969 lines
		
	
	
		
			36 KiB
		
	
	
	
		
			Python
		
	
	
			
		
		
	
	
			969 lines
		
	
	
		
			36 KiB
		
	
	
	
		
			Python
		
	
	
# Copyright 2021 The Matrix.org Foundation C.I.C.
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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#     http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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import itertools
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import logging
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import re
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from typing import TYPE_CHECKING, Dict, Iterable, List, Optional, Sequence, Set, Tuple
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import attr
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from synapse.api.constants import (
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    EventTypes,
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    HistoryVisibility,
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    JoinRules,
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    Membership,
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    RoomTypes,
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)
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from synapse.api.errors import (
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    Codes,
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    NotFoundError,
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    StoreError,
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    SynapseError,
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    UnstableSpecAuthError,
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    UnsupportedRoomVersionError,
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)
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from synapse.api.ratelimiting import Ratelimiter
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from synapse.events import EventBase
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from synapse.types import JsonDict, Requester, StrCollection
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from synapse.util.caches.response_cache import ResponseCache
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if TYPE_CHECKING:
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    from synapse.server import HomeServer
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logger = logging.getLogger(__name__)
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# number of rooms to return. We'll stop once we hit this limit.
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MAX_ROOMS = 50
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# max number of events to return per room.
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MAX_ROOMS_PER_SPACE = 50
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# max number of federation servers to hit per room
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MAX_SERVERS_PER_SPACE = 3
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@attr.s(slots=True, frozen=True, auto_attribs=True)
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class _PaginationKey:
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    """The key used to find unique pagination session."""
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    # The first three entries match the request parameters (and cannot change
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    # during a pagination session).
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    room_id: str
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    suggested_only: bool
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    max_depth: Optional[int]
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    # The randomly generated token.
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    token: str
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@attr.s(slots=True, frozen=True, auto_attribs=True)
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class _PaginationSession:
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    """The information that is stored for pagination."""
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    # The time the pagination session was created, in milliseconds.
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    creation_time_ms: int
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    # The queue of rooms which are still to process.
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    room_queue: List["_RoomQueueEntry"]
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    # A set of rooms which have been processed.
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    processed_rooms: Set[str]
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class RoomSummaryHandler:
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    # A unique key used for pagination sessions for the room hierarchy endpoint.
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    _PAGINATION_SESSION_TYPE = "room_hierarchy_pagination"
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    # The time a pagination session remains valid for.
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    _PAGINATION_SESSION_VALIDITY_PERIOD_MS = 5 * 60 * 1000
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    def __init__(self, hs: "HomeServer"):
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        self._event_auth_handler = hs.get_event_auth_handler()
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        self._store = hs.get_datastores().main
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        self._storage_controllers = hs.get_storage_controllers()
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        self._event_serializer = hs.get_event_client_serializer()
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        self._server_name = hs.hostname
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        self._federation_client = hs.get_federation_client()
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        self._ratelimiter = Ratelimiter(
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            store=self._store, clock=hs.get_clock(), rate_hz=5, burst_count=10
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        )
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        # If a user tries to fetch the same page multiple times in quick succession,
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        # only process the first attempt and return its result to subsequent requests.
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        self._pagination_response_cache: ResponseCache[
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            Tuple[str, str, bool, Optional[int], Optional[int], Optional[str]]
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        ] = ResponseCache(
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            hs.get_clock(),
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            "get_room_hierarchy",
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        )
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        self._msc3266_enabled = hs.config.experimental.msc3266_enabled
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    async def get_room_hierarchy(
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        self,
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        requester: Requester,
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        requested_room_id: str,
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        suggested_only: bool = False,
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        max_depth: Optional[int] = None,
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        limit: Optional[int] = None,
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        from_token: Optional[str] = None,
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    ) -> JsonDict:
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        """
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        Implementation of the room hierarchy C-S API.
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        Args:
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            requester: The user ID of the user making this request.
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            requested_room_id: The room ID to start the hierarchy at (the "root" room).
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            suggested_only: Whether we should only return children with the "suggested"
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                flag set.
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            max_depth: The maximum depth in the tree to explore, must be a
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                non-negative integer.
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                0 would correspond to just the root room, 1 would include just
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                the root room's children, etc.
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            limit: An optional limit on the number of rooms to return per
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                page. Must be a positive integer.
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            from_token: An optional pagination token.
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        Returns:
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            The JSON hierarchy dictionary.
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        """
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        await self._ratelimiter.ratelimit(requester)
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        # If a user tries to fetch the same page multiple times in quick succession,
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        # only process the first attempt and return its result to subsequent requests.
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        #
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        # This is due to the pagination process mutating internal state, attempting
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        # to process multiple requests for the same page will result in errors.
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        return await self._pagination_response_cache.wrap(
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            (
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                requester.user.to_string(),
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                requested_room_id,
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                suggested_only,
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                max_depth,
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                limit,
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                from_token,
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            ),
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            self._get_room_hierarchy,
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            requester.user.to_string(),
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            requested_room_id,
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            suggested_only,
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            max_depth,
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            limit,
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            from_token,
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        )
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    async def _get_room_hierarchy(
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        self,
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        requester: str,
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        requested_room_id: str,
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        suggested_only: bool = False,
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        max_depth: Optional[int] = None,
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        limit: Optional[int] = None,
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        from_token: Optional[str] = None,
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    ) -> JsonDict:
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        """See docstring for SpaceSummaryHandler.get_room_hierarchy."""
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        # First of all, check that the room is accessible.
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        if not await self._is_local_room_accessible(requested_room_id, requester):
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            raise UnstableSpecAuthError(
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                403,
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                "User %s not in room %s, and room previews are disabled"
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                % (requester, requested_room_id),
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                errcode=Codes.NOT_JOINED,
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            )
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        # If this is continuing a previous session, pull the persisted data.
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        if from_token:
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            try:
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                pagination_session = await self._store.get_session(
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                    session_type=self._PAGINATION_SESSION_TYPE,
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                    session_id=from_token,
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                )
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            except StoreError:
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                raise SynapseError(400, "Unknown pagination token", Codes.INVALID_PARAM)
