooms with full state. + hosts_at_join = await self.stores.main.get_partial_state_servers_at_join( + room_id + ) + + hosts_from_state = await self.stores.main.get_current_hosts_in_room(room_id) + hosts_from_state_set = set(hosts_from_state) + + # First take the list of hosts based on the current state. + # For rooms with partial state, this will be missing most hosts. + hosts = list(hosts_from_state) + # Then add in the list of hosts in the room at the time we joined. + # This will be an empty list for rooms with full state. + hosts.extend(host for host in hosts_at_join if host not in hosts_from_state_set) + + return hosts + async def get_users_in_room_with_profiles( self, room_id: str ) -> Dict[str, ProfileInfo]: diff --git a/synapse/storage/databases/main/room.py b/synapse/storage/databases/main/room.py index bef66f199..5dd116d76 100644 --- a/synapse/storage/databases/main/room.py +++ b/synapse/storage/databases/main/room.py @@ -25,6 +25,7 @@ from typing import ( List, Mapping, Optional, + Sequence, Tuple, Union, cast, @@ -1133,6 +1134,22 @@ class RoomWorkerStore(CacheInvalidationWorkerStore): get_rooms_for_retention_period_in_range_txn, ) + async def get_partial_state_servers_at_join(self, room_id: str) -> Sequence[str]: + """Gets the list of servers in a partial state room at the time we joined it. + + Returns: + The `servers_in_room` list from the `/send_join` response for partial state + rooms. May not be accurate or complete, as it comes from a remote + homeserver. + An empty list for full state rooms. + """ + return await self.db_pool.simple_select_onecol( + "partial_state_rooms_servers", + keyvalues={"room_id": room_id}, + retcol="server_name", + desc="get_partial_state_servers_at_join", + ) + async def get_partial_state_rooms_and_servers( self, ) -> Mapping[str, Collection[str]]: