# -*- coding: utf-8 -*-
# Copyright 2015 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 ._base import BaseHandler
from synapse.streams.config import PaginationConfig
from synapse.api.constants import Membership
from twisted.internet import defer
import collections
import logging
logger = logging.getLogger(__name__)
SyncConfig = collections.namedtuple("SyncConfig", [
"user",
"device",
"limit",
"gap",
"sort",
"backfill",
"filter",
])
class RoomSyncResult(collections.namedtuple("RoomSyncResult", [
"room_id",
"limited",
"published",
"events",
"state",
"prev_batch",
])):
__slots__ = []
def __nonzero__(self):
return bool(self.events or self.state)
class SyncResult(collections.namedtuple("SyncResult", [
"next_batch", # Token for the next sync
"private_user_data", # List of private events for the user.
"public_user_data", # List of public events for all users.
"rooms", # RoomSyncResult for each room.
])):
__slots__ = []
def __nonzero__(self):
return bool(
self.private_user_data or self.public_user_data or self.rooms
)
class SyncHandler(BaseHandler):
def __init__(self, hs):
super(SyncHandler, self).__init__(hs)
self.event_sources = hs.get_event_sources()
self.clock = hs.get_clock()
def wait_for_sync_for_user(self, sync_config, since_token=None, timeout=0):
"""Get the sync for a client if we have new data for it now. Otherwise
wait for new data to arrive on the server. If the timeout expires, then
return an empty sync result.
Returns:
A Deferred SyncResult.
"""
if timeout == 0 or since_token is None:
return self.current_sync_for_user(sync_config, since_token)
else:
def current_sync_callback(since_token):
return self.current_sync_for_user(
self, since_token, sync_config
)
return self.notifier.wait_for_events(
sync_config.filter, since_token, current_sync_callback
)
def current_sync_for_user(self, sync_config, since_token=None):
"""Get the sync for client needed to match what the server has now.
Returns:
A Deferred SyncResult.
"""
if since_token is None:
return self.initial_sync(sync_config)
else:
if sync_config.gap:
return self.incremental_sync_with_gap(sync_config, since_token)
else:
#TODO(mjark): Handle gapless sync
pass
@defer.inlineCallbacks
def initial_sync(self, sync_config):
"""Get a sync for a client which is starting without any state
Returns:
A Deferred SyncResult.
"""
if sync_config.sort == "timeline,desc":
# TODO(mjark): Handle going through events in reverse order?.
# What does "most recent events" mean when applying the limits mean
# in this case?
raise NotImplementedError()
now_token = yield self.event_sources.get_current_token()
presence_stream = self.event_sources.sources["presence"]
# TODO (mjark): This looks wrong, shouldn't we be getting the presence
# UP to the present rather than after the present?
pagination_config = PaginationConfig(from_token=now_token)
presence, _ = yield presence_stream.get_pagination_rows(
user=sync_config.user,
pagination_config=pagination_config.get_source_config("presence"),
key=None
)
room_list = yield self.store.get_rooms_for_user_where_membership_is(
user_id=sync_config.user.to_string(),
membership_list=[Membership.INVITE, Membership.JOIN]
)
# TODO (mjark): Does public mean "published"?
published_rooms = yield self.store.get_rooms(is_public=True)
published_room_ids = set(r["room_id"] for r in published_rooms)
rooms = []
for event in room_list:
room_sync = yield self.initial_sync_for_room(
event.room_id, sync_config, now_token, published_room_ids
)
rooms.append(room_sync)
defer.returnValue(SyncResult(
public_user_data=presence,
private_user_data=[],
rooms=rooms,
next_batch=now_token,
))
@defer.inlineCallbacks
def intial_sync_for_room(self, room_id, sync_config, now_token,
published_room_ids):
"""Sync a room for a client which is starting without any state
Returns:
A Deferred RoomSyncResult.
"""
recent_events, token = yield self.store.get_recent_events_for_room(
room_id,
limit=sync_config.limit,
end_token=now_token.room_key,
)
prev_batch_token = now_token.copy_and_replace("room_key", token[0])
current_state_events = yield self.state_handler.get_current_state(
room_id
)
defer.returnValue(RoomSyncResult(
room_id=room_id,
published=room_id in published_room_ids,
events=recent_events,
prev_batch=prev_batch_token,
state=current_state_events,
limited=True,
))
@defer.inlineCallbacks
def incremental_sync_with_gap(self, sync_config, since_token):
""" Get the incremental delta needed to bring the client up to
date with the server.
