forked-synapse/synapse/handlers/room_list.py
Richard van der Hoff 44a1bfd6a6 Reshuffle room list request code
I'm not entirely sure if this will actually help anything, but it simplifies
the code and might give further clues about why room list search requests are
blowing out the get_current_state_ids caches.
2017-11-14 10:29:58 +00:00

486 lines
19 KiB
Python

# -*- coding: utf-8 -*-
# Copyright 2014 - 2016 OpenMarket Ltd
#
# 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.
from twisted.internet import defer
from ._base import BaseHandler
from synapse.api.constants import (
EventTypes, JoinRules,
)
from synapse.util.logcontext import make_deferred_yieldable, preserve_fn
from synapse.util.async import concurrently_execute
from synapse.util.caches.descriptors import cachedInlineCallbacks
from synapse.util.caches.response_cache import ResponseCache
from synapse.types import ThirdPartyInstanceID
from collections import namedtuple
from unpaddedbase64 import encode_base64, decode_base64
import logging
import msgpack
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.
EMTPY_THIRD_PARTY_ID = ThirdPartyInstanceID(None, None)
class RoomListHandler(BaseHandler):
def __init__(self, hs):
super(RoomListHandler, self).__init__(hs)
self.response_cache = ResponseCache(hs)
self.remote_response_cache = ResponseCache(hs, timeout_ms=30 * 1000)
def get_local_public_room_list(self, limit=None, since_token=None,
search_filter=None,
network_tuple=EMTPY_THIRD_PARTY_ID,):
"""Generate a local public room list.
There are multiple different lists: the main one plus one per third
party network. A client can ask for a specific list or to return all.
Args:
limit (int)
since_token (str)
search_filter (dict)
network_tuple (ThirdPartyInstanceID): Which public list to use.
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.
"""
logger.info(
"Getting public room list: limit=%r, since=%r, search=%r, network=%r",
limit, since_token, bool(search_filter), network_tuple,
)
if search_filter:
# We explicitly don't bother caching searches or requests for
# appservice specific lists.
logger.info("Bypassing cache as search request.")
return self._get_public_room_list(
limit, since_token, search_filter, network_tuple=network_tuple,
)
key = (limit, since_token, network_tuple)
result = self.response_cache.get(key)
if not result:
logger.info("No cached result, calculating one.")
result = self.response_cache.set(
key,
preserve_fn(self._get_public_room_list)(
limit, since_token, network_tuple=network_tuple
)
)
else:
logger.info("Using cached deferred result.")
return make_deferred_yieldable(result)
@defer.inlineCallbacks
def _get_public_room_list(self, limit=None, since_token=None,
search_filter=None,
network_tuple=EMTPY_THIRD_PARTY_ID,):
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 = {}
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
joined_users = yield self.state_handler.get_current_user_in_room(
room_id, latest_event_ids,
)
num_joined_users = len(joined_users)
rooms_to_num_joined[room_id] = num_joined_users
if num_joined_users == 0:
return
# We want larger rooms to be first, hence negating num_joined_users
rooms_to_order_value[room_id] = (-num_joined_users, room_id)
logger.info("Getting ordering for %i rooms since %s",
len(room_ids), stream_token)
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]
# `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 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[room_id] > 0
]
total_room_count = len(rooms_to_scan)
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:]
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
else:
step = len(rooms_to_scan)
chunk = []
for i in xrange(0, len(rooms_to_scan), step):
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
),
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"]
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()
defer.returnValue(results)
@defer.inlineCallbacks
def _append_room_entry_to_chunk(self, room_id, num_joined_users, chunk, limit,
search_filter):
"""Generate the entry for a room in the public room list and append it
to the `chunk` if it matches the search filter
"""
if limit and len(chunk) > limit + 1:
# We've already got enough, so lets just drop it.
return
result = yield self.generate_room_entry(room_id, num_joined_users)
if result and _matches_room_entry(result, search_filter):
chunk.append(result)
@cachedInlineCallbacks(num_args=1, cache_context=True)
def generate_room_entry(self, room_id, num_joined_users, cache_context,
with_alias=True, allow_private=False):
"""Returns the entry for a room
"""
result = {
"room_id": room_id,
"num_joined_members": num_joined_users,
}
current_state_ids = yield self.store.get_current_state_ids(
room_id, on_invalidate=cache_context.invalidate,
)
event_map = yield self.store.get_events([
event_id for key, event_id in current_state_ids.iteritems()
if key[0] in (
EventTypes.JoinRules,
EventTypes.Name,
EventTypes.Topic,
EventTypes.CanonicalAlias,
EventTypes.RoomHistoryVisibility,
EventTypes.GuestAccess,
"m.room.avatar",
)
])
current_state = {
(ev.type, ev.state_key): ev
for ev in event_map.values()