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            # If the requester, room ID, suggested-only, or max depth were modified
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            # the session is invalid.
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            if (
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                requester != pagination_session["requester"]
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                or requested_room_id != pagination_session["room_id"]
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                or suggested_only != pagination_session["suggested_only"]
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                or max_depth != pagination_session["max_depth"]
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            ):
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                raise SynapseError(400, "Unknown pagination token", Codes.INVALID_PARAM)
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            # Load the previous state.
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            room_queue = [
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                _RoomQueueEntry(*fields) for fields in pagination_session["room_queue"]
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            ]
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            processed_rooms = set(pagination_session["processed_rooms"])
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        else:
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            # The queue of rooms to process, the next room is last on the stack.
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            room_queue = [_RoomQueueEntry(requested_room_id, ())]
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            # Rooms we have already processed.
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            processed_rooms = set()
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        rooms_result: List[JsonDict] = []
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        # Cap the limit to a server-side maximum.
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        if limit is None:
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            limit = MAX_ROOMS
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        else:
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            limit = min(limit, MAX_ROOMS)
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        # Iterate through the queue until we reach the limit or run out of
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        # rooms to include.
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        while room_queue and len(rooms_result) < limit:
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            queue_entry = room_queue.pop()
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            room_id = queue_entry.room_id
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            current_depth = queue_entry.depth
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            if room_id in processed_rooms:
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                # already done this room
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                continue
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            logger.debug("Processing room %s", room_id)
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            # A map of summaries for children rooms that might be returned over
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            # federation. The rationale for caching these and *maybe* using them
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            # is to prefer any information local to the homeserver before trusting
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            # data received over federation.
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            children_room_entries: Dict[str, JsonDict] = {}
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            # A set of room IDs which are children that did not have information
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            # returned over federation and are known to be inaccessible to the
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            # current server. We should not reach out over federation to try to
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            # summarise these rooms.
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            inaccessible_children: Set[str] = set()
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            # If the room is known locally, summarise it!
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            is_in_room = await self._store.is_host_joined(room_id, self._server_name)
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            if is_in_room:
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                room_entry = await self._summarize_local_room(
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                    requester,
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                    None,
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                    room_id,
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                    suggested_only,
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                )
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            # Otherwise, attempt to use information for federation.
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            else:
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                # A previous call might have included information for this room.
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                # It can be used if either:
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                #
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                # 1. The room is not a space.
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                # 2. The maximum depth has been achieved (since no children
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                #    information is needed).
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                if queue_entry.remote_room and (
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                    queue_entry.remote_room.get("room_type") != RoomTypes.SPACE
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                    or (max_depth is not None and current_depth >= max_depth)
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                ):
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                    room_entry = _RoomEntry(
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                        queue_entry.room_id, queue_entry.remote_room
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                    )
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                # If the above isn't true, attempt to fetch the room
