From a5166e4d5febc0e03ba9da9db99127a797a0bc4d Mon Sep 17 00:00:00 2001 From: Erik Johnston Date: Wed, 2 Oct 2019 14:08:35 +0100 Subject: Land improved room list based on room stats (#6019) Use room_stats and room_state for room directory search --- synapse/handlers/room_list.py | 323 ++++++++++++------------------------------ 1 file changed, 89 insertions(+), 234 deletions(-) (limited to 'synapse/handlers/room_list.py') diff --git a/synapse/handlers/room_list.py b/synapse/handlers/room_list.py index a7e55f00e5..4e1cc5460f 100644 --- a/synapse/handlers/room_list.py +++ b/synapse/handlers/room_list.py @@ -16,8 +16,7 @@ import logging from collections import namedtuple -from six import PY3, iteritems -from six.moves import range +from six import iteritems import msgpack from unpaddedbase64 import decode_base64, encode_base64 @@ -27,7 +26,6 @@ from twisted.internet import defer from synapse.api.constants import EventTypes, JoinRules from synapse.api.errors import Codes, HttpResponseException from synapse.types import ThirdPartyInstanceID -from synapse.util.async_helpers import concurrently_execute from synapse.util.caches.descriptors import cachedInlineCallbacks from synapse.util.caches.response_cache import ResponseCache @@ -37,7 +35,6 @@ logger = logging.getLogger(__name__) REMOTE_ROOM_LIST_POLL_INTERVAL = 60 * 1000 - # This is used to indicate we should only return rooms published to the main list. EMPTY_THIRD_PARTY_ID = ThirdPartyInstanceID(None, None) @@ -72,6 +69,8 @@ class RoomListHandler(BaseHandler): This can be (None, None) to indicate the main list, or a particular appservice and network id to use an appservice specific one. Setting to None returns all public rooms across all lists. + from_federation (bool): true iff the request comes from the federation + API """ if not self.enable_room_list_search: return defer.succeed({"chunk": [], "total_room_count_estimate": 0}) @@ -133,239 +132,109 @@ class RoomListHandler(BaseHandler): from_federation (bool): Whether this request originated from a federating server or a client. Used for room filtering. timeout (int|None): Amount of seconds to wait for a response before - timing out. + timing out. TODO """ - if since_token and since_token != "END": - since_token = RoomListNextBatch.from_token(since_token) - else: - since_token = None - rooms_to_order_value = {} - rooms_to_num_joined = {} + # Pagination tokens work by storing the room ID sent in the last batch, + # plus the direction (forwards or backwards). Next batch tokens always + # go forwards, prev batch tokens always go backwards. - newly_visible = [] - newly_unpublished = [] if since_token: - stream_token = since_token.stream_ordering - current_public_id = yield self.store.get_current_public_room_stream_id() - public_room_stream_id = since_token.public_room_stream_id - newly_visible, newly_unpublished = yield self.store.get_public_room_changes( - public_room_stream_id, current_public_id, network_tuple=network_tuple - ) - else: - stream_token = yield self.store.get_room_max_stream_ordering() - public_room_stream_id = yield self.store.get_current_public_room_stream_id() - - room_ids = yield self.store.get_public_room_ids_at_stream_id( - public_room_stream_id, network_tuple=network_tuple - ) - - # We want to return rooms in a particular order: the number of joined - # users. We then arbitrarily use the room_id as a tie breaker. - - @defer.inlineCallbacks - def get_order_for_room(room_id): - # Most of the rooms won't have changed between the since token and - # now (especially if the since token is "now"). So, we can ask what - # the current users are in a room (that will hit a cache) and then - # check if the room has changed since the since token. (We have to - # do it in that order to avoid races). - # If things have changed then fall back to getting the current state - # at the since token. - joined_users = yield self.store.get_users_in_room(room_id) - if self.store.has_room_changed_since(room_id, stream_token): - latest_event_ids = yield self.store.get_forward_extremeties_for_room( - room_id, stream_token - ) - - if not latest_event_ids: - return + batch_token = RoomListNextBatch.from_token(since_token) - joined_users = yield self.state_handler.get_current_users_in_room( - room_id, latest_event_ids - ) - - num_joined_users = len(joined_users) - rooms_to_num_joined[room_id] = num_joined_users + last_room_id = batch_token.last_room_id + forwards = batch_token.direction_is_forward + else: + batch_token = None - if num_joined_users == 0: - return + last_room_id = None + forwards = True - # We want larger rooms to be first, hence negating num_joined_users - rooms_to_order_value[room_id] = (-num_joined_users, room_id) + # we request one more than wanted to see if there are more pages to come + probing_limit = limit + 1 if limit is not None else None - logger.info( - "Getting ordering for %i rooms since %s", len(room_ids), stream_token + results = yield self.store.get_largest_public_rooms( + network_tuple, + search_filter, + probing_limit, + last_room_id=last_room_id, + forwards=forwards, + ignore_non_federatable=from_federation, ) - yield concurrently_execute(get_order_for_room, room_ids, 10) - sorted_entries = sorted(rooms_to_order_value.items(), key=lambda e: e[1]) - sorted_rooms = [room_id for room_id, _ in sorted_entries] + def build_room_entry(room): + entry = { + "room_id": room["room_id"], + "name": room["name"], + "topic": room["topic"], + "canonical_alias": room["canonical_alias"], + "num_joined_members": room["joined_members"], + "avatar_url": room["avatar"], + "world_readable": room["history_visibility"] == "world_readable", + "guest_can_join": room["guest_access"] == "can_join", + } - # `sorted_rooms` should now be a list of all public room ids that is - # stable across pagination. Therefore, we can use indices into this - # list as our pagination tokens. + # Filter out Nones – rather omit the field altogether + return {k: v for k, v in entry.items() if v is not None} - # Filter out rooms that we don't want to return - rooms_to_scan = [ - r - for r in sorted_rooms - if r not in newly_unpublished and rooms_to_num_joined[r] > 0 - ] + results = [build_room_entry(r) for r in results] - total_room_count = len(rooms_to_scan) + response = {} + num_results = len(results) + if limit is not None: + more_to_come = num_results == probing_limit - if since_token: - # Filter out rooms we've already returned previously - # `since_token.current_limit` is the index of the last room we - # sent down, so we exclude it and everything before/after it. - if since_token.direction_is_forward: - rooms_to_scan = rooms_to_scan[since_token.current_limit + 1 :] + # Depending on direction we trim either the front or back. + if forwards: + results = results[:limit] else: - rooms_to_scan = rooms_to_scan[: since_token.current_limit] - rooms_to_scan.reverse() - - logger.info("After sorting and filtering, %i rooms remain", len(rooms_to_scan)) - - # _append_room_entry_to_chunk will append to chunk but will stop if - # len(chunk) > limit - # - # Normally we will generate enough results on the first iteration here, - # but if there is a search filter, _append_room_entry_to_chunk may - # filter some results out, in which case we loop again. - # - # We don't want to scan over the entire range either as that - # would potentially waste a lot of work. - # - # XXX if there is no limit, we may end up DoSing the server with - # calls to get_current_state_ids for every single room on the - # server. Surely we should cap this somehow? - # - if limit: - step = limit + 1 + results = results[-limit:] else: - # step cannot be zero - step = len(rooms_to_scan) if len(rooms_to_scan) != 0 else 1 - - chunk = [] - for i in range(0, len(rooms_to_scan), step): - if timeout and self.clock.time() > timeout: - raise Exception("Timed out searching room directory") - - batch = rooms_to_scan[i : i + step] - logger.info("Processing %i rooms for result", len(batch)) - yield concurrently_execute( - lambda r: self._append_room_entry_to_chunk( - r, - rooms_to_num_joined[r], - chunk, - limit, - search_filter, - from_federation=from_federation, - ), - batch, - 5, - ) - logger.info("Now %i rooms in result", len(chunk)) - if len(chunk) >= limit + 1: - break - - chunk.sort(key=lambda e: (-e["num_joined_members"], e["room_id"])) - - # Work out the new limit of the batch for pagination, or None if we - # know there are no more results that would be returned. - # i.e., [since_token.current_limit..new_limit] is the batch of rooms - # we've returned (or the reverse if we paginated backwards) - # We tried to pull out limit + 1 rooms above, so if we have <= limit - # then we know there are no more results to return - new_limit = None - if chunk and (not limit or len(chunk) > limit): - - if not since_token or since_token.direction_is_forward: - if limit: - chunk = chunk[:limit] - last_room_id = chunk[-1]["room_id"] + more_to_come = False + + if num_results > 0: + final_room_id = results[-1]["room_id"] + initial_room_id = results[0]["room_id"] + + if forwards: + if batch_token: + # If there was a token given then we