diff --git a/changelog.d/14442.feature b/changelog.d/14442.feature new file mode 100644 index 000000000..917e7edfb --- /dev/null +++ b/changelog.d/14442.feature @@ -0,0 +1 @@ +Faster joins: include heroes' membership events in the partial join response, for rooms without a name or canonical alias. diff --git a/synapse/federation/federation_server.py b/synapse/federation/federation_server.py index 59e351595..bb20af6e9 100644 --- a/synapse/federation/federation_server.py +++ b/synapse/federation/federation_server.py @@ -74,6 +74,8 @@ from synapse.replication.http.federation import ( ) from synapse.storage.databases.main.events import PartialStateConflictError from synapse.storage.databases.main.lock import Lock +from synapse.storage.databases.main.roommember import extract_heroes_from_room_summary +from synapse.storage.roommember import MemberSummary from synapse.types import JsonDict, StateMap, get_domain_from_id from synapse.util import json_decoder, unwrapFirstError from synapse.util.async_helpers import Linearizer, concurrently_execute, gather_results @@ -691,8 +693,9 @@ class FederationServer(FederationBase): state_event_ids: Collection[str] servers_in_room: Optional[Collection[str]] if caller_supports_partial_state: + summary = await self.store.get_room_summary(room_id) state_event_ids = _get_event_ids_for_partial_state_join( - event, prev_state_ids + event, prev_state_ids, summary ) servers_in_room = await self.state.get_hosts_in_room_at_events( room_id, event_ids=event.prev_event_ids() @@ -1495,6 +1498,7 @@ class FederationHandlerRegistry: def _get_event_ids_for_partial_state_join( join_event: EventBase, prev_state_ids: StateMap[str], + summary: Dict[str, MemberSummary], ) -> Collection[str]: """Calculate state to be retuned in a partial_state send_join @@ -1521,8 +1525,19 @@ def _get_event_ids_for_partial_state_join( if current_membership_event_id is not None: state_event_ids.add(current_membership_event_id) - # TODO: return a few more members: - # - those with invites - # - those that are kicked? / banned + name_id = prev_state_ids.get((EventTypes.Name, "")) + canonical_alias_id = prev_state_ids.get((EventTypes.CanonicalAlias, "")) + if not name_id and not canonical_alias_id: + # Also include the hero members of the room (for DM rooms without a title). + # To do this properly, we should select the correct subset of membership events + # from `prev_state_ids`. Instead, we are lazier and use the (cached) + # `get_room_summary` function, which is based on the current state of the room. + # This introduces races; we choose to ignore them because a) they should be rare + # and b) even if it's wrong, joining servers will get the full state eventually. + heroes = extract_heroes_from_room_summary(summary, join_event.state_key) + for hero in heroes: + membership_event_id = prev_state_ids.get((EventTypes.Member, hero)) + if membership_event_id: + state_event_ids.add(membership_event_id) return state_event_ids diff --git a/synapse/handlers/sync.py b/synapse/handlers/sync.py index 1db5d6802..259456b55 100644 --- a/synapse/handlers/sync.py +++ b/synapse/handlers/sync.py @@ -41,6 +41,7 @@ from synapse.logging.context import current_context from synapse.logging.opentracing import SynapseTags, log_kv, set_tag, start_active_span from synapse.push.clientformat import format_push_rules_for_user from synapse.storage.databases.main.event_push_actions import RoomNotifCounts +from synapse.storage.databases.main.roommember import extract_heroes_from_room_summary from synapse.storage.roommember import MemberSummary from synapse.storage.state import StateFilter from synapse.types import ( @@ -805,18 +806,6 @@ class SyncHandler: if canonical_alias and canonical_alias.content.get("alias"): return summary - me = sync_config.user.to_string() - - joined_user_ids = [ - r[0] for r in details.get(Membership.JOIN, empty_ms).members