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                # information over federation.
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                else:
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                    (
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                        room_entry,
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                        children_room_entries,
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                        inaccessible_children,
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                    ) = await self._summarize_remote_room_hierarchy(
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                        queue_entry,
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                        suggested_only,
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                    )
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                # Ensure this room is accessible to the requester (and not just
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                # the homeserver).
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                if room_entry and not await self._is_remote_room_accessible(
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                    requester, queue_entry.room_id, room_entry.room
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                ):
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                    room_entry = None
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            # This room has been processed and should be ignored if it appears
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            # elsewhere in the hierarchy.
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            processed_rooms.add(room_id)
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            # There may or may not be a room entry based on whether it is
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            # inaccessible to the requesting user.
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            if room_entry:
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                # Add the room (including the stripped m.space.child events).
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                rooms_result.append(room_entry.as_json(for_client=True))
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                # If this room is not at the max-depth, check if there are any
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                # children to process.
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                if max_depth is None or current_depth < max_depth:
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                    # The children get added in reverse order so that the next
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                    # room to process, according to the ordering, is the last
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                    # item in the list.
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                    room_queue.extend(
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                        _RoomQueueEntry(
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                            ev["state_key"],
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                            ev["content"]["via"],
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                            current_depth + 1,
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                            children_room_entries.get(ev["state_key"]),
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                        )
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                        for ev in reversed(room_entry.children_state_events)
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                        if ev["type"] == EventTypes.SpaceChild
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                        and ev["state_key"] not in inaccessible_children
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                    )
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        result: JsonDict = {"rooms": rooms_result}
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        # If there's additional data, generate a pagination token (and persist state).
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        if room_queue:
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            result["next_batch"] = await self._store.create_session(
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                session_type=self._PAGINATION_SESSION_TYPE,
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                value={
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                    # Information which must be identical across pagination.
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                    "requester": requester,
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                    "room_id": requested_room_id,
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                    "suggested_only": suggested_only,
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                    "max_depth": max_depth,
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                    # The stored state.
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                    "room_queue": [
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                        attr.astuple(room_entry) for room_entry in room_queue
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                    ],
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                    "processed_rooms": list(processed_rooms),
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                },
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                expiry_ms=self._PAGINATION_SESSION_VALIDITY_PERIOD_MS,
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            )
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        return result
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    async def get_federation_hierarchy(
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        self,
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        origin: str,
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        requested_room_id: str,
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        suggested_only: bool,
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    ) -> JsonDict:
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        """
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        Implementation of the room hierarchy Federation API.
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        This is similar to get_room_hierarchy, but does not recurse into the space.
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        It also considers whether anyone on the server may be able to access the
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        room, as opposed to whether a specific user can.
