diff options
Diffstat (limited to '')
| -rw-r--r-- | synapse/handlers/room.py | 59 |
1 files changed, 45 insertions, 14 deletions
diff --git a/synapse/handlers/room.py b/synapse/handlers/room.py index 978d3ee39f..55395457c3 100644 --- a/synapse/handlers/room.py +++ b/synapse/handlers/room.py @@ -1384,6 +1384,7 @@ class TimestampLookupHandler: self.store = hs.get_datastores().main self.state_handler = hs.get_state_handler() self.federation_client = hs.get_federation_client() + self.federation_event_handler = hs.get_federation_event_handler() self._storage_controllers = hs.get_storage_controllers() async def get_event_for_timestamp( @@ -1479,38 +1480,68 @@ class TimestampLookupHandler: remote_response, ) - # TODO: Do we want to persist this as an extremity? - # TODO: I think ideally, we would try to backfill from - # this event and run this whole - # `get_event_for_timestamp` function again to make sure - # they didn't give us an event from their gappy history. remote_event_id = remote_response.event_id - origin_server_ts = remote_response.origin_server_ts + remote_origin_server_ts = remote_response.origin_server_ts + + # Backfill this event so we can get a pagination token for + # it with `/context` and paginate `/messages` from this + # point. + # + # TODO: The requested timestamp may lie in a part of the + # event graph that the remote server *also* didn't have, + # in which case they will have returned another event + # which may be nowhere near the requested timestamp. In + # the future, we may need to reconcile that gap and ask + # other homeservers, and/or extend `/timestamp_to_event` + # to return events on *both* sides of the timestamp to + # help reconcile the gap faster. + remote_event = ( + await self.federation_event_handler.backfill_event_id( + domain, room_id, remote_event_id + ) + ) + + # XXX: When we see that the remote server is not trustworthy, + # maybe we should not ask them first in the future. + if remote_origin_server_ts != remote_event.origin_server_ts: + logger.info( + "get_event_for_timestamp: Remote server (%s) claimed that remote_event_id=%s occured at remote_origin_server_ts=%s but that isn't true (actually occured at %s). Their claims are dubious and we should consider not trusting them.", + domain, + remote_event_id, + remote_origin_server_ts, + remote_event.origin_server_ts, + ) # Only return the remote event if it's closer than the local event if not local_event or ( - abs(origin_server_ts - timestamp) + abs(remote_event.origin_server_ts - timestamp) < abs(local_event.origin_server_ts - timestamp) ): - return remote_event_id, origin_server_ts + logger.info( + "get_event_for_timestamp: returning remote_event_id=%s (%s) since it's closer to timestamp=%s than local_event=%s (%s)", + remote_event_id, + remote_event.origin_server_ts, + timestamp, + local_event.event_id if local_event else None, + local_event.origin_server_ts if local_event else None, + ) + return remote_event_id, remote_origin_server_ts except (HttpResponseException, InvalidResponseError) as ex: # Let's not put a high priority on some other homeserver # failing to respond or giving a random response logger.debug( - "Failed to fetch /timestamp_to_event from %s because of exception(%s) %s args=%s", + "get_event_for_timestamp: Failed to fetch /timestamp_to_event from %s because of exception(%s) %s args=%s", domain, type(ex).__name__, ex, ex.args, ) - except Exception as ex: + except Exception: # But we do want to see some exceptions in our code logger.warning( - "Failed to fetch /timestamp_to_event from %s because of exception(%s) %s args=%s", + "get_event_for_timestamp: Failed to fetch /timestamp_to_event from %s because of exception", domain, - type(ex).__name__, - ex, - ex.args, + exc_info=True, ) # To appease mypy, we have to add both of these conditions to check for |