Returns:
A Deferred SyncResult.
"""
if sync_config.sort == "timeline,desc":
# TODO(mjark): Handle going through events in reverse order?.
# What does "most recent events" mean when applying the limits mean
# in this case?
raise NotImplementedError()
now_token = yield self.event_sources.get_current_token()
presence_stream = self.event_sources.sources["presence"]
pagination_config = PaginationConfig(
from_token=since_token, to_token=now_token
)
presence, _ = yield presence_stream.get_pagination_rows(
user=sync_config.user,
pagination_config=pagination_config.get_source_config("presence"),
key=None
)
room_list = yield self.store.get_rooms_for_user_where_membership_is(
user_id=sync_config.user.to_string(),
membership_list=[Membership.INVITE, Membership.JOIN]
)
# TODO (mjark): Does public mean "published"?
published_rooms = yield self.store.get_rooms(is_public=True)
published_room_ids = set(r["room_id"] for r in published_rooms)
rooms = []
for event in room_list:
room_sync = yield self.incremental_sync_with_gap_for_room(
event.room_id, sync_config, since_token, now_token,
published_room_ids
)
if room_sync:
rooms.append(room_sync)
defer.returnValue(SyncResult(
public_user_data=presence,
private_user_data=[],
rooms=rooms,
next_batch=now_token,
))
@defer.inlineCallbacks
def incremental_sync_with_gap_for_room(self, room_id, sync_config,
since_token, now_token,
published_room_ids):
""" Get the incremental delta needed to bring the client up to date for
the room. Gives the client the most recent events and the changes to
state.
Returns:
A Deferred RoomSyncResult
"""
# TODO(mjark): Check if they have joined the room between
# the previous sync and this one.
# TODO(mjark): Apply the event filter in sync_config
# TODO(mjark): Check for redactions we might have missed.
# TODO(mjark): Typing notifications.
recents, token = yield self.store.get_recent_events_for_room(
room_id,
limit=sync_config.limit + 1,
from_token=since_token.room_key,
end_token=now_token.room_key,
)
logging.debug("Recents %r", recents)
if len(recents) > sync_config.limit:
limited = True
recents = recents[1:]
else:
limited = False
prev_batch_token = now_token.copy_and_replace("room_key", token[0])
# TODO(mjark): This seems racy since this isn't being passed a
# token to indicate what point in the stream this is
current_state_events = yield self.state_handler.get_current_state(
room_id
)
state_at_previous_sync = yield self.get_state_at_previous_sync(
room_id, since_token=since_token
)
state_events_delta = yield self.compute_state_delta(
since_token=since_token,
previous_state=state_at_previous_sync,
current_state=current_state_events,
)
room_sync = RoomSyncResult(
room_id=room_id,
published=room_id in published_room_ids,
events=recents,
prev_batch=prev_batch_token,
state=state_events_delta,
limited=limited,
)
logging.debug("Room sync: %r", room_sync)
defer.returnValue(room_sync)
@defer.inlineCallbacks
def get_state_at_previous_sync(self, room_id, since_token):
""" Get the room state at the previous sync the client made.
Returns:
A Deferred list of Events.
"""
last_events, token = yield self.store.get_recent_events_for_room(
room_id, end_token=since_token.room_key, limit=1,
)
if last_events:
last_event = last_events[0]
last_context = yield self.state_handler.compute_event_context(
last_event
)
if last_event.is_state():
state = [last_event] + last_context.current_state.values()
else:
state = last_context.current_state.values()
else:
state = ()
defer.returnValue(state)
def compute_state_delta(self, since_token, previous_state, current_state):
""" Works out the differnce in state between the current state and the
state the client got when it last performed a sync.
Returns:
A list of events.
"""
# TODO(mjark) Check if the state events were received by the server
# after the previous sync, since we need to include those state
# updates even if they occured logically before the previous event.
# TODO(mjark) Check for new redactions in the state events.
previous_dict = {event.event_id:event for event in previous_state}
state_delta = []
for event in current_state:
if event.event_id not in previous_dict:
state_delta.append(event)
return state_delta