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        Args:
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            origin: The server requesting the spaces summary.
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            requested_room_id: The room ID to start the hierarchy at (the "root" room).
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            suggested_only: whether we should only return children with the "suggested"
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                flag set.
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        Returns:
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            The JSON hierarchy dictionary.
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        """
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        root_room_entry = await self._summarize_local_room(
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            None, origin, requested_room_id, suggested_only
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        )
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        if root_room_entry is None:
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            # Room is inaccessible to the requesting server.
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            raise SynapseError(404, "Unknown room: %s" % (requested_room_id,))
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        children_rooms_result: List[JsonDict] = []
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        inaccessible_children: List[str] = []
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        # Iterate through each child and potentially add it, but not its children,
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        # to the response.
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        for child_room in itertools.islice(
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            root_room_entry.children_state_events, MAX_ROOMS_PER_SPACE
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        ):
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            room_id = child_room.get("state_key")
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            assert isinstance(room_id, str)
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            # If the room is unknown, skip it.
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            if not await self._store.is_host_joined(room_id, self._server_name):
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                continue
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            room_entry = await self._summarize_local_room(
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                None, origin, room_id, suggested_only, include_children=False
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            )
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            # If the room is accessible, include it in the results.
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            #
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            # Note that only the room summary (without information on children)
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            # is included in the summary.
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            if room_entry:
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                children_rooms_result.append(room_entry.room)
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            #  Otherwise, note that the requesting server shouldn't bother
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            #  trying to summarize this room - they do not have access to it.
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            else:
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                inaccessible_children.append(room_id)
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        return {
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            # Include the requested room (including the stripped children events).
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            "room": root_room_entry.as_json(),
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            "children": children_rooms_result,
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            "inaccessible_children": inaccessible_children,
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        }
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    async def _summarize_local_room(
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        self,
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        requester: Optional[str],
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        origin: Optional[str],
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        room_id: str,
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        suggested_only: bool,
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        include_children: bool = True,
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    ) -> Optional["_RoomEntry"]:
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        """
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        Generate a room entry and a list of event entries for a given room.
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        Args:
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            requester:
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                The user requesting the summary, if it is a local request. None
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                if this is a federation request.
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            origin:
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                The server requesting the summary, if it is a federation request.
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                None if this is a local request.
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            room_id: The room ID to summarize.
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            suggested_only: True if only suggested children should be returned.
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                Otherwise, all children are returned.
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            include_children:
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                Whether to include the events of any children.
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        Returns:
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            A room entry if the room should be returned. None, otherwise.
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        """
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        if not await self._is_local_room_accessible(room_id, requester, origin):
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            return None
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        room_entry = await self._build_room_entry(room_id, for_federation=bool(origin))
