From c6516adbe03a0acdd614ba6eb9d6f447dd4259e9 Mon Sep 17 00:00:00 2001 From: Richard van der Hoff <1389908+richvdh@users.noreply.github.com> Date: Fri, 1 Nov 2019 16:19:09 +0000 Subject: [PATCH] Factor out an _AsyncEventContextImpl (#6298) The intention here is to make it clearer which fields we can expect to be populated when: notably, that the _event_type etc aren't used for the synchronous impl of EventContext. --- changelog.d/6298.misc | 1 + synapse/events/snapshot.py | 107 +++++++++++++-------------------- synapse/handlers/federation.py | 38 ++++++------ tests/test_federation.py | 4 +- 4 files changed, 65 insertions(+), 85 deletions(-) create mode 100644 changelog.d/6298.misc diff --git a/changelog.d/6298.misc b/changelog.d/6298.misc new file mode 100644 index 0000000000..d4190730b2 --- /dev/null +++ b/changelog.d/6298.misc @@ -0,0 +1 @@ +Refactor EventContext for clarity. \ No newline at end of file diff --git a/synapse/events/snapshot.py b/synapse/events/snapshot.py index 27cd8a63ff..a269de5482 100644 --- a/synapse/events/snapshot.py +++ b/synapse/events/snapshot.py @@ -37,9 +37,6 @@ class EventContext: delta_ids (dict[(str, str), str]): Delta from ``prev_group``. (type, state_key) -> event_id. ``None`` for an outlier. - prev_state_events (?): XXX: is this ever set to anything other than - the empty list? - app_service: FIXME _current_state_ids (dict[(str, str), str]|None): @@ -51,36 +48,16 @@ class EventContext: The current state map excluding the current event. None if outlier or we haven't fetched the state from DB yet. (type, state_key) -> event_id - - _fetching_state_deferred (Deferred|None): Resolves when *_state_ids have - been calculated. None if we haven't started calculating yet - - _event_type (str): The type of the event the context is associated with. - Only set when state has not been fetched yet. - - _event_state_key (str|None): The state_key of the event the context is - associated with. Only set when state has not been fetched yet. - - _prev_state_id (str|None): If the event associated with the context is - a state event, then `_prev_state_id` is the event_id of the state - that was replaced. - Only set when state has not been fetched yet. """ state_group = attr.ib(default=None) rejected = attr.ib(default=False) prev_group = attr.ib(default=None) delta_ids = attr.ib(default=None) - prev_state_events = attr.ib(default=attr.Factory(list)) app_service = attr.ib(default=None) - _current_state_ids = attr.ib(default=None) _prev_state_ids = attr.ib(default=None) - _prev_state_id = attr.ib(default=None) - - _event_type = attr.ib(default=None) - _event_state_key = attr.ib(default=None) - _fetching_state_deferred = attr.ib(default=None) + _current_state_ids = attr.ib(default=None) @staticmethod def with_state( @@ -90,7 +67,6 @@ class EventContext: current_state_ids=current_state_ids, prev_state_ids=prev_state_ids, state_group=state_group, - fetching_state_deferred=defer.succeed(None), prev_group=prev_group, delta_ids=delta_ids, ) @@ -125,7 +101,6 @@ class EventContext: "rejected": self.rejected, "prev_group": self.prev_group, "delta_ids": _encode_state_dict(self.delta_ids), - "prev_state_events": self.prev_state_events, "app_service_id": self.app_service.id if self.app_service else None, } @@ -141,7 +116,7 @@ class EventContext: Returns: EventContext """ - context = EventContext( + context = _AsyncEventContextImpl( # We use the state_group and prev_state_id stuff to pull the # current_state_ids out of the DB and construct prev_state_ids. prev_state_id=input["prev_state_id"], @@ -151,7 +126,6 @@ class EventContext: prev_group=input["prev_group"], delta_ids=_decode_state_dict(input["delta_ids"]), rejected=input["rejected"], - prev_state_events=input["prev_state_events"], ) app_service_id = input["app_service_id"] @@ -170,14 +144,7 @@ class EventContext: Maps a (type, state_key) to the event ID of the state event matching this