diff options
Diffstat (limited to 'synapse/handlers')
| -rw-r--r-- | synapse/handlers/federation_event.py | 126 |
1 files changed, 44 insertions, 82 deletions
diff --git a/synapse/handlers/federation_event.py b/synapse/handlers/federation_event.py index bcc755a376..612e5aaa5b 100644 --- a/synapse/handlers/federation_event.py +++ b/synapse/handlers/federation_event.py @@ -23,7 +23,6 @@ from typing import ( Dict, Iterable, List, - Optional, Sequence, Set, Tuple, @@ -278,9 +277,8 @@ class FederationEventHandler: ) try: - await self._process_received_pdu( - origin, pdu, state_ids=None, partial_state=None - ) + context = await self._state_handler.compute_event_context(pdu) + await self._process_received_pdu(origin, pdu, context) except PartialStateConflictError: # The room was un-partial stated while we were processing the PDU. # Try once more, with full state this time. @@ -288,9 +286,8 @@ 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, partial_state=None - ) + context = await self._state_handler.compute_event_context(pdu) + await self._process_received_pdu(origin, pdu, context) async def on_send_membership_event( self, origin: str, event: EventBase @@ -320,6 +317,7 @@ class FederationEventHandler: The event and context of the event after inserting it into the room graph. Raises: + RuntimeError if any prev_events are missing SynapseError if the event is not accepted into the room PartialStateConflictError if the room was un-partial stated in between computing the state at the event and persisting it. The caller should @@ -380,7 +378,7 @@ class FederationEventHandler: # need to. await self._event_creation_handler.cache_joined_hosts_for_event(event, context) - await self._check_for_soft_fail(event, None, origin=origin) + await self._check_for_soft_fail(event, context=context, origin=origin) await self._run_push_actions_and_persist_event(event, context) return event, context @@ -538,36 +536,10 @@ class FederationEventHandler: # # This is the same operation as we do when we receive a regular event # over federation. - state_ids, partial_state = await self._resolve_state_at_missing_prevs( + context = await self._compute_event_context_with_maybe_missing_prevs( destination, event ) - - # 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: + if context.partial_state: # this can happen if some or all of the event's prev_events still have # partial state. We were careful to only pick events from the db without # partial-state prev events, so that implies that a prev event has @@ -840,26 +812,25 @@ class FederationEventHandler: try: try: - state_ids, partial_state = await self._resolve_state_at_missing_prevs( + context = await self._compute_event_context_with_maybe_missing_prevs( origin, event ) await self._process_received_pdu( origin, event, - state_ids=state_ids, - partial_state=partial_state, + context, 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( + context = await self._compute_event_context_with_maybe_missing_prevs( origin, event ) # 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: + if context.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" @@ -868,8 +839,7 @@ class FederationEventHandler: await self._process_received_pdu( origin, event, - state_ids=state_ids, - partial_state=partial_state, + context, backfilled=backfilled, ) except FederationError as e: @@ -878,15 +848,18 @@ class FederationEventHandler: else: raise - async def _resolve_state_at_missing_prevs( + async def _compute_event_context_with_maybe_missing_prevs( self, dest: str, event: EventBase - ) -> Tuple[Optional[StateMap[str]], Optional[bool]]: - """Calculate the state at an event with missing prev_events. + ) -> EventContext: + """Build an EventContext structure for a non-outlier event whose prev_events may + be missing. - This is used when we have pulled a batch of events from a remote server, and - still don't have all the prev_events. + This is used when we have pulled a batch of events from a remote server, and may + not have all the prev_events. - If we already have all the prev_events for `event`, this method does nothing. + To build an EventContext, we need to calculate the state before the event. If we + already have all the prev_events for `event`, we can simply use the state after + the prev_events to calculate the state before `event`. Otherwise, the missing prevs become new backwards extremities, and we fall back to asking the remote server for the state after each missing `prev_event`, @@ -907,10 +880,7 @@ class FederationEventHandler: event: an event to check for missing prevs. Returns: - 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. + The event context. Raises: FederationError if we fail to get the state from the remote server after any @@ -924,7 +894,7 @@ class FederationEventHandler: missing_prevs = prevs - seen if not missing_prevs: - return None, None + return await self._state_handler.compute_event_context(event) logger.info( "Event %s is missing prev_events %s: calculating state for a " @@ -990,7 +960,9 @@ class FederationEventHandler: "We can't get valid state history.", affected=event_id, ) - return state_map, partial_state + return await self._state_handler.compute_event_context( + event, state_ids_before_event=state_map, partial_state=partial_state + ) async def _get_state_ids_after_missing_prev_event( self, @@ -1159,8 +1131,7 @@ class FederationEventHandler: self, origin: str, event: EventBase, - state_ids: Optional[StateMap[str]], - partial_state: Optional[bool], + context: EventContext, backfilled: bool = False, ) -> None: """Called when we have a new non-outlier event. @@ -1182,32 +1153,18 @@ class FederationEventHandler: event: event to be persisted - 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 - - 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. + context: The `EventContext` to persist the event with. 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. + computing the state at the event and persisting it. The caller should + recompute `context` and retry exactly once when this happens. """ logger.debug("Processing event: %s", event) assert not event.internal_metadata.outlier - 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) except AuthError as e: @@ -1219,7 +1176,7 @@ class FederationEventHandler: # For new (non-backfilled and non-outlier) events we check if the event # passes auth based on the current state. If it doesn't then we # "soft-fail" the event. - await self._check_for_soft_fail(event, state_ids, origin=origin) + await self._check_for_soft_fail(event, context=context, origin=origin) await self._run_push_actions_and_persist_event(event, context, backfilled) @@ -1782,7 +1739,7 @@ class FederationEventHandler: async def _check_for_soft_fail( self, event: EventBase, - state_ids: Optional[StateMap[str]], + context: EventContext, origin: str, ) -> None: """Checks if we should soft fail the event; if so, marks the event as @@ -1793,7 +1750,7 @@ class FederationEventHandler: Args: event - state_ids: The state at the event if we don't have all the event's prev events + context: The `EventContext` which we are about to persist the event with. origin: The host the event originates from. """ if await self._store.is_partial_state_room(event.room_id): @@ -1819,11 +1776,15 @@ class FederationEventHandler: auth_types = auth_types_for_event(room_version_obj, event) # Calculate the "current state". - if state_ids is not None: - # If we're explicitly given the state then we won't have all the - # prev events, and so we have a gap in the graph. In this case - # we want to be a little careful as we might have been down for - # a while and have an incorrect view of the current state, + seen_event_ids = await self._store.have_events_in_timeline(prev_event_ids) + has_missing_prevs = bool(prev_event_ids - seen_event_ids) + if has_missing_prevs: + # We don't have all the prev_events of this event, which means we have a + # gap in the graph, and the new event is going to become a new backwards + # extremity. + # + # In this case we want to be a little careful as we might have been + # down for a while and have an incorrect view of the current state, # however we still want to do checks as gaps are easy to # maliciously manufacture. # @@ -1836,6 +1797,7 @@ class FederationEventHandler: event.room_id, extrem_ids ) state_sets: List[StateMap[str]] = list(state_sets_d.values()) + state_ids = await context.get_prev_state_ids() state_sets.append(state_ids) current_state_ids = ( await self._state_resolution_handler.resolve_events_with_store( |