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 | 
						||
        # If the room is not a space return just the room information.
 | 
						||
        if room_entry.get("room_type") != RoomTypes.SPACE or not include_children:
 | 
						||
            return _RoomEntry(room_id, room_entry)
 | 
						||
 | 
						||
        # Otherwise, 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)
 | 
						||
 | 
						||
        stripped_events: List[JsonDict] = [
 | 
						||
            {
 | 
						||
                "type": e.type,
 | 
						||
                "state_key": e.state_key,
 | 
						||
                "content": e.content,
 | 
						||
                "sender": e.sender,
 | 
						||
                "origin_server_ts": e.origin_server_ts,
 | 
						||
            }
 | 
						||
            for e in child_events
 | 
						||
        ]
 | 
						||
        return _RoomEntry(room_id, room_entry, stripped_events)
 | 
						||
 | 
						||
    async def _summarize_remote_room_hierarchy(
 | 
						||
        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_state_events,
 | 
						||
                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, children_state_events),
 | 
						||
            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:
 | 
						||
        """
 | 
						||
        Calculate whether the room should be shown to the requester.
 | 
						||
 | 
						||
        It should return true if:
 | 
						||
 | 
						||
        * The requesting user is joined or can join the room (per MSC3173); or
 | 
						||
        * The origin server has any user that is joined or can join the room; or
 | 
						||
        * The history visibility is set to world readable.
 | 
						||
 | 
						||
        Args:
 | 
						||
            room_id: The room ID to check accessibility of.
 | 
						||
            requester:
 | 
						||
                The user making the request, if it is a local request.
 | 
						||
                None if this is a federation request.
 | 
						||
            origin:
 | 
						||
                The server making the request, if it is a federation request.
 | 
						||
                None if this is a local request.
 | 
						||
 | 
						||
        Returns:
 | 
						||
             True if the room is accessible to the requesting user or server.
 | 
						||
        """
 | 
						||
        state_ids = await self._storage_controllers.state.get_current_state_ids(room_id)
 | 
						||
 | 
						||
        # If there's no state for the room, it isn't known.
 | 
						||
        if not state_ids:
 | 
						||
            # The user might have a pending invite for the room.
 | 
						||
            if requester and await self._store.get_invite_for_local_user_in_room(
 | 
						||
                requester, room_id
 | 
						||
            ):
 | 
						||
                return True
 | 
						||
 | 
						||
            logger.info("room %s is unknown, omitting from summary", room_id)
 | 
						||
            return False
 | 
						||
 | 
						||
        try:
 | 
						||
            room_version = await self._store.get_room_version(room_id)
 | 
						||
        except UnsupportedRoomVersionError:
 | 
						||
            # If a room with an unsupported room version is encountered, ignore
 | 
						||
            # it to avoid breaking the entire summary response.
 | 
						||
            return False
 | 
						||
 | 
						||
        # Include the room if it has join rules of public or knock.
 | 
						||
        join_rules_event_id = state_ids.get((EventTypes.JoinRules, ""))
 | 
						||
        if join_rules_event_id:
 | 
						||
            join_rules_event = await self._store.get_event(join_rules_event_id)
 | 
						||
            join_rule = join_rules_event.content.get("join_rule")
 | 
						||
            if (
 | 
						||
                join_rule == JoinRules.PUBLIC
 | 
						||
                or (room_version.msc2403_knocking and join_rule == JoinRules.KNOCK)
 | 
						||
                or (
 | 
						||
                    room_version.msc3787_knock_restricted_join_rule
 | 
						||
                    and join_rule == JoinRules.KNOCK_RESTRICTED
 | 
						||
                )
 | 
						||
            ):
 | 
						||
                return True
 | 
						||
 | 
						||
        # Include the room if it is peekable.
 | 
						||
        hist_vis_event_id = state_ids.get((EventTypes.RoomHistoryVisibility, ""))
 | 
						||
        if hist_vis_event_id:
 | 
						||
            hist_vis_ev = await self._store.get_event(hist_vis_event_id)
 | 
						||
            hist_vis = hist_vis_ev.content.get("history_visibility")
 | 
						||
            if hist_vis == HistoryVisibility.WORLD_READABLE:
 | 
						||
                return True
 | 
						||
 | 
						||
        # Otherwise we need to check information specific to the user or server.
 | 
						||
 | 
						||
        # If we have an authenticated requesting user, check if they are a member
 | 
						||
        # of the room (or can join the room).
 | 
						||
        if requester:
 | 
						||
            member_event_id = state_ids.get((EventTypes.Member, requester), None)
 | 
						||
 | 
						||
            # If they're in the room they can see info on it.
 | 
						||
            if member_event_id:
 | 
						||
                member_event = await self._store.get_event(member_event_id)
 | 
						||
                if member_event.membership in (Membership.JOIN, Membership.INVITE):
 | 
						||
                    return True
 | 
						||
 | 
						||
            # Otherwise, check if they should be allowed access via membership in a space.
 | 
						||
            if await self._event_auth_handler.has_restricted_join_rules(
 | 
						||
                state_ids, room_version
 | 
						||
            ):
 | 
						||
                allowed_rooms = (
 | 
						||
                    await self._event_auth_handler.get_rooms_that_allow_join(state_ids)
 | 
						||
                )
 | 
						||
                if await self._event_auth_handler.is_user_in_rooms(
 | 
						||
                    allowed_rooms, requester
 | 
						||
                ):
 | 
						||
                    return True
 | 
						||
 | 
						||
        # If this is a request over federation, check if the host is in the room or
 | 
						||
        # has a user who could join the room.
 | 
						||
        elif origin:
 | 
						||
            if await self._event_auth_handler.is_host_in_room(
 | 
						||
                room_id, origin
 | 
						||
            ) or await self._store.is_host_invited(room_id, origin):
 | 
						||
                return True
 | 
						||
 | 
						||
            # Alternately, if the host has a user in any of the spaces specified
 | 
						||
            # for access, then the host can see this room (and should do filtering
 | 
						||
            # if the requester cannot see it).
 | 
						||
            if await self._event_auth_handler.has_restricted_join_rules(
 | 
						||
                state_ids, room_version
 | 
						||
            ):
 | 
						||
                allowed_rooms = (
 | 
						||
                    await self._event_auth_handler.get_rooms_that_allow_join(state_ids)
