From 8cb44da4aa569188faa2a94aae6bc093aa8e22ec Mon Sep 17 00:00:00 2001 From: Erik Johnston Date: Mon, 5 Mar 2018 12:06:19 +0000 Subject: [PATCH 1/3] Fix race in sync when joining room The race happens when the user joins a room at the same time as doing a sync. We fetch the current token and then get the rooms the user is in. If the join happens after the current token, but before we get the rooms we end up sending down a partial room entry in the sync. This is fixed by looking at the stream ordering of the membership returned by get_rooms_for_user, and handling the case when that stream ordering is after the current token. --- synapse/handlers/sync.py | 103 +++++++++++++++++++++++++--------- synapse/storage/events.py | 2 +- synapse/storage/roommember.py | 27 ++++++++- 3 files changed, 102 insertions(+), 30 deletions(-) diff --git a/synapse/handlers/sync.py b/synapse/handlers/sync.py index 56b86356f..163d80417 100644 --- a/synapse/handlers/sync.py +++ b/synapse/handlers/sync.py @@ -235,10 +235,10 @@ class SyncHandler(object): defer.returnValue(rules) @defer.inlineCallbacks - def ephemeral_by_room(self, sync_config, now_token, since_token=None): + def ephemeral_by_room(self, sync_result_builder, now_token, since_token=None): """Get the ephemeral events for each room the user is in Args: - sync_config (SyncConfig): The flags, filters and user for the sync. + sync_result_builder(SyncResultBuilder) now_token (StreamToken): Where the server is currently up to. since_token (StreamToken): Where the server was when the client last synced. @@ -248,10 +248,12 @@ class SyncHandler(object): typing events for that room. """ + sync_config = sync_result_builder.sync_config + with Measure(self.clock, "ephemeral_by_room"): typing_key = since_token.typing_key if since_token else "0" - room_ids = yield self.store.get_rooms_for_user(sync_config.user.to_string()) + room_ids = sync_result_builder.joined_room_ids typing_source = self.event_sources.sources["typing"] typing, typing_key = yield typing_source.get_new_events( @@ -565,10 +567,22 @@ class SyncHandler(object): # Always use the `now_token` in `SyncResultBuilder` now_token = yield self.event_sources.get_current_token() + user_id = sync_config.user.to_string() + app_service = self.store.get_app_service_by_user_id(user_id) + if app_service: + # We no longer support AS users using /sync directly. + # See https://github.com/matrix-org/matrix-doc/issues/1144 + raise NotImplementedError() + else: + joined_room_ids = yield self.get_rooms_for_user_at( + user_id, now_token.room_stream_id, + ) + sync_result_builder = SyncResultBuilder( sync_config, full_state, since_token=since_token, now_token=now_token, + joined_room_ids=joined_room_ids, ) account_data_by_room = yield self._generate_sync_entry_for_account_data( @@ -603,7 +617,6 @@ class SyncHandler(object): device_id = sync_config.device_id one_time_key_counts = {} if device_id: - user_id = sync_config.user.to_string() one_time_key_counts = yield self.store.count_e2e_one_time_keys( user_id, device_id ) @@ -891,7 +904,7 @@ class SyncHandler(object): ephemeral_by_room = {} else: now_token, ephemeral_by_room = yield self.ephemeral_by_room( - sync_result_builder.sync_config, + sync_result_builder, now_token=sync_result_builder.now_token, since_token=sync_result_builder.since_token, ) @@ -996,16 +1009,8 @@ class SyncHandler(object): if rooms_changed: defer.returnValue(True) - app_service = self.store.get_app_service_by_user_id(user_id) - if app_service: - # We no longer support AS users using /sync directly. - # See https://github.com/matrix-org/matrix-doc/issues/1144 - raise NotImplementedError() - else: - joined_room_ids = yield self.store.get_rooms_for_user(user_id) - stream_id = RoomStreamToken.parse_stream_token(since_token.room_key).stream - for room_id in joined_room_ids: + for room_id in sync_result_builder.joined_room_ids: if self.store.has_room_changed_since(room_id, stream_id): defer.returnValue(True) defer.returnValue(False) @@ -1029,14 +1034,6 @@ class SyncHandler(object): assert since_token - app_service = self.store.get_app_service_by_user_id(user_id) - if