}
# Double check that this is actually a public room.
join_rules_event = current_state.get((EventTypes.JoinRules, ""))
if join_rules_event:
join_rule = join_rules_event.content.get("join_rule", None)
if not allow_private and join_rule and join_rule != JoinRules.PUBLIC:
defer.returnValue(None)
if with_alias:
aliases = yield self.store.get_aliases_for_room(
room_id, on_invalidate=cache_context.invalidate
)
if aliases:
result["aliases"] = aliases
name_event = yield current_state.get((EventTypes.Name, ""))
if name_event:
name = name_event.content.get("name", None)
if name:
result["name"] = name
topic_event = current_state.get((EventTypes.Topic, ""))
if topic_event:
topic = topic_event.content.get("topic", None)
if topic:
result["topic"] = topic
canonical_event = current_state.get((EventTypes.CanonicalAlias, ""))
if canonical_event:
canonical_alias = canonical_event.content.get("alias", None)
if canonical_alias:
result["canonical_alias"] = canonical_alias
visibility_event = current_state.get((EventTypes.RoomHistoryVisibility, ""))
visibility = None
if visibility_event:
visibility = visibility_event.content.get("history_visibility", None)
result["world_readable"] = visibility == "world_readable"
guest_event = current_state.get((EventTypes.GuestAccess, ""))
guest = None
if guest_event:
guest = guest_event.content.get("guest_access", None)
result["guest_can_join"] = guest == "can_join"
avatar_event = current_state.get(("m.room.avatar", ""))
if avatar_event:
avatar_url = avatar_event.content.get("url", None)
if avatar_url:
result["avatar_url"] = avatar_url
defer.returnValue(result)
@defer.inlineCallbacks
def get_remote_public_room_list(self, server_name, limit=None, since_token=None,
search_filter=None, include_all_networks=False,
third_party_instance_id=None,):
if search_filter:
# We currently don't support searching across federation, so we have
# to do it manually without pagination
limit = None
since_token = None
res = yield self._get_remote_list_cached(
server_name, limit=limit, since_token=since_token,
include_all_networks=include_all_networks,
third_party_instance_id=third_party_instance_id,
)
if search_filter:
res = {"chunk": [
entry
for entry in list(res.get("chunk", []))
if _matches_room_entry(entry, search_filter)
]}
defer.returnValue(res)
def _get_remote_list_cached(self, server_name, limit=None, since_token=None,
search_filter=None, include_all_networks=False,
third_party_instance_id=None,):
repl_layer = self.hs.get_replication_layer()
if search_filter:
# We can't cache when asking for search
return repl_layer.get_public_rooms(
server_name, limit=limit, since_token=since_token,
search_filter=search_filter, include_all_networks=include_all_networks,
third_party_instance_id=third_party_instance_id,
)
key = (
server_name, limit, since_token, include_all_networks,
third_party_instance_id,
)
result = self.remote_response_cache.get(key)
if not result:
result = self.remote_response_cache.set(
key,
repl_layer.get_public_rooms(
server_name, limit=limit, since_token=since_token,
search_filter=search_filter,
include_all_networks=include_all_networks,
third_party_instance_id=third_party_instance_id,
)
)
return result
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
"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",
}
REVERSE_KEY_DICT = {v: k for k, v in KEY_DICT.items()}
@classmethod
def from_token(cls, token):
return RoomListNextBatch(**{
cls.REVERSE_KEY_DICT[key]: val
for key, val in msgpack.loads(decode_base64(token)).items()
})
def to_token(self):
return encode_base64(msgpack.dumps({
self.KEY_DICT[key]: val
for key, val in self._asdict().items()
}))
def copy_and_replace(self, **kwds):
return self._replace(
**kwds
)
def _matches_room_entry(room_entry, search_filter):
if search_filter and search_filter.get("generic_search_term", None):
generic_search_term = search_filter["generic_search_term"].upper()
if generic_search_term in room_entry.get("name", "").upper():
return True
elif generic_search_term in room_entry.get("topic", "").upper():
return True
elif generic_search_term in room_entry.get("canonical_alias", "").upper():
return True
else:
return True
return False