 | 
						||
                )
 | 
						||
                for space_id in allowed_rooms:
 | 
						||
                    if await self._event_auth_handler.is_host_in_room(space_id, origin):
 | 
						||
                        return True
 | 
						||
 | 
						||
        logger.info(
 | 
						||
            "room %s is unpeekable and requester %s is not a member / not allowed to join, omitting from summary",
 | 
						||
            room_id,
 | 
						||
            requester or origin,
 | 
						||
        )
 | 
						||
        return False
 | 
						||
 | 
						||
    async def _is_remote_room_accessible(
 | 
						||
        self, requester: Optional[str], room_id: str, room: JsonDict
 | 
						||
    ) -> bool:
 | 
						||
        """
 | 
						||
        Calculate whether the room received over federation should be shown to the requester.
 | 
						||
 | 
						||
        It should return true if:
 | 
						||
 | 
						||
        * The requester is joined or can join the room (per MSC3173).
 | 
						||
        * The history visibility is set to world readable.
 | 
						||
 | 
						||
        Note that the local server is not in the requested room (which is why the
 | 
						||
        remote call was made in the first place), but the user could have access
 | 
						||
        due to an invite, etc.
 | 
						||
 | 
						||
        Args:
 | 
						||
            requester: The user requesting the summary. If not passed only world
 | 
						||
                readability is checked.
 | 
						||
            room_id: The room ID returned over federation.
 | 
						||
            room: The summary of the room returned over federation.
 | 
						||
 | 
						||
        Returns:
 | 
						||
            True if the room is accessible to the requesting user.
 | 
						||
        """
 | 
						||
        # The API doesn't return the room version so assume that a
 | 
						||
        # join rule of knock is valid.
 | 
						||
        if (
 | 
						||
            room.get("join_rule")
 | 
						||
            in (JoinRules.PUBLIC, JoinRules.KNOCK, JoinRules.KNOCK_RESTRICTED)
 | 
						||
            or room.get("world_readable") is True
 | 
						||
        ):
 | 
						||
            return True
 | 
						||
        elif not requester:
 | 
						||
            return False
 | 
						||
 | 
						||
        # Check if the user is a member of any of the allowed rooms from the response.
 | 
						||
        allowed_rooms = room.get("allowed_room_ids")
 | 
						||
        if allowed_rooms and isinstance(allowed_rooms, list):
 | 
						||
            if await self._event_auth_handler.is_user_in_rooms(
 | 
						||
                allowed_rooms, requester
 | 
						||
            ):
 | 
						||
                return True
 | 
						||
 | 
						||
        # Finally, check locally if we can access the room. The user might
 | 
						||
        # already be in the room (if it was a child room), or there might be a
 | 
						||
        # pending invite, etc.
 | 
						||
        return await self._is_local_room_accessible(room_id, requester)
 | 
						||
 | 
						||
    async def _build_room_entry(self, room_id: str, for_federation: bool) -> JsonDict:
 | 
						||
        """
 | 
						||
        Generate en entry summarising a single room.
 | 
						||
 | 
						||
        Args:
 | 
						||
            room_id: The room ID to summarize.
 | 
						||
            for_federation: True if this is a summary requested over federation
 | 
						||
                (which includes additional fields).
 | 
						||
 | 
						||
        Returns:
 | 
						||
            The JSON dictionary for the room.
 | 
						||
        """
 | 
						||
        stats = await self._store.get_room_with_stats(room_id)
 | 
						||
 | 
						||
        # currently this should be impossible because we call
 | 
						||
        # _is_local_room_accessible 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,)
 | 
						||
 | 
						||
        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"],
 | 
						||
            "join_rule": stats["join_rules"],
 | 
						||
            "world_readable": (
 | 
						||
                stats["history_visibility"] == HistoryVisibility.WORLD_READABLE
 | 
						||
            ),
 | 
						||
            "guest_can_join": stats["guest_access"] == "can_join",
 | 
						||
            "room_type": stats["room_type"],
 | 
						||
        }
 | 
						||
 | 
						||
        if self._msc3266_enabled:
 | 
						||
            entry["im.nheko.summary.version"] = stats["version"]
 | 
						||
            entry["im.nheko.summary.encryption"] = stats["encryption"]
 | 
						||
 | 
						||
        # Federation requests need to provide additional information so the
 | 
						||
        # requested server is able to filter the response appropriately.
 | 
						||
        if for_federation:
 | 
						||
            current_state_ids = (
 | 
						||
                await self._storage_controllers.state.get_current_state_ids(room_id)
 | 
						||
            )
 | 
						||
            room_version = await self._store.get_room_version(room_id)
 | 
						||
 | 
						||
            if await self._event_auth_handler.has_restricted_join_rules(
 | 
						||
                current_state_ids, room_version
 | 
						||
            ):
 | 
						||
                allowed_rooms = (
 | 
						||
                    await self._event_auth_handler.get_rooms_that_allow_join(
 | 
						||
                        current_state_ids
 | 
						||
                    )
 | 
						||
                )
 | 
						||
                if allowed_rooms:
 | 
						||
                    entry["allowed_room_ids"] = allowed_rooms
 | 
						||
 | 
						||
        # 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]:
 | 
						||
        """
 | 
						||
        Get the child events for a given room.
 | 
						||
 | 
						||
        The returned results are sorted for stability.
 | 
						||
 | 
						||
        Args:
 | 
						||
            room_id: The room id to get the children of.
 | 
						||
 | 
						||
        Returns:
 | 
						||
            An iterable of sorted child events.
 | 
						||
        """
 | 
						||
 | 
						||
        # look for child rooms/spaces.
 | 
						||
        current_state_ids = await self._storage_controllers.state.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()
 | 
						||
                if key[0] == EventTypes.SpaceChild
 | 
						||
            ]
 | 
						||
        )
 | 
						||
 | 
						||
        # filter out any events without a "via" (which implies it has been redacted),
 | 
						||
        # and order to ensure we return stable results.
 | 
						||
        return sorted(filter(_has_valid_via, events), key=_child_events_comparison_key)
 | 
						||
 | 
						||
    async def get_room_summary(
 | 
						||
        self,
 | 
						||
        requester: Optional[str],
 | 
						||
        room_id: str,
 | 
						||
        remote_room_hosts: Optional[List[str]] = None,
 | 
						||
    ) -> JsonDict:
 | 
						||
        """
 | 
						||
        Implementation of the room summary C-S API from MSC3266
 | 
						||
 | 
						||
        Args:
 | 
						||