app_service: - # We no longer support AS users using /sync directly. - # See https://github.com/matrix-org/matrix-doc/issues/1144 - raise NotImplementedError() - else: - joined_room_ids = yield self.store.get_rooms_for_user(user_id) - # Get a list of membership change events that have happened. rooms_changed = yield self.store.get_membership_changes_for_user( user_id, since_token.room_key, now_token.room_key @@ -1059,7 +1056,7 @@ class SyncHandler(object): # we do send down the room, and with full state, where necessary old_state_ids = None - if room_id in joined_room_ids and non_joins: + if room_id in sync_result_builder.joined_room_ids and non_joins: # Always include if the user (re)joined the room, especially # important so that device list changes are calculated correctly. # If there are non join member events, but we are still in the room, @@ -1069,7 +1066,7 @@ class SyncHandler(object): # User is in the room so we don't need to do the invite/leave checks continue - if room_id in joined_room_ids or has_join: + if room_id in sync_result_builder.joined_room_ids or has_join: old_state_ids = yield self.get_state_at(room_id, since_token) old_mem_ev_id = old_state_ids.get((EventTypes.Member, user_id), None) old_mem_ev = None @@ -1081,7 +1078,7 @@ class SyncHandler(object): newly_joined_rooms.append(room_id) # If user is in the room then we don't need to do the invite/leave checks - if room_id in joined_room_ids: + if room_id in sync_result_builder.joined_room_ids: continue if not non_joins: @@ -1148,7 +1145,7 @@ class SyncHandler(object): # Get all events for rooms we're currently joined to. room_to_events = yield self.store.get_room_events_stream_for_rooms( - room_ids=joined_room_ids, + room_ids=sync_result_builder.joined_room_ids, from_key=since_token.room_key, to_key=now_token.room_key, limit=timeline_limit + 1, @@ -1156,7 +1153,7 @@ class SyncHandler(object): # We loop through all room ids, even if there are no new events, in case # there are non room events taht we need to notify about. - for room_id in joined_room_ids: + for room_id in sync_result_builder.joined_room_ids: room_entry = room_to_events.get(room_id, None) if room_entry: @@ -1364,6 +1361,54 @@ class SyncHandler(object): else: raise Exception("Unrecognized rtype: %r", room_builder.rtype) + @defer.inlineCallbacks + def get_rooms_for_user_at(self, user_id, stream_ordering): + """Get set of joined rooms for a user at the given stream ordering. + + The stream ordering *must* be recent, otherwise this may throw an + exception if older than a month. (This function is called with the + current token, which should be perfectly fine). + + Args: + user_id (str) + stream_ordering (int) + + ReturnValue: + Deferred[frozenset[str]]: Set of room_ids the user is in at given + stream_ordering. + """ + joined_rooms = yield self.store.get_rooms_for_user_with_stream_ordering( + user_id, + ) + + joined_room_ids = set() + + # We need to check that the stream ordering of the join for each room + # is before the stream_ordering asked for. This might not be the case + # if the user joins a room between us getting the current token and + # calling `get_rooms_for_user_with_stream_ordering`. + # If the membership's stream ordering is after the given stream + # ordering, we need to go and work out if the user was in the room + # before. + for room_id, membeship_stream_ordering in joined_rooms: + if membeship_stream_ordering <= stream_ordering: + joined_room_ids.add(room_id) + continue + + logger.info("SH joined_room_ids membership after current token") + + extrems = yield self.store.get_forward_extremeties_for_room( + room_id, stream_ordering, + ) + users_in_room = yield self.state.get_current_user_in_room( + room_id, extrems, + ) + if user_id in users_in_room: + joined_room_ids.add(room_id) + + joined_room_ids = frozenset(joined_room_ids) + defer.returnValue(joined_room_ids) + def _action_has_highlight(actions): for action in actions: @@ -1413,7 +1458,8 @@ def _calculate_state(timeline_contains, timeline_start, previous, current): class SyncResultBuilder(object): "Used to help build up a new