From af13a3be29dd2d84d9255f8e613ca70c16819436 Mon Sep 17 00:00:00 2001 From: Sean Quah <8349537+squahtx@users.noreply.github.com> Date: Thu, 20 Jan 2022 11:03:42 +0000 Subject: [PATCH] Fix a bug that corrupted the cache of federated space hierarchies (#11775) `FederationClient.get_room_hierarchy()` caches its return values, so refactor the code to avoid modifying the returned room summary. --- changelog.d/11775.bugfix | 1 + synapse/federation/federation_client.py | 18 ++--- synapse/handlers/room_summary.py | 3 +- tests/handlers/test_room_summary.py | 92 ++++++++++++++++++++++++- 4 files changed, 102 insertions(+), 12 deletions(-) create mode 100644 changelog.d/11775.bugfix diff --git a/changelog.d/11775.bugfix b/changelog.d/11775.bugfix new file mode 100644 index 000000000..2c548dbf3 --- /dev/null +++ b/changelog.d/11775.bugfix @@ -0,0 +1 @@ +Fix a long-standing bug where space hierarchy over federation would only work correctly some of the time. diff --git a/synapse/federation/federation_client.py b/synapse/federation/federation_client.py index 57cf35bd9..74f17aa4d 100644 --- a/synapse/federation/federation_client.py +++ b/synapse/federation/federation_client.py @@ -118,7 +118,8 @@ class FederationClient(FederationBase): # It is a map of (room ID, suggested-only) -> the response of # get_room_hierarchy. self._get_room_hierarchy_cache: ExpiringCache[ - Tuple[str, bool], Tuple[JsonDict, Sequence[JsonDict], Sequence[str]] + Tuple[str, bool], + Tuple[JsonDict, Sequence[JsonDict], Sequence[JsonDict], Sequence[str]], ] = ExpiringCache( cache_name="get_room_hierarchy_cache", clock=self._clock, @@ -1333,7 +1334,7 @@ class FederationClient(FederationBase): destinations: Iterable[str], room_id: str, suggested_only: bool, - ) -> Tuple[JsonDict, Sequence[JsonDict], Sequence[str]]: + ) -> Tuple[JsonDict, Sequence[JsonDict], Sequence[JsonDict], Sequence[str]]: """ Call other servers to get a hierarchy of the given room. @@ -1348,7 +1349,8 @@ class FederationClient(FederationBase): Returns: A tuple of: - The room as a JSON dictionary. + The room as a JSON dictionary, without a "children_state" key. + A list of `m.space.child` state events. A list of children rooms, as JSON dictionaries. A list of inaccessible children room IDs. @@ -1363,7 +1365,7 @@ class FederationClient(FederationBase): async def send_request( destination: str, - ) -> Tuple[JsonDict, Sequence[JsonDict], Sequence[str]]: + ) -> Tuple[JsonDict, Sequence[JsonDict], Sequence[JsonDict], Sequence[str]]: try: res = await self.transport_layer.get_room_hierarchy( destination=destination, @@ -1392,7 +1394,7 @@ class FederationClient(FederationBase): raise InvalidResponseError("'room' must be a dict") # Validate children_state of the room. - children_state = room.get("children_state", []) + children_state = room.pop("children_state", []) if not isinstance(children_state, Sequence): raise InvalidResponseError("'room.children_state' must be a list") if any(not isinstance(e, dict) for e in children_state): @@ -1421,7 +1423,7 @@ class FederationClient(FederationBase): "Invalid room ID in 'inaccessible_children' list" ) - return room, children, inaccessible_children + return room, children_state, children, inaccessible_children try: result = await self._try_destination_list( @@ -1469,8 +1471,6 @@ class FederationClient(FederationBase): if event.room_id == room_id: children_events.append(event.data) children_room_ids.add(event.state_key) - # And add them under the requested room. - requested_room["children_state"] = children_events # Find the children rooms. children = [] @@ -1480,7 +1480,7 @@ class FederationClient(FederationBase): # It isn't clear from the response whether some of the rooms are # not accessible. - result = (requested_room, children, ()) + result = (requested_room, children_events, children, ()) # Cache the result to avoid fetching data over federation every time. self._get_room_hierarchy_cache[(room_id, suggested_only)] = result diff --git a/synapse/handlers/room_summary.py