            requester:  user id of the user making this request, will be None
 | 
						||
                for unauthenticated requests
 | 
						||
 | 
						||
            room_id: room id to summarise.
 | 
						||
 | 
						||
            remote_room_hosts: a list of homeservers to try fetching data through
 | 
						||
                if we don't know it ourselves
 | 
						||
 | 
						||
        Returns:
 | 
						||
            summary dict to return
 | 
						||
        """
 | 
						||
        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(
 | 
						||
                requester,
 | 
						||
                None,
 | 
						||
                room_id,
 | 
						||
                # Suggested-only doesn't matter since no children are requested.
 | 
						||
                suggested_only=False,
 | 
						||
                include_children=False,
 | 
						||
            )
 | 
						||
 | 
						||
            if not room_entry:
 | 
						||
                raise NotFoundError("Room not found or is not accessible")
 | 
						||
 | 
						||
            room_summary = room_entry.room
 | 
						||
 | 
						||
            # If there was a requester, add their membership.
 | 
						||
            if requester:
 | 
						||
                (
 | 
						||
                    membership,
 | 
						||
                    _,
 | 
						||
                ) = await self._store.get_local_current_membership_for_user_in_room(
 | 
						||
                    requester, room_id
 | 
						||
                )
 | 
						||
 | 
						||
                room_summary["membership"] = membership or "leave"
 | 
						||
        else:
 | 
						||
            # Reuse the hierarchy query over federation
 | 
						||
            if remote_room_hosts is None:
 | 
						||
                raise SynapseError(400, "Missing via to query remote room")
 | 
						||
 | 
						||
            (
 | 
						||
                room_entry,
 | 
						||
                children_room_entries,
 | 
						||
                inaccessible_children,
 | 
						||
            ) = await self._summarize_remote_room_hierarchy(
 | 
						||
                _RoomQueueEntry(room_id, remote_room_hosts),
 | 
						||
                suggested_only=True,
 | 
						||
            )
 | 
						||
 | 
						||
            # The results over federation might include rooms that we, as the
 | 
						||
            # requesting server, are allowed to see, but the requesting user is
 | 
						||
            # not permitted to see.
 | 
						||
            #
 | 
						||
            # Filter the returned results to only what is accessible to the user.
 | 
						||
            if not room_entry or not await self._is_remote_room_accessible(
 | 
						||
                requester, room_entry.room_id, room_entry.room
 | 
						||
            ):
 | 
						||
                raise NotFoundError("Room not found or is not accessible")
 | 
						||
 | 
						||
            room = dict(room_entry.room)
 | 
						||
            room.pop("allowed_room_ids", None)
 | 
						||
 | 
						||
            # If there was a requester, add their membership.
 | 
						||
            # We keep the membership in the local membership table unless the
 | 
						||
            # room is purged even for remote rooms.
 | 
						||
            if requester:
 | 
						||
                (
 | 
						||
                    membership,
 | 
						||
                    _,
 | 
						||
                ) = await self._store.get_local_current_membership_for_user_in_room(
 | 
						||
                    requester, room_id
 | 
						||
                )
 | 
						||
                room["membership"] = membership or "leave"
 | 
						||
 | 
						||
            return room
 | 
						||
 | 
						||
        return room_summary
 | 
						||
 | 
						||
 | 
						||
@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: StrCollection
 | 
						||
    # 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)
 | 
						||
class _RoomEntry:
 | 
						||
    room_id: str
 | 
						||
    # The room summary for this room.
 | 
						||
    room: JsonDict
 | 
						||
    # An iterable of the sorted, stripped children events for children of this room.
 | 
						||
    #
 | 
						||
    # This may not include all children.
 | 
						||
    children_state_events: Sequence[JsonDict] = ()
 | 
						||
 | 
						||
    def as_json(self, for_client: bool = False) -> 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.
 | 
						||
 | 
						||
        Args:
 | 
						||
            for_client: If true, any server-server only fields are stripped from
 | 
						||
                the result.
 | 
						||
 | 
						||
        """
 | 
						||
        result = dict(self.room)
 | 
						||
 | 
						||
        # Before returning to the client, remove the allowed_room_ids key, if it
 | 
						||
        # exists.
 | 
						||
        if for_client:
 | 
						||
            result.pop("allowed_room_ids", False)
 | 
						||
 | 
						||
        result["children_state"] = self.children_state_events
 | 
						||
        return result
 | 
						||
 | 
						||
 | 
						||
def _has_valid_via(e: EventBase) -> bool:
 | 
						||
    via = e.content.get("via")
 | 
						||
    if not via or not isinstance(via, list):
 | 
						||
        return False
 | 
						||
    for v in via:
 | 
						||
        if not isinstance(v, str):
 | 
						||
            logger.debug("Ignoring edge event %s with invalid via entry", e.event_id)
 | 
						||
            return False
 | 
						||
    return True
 | 
						||
 | 
						||
 | 
						||
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
 | 
						||
 | 
						||
 | 
						||
# Order may only contain characters in the range of \x20 (space) to \x7E (~) inclusive.
 | 
						||
_INVALID_ORDER_CHARS_RE = re.compile(r"[^\x20-\x7E]")
 | 
						||
 | 
						||
 | 
						||
def _child_events_comparison_key(
 | 
						||
    child: EventBase,
 | 
						||
) -> Tuple[bool, Optional[str], int, str]:
 | 
						||
    """
 | 
						||
    Generate a value for comparing two child events for ordering.
 | 
						||
 | 
						||
    The rules for ordering are:
 | 
						||
 | 
						||
    1. The 'order' key, if it is valid.
 | 
						||
    2. The 'origin_server_ts' of the 'm.space.child' event.
 | 
						||
    3. The 'room_id'.
 | 
						||
 | 
						||
    Args:
 | 
						||
        child: The event for generating a comparison key.
 | 
						||
 | 
						||
    Returns:
 | 
						||
        The comparison key as a tuple of:
 | 
						||
            False if the ordering is valid.
 | 
						||
            The 'order' field or None if it is not given or invalid.
 | 
						||
            The 'origin_server_ts' field.
 | 
						||
            The room ID.
 | 
						||
    """
 | 
						||
    order = child.content.get("order")
 | 
						||
    # If order is not a string or doesn't meet the requirements, ignore it.
 | 
						||
    if not isinstance(order, str):
 | 
						||
        order = None
 | 
						||
    elif len(order) > 50 or _INVALID_ORDER_CHARS_RE.search(order):
 | 
						||
        order = None
 | 
						||
 | 
						||
    # Items without an order come last.
 | 
						||
    return order is None, order, child.origin_server_ts, child.room_id
 |