if r[0] != me - ] - invited_user_ids = [ - r[0] for r in details.get(Membership.INVITE, empty_ms).members if r[0] != me - ] - gone_user_ids = [ - r[0] for r in details.get(Membership.LEAVE, empty_ms).members if r[0] != me - ] + [r[0] for r in details.get(Membership.BAN, empty_ms).members if r[0] != me] - # FIXME: only build up a member_ids list for our heroes member_ids = {} for membership in ( @@ -828,11 +817,8 @@ class SyncHandler: for user_id, event_id in details.get(membership, empty_ms).members: member_ids[user_id] = event_id - # FIXME: order by stream ordering rather than as returned by SQL - if joined_user_ids or invited_user_ids: - summary["m.heroes"] = sorted(joined_user_ids + invited_user_ids)[0:5] - else: - summary["m.heroes"] = sorted(gone_user_ids)[0:5] + me = sync_config.user.to_string() + summary["m.heroes"] = extract_heroes_from_room_summary(details, me) if not sync_config.filter_collection.lazy_load_members(): return summary diff --git a/synapse/storage/databases/main/roommember.py b/synapse/storage/databases/main/roommember.py index e56a13f21..f02c1d7ea 100644 --- a/synapse/storage/databases/main/roommember.py +++ b/synapse/storage/databases/main/roommember.py @@ -1517,6 +1517,36 @@ class RoomMemberStore( await self.db_pool.runInteraction("forget_membership", f) +def extract_heroes_from_room_summary( + details: Mapping[str, MemberSummary], me: str +) -> List[str]: + """Determine the users that represent a room, from the perspective of the `me` user. + + The rules which say which users we select are specified in the "Room Summary" + section of + https://spec.matrix.org/v1.4/client-server-api/#get_matrixclientv3sync + + Returns a list (possibly empty) of heroes' mxids. + """ + empty_ms = MemberSummary([], 0) + + joined_user_ids = [ + r[0] for r in details.get(Membership.JOIN, empty_ms).members if r[0] != me + ] + invited_user_ids = [ + r[0] for r in details.get(Membership.INVITE, empty_ms).members if r[0] != me + ] + gone_user_ids = [ + r[0] for r in details.get(Membership.LEAVE, empty_ms).members if r[0] != me + ] + [r[0] for r in details.get(Membership.BAN, empty_ms).members if r[0] != me] + + # FIXME: order by stream ordering rather than as returned by SQL + if joined_user_ids or invited_user_ids: + return sorted(joined_user_ids + invited_user_ids)[0:5] + else: + return sorted(gone_user_ids)[0:5] + + @attr.s(slots=True, auto_attribs=True) class _JoinedHostsCache: """The cached data used by the `_get_joined_hosts_cache`.""" diff --git a/tests/federation/test_federation_server.py b/tests/federation/test_federation_server.py index 3a6ef221a..177e5b5af 100644 --- a/tests/federation/test_federation_server.py +++ b/tests/federation/test_federation_server.py @@ -212,7 +212,7 @@ class SendJoinFederationTests(unittest.FederatingHomeserverTestCase): self.assertEqual(r[("m.room.member", joining_user)].membership, "join") @override_config({"experimental_features": {"msc3706_enabled": True}}) - def test_send_join_partial_state(self): + def test_send_join_partial_state(self) -> None: """When MSC3706 support is enabled, /send_join should return partial state""" joining_user = "@misspiggy:" + self.OTHER_SERVER_NAME join_result = self._make_join(joining_user) @@ -240,6 +240,9 @@ class SendJoinFederationTests(unittest.FederatingHomeserverTestCase): ("m.room.power_levels", ""), ("m.room.join_rules", ""), ("m.room.history_visibility", ""), + # Users included here because they're heroes. + ("m.room.member", "@kermit:test"), + ("m.room.member", "@fozzie:test"), ], ) @@ -249,9 +252,9 @@ class SendJoinFederationTests(unittest.FederatingHomeserverTestCase): ] self.assertCountEqual( returned_auth_chain_events, - [ - ("m.room.member", "@kermit:test"), - ], + # TODO: change the test so that we get at least one event in the auth chain + # here. + [], ) # the room should show that the new user is a member