Add include_event_in_state to _get_state_for_room (#6521)

Make it return the state *after* the requested event, rather than the one
before it. This is a bit easier and requires fewer calls to
get_events_from_store_or_dest.
This commit is contained in:
Richard van der Hoff 2019-12-11 16:37:51 +00:00 committed by Richard van der Hoff
parent be294d6fde
commit 20d5ba16e6
2 changed files with 22 additions and 18 deletions

1
changelog.d/6521.misc Normal file
View file

@ -0,0 +1 @@
Refactor some code in the event authentication path for clarity.

View file

@ -379,22 +379,10 @@ class FederationHandler(BaseHandler):
(
remote_state,
got_auth_chain,
) = yield self._get_state_for_room(origin, room_id, p)
# we want the state *after* p; _get_state_for_room returns the
# state *before* p.
remote_event = yield self.federation_client.get_pdu(
[origin], p, room_version, outlier=True
) = yield self._get_state_for_room(
origin, room_id, p, include_event_in_state=True
)
if remote_event is None:
raise Exception(
"Unable to get missing prev_event %s" % (p,)
)
if remote_event.is_state():
remote_state.append(remote_event)
# XXX hrm I'm not convinced that duplicate events will compare
# for equality, so I'm not sure this does what the author
# hoped.
@ -583,13 +571,15 @@ class FederationHandler(BaseHandler):
@defer.inlineCallbacks
@log_function
def _get_state_for_room(self, destination, room_id, event_id):
def _get_state_for_room(self, destination, room_id, event_id, include_event_in_state):
"""Requests all of the room state at a given event from a remote homeserver.
Args:
destination (str): The remote homeserver to query for the state.
room_id (str): The id of the room we're interested in.
event_id (str): The id of the event we want the state at.
include_event_in_state: if true, the event itself will be included in the
returned state event list.
Returns:
Deferred[Tuple[List[EventBase], List[EventBase]]]:
@ -604,6 +594,10 @@ class FederationHandler(BaseHandler):
)
desired_events = set(state_event_ids + auth_event_ids)
if include_event_in_state:
desired_events.add(event_id)
event_map = yield self._get_events_from_store_or_dest(
destination, room_id, desired_events
)
@ -616,12 +610,21 @@ class FederationHandler(BaseHandler):
failed_to_fetch,
)
pdus = [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]
remote_state = [
event_map[e_id] for e_id in state_event_ids if e_id in event_map
]
if include_event_in_state:
remote_event = event_map.get(event_id)
if not remote_event:
raise Exception("Unable to get missing prev_event %s" % (event_id,))
if remote_event.is_state():
remote_state.append(remote_event)
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 pdus, auth_chain
return remote_state, auth_chain
@defer.inlineCallbacks
def _get_events_from_store_or_dest(self, destination, room_id, event_ids):