diff options
Diffstat (limited to 'synapse/handlers/federation_event.py')
| -rw-r--r-- | synapse/handlers/federation_event.py | 116 |
1 files changed, 92 insertions, 24 deletions
diff --git a/synapse/handlers/federation_event.py b/synapse/handlers/federation_event.py index 16f20c8be7..fc1254d2ad 100644 --- a/synapse/handlers/federation_event.py +++ b/synapse/handlers/federation_event.py @@ -278,7 +278,9 @@ class FederationEventHandler: ) try: - await self._process_received_pdu(origin, pdu, state_ids=None) + await self._process_received_pdu( + origin, pdu, state_ids=None, partial_state=None + ) except PartialStateConflictError: # The room was un-partial stated while we were processing the PDU. # Try once more, with full state this time. @@ -286,7 +288,9 @@ class FederationEventHandler: "Room %s was un-partial stated while processing the PDU, trying again.", room_id, ) - await self._process_received_pdu(origin, pdu, state_ids=None) + await self._process_received_pdu( + origin, pdu, state_ids=None, partial_state=None + ) async def on_send_membership_event( self, origin: str, event: EventBase @@ -534,14 +538,36 @@ class FederationEventHandler: # # This is the same operation as we do when we receive a regular event # over federation. - state_ids = await self._resolve_state_at_missing_prevs(destination, event) - - # build a new state group for it if need be - context = await self._state_handler.compute_event_context( - event, - state_ids_before_event=state_ids, + state_ids, partial_state = await self._resolve_state_at_missing_prevs( + destination, event ) - if context.partial_state: + + # There are three possible cases for (state_ids, partial_state): + # * `state_ids` and `partial_state` are both `None` if we had all the + # prev_events. The prev_events may or may not have partial state and + # we won't know until we compute the event context. + # * `state_ids` is not `None` and `partial_state` is `False` if we were + # missing some prev_events (but we have full state for any we did + # have). We calculated the full state after the prev_events. + # * `state_ids` is not `None` and `partial_state` is `True` if we were + # missing some, but not all, prev_events. At least one of the + # prev_events we did have had partial state, so we calculated a partial + # state after the prev_events. + + context = None + if state_ids is not None and partial_state: + # the state after the prev events is still partial. We can't de-partial + # state the event, so don't bother building the event context. + pass + else: + # build a new state group for it if need be + context = await self._state_handler.compute_event_context( + event, + state_ids_before_event=state_ids, + partial_state=partial_state, + ) + + if context is None or context.partial_state: # this can happen if some or all of the event's prev_events still have # partial state - ie, an event has an earlier stream_ordering than one # or more of its prev_events, so we de-partial-state it before its @@ -806,14 +832,39 @@ class FederationEventHandler: return try: - state_ids = await self._resolve_state_at_missing_prevs(origin, event) - # TODO(faster_joins): make sure that _resolve_state_at_missing_prevs does - # not return partial state - # https://github.com/matrix-org/synapse/issues/13002 + try: + state_ids, partial_state = await self._resolve_state_at_missing_prevs( + origin, event + ) + await self._process_received_pdu( + origin, + event, + state_ids=state_ids, + partial_state=partial_state, + backfilled=backfilled, + ) + except PartialStateConflictError: + # The room was un-partial stated while we were processing the event. + # Try once more, with full state this time. + state_ids, partial_state = await self._resolve_state_at_missing_prevs( + origin, event + ) - await self._process_received_pdu( - origin, event, state_ids=state_ids, backfilled=backfilled - ) + # We ought to have full state now, barring some unlikely race where we left and + # rejoned the room in the background. + if state_ids is not None and partial_state: + raise AssertionError( + f"Event {event.event_id} still has a partial resolved state " + f"after room {event.room_id} was un-partial stated" + ) + + await self._process_received_pdu( + origin, + event, + state_ids=state_ids, + partial_state=partial_state, + backfilled=backfilled, + ) except FederationError as e: if e.code == 403: logger.warning("Pulled event %s failed history check.", event_id) @@ -822,7 +873,7 @@ class FederationEventHandler: async def _resolve_state_at_missing_prevs( self, dest: str, event: EventBase - ) -> Optional[StateMap[str]]: + ) -> Tuple[Optional[StateMap[str]], Optional[bool]]: """Calculate the state at an event with missing prev_events. This is used when we have pulled a batch of events from a remote server, and @@ -849,8 +900,10 @@ class FederationEventHandler: event: an event to check for missing prevs. Returns: - if we already had all the prev events, `None`. Otherwise, returns - the event ids of the state at `event`. + if we already had all the prev events, `None, None`. Otherwise, returns a + tuple containing: + * the event ids of the state at `event`. + * a boolean indicating whether the state may be partial. Raises: FederationError if we fail to get the state from the remote server after any @@ -864,7 +917,7 @@ class FederationEventHandler: missing_prevs = prevs - seen if not missing_prevs: - return None + return None, None logger.info( "Event %s is missing prev_events %s: calculating state for a " @@ -876,9 +929,15 @@ class FederationEventHandler: # resolve them to find the correct state at the current event. try: + # Determine whether we may be about to retrieve partial state + # Events may be un-partial stated right after we compute the partial state + # flag, but that's okay, as long as the flag errs on the conservative side. + partial_state_flags = await self._store.get_partial_state_events(seen) + partial_state = any(partial_state_flags.values()) + # Get the state of the events we know about ours = await self._state_storage_controller.get_state_groups_ids( - room_id, seen + room_id, seen, await_full_state=False ) # state_maps is a list of mappings from (type, state_key) to event_id @@ -924,7 +983,7 @@ class FederationEventHandler: "We can't get valid state history.", affected=event_id, ) - return state_map + return state_map, partial_state async def _get_state_ids_after_missing_prev_event( self, @@ -1094,6 +1153,7 @@ class FederationEventHandler: origin: str, event: EventBase, state_ids: Optional[StateMap[str]], + partial_state: Optional[bool], backfilled: bool = False, ) -> None: """Called when we have a new non-outlier event. @@ -1117,14 +1177,21 @@ class FederationEventHandler: state_ids: Normally None, but if we are handling a gap in the graph (ie, we are missing one or more prev_events), the resolved state at the - event. Must not be partial state. + event + + partial_state: + `True` if `state_ids` is partial and omits non-critical membership + events. + `False` if `state_ids` is the full state. + `None` if `state_ids` is not provided. In this case, the flag will be + calculated based on `event`'s prev events. backfilled: True if this is part of a historical batch of events (inhibits notification to clients, and validation of device keys.) PartialStateConflictError: if the room was un-partial stated in between computing the state at the event and persisting it. The caller should retry - exactly once in this case. Will never be raised if `state_ids` is provided. + exactly once in this case. """ logger.debug("Processing event: %s", event) assert not event.internal_metadata.outlier @@ -1132,6 +1199,7 @@ class FederationEventHandler: context = await self._state_handler.compute_event_context( event, state_ids_before_event=state_ids, + partial_state=partial_state, ) try: await self._check_event_auth(origin, event, context) |