Matrix-Mirrors/anonymousland-synapse
1
0
Fork 0
mirror of https://git.anonymousland.org/anonymousland/synapse.git synced 2025-05-06 12:54:55 -04:00
Code Issues Projects Releases Packages Wiki Activity

Backfill remote event fetched by MSC3030 so we can paginate from it later (#13205)

Browse source 
Depends on https://github.com/matrix-org/synapse/pull/13320

Complement tests: https://github.com/matrix-org/complement/pull/406

We could use the same method to backfill for `/context` as well in the future, see https://github.com/matrix-org/synapse/issues/3848
This commit is contained in:
Eric Eastwood 2022-07-22 16:00:11 -05:00 • committed by GitHub
parent c7c84b81e3
commit 357561c1a2
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
3 changed files with 94 additions and 15 deletions
Download patch file Download diff file Expand all files Collapse all files

59
synapse/handlers/room.py
View file

@ -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