b/synapse/handlers/room_summary.py index 7c60cb0bd..4844b69a0 100644 --- a/synapse/handlers/room_summary.py +++ b/synapse/handlers/room_summary.py @@ -780,6 +780,7 @@ class RoomSummaryHandler: try: ( room_response, + children_state_events, children, inaccessible_children, ) = await self._federation_client.get_room_hierarchy( @@ -804,7 +805,7 @@ class RoomSummaryHandler: } return ( - _RoomEntry(room_id, room_response, room_response.pop("children_state", ())), + _RoomEntry(room_id, room_response, children_state_events), children_by_room_id, set(inaccessible_children), ) diff --git a/tests/handlers/test_room_summary.py b/tests/handlers/test_room_summary.py index ce3ebcf2f..51b22d299 100644 --- a/tests/handlers/test_room_summary.py +++ b/tests/handlers/test_room_summary.py @@ -28,6 +28,7 @@ from synapse.api.constants import ( from synapse.api.errors import AuthError, NotFoundError, SynapseError from synapse.api.room_versions import RoomVersions from synapse.events import make_event_from_dict +from synapse.federation.transport.client import TransportLayerClient from synapse.handlers.room_summary import _child_events_comparison_key, _RoomEntry from synapse.rest import admin from synapse.rest.client import login, room @@ -134,10 +135,18 @@ class SpaceSummaryTestCase(unittest.HomeserverTestCase): self._add_child(self.space, self.room, self.token) def _add_child( - self, space_id: str, room_id: str, token: str, order: Optional[str] = None + self, + space_id: str, + room_id: str, + token: str, + order: Optional[str] = None, + via: Optional[List[str]] = None, ) -> None: """Add a child room to a space.""" - content: JsonDict = {"via": [self.hs.hostname]} + if via is None: + via = [self.hs.hostname] + + content: JsonDict = {"via": via} if order is not None: content["order"] = order self.helper.send_state( @@ -1036,6 +1045,85 @@ class SpaceSummaryTestCase(unittest.HomeserverTestCase): ) self._assert_hierarchy(result, expected) + def test_fed_caching(self): + """ + Federation `/hierarchy` responses should be cached. + """ + fed_hostname = self.hs.hostname + "2" + fed_subspace = "#space:" + fed_hostname + fed_room = "#room:" + fed_hostname + + # Add a room to the space which is on another server. + self._add_child(self.space, fed_subspace, self.token, via=[fed_hostname]) + + federation_requests = 0 + + async def get_room_hierarchy( + _self: TransportLayerClient, + destination: str, + room_id: str, + suggested_only: bool, + ) -> JsonDict: + nonlocal federation_requests + federation_requests += 1 + + return { + "room": { + "room_id": fed_subspace, + "world_readable": True, + "room_type": RoomTypes.SPACE, + "children_state": [ + { + "type": EventTypes.SpaceChild, + "room_id": fed_subspace, + "state_key": fed_room, + "content": {"via": [fed_hostname]}, + }, + ], + }, + "children": [ + { + "room_id": fed_room, + "world_readable": True, + }, + ], + "inaccessible_children": [], + } + + expected = [ + (self.space, [self.room, fed_subspace]), + (self.room, ()), + (fed_subspace, [fed_room]), + (fed_room, ()), + ] + + with mock.patch( + "synapse.federation.transport.client.TransportLayerClient.get_room_hierarchy", + new=get_room_hierarchy, + ): + result = self.get_success( + self.handler.get_room_hierarchy(create_requester(self.user), self.space) + ) + self.assertEqual(federation_requests, 1) + self._assert_hierarchy(result, expected) + + # The previous federation response should be reused. + result = self.get_success( + self.handler.get_room_hierarchy(create_requester(self.user), self.space) + ) + self.assertEqual(federation_requests, 1) + self._assert_hierarchy(result, expected) + + # Expire the response cache + self.reactor.advance(5 * 60 + 1) + + # A new federation request should be made. + result = self.get_success( + self.handler.get_room_hierarchy(create_requester(self.user), self.space) + ) + self.assertEqual(federation_requests, 2) + self._assert_hierarchy(result, expected) + class RoomSummaryTestCase(unittest.HomeserverTestCase): servlets = [