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Diffstat (limited to 'synapse/handlers/space_summary.py')
| -rw-r--r-- | synapse/handlers/space_summary.py | 199 |
1 files changed, 199 insertions, 0 deletions
diff --git a/synapse/handlers/space_summary.py b/synapse/handlers/space_summary.py new file mode 100644 index 0000000000..513dc0c71a --- /dev/null +++ b/synapse/handlers/space_summary.py @@ -0,0 +1,199 @@ +# -*- coding: utf-8 -*- +# Copyright 2021 The Matrix.org Foundation C.I.C. +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. + +import itertools +import logging +from collections import deque +from typing import TYPE_CHECKING, Iterable, List, Optional, Set + +from synapse.api.constants import EventContentFields, EventTypes, HistoryVisibility +from synapse.api.errors import AuthError +from synapse.events import EventBase +from synapse.events.utils import format_event_for_client_v2 +from synapse.types import JsonDict + +if TYPE_CHECKING: + from synapse.server import HomeServer + +logger = logging.getLogger(__name__) + +# number of rooms to return. We'll stop once we hit this limit. +# TODO: allow clients to reduce this with a request param. +MAX_ROOMS = 50 + +# max number of events to return per room. +MAX_ROOMS_PER_SPACE = 50 + + +class SpaceSummaryHandler: + def __init__(self, hs: "HomeServer"): + self._clock = hs.get_clock() + self._auth = hs.get_auth() + self._room_list_handler = hs.get_room_list_handler() + self._state_handler = hs.get_state_handler() + self._store = hs.get_datastore() + self._event_serializer = hs.get_event_client_serializer() + + async def get_space_summary( + self, + requester: str, + room_id: str, + suggested_only: bool = False, + max_rooms_per_space: Optional[int] = None, + ) -> JsonDict: + """ + Implementation of the space summary API + + Args: + requester: user id of the user making this request + + room_id: room id to start the summary at + + suggested_only: whether we should only return children with the "suggested" + flag set. + + max_rooms_per_space: an optional limit on the number of child rooms we will + return. This does not apply to the root room (ie, room_id), and + is overridden by ROOMS_PER_SPACE_LIMIT. + + Returns: + summary dict to return + """ + # first of all, check that the user is in the room in question (or it's + # world-readable) + await self._auth.check_user_in_room_or_world_readable(room_id, requester) + + # the queue of rooms to process + room_queue = deque((room_id,)) + + processed_rooms = set() # type: Set[str] + + rooms_result = [] # type: List[JsonDict] + events_result = [] # type: List[JsonDict] + + now = self._clock.time_msec() + + while room_queue and len(rooms_result) < MAX_ROOMS: + room_id = room_queue.popleft() + logger.debug("Processing room %s", room_id) + processed_rooms.add(room_id) + + try: + await self._auth.check_user_in_room_or_world_readable( + room_id, requester + ) + except AuthError: + logger.info( + "user %s cannot view room %s, omitting from summary", + requester, + room_id, + ) + continue + + room_entry = await self._build_room_entry(room_id) + rooms_result.append(room_entry) + + # look for child rooms/spaces. + child_events = await self._get_child_events(room_id) + + if suggested_only: + # we only care about suggested children + child_events = filter(_is_suggested_child_event, child_events) + + # The client-specified max_rooms_per_space limit doesn't apply to the + # room_id specified in the request, so we ignore it if this is the + # first room we are processing. Otherwise, apply any client-specified + # limit, capping to our built-in limit. + if max_rooms_per_space is not None and len(processed_rooms) > 1: + max_rooms = min(MAX_ROOMS_PER_SPACE, max_rooms_per_space) + else: + max_rooms = MAX_ROOMS_PER_SPACE + + for edge_event in itertools.islice(child_events, max_rooms): + edge_room_id = edge_event.state_key + + events_result.append( + await self._event_serializer.serialize_event( + edge_event, + time_now=now, + event_format=format_event_for_client_v2, + ) + ) + + # if we haven't yet visited the target of this link, add it to the queue + if edge_room_id not in processed_rooms: + room_queue.append(edge_room_id) + + return {"rooms": rooms_result, "events": events_result} + + async def _build_room_entry(self, room_id: str) -> JsonDict: + """Generate en entry suitable for the 'rooms' list in the summary response""" + stats = await self._store.get_room_with_stats(room_id) + + # currently this should be impossible because we call + # check_user_in_room_or_world_readable on the room before we get here, so + # there should always be an entry + assert stats is not None, "unable to retrieve stats for %s" % (room_id,) + + current_state_ids = await self._store.get_current_state_ids(room_id) + create_event = await self._store.get_event( + current_state_ids[(EventTypes.Create, "")] + ) + + # TODO: update once MSC1772 lands + room_type = create_event.content.get(EventContentFields.MSC1772_ROOM_TYPE) + + entry = { + "room_id": stats["room_id"], + "name": stats["name"], + "topic": stats["topic"], + "canonical_alias": stats["canonical_alias"], + "num_joined_members": stats["joined_members"], + "avatar_url": stats["avatar"], + "world_readable": ( + stats["history_visibility"] == HistoryVisibility.WORLD_READABLE + ), + "guest_can_join": stats["guest_access"] == "can_join", + "room_type": room_type, + } + + # Filter out Nones – rather omit the field altogether + room_entry = {k: v for k, v in entry.items() if v is not None} + + return room_entry + + async def _get_child_events(self, room_id: str) -> Iterable[EventBase]: + # look for child rooms/spaces. + current_state_ids = await self._store.get_current_state_ids(room_id) + + events = await self._store.get_events_as_list( + [ + event_id + for key, event_id in current_state_ids.items() + # TODO: update once MSC1772 lands + if key[0] == EventTypes.MSC1772_SPACE_CHILD + ] + ) + + # filter out any events without a "via" (which implies it has been redacted) + return (e for e in events if e.content.get("via")) + + +def _is_suggested_child_event(edge_event: EventBase) -> bool: + suggested = edge_event.content.get("suggested") + if isinstance(suggested, bool) and suggested: + return True + logger.debug("Ignorning not-suggested child %s", edge_event.state_key) + return False |