diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py
index e8330a2b50..798ed75b30 100644
--- a/synapse/handlers/federation.py
+++ b/synapse/handlers/federation.py
@@ -552,8 +552,12 @@ class FederationHandler(BaseHandler):
destination: str,
room_id: str,
event_id: str,
- ) -> Tuple[List[EventBase], List[EventBase]]:
- """Requests all of the room state at a given event from a remote homeserver.
+ ) -> List[EventBase]:
+ """Requests all of the room state at a given event from a remote
+ homeserver.
+
+ Will also fetch any missing events reported in the `auth_chain_ids`
+ section of `/state_ids`.
Args:
destination: The remote homeserver to query for the state.
@@ -561,8 +565,7 @@ class FederationHandler(BaseHandler):
event_id: The id of the event we want the state at.
Returns:
- A list of events in the state, not including the event itself, and
- a list of events in the auth chain for the given event.
+ A list of events in the state, not including the event itself.
"""
(
state_event_ids,
@@ -571,68 +574,53 @@ class FederationHandler(BaseHandler):
destination, room_id, event_id=event_id
)
- desired_events = set(state_event_ids + auth_event_ids)
-
- event_map = await self._get_events_from_store_or_dest(
- destination, room_id, desired_events
- )
+ # Fetch the state events from the DB, and check we have the auth events.
+ event_map = await self.store.get_events(state_event_ids, allow_rejected=True)
+ auth_events_in_store = await self.store.have_seen_events(auth_event_ids)
- failed_to_fetch = desired_events - event_map.keys()
- if failed_to_fetch:
- logger.warning(
- "Failed to fetch missing state/auth events for %s %s",
- event_id,
- failed_to_fetch,
+ # Check for missing events. We handle state and auth event seperately,
+ # as we want to pull the state from the DB, but we don't for the auth
+ # events. (Note: we likely won't use the majority of the auth chain, and
+ # it can be *huge* for large rooms, so it's worth ensuring that we don't
+ # unnecessarily pull it from the DB).
+ missing_state_events = set(state_event_ids) - set(event_map)
+ missing_auth_events = set(auth_event_ids) - set(auth_events_in_store)
+ if missing_state_events or missing_auth_events:
+ await self._get_events_and_persist(
+ destination=destination,
+ room_id=room_id,
+ events=missing_state_events | missing_auth_events,
)
- remote_state = [
- event_map[e_id] for e_id in state_event_ids if e_id in event_map
- ]
-
- auth_chain = [event_map[e_id] for e_id in auth_event_ids if e_id in event_map]
- auth_chain.sort(key=lambda e: e.depth)
-
- return remote_state, auth_chain
-
- async def _get_events_from_store_or_dest(
- self, destination: str, room_id: str, event_ids: Iterable[str]
- ) -> Dict[str, EventBase]:
- """Fetch events from a remote destination, checking if we already have them.
-
- Persists any events we don't already have as outliers.
-
- If we fail to fetch any of the events, a warning will be logged, and the event
- will be omitted from the result. Likewise, any events which turn out not to
- be in the given room.
+ if missing_state_events:
+ new_events = await self.store.get_events(
+ missing_state_events, allow_rejected=True
+ )
+ event_map.update(new_events)
- This function *does not* automatically get missing auth events of the
- newly fetched events. Callers must include the full auth chain of
- of the missing events in the `event_ids` argument, to ensure that any
- missing auth events are correctly fetched.
+ missing_state_events.difference_update(new_events)
- Returns:
- map from event_id to event
- """
- fetched_events = await self.store.get_events(event_ids, allow_rejected=True)
-
- missing_events = set(event_ids) - fetched_events.keys()
+ if missing_state_events:
+ logger.warning(
+ "Failed to fetch missing state events for %s %s",
+ event_id,
+ missing_state_events,
+ )
- if missing_events:
- logger.debug(
- "Fetching unknown state/auth events %s for room %s",
- missing_events,
- room_id,
- )
+ if missing_auth_events:
+ auth_events_in_store = await self.store.have_seen_events(
+ missing_auth_events
+ )
+ missing_auth_events.difference_update(auth_events_in_store)
- await self._get_events_and_persist(
- destination=destination, room_id=room_id, events=missing_events
- )
+ if missing_auth_events:
+ logger.warning(
+ "Failed to fetch missing auth events for %s %s",
+ event_id,
+ missing_auth_events,
+ )
- # we need to make sure we re-load from the database to get the rejected
- # state correct.
- fetched_events.update(
- (await self.store.get_events(missing_events, allow_rejected=True))
- )
+ remote_state = list(event_map.values())
# check for events which were in the wrong room.
#
@@ -640,8 +628,8 @@ class FederationHandler(BaseHandler):
# auth_events at an event in room A are actually events in room B
bad_events = [
- (event_id, event.room_id)
- for event_id, event in fetched_events.items()
+ (event.event_id, event.room_id)
+ for event in remote_state
if event.room_id != room_id
]
@@ -658,9 +646,10 @@ class FederationHandler(BaseHandler):
room_id,
)
- del fetched_events[bad_event_id]
+ if bad_events:
+ remote_state = [e for e in remote_state if e.room_id == room_id]
- return fetched_events
+ return remote_state
async def _get_state_after_missing_prev_event(
self,
@@ -963,27 +952,23 @@ class FederationHandler(BaseHandler):
# For each edge get the current state.
- auth_events = {}
state_events = {}
events_to_state = {}
for e_id in edges:
- state, auth = await self._get_state_for_room(
+ state = await self._get_state_for_room(
destination=dest,
room_id=room_id,
event_id=e_id,
)
- auth_events.update({a.event_id: a for a in auth})
- auth_events.update({s.event_id: s for s in state})
state_events.update({s.event_id: s for s in state})
events_to_state[e_id] = state
required_auth = {
a_id
- for event in events
- + list(state_events.values())
- + list(auth_events.values())
+ for event in events + list(state_events.values())
for a_id in event.auth_event_ids()
}
+ auth_events = await self.store.get_events(required_auth, allow_rejected=True)
auth_events.update(
{e_id: event_map[e_id] for e_id in required_auth if e_id in event_map}
)
|
