diff options
Diffstat (limited to 'synapse/handlers')
| -rw-r--r-- | synapse/handlers/space_summary.py | 258 |
1 files changed, 216 insertions, 42 deletions
diff --git a/synapse/handlers/space_summary.py b/synapse/handlers/space_summary.py index d0060f9046..c74e90abbc 100644 --- a/synapse/handlers/space_summary.py +++ b/synapse/handlers/space_summary.py @@ -16,17 +16,7 @@ import itertools import logging import re from collections import deque -from typing import ( - TYPE_CHECKING, - Deque, - Dict, - Iterable, - List, - Optional, - Sequence, - Set, - Tuple, -) +from typing import TYPE_CHECKING, Dict, Iterable, List, Optional, Sequence, Set, Tuple import attr @@ -80,7 +70,7 @@ class _PaginationSession: # The time the pagination session was created, in milliseconds. creation_time_ms: int # The queue of rooms which are still to process. - room_queue: Deque["_RoomQueueEntry"] + room_queue: List["_RoomQueueEntry"] # A set of rooms which have been processed. processed_rooms: Set[str] @@ -197,7 +187,7 @@ class SpaceSummaryHandler: events: Sequence[JsonDict] = [] if room_entry: rooms_result.append(room_entry.room) - events = room_entry.children + events = room_entry.children_state_events logger.debug( "Query of local room %s returned events %s", @@ -232,7 +222,7 @@ class SpaceSummaryHandler: room.pop("allowed_spaces", None) rooms_result.append(room) - events.extend(room_entry.children) + events.extend(room_entry.children_state_events) # All rooms returned don't need visiting again (even if the user # didn't have access to them). @@ -350,8 +340,8 @@ class SpaceSummaryHandler: room_queue = pagination_session.room_queue processed_rooms = pagination_session.processed_rooms else: - # the queue of rooms to process - room_queue = deque((_RoomQueueEntry(requested_room_id, ()),)) + # The queue of rooms to process, the next room is last on the stack. + room_queue = [_RoomQueueEntry(requested_room_id, ())] # Rooms we have already processed. processed_rooms = set() @@ -367,7 +357,7 @@ class SpaceSummaryHandler: # Iterate through the queue until we reach the limit or run out of # rooms to include. while room_queue and len(rooms_result) < limit: - queue_entry = room_queue.popleft() + queue_entry = room_queue.pop() room_id = queue_entry.room_id current_depth = queue_entry.depth if room_id in processed_rooms: @@ -376,6 +366,18 @@ class SpaceSummaryHandler: logger.debug("Processing room %s", room_id) + # A map of summaries for children rooms that might be returned over + # federation. The rationale for caching these and *maybe* using them + # is to prefer any information local to the homeserver before trusting + # data received over federation. + children_room_entries: Dict[str, JsonDict] = {} + # A set of room IDs which are children that did not have information + # returned over federation and are known to be inaccessible to the + # current server. We should not reach out over federation to try to + # summarise these rooms. + inaccessible_children: Set[str] = set() + + # If the room is known locally, summarise it! is_in_room = await self._store.is_host_joined(room_id, self._server_name) if is_in_room: room_entry = await self._summarize_local_room( @@ -387,26 +389,68 @@ class SpaceSummaryHandler: max_children=None, ) - if room_entry: - rooms_result.append(room_entry.as_json()) - - # Add the child to the queue. We have already validated - # that the vias are a list of server names. - # - # If the current depth is the maximum depth, do not queue - # more entries. - if max_depth is None or current_depth < max_depth: - room_queue.extendleft( - _RoomQueueEntry( - ev["state_key"], ev["content"]["via"], current_depth + 1 - ) - for ev in reversed(room_entry.children) - ) - - processed_rooms.add(room_id) + # Otherwise, attempt to use information for federation. else: - # TODO Federation. - pass + # A previous call might have included information for this room. + # It can be used if either: + # + # 1. The room is not a space. + # 2. The maximum depth has been achieved (since no children + # information is needed). + if queue_entry.remote_room and ( + queue_entry.remote_room.get("room_type") != RoomTypes.SPACE + or (max_depth is not None and current_depth >= max_depth) + ): + room_entry = _RoomEntry( + queue_entry.room_id, queue_entry.remote_room + ) + + # If the above isn't true, attempt to fetch the room + # information over federation. + else: + ( + room_entry, + children_room_entries, + inaccessible_children, + ) = await self._summarize_remote_room_hiearchy( + queue_entry, + suggested_only, + ) + + # Ensure this room is accessible to the requester (and not just + # the homeserver). + if room_entry and not await self._is_remote_room_accessible( + requester, queue_entry.room_id, room_entry.room + ): + room_entry = None + + # This room has been processed and should be ignored if it appears + # elsewhere in the hierarchy. + processed_rooms.add(room_id) + + # There may or may not be a room entry based on whether it is + # inaccessible to the requesting user. + if room_entry: + # Add the room (including the stripped m.space.child events). + rooms_result.append(room_entry.as_json()) + + # If this room is not at the max-depth, check if there are any + # children to process. + if max_depth is None or current_depth < max_depth: + # The children get added in reverse order so that the next + # room to process, according to the ordering, is the last + # item in the list. + room_queue.extend( + _RoomQueueEntry( + ev["state_key"], + ev["content"]["via"], + current_depth + 1, + children_room_entries.get(ev["state_key"]), + ) + for ev in reversed(room_entry.children_state_events) + if ev["type"] == EventTypes.SpaceChild + and ev["state_key"] not in inaccessible_children + ) result: JsonDict = {"rooms": rooms_result} @@ -477,15 +521,78 @@ class SpaceSummaryHandler: if room_entry: