forked-synapse/synapse/replication/http/membership.py
Erik Johnston 1531b214fc
Add ability to wait for replication streams (#7542)
The idea here is that if an instance persists an event via the replication HTTP API it can return before we receive that event over replication, which can lead to races where code assumes that persisting an event immediately updates various caches (e.g. current state of the room).

Most of Synapse doesn't hit such races, so we don't do the waiting automagically, instead we do so where necessary to avoid unnecessary delays. We may decide to change our minds here if it turns out there are a lot of subtle races going on.

People probably want to look at this commit by commit.
2020-05-22 14:21:54 +01:00

211 lines
6.7 KiB
Python

# -*- coding: utf-8 -*-
# Copyright 2018 New Vector 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.
import logging
from synapse.http.servlet import parse_json_object_from_request
from synapse.replication.http._base import ReplicationEndpoint
from synapse.types import Requester, UserID
from synapse.util.distributor import user_joined_room, user_left_room
logger = logging.getLogger(__name__)
class ReplicationRemoteJoinRestServlet(ReplicationEndpoint):
"""Does a remote join for the given user to the given room
Request format:
POST /_synapse/replication/remote_join/:room_id/:user_id
{
"requester": ...,
"remote_room_hosts": [...],
"content": { ... }
}
"""
NAME = "remote_join"
PATH_ARGS = ("room_id", "user_id")
def __init__(self, hs):
super(ReplicationRemoteJoinRestServlet, self).__init__(hs)
self.federation_handler = hs.get_handlers().federation_handler
self.store = hs.get_datastore()
self.clock = hs.get_clock()
@staticmethod
def _serialize_payload(requester, room_id, user_id, remote_room_hosts, content):
"""
Args:
requester(Requester)
room_id (str)
user_id (str)
remote_room_hosts (list[str]): Servers to try and join via
content(dict): The event content to use for the join event
"""
return {
"requester": requester.serialize(),
"remote_room_hosts": remote_room_hosts,
"content": content,
}
async def _handle_request(self, request, room_id, user_id):
content = parse_json_object_from_request(request)
remote_room_hosts = content["remote_room_hosts"]
event_content = content["content"]
requester = Requester.deserialize(self.store, content["requester"])
if requester.user:
request.authenticated_entity = requester.user.to_string()
logger.info("remote_join: %s into room: %s", user_id, room_id)
event_id, stream_id = await self.federation_handler.do_invite_join(
remote_room_hosts, room_id, user_id, event_content
)
return 200, {"event_id": event_id, "stream_id": stream_id}
class ReplicationRemoteRejectInviteRestServlet(ReplicationEndpoint):
"""Rejects the invite for the user and room.
Request format:
POST /_synapse/replication/remote_reject_invite/:room_id/:user_id
{
"requester": ...,
"remote_room_hosts": [...],
"content": { ... }
}
"""
NAME = "remote_reject_invite"
PATH_ARGS = ("room_id", "user_id")
def __init__(self, hs):
super(ReplicationRemoteRejectInviteRestServlet, self).__init__(hs)
self.federation_handler = hs.get_handlers().federation_handler
self.store = hs.get_datastore()
self.clock = hs.get_clock()
@staticmethod
def _serialize_payload(requester, room_id, user_id, remote_room_hosts, content):
"""
Args:
requester(Requester)
room_id (str)
user_id (str)
remote_room_hosts (list[str]): Servers to try and reject via
"""
return {
"requester": requester.serialize(),
"remote_room_hosts": remote_room_hosts,
"content": content,
}
async def _handle_request(self, request, room_id, user_id):
content = parse_json_object_from_request(request)
remote_room_hosts = content["remote_room_hosts"]
event_content = content["content"]
requester = Requester.deserialize(self.store, content["requester"])
if requester.user:
request.authenticated_entity = requester.user.to_string()
logger.info("remote_reject_invite: %s out of room: %s", user_id, room_id)
try:
event, stream_id = await self.federation_handler.do_remotely_reject_invite(
remote_room_hosts, room_id, user_id, event_content,
)
event_id = event.event_id
except Exception as e:
# if we were unable to reject the exception, just mark
# it as rejected on our end and plough ahead.
#
# The 'except' clause is very broad, but we need to
# capture everything from DNS failures upwards
#
logger.warning("Failed to reject invite: %s", e)
stream_id = await self.store.locally_reject_invite(user_id, room_id)
event_id = None
return 200, {"event_id": event_id, "stream_id": stream_id}
class ReplicationUserJoinedLeftRoomRestServlet(ReplicationEndpoint):
"""Notifies that a user has joined or left the room
Request format:
POST /_synapse/replication/membership_change/:room_id/:user_id/:change
{}
"""
NAME = "membership_change"
PATH_ARGS = ("room_id", "user_id", "change")
CACHE = False # No point caching as should return instantly.
def __init__(self, hs):
super(ReplicationUserJoinedLeftRoomRestServlet, self).__init__(hs)
self.registeration_handler = hs.get_registration_handler()
self.store = hs.get_datastore()
self.clock = hs.get_clock()
self.distributor = hs.get_distributor()
@staticmethod
def _serialize_payload(room_id, user_id, change):
"""
Args:
room_id (str)
user_id (str)
change (str): Either "joined" or "left"
"""
assert change in ("joined", "left")
return {}
def _handle_request(self, request, room_id, user_id, change):
logger.info("user membership change: %s in %s", user_id, room_id)
user = UserID.from_string(user_id)
if change == "joined":
user_joined_room(self.distributor, user, room_id)
elif change == "left":
user_left_room(self.distributor, user, room_id)
else:
raise Exception("Unrecognized change: %r", change)
return 200, {}
def register_servlets(hs, http_server):
ReplicationRemoteJoinRestServlet(hs).register(http_server)
ReplicationRemoteRejectInviteRestServlet(hs).register(http_server)
ReplicationUserJoinedLeftRoomRestServlet(hs).register(http_server)