tuple. """ - - if not self._fetching_state_deferred: - self._fetching_state_deferred = run_in_background( - self._fill_out_state, store - ) - - yield make_deferred_yieldable(self._fetching_state_deferred) - + yield self._ensure_fetched(store) return self._current_state_ids @defer.inlineCallbacks @@ -190,14 +157,7 @@ class EventContext: Maps a (type, state_key) to the event ID of the state event matching this tuple. """ - - if not self._fetching_state_deferred: - self._fetching_state_deferred = run_in_background( - self._fill_out_state, store - ) - - yield make_deferred_yieldable(self._fetching_state_deferred) - + yield self._ensure_fetched(store) return self._prev_state_ids def get_cached_current_state_ids(self): @@ -211,6 +171,44 @@ class EventContext: return self._current_state_ids + def _ensure_fetched(self, store): + return defer.succeed(None) + + +@attr.s(slots=True) +class _AsyncEventContextImpl(EventContext): + """ + An implementation of EventContext which fetches _current_state_ids and + _prev_state_ids from the database on demand. + + Attributes: + + _fetching_state_deferred (Deferred|None): Resolves when *_state_ids have + been calculated. None if we haven't started calculating yet + + _event_type (str): The type of the event the context is associated with. + + _event_state_key (str): The state_key of the event the context is + associated with. + + _prev_state_id (str|None): If the event associated with the context is + a state event, then `_prev_state_id` is the event_id of the state + that was replaced. + """ + + _prev_state_id = attr.ib(default=None) + _event_type = attr.ib(default=None) + _event_state_key = attr.ib(default=None) + _fetching_state_deferred = attr.ib(default=None) + + def _ensure_fetched(self, store): + if not self._fetching_state_deferred: + self._fetching_state_deferred = run_in_background( + self._fill_out_state, store + ) + + return make_deferred_yieldable(self._fetching_state_deferred) + @defer.inlineCallbacks def _fill_out_state(self, store): """Called to populate the _current_state_ids and _prev_state_ids @@ -228,27 +226,6 @@ class EventContext: else: self._prev_state_ids = self._current_state_ids - @defer.inlineCallbacks - def update_state( - self, state_group, prev_state_ids, current_state_ids, prev_group, delta_ids - ): - """Replace the state in the context - """ - - # We need to make sure we wait for any ongoing fetching of state - # to complete so that the updated state doesn't get clobbered - if self._fetching_state_deferred: - yield make_deferred_yieldable(self._fetching_state_deferred) - - self.state_group = state_group - self._prev_state_ids = prev_state_ids - self.prev_group = prev_group - self._current_state_ids = current_state_ids - self.delta_ids = delta_ids - - # We need to ensure that that we've marked as having fetched the state - self._fetching_state_deferred = defer.succeed(None) - def _encode_state_dict(state_dict): """Since dicts of (type, state_key) -> event_id cannot be serialized in diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py index dab6be9573..8cafcfdab0 100644 --- a/synapse/handlers/federation.py +++ b/synapse/handlers/federation.py @@ -45,6 +45,7 @@ from synapse.api.errors import ( from synapse.api.room_versions import KNOWN_ROOM_VERSIONS, RoomVersions from synapse.crypto.event_signing import compute_event_signature from synapse.event_auth import auth_types_for_event +from synapse.events.snapshot import EventContext from synapse.events.validator import EventValidator from synapse.logging.context import ( make_deferred_yieldable, @@ -1871,14 +1872,7 @@ class FederationHandler(BaseHandler): if c and c.type == EventTypes.Create: auth_events[(c.type, c.state_key)] = c - try: - yield self.do_auth(origin, event, context, auth_events=auth_events) - except AuthError as e: - logger.warning( - "[%s %s] Rejecting: %s", event.room_id, event.event_id, e.msg - ) - - context.rejected = RejectedReason.AUTH_ERROR + context = yield self.do_auth(origin, event, context, auth_events=auth_events) if not context.rejected: yield self._check_for_soft_fail(event, state, backfilled) @@ -2047,12 +2041,12 @@ class FederationHandler(BaseHandler): Also NB that this function adds entries to it. Returns: - defer.Deferred[None] + defer.Deferred[EventContext]: updated context object """ room_version = yield self.store.get_room_version(event.room_id) try: - yield self._update_auth_events_and_context_for_auth( + context = yield self._update_auth_events_and_context_for_auth( origin, event, context, auth_events ) except Exception: @@ -2070,7 +2064,9 @@ class FederationHandler(BaseHandler): event_auth.check(room_version, event, auth_events=auth_events) except AuthError as e: logger.warning("Failed auth resolution for %r because %s", event, e) - raise e + context.rejected = RejectedReason.AUTH_ERROR + + return context @defer.inlineCallbacks def _update_auth_events_and_context_for_auth( @@ -2094,7 +2090,7 @@ class FederationHandler(BaseHandler): auth_events (dict[(str, str)->synapse.events.EventBase]): Returns: - defer.Deferred[None] + defer.Deferred[EventContext]: updated context """ event_auth_events = set(event.auth_event_ids()) @@ -2133,7 +2129,7 @@ class FederationHandler(BaseHandler): # The other side isn't around or doesn't implement the # endpoint, so lets just bail out. logger.info("Failed to get event auth from remote: %s", e) - return + return context seen_remotes = yield self.store.have_seen_events( [e.event_id for e in remote_auth_chain] @@ -2174,7 +2170,7 @@ class FederationHandler(BaseHandler): if event.internal_metadata.is_outlier(): logger.info("Skipping auth_event fetch for outlier") - return + return context # FIXME: Assumes we have and stored all the state for all the # prev_events @@ -2183,7 +2179,7 @@ class FederationHandler(BaseHandler): ) if not different_auth: - return + return context logger.info( "auth_events refers to events which are not in our calculated auth " @@ -2230,10 +2226,12 @@ class FederationHandler(BaseHandler): auth_events.update(new_state) - yield self._update_context_for_auth_events( + context = yield self._update_context_for_auth_events( event, context, auth_events, event_key ) + return context + @defer.inlineCallbacks def _update_context_for_auth_events(self, event, context, auth_events, event_key): """Update the state_ids in an event context after auth event resolution, @@ -2242,14 +2240,16 @@ class FederationHandler(BaseHandler): Args: event (Event): The event we're handling the context for - context (synapse.events.snapshot.EventContext): event context - to be updated + context (synapse.events.snapshot.EventContext): initial event context auth_events (dict[(str, str)->str]): Events to update in the event context. event_key ((str, str)): (type, state_key) for the current event. this will not be included in the current_state in the context. + + Returns: + Deferred[EventContext]: new event context """ state_updates = { k: a.event_id for k, a in iteritems(auth_events) if k != event_key @@ -2274,7 +2274,7 @@ class FederationHandler(BaseHandler): current_state_ids=current_state_ids, ) - yield context.update_state( + return EventContext.with_state( state_group=state_group, current_state_ids=current_state_ids, prev_state_ids=prev_state_ids, diff --git a/tests/test_federation.py b/tests/test_federation.py index d1acb16f30..7d82b58466 100644 --- a/tests/test_federation.py +++ b/tests/test_federation.py @@ -59,7 +59,9 @@ class MessageAcceptTests(unittest.TestCase): ) self.handler = self.homeserver.get_handlers().federation_handler - self.handler.do_auth = lambda *a, **b: succeed(True) + self.handler.do_auth = lambda origin, event, context, auth_events: succeed( + context + ) self.client = self.homeserver.get_federation_client() self.client._check_sigs_and_hash_and_fetch = lambda dest, pdus, **k: succeed( pdus