rooms_result.append(room_entry.room) - events_result.extend(room_entry.children) + events_result.extend(room_entry.children_state_events) # add any children to the queue room_queue.extend( - edge_event["state_key"] for edge_event in room_entry.children + edge_event["state_key"] + for edge_event in room_entry.children_state_events ) return {"rooms": rooms_result, "events": events_result} + async def get_federation_hierarchy( + self, + origin: str, + requested_room_id: str, + suggested_only: bool, + ): + """ + Implementation of the room hierarchy Federation API. + + This is similar to get_room_hierarchy, but does not recurse into the space. + It also considers whether anyone on the server may be able to access the + room, as opposed to whether a specific user can. + + Args: + origin: The server requesting the spaces summary. + requested_room_id: The room ID to start the hierarchy at (the "root" room). + suggested_only: whether we should only return children with the "suggested" + flag set. + + Returns: + The JSON hierarchy dictionary. + """ + root_room_entry = await self._summarize_local_room( + None, origin, requested_room_id, suggested_only, max_children=None + ) + if root_room_entry is None: + # Room is inaccessible to the requesting server. + raise SynapseError(404, "Unknown room: %s" % (requested_room_id,)) + + children_rooms_result: List[JsonDict] = [] + inaccessible_children: List[str] = [] + + # Iterate through each child and potentially add it, but not its children, + # to the response. + for child_room in root_room_entry.children_state_events: + room_id = child_room.get("state_key") + assert isinstance(room_id, str) + # If the room is unknown, skip it. + if not await self._store.is_host_joined(room_id, self._server_name): + continue + + room_entry = await self._summarize_local_room( + None, origin, room_id, suggested_only, max_children=0 + ) + # If the room is accessible, include it in the results. + # + # Note that only the room summary (without information on children) + # is included in the summary. + if room_entry: + children_rooms_result.append(room_entry.room) + # Otherwise, note that the requesting server shouldn't bother + # trying to summarize this room - they do not have access to it. + else: + inaccessible_children.append(room_id) + + return { + # Include the requested room (including the stripped children events). + "room": root_room_entry.as_json(), + "children": children_rooms_result, + "inaccessible_children": inaccessible_children, + } + async def _summarize_local_room( self, requester: Optional[str], @@ -519,8 +626,9 @@ class SpaceSummaryHandler: room_entry = await self._build_room_entry(room_id, for_federation=bool(origin)) - # If the room is not a space, return just the room information. - if room_entry.get("room_type") != RoomTypes.SPACE: + # If the room is not a space or the children don't matter, return just + # the room information. + if room_entry.get("room_type") != RoomTypes.SPACE or max_children == 0: return _RoomEntry(room_id, room_entry) # Otherwise, look for child rooms/spaces. @@ -616,6 +724,59 @@ class SpaceSummaryHandler: return results + async def _summarize_remote_room_hiearchy( + self, room: "_RoomQueueEntry", suggested_only: bool + ) -> Tuple[Optional["_RoomEntry"], Dict[str, JsonDict], Set[str]]: + """ + Request room entries and a list of event entries for a given room by querying a remote server. + + Args: + room: The room to summarize. + suggested_only: True if only suggested children should be returned. + Otherwise, all children are returned. + + Returns: + A tuple of: + The room entry. + Partial room data return over federation. + A set of inaccessible children room IDs. + """ + room_id = room.room_id + logger.info("Requesting summary for %s via %s", room_id, room.via) + + via = itertools.islice(room.via, MAX_SERVERS_PER_SPACE) + try: + ( + room_response, + children, + inaccessible_children, + ) = await self._federation_client.get_room_hierarchy( + via, + room_id, + suggested_only=suggested_only, + ) + except Exception as e: + logger.warning( + "Unable to get hierarchy of %s via federation: %s", + room_id, + e, + exc_info=logger.isEnabledFor(logging.DEBUG), + ) + return None, {}, set() + + # Map the children to their room ID. + children_by_room_id = { + c["room_id"]: c + for c in children + if "room_id" in c and isinstance(c["room_id"], str) + } + + return ( + _RoomEntry(room_id, room_response, room_response.pop("children_state", ())), + children_by_room_id, + set(inaccessible_children), + ) + async def _is_local_room_accessible( self, room_id: str, requester: Optional[str], origin: Optional[str] = None ) -> bool: @@ -866,9 +1027,16 @@ class SpaceSummaryHandler: @attr.s(frozen=True, slots=True, auto_attribs=True) class _RoomQueueEntry: + # The room ID of this entry. room_id: str + # The server to query if the room is not known locally. via: Sequence[str] + # The minimum number of hops necessary to get to this room (compared to the + # originally requested room). depth: int = 0 + # The room summary for this room returned via federation. This will only be + # used if the room is not known locally (and is not a space). + remote_room: Optional[JsonDict] = None @attr.s(frozen=True, slots=True, auto_attribs=True) @@ -879,11 +1047,17 @@ class _RoomEntry: # An iterable of the sorted, stripped children events for children of this room. # # This may not include all children. - children: Sequence[JsonDict] = () + children_state_events: Sequence[JsonDict] = () def as_json(self) -> JsonDict: + """ + Returns a JSON dictionary suitable for the room hierarchy endpoint. + + It returns the room summary including the stripped m.space.child events + as a sub-key. + """ result = dict(self.room) - result["children_state"] = self.children + result["children_state"] = self.children_state_events return result |