SyncResult for a user" - def __init__(self, sync_config, full_state, since_token, now_token): + def __init__(self, sync_config, full_state, since_token, now_token, + joined_room_ids): """ Args: sync_config(SyncConfig) @@ -1425,6 +1471,7 @@ class SyncResultBuilder(object): self.full_state = full_state self.since_token = since_token self.now_token = now_token + self.joined_room_ids = joined_room_ids self.presence = [] self.account_data = [] diff --git a/synapse/storage/events.py b/synapse/storage/events.py index 057b1be4d..826fad307 100644 --- a/synapse/storage/events.py +++ b/synapse/storage/events.py @@ -754,7 +754,7 @@ class EventsStore(EventsWorkerStore): for member in members_changed: self._invalidate_cache_and_stream( - txn, self.get_rooms_for_user, (member,) + txn, self.get_rooms_for_user_with_stream_ordering, (member,) ) for host in set(get_domain_from_id(u) for u in members_changed): diff --git a/synapse/storage/roommember.py b/synapse/storage/roommember.py index d79877dac..52e19e16b 100644 --- a/synapse/storage/roommember.py +++ b/synapse/storage/roommember.py @@ -38,6 +38,11 @@ RoomsForUser = namedtuple( ("room_id", "sender", "membership", "event_id", "stream_ordering") ) +GetRoomsForUserWithStreamOrdering = namedtuple( + "_GetRoomsForUserWithStreamOrdering", + ("room_id", "stream_ordering",) +) + # We store this using a namedtuple so that we save about 3x space over using a # dict. @@ -181,12 +186,32 @@ class RoomMemberWorkerStore(EventsWorkerStore): return results @cachedInlineCallbacks(max_entries=500000, iterable=True) - def get_rooms_for_user(self, user_id): + def get_rooms_for_user_with_stream_ordering(self, user_id): """Returns a set of room_ids the user is currently joined to + + Args: + user_id (str) + + Returns: + Deferred[frozenset[GetRoomsForUserWithStreamOrdering]]: Returns + the rooms the user is in currently, along with the stream ordering + of the most recent join for that user and room. """ rooms = yield self.get_rooms_for_user_where_membership_is( user_id, membership_list=[Membership.JOIN], ) + defer.returnValue(frozenset( + GetRoomsForUserWithStreamOrdering(r.room_id, r.stream_ordering) + for r in rooms + )) + + @defer.inlineCallbacks + def get_rooms_for_user(self, user_id, on_invalidate=None): + """Returns a set of room_ids the user is currently joined to + """ + rooms = yield self.get_rooms_for_user_with_stream_ordering( + user_id, on_invalidate=on_invalidate, + ) defer.returnValue(frozenset(r.room_id for r in rooms)) @cachedInlineCallbacks(max_entries=500000, cache_context=True, iterable=True) From 02a1296ad634ff8200abe539d27a53a6f850081d Mon Sep 17 00:00:00 2001 From: Erik Johnston Date: Mon, 5 Mar 2018 13:12:08 +0000 Subject: [PATCH 2/3] Fix typo --- synapse/handlers/sync.py | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/synapse/handlers/sync.py b/synapse/handlers/sync.py index 163d80417..b323e0e6b 100644 --- a/synapse/handlers/sync.py +++ b/synapse/handlers/sync.py @@ -1390,8 +1390,8 @@ class SyncHandler(object): # If the membership's stream ordering is after the given stream # ordering, we need to go and work out if the user was in the room # before. - for room_id, membeship_stream_ordering in joined_rooms: - if membeship_stream_ordering <= stream_ordering: + for room_id, membership_stream_ordering in joined_rooms: + if membership_stream_ordering <= stream_ordering: joined_room_ids.add(room_id) continue From a56d54dcb7d3d42fc417d6af82a46d86edf6f73d Mon Sep 17 00:00:00 2001 From: Erik Johnston Date: Mon, 5 Mar 2018 13:29:49 +0000 Subject: [PATCH 3/3] Fix up log message --- synapse/handlers/sync.py | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/synapse/handlers/sync.py b/synapse/handlers/sync.py index b323e0e6b..0f713ce03 100644 --- a/synapse/handlers/sync.py +++ b/synapse/handlers/sync.py @@ -1395,7 +1395,7 @@ class SyncHandler(object): joined_room_ids.add(room_id) continue - logger.info("SH joined_room_ids membership after current token") + logger.info("User joined room after current token: %s", room_id) extrems = yield self.store.get_forward_extremeties_for_room( room_id, stream_ordering,