assume that there + # must be previous results. + response["prev_batch"] = RoomListNextBatch( + last_room_id=initial_room_id, direction_is_forward=False + ).to_token() + + if more_to_come: + response["next_batch"] = RoomListNextBatch( + last_room_id=final_room_id, direction_is_forward=True + ).to_token() else: - if limit: - chunk = chunk[-limit:] - last_room_id = chunk[0]["room_id"] - - new_limit = sorted_rooms.index(last_room_id) - - results = {"chunk": chunk, "total_room_count_estimate": total_room_count} - - if since_token: - results["new_rooms"] = bool(newly_visible) - - if not since_token or since_token.direction_is_forward: - if new_limit is not None: - results["next_batch"] = RoomListNextBatch( - stream_ordering=stream_token, - public_room_stream_id=public_room_stream_id, - current_limit=new_limit, - direction_is_forward=True, - ).to_token() - - if since_token: - results["prev_batch"] = since_token.copy_and_replace( - direction_is_forward=False, - current_limit=since_token.current_limit + 1, - ).to_token() - else: - if new_limit is not None: - results["prev_batch"] = RoomListNextBatch( - stream_ordering=stream_token, - public_room_stream_id=public_room_stream_id, - current_limit=new_limit, - direction_is_forward=False, - ).to_token() - - if since_token: - results["next_batch"] = since_token.copy_and_replace( - direction_is_forward=True, - current_limit=since_token.current_limit - 1, - ).to_token() - - return results - - @defer.inlineCallbacks - def _append_room_entry_to_chunk( - self, - room_id, - num_joined_users, - chunk, - limit, - search_filter, - from_federation=False, - ): - """Generate the entry for a room in the public room list and append it - to the `chunk` if it matches the search filter - - Args: - room_id (str): The ID of the room. - num_joined_users (int): The number of joined users in the room. - chunk (list) - limit (int|None): Maximum amount of rooms to display. Function will - return if length of chunk is greater than limit + 1. - search_filter (dict|None) - from_federation (bool): Whether this request originated from a - federating server or a client. Used for room filtering. - """ - if limit and len(chunk) > limit + 1: - # We've already got enough, so lets just drop it. - return + if batch_token: + response["next_batch"] = RoomListNextBatch( + last_room_id=final_room_id, direction_is_forward=True + ).to_token() + + if more_to_come: + response["prev_batch"] = RoomListNextBatch( + last_room_id=initial_room_id, direction_is_forward=False + ).to_token() + + for room in results: + # populate search result entries with additional fields, namely + # 'aliases' + room_id = room["room_id"] + + aliases = yield self.store.get_aliases_for_room(room_id) + if aliases: + room["aliases"] = aliases - result = yield self.generate_room_entry(room_id, num_joined_users) - if not result: - return + response["chunk"] = results - if from_federation and not result.get("m.federate", True): - # This is a room that other servers cannot join. Do not show them - # this room. - return + response["total_room_count_estimate"] = yield self.store.count_public_rooms( + network_tuple, ignore_non_federatable=from_federation + ) - if _matches_room_entry(result, search_filter): - chunk.append(result) + return response @cachedInlineCallbacks(num_args=1, cache_context=True) def generate_room_entry( @@ -580,32 +449,18 @@ class RoomListNextBatch( namedtuple( "RoomListNextBatch", ( - "stream_ordering", # stream_ordering of the first public room list - "public_room_stream_id", # public room stream id for first public room list - "current_limit", # The number of previous rooms returned + "last_room_id", # The room_id to get rooms after/before "direction_is_forward", # Bool if this is a next_batch, false if prev_batch ), ) ): - - KEY_DICT = { - "stream_ordering": "s", - "public_room_stream_id": "p", - "current_limit": "n", - "direction_is_forward": "d", - } + KEY_DICT = {"last_room_id": "r", "direction_is_forward": "d"} REVERSE_KEY_DICT = {v: k for k, v in KEY_DICT.items()} @classmethod def from_token(cls, token): - if PY3: - # The argument raw=False is only available on new versions of - # msgpack, and only really needed on Python 3. Gate it behind - # a PY3 check to avoid causing issues on Debian-packaged versions. - decoded = msgpack.loads(decode_base64(token), raw=False) - else: - decoded = msgpack.loads(decode_base64(token)) + decoded = msgpack.loads(decode_base64(token), raw=False) return RoomListNextBatch( **{cls.REVERSE_KEY_DICT[key]: val for key, val in decoded.items()} ) -- cgit 1.4.1