652 lines
23 KiB
Python
652 lines
23 KiB
Python
# -*- coding: utf-8 -*-
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# Copyright 2014-2016 OpenMarket Ltd
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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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from twisted.internet import defer
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from synapse import event_auth
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from synapse.util.logutils import log_function
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from synapse.util.caches.expiringcache import ExpiringCache
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from synapse.util.metrics import Measure
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from synapse.api.constants import EventTypes
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from synapse.api.errors import AuthError
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from synapse.events.snapshot import EventContext
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from synapse.util.async import Linearizer
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from synapse.util.caches import CACHE_SIZE_FACTOR
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from collections import namedtuple
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from frozendict import frozendict
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import logging
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import hashlib
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logger = logging.getLogger(__name__)
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KeyStateTuple = namedtuple("KeyStateTuple", ("context", "type", "state_key"))
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SIZE_OF_CACHE = int(100000 * CACHE_SIZE_FACTOR)
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EVICTION_TIMEOUT_SECONDS = 60 * 60
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_NEXT_STATE_ID = 1
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POWER_KEY = (EventTypes.PowerLevels, "")
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def _gen_state_id():
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global _NEXT_STATE_ID
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s = "X%d" % (_NEXT_STATE_ID,)
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_NEXT_STATE_ID += 1
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return s
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class _StateCacheEntry(object):
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__slots__ = ["state", "state_group", "state_id", "prev_group", "delta_ids"]
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def __init__(self, state, state_group, prev_group=None, delta_ids=None):
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self.state = frozendict(state)
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self.state_group = state_group
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self.prev_group = prev_group
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self.delta_ids = frozendict(delta_ids) if delta_ids is not None else None
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# The `state_id` is a unique ID we generate that can be used as ID for
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# this collection of state. Usually this would be the same as the
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# state group, but on worker instances we can't generate a new state
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# group each time we resolve state, so we generate a separate one that
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# isn't persisted and is used solely for caches.
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# `state_id` is either a state_group (and so an int) or a string. This
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# ensures we don't accidentally persist a state_id as a stateg_group
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if state_group:
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self.state_id = state_group
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else:
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self.state_id = _gen_state_id()
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def __len__(self):
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return len(self.state)
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class StateHandler(object):
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""" Responsible for doing state conflict resolution.
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"""
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def __init__(self, hs):
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self.clock = hs.get_clock()
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self.store = hs.get_datastore()
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self.hs = hs
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# dict of set of event_ids -> _StateCacheEntry.
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self._state_cache = None
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self.resolve_linearizer = Linearizer(name="state_resolve_lock")
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def start_caching(self):
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logger.debug("start_caching")
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self._state_cache = ExpiringCache(
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cache_name="state_cache",
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clock=self.clock,
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max_len=SIZE_OF_CACHE,
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expiry_ms=EVICTION_TIMEOUT_SECONDS * 1000,
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iterable=True,
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reset_expiry_on_get=True,
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)
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self._state_cache.start()
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@defer.inlineCallbacks
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def get_current_state(self, room_id, event_type=None, state_key="",
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latest_event_ids=None):
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""" Retrieves the current state for the room. This is done by
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calling `get_latest_events_in_room` to get the leading edges of the
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event graph and then resolving any of the state conflicts.
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This is equivalent to getting the state of an event that were to send
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next before receiving any new events.
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If `event_type` is specified, then the method returns only the one
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event (or None) with that `event_type` and `state_key`.
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Returns:
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map from (type, state_key) to event
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"""
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if not latest_event_ids:
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latest_event_ids = yield self.store.get_latest_event_ids_in_room(room_id)
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logger.debug("calling resolve_state_groups from get_current_state")
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ret = yield self.resolve_state_groups(room_id, latest_event_ids)
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state = ret.state
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if event_type:
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event_id = state.get((event_type, state_key))
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event = None
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if event_id:
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event = yield self.store.get_event(event_id, allow_none=True)
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defer.returnValue(event)
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return
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state_map = yield self.store.get_events(state.values(), get_prev_content=False)
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state = {
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key: state_map[e_id] for key, e_id in state.items() if e_id in state_map
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}
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defer.returnValue(state)
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@defer.inlineCallbacks
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def get_current_state_ids(self, room_id, event_type=None, state_key="",
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latest_event_ids=None):
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if not latest_event_ids:
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latest_event_ids = yield self.store.get_latest_event_ids_in_room(room_id)
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logger.debug("calling resolve_state_groups from get_current_state_ids")
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ret = yield self.resolve_state_groups(room_id, latest_event_ids)
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state = ret.state
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if event_type:
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defer.returnValue(state.get((event_type, state_key)))
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return
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defer.returnValue(state)
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@defer.inlineCallbacks
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def get_current_user_in_room(self, room_id, latest_event_ids=None):
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if not latest_event_ids:
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latest_event_ids = yield self.store.get_latest_event_ids_in_room(room_id)
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logger.debug("calling resolve_state_groups from get_current_user_in_room")
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entry = yield self.resolve_state_groups(room_id, latest_event_ids)
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joined_users = yield self.store.get_joined_users_from_state(room_id, entry)
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defer.returnValue(joined_users)
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@defer.inlineCallbacks
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def get_current_hosts_in_room(self, room_id, latest_event_ids=None):
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if not latest_event_ids:
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latest_event_ids = yield self.store.get_latest_event_ids_in_room(room_id)
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logger.debug("calling resolve_state_groups from get_current_hosts_in_room")
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entry = yield self.resolve_state_groups(room_id, latest_event_ids)
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joined_hosts = yield self.store.get_joined_hosts(room_id, entry)
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defer.returnValue(joined_hosts)
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@defer.inlineCallbacks
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def compute_event_context(self, event, old_state=None):
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"""Build an EventContext structure for the event.
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Args:
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event (synapse.events.EventBase):
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Returns:
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synapse.events.snapshot.EventContext:
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"""
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if event.internal_metadata.is_outlier():
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# If this is an outlier, then we know it shouldn't have any current
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# state. Certainly store.get_current_state won't return any, and
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# persisting the event won't store the state group.
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context = EventContext()
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if old_state:
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context.prev_state_ids = {
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(s.type, s.state_key): s.event_id for s in old_state
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}
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if event.is_state():
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context.current_state_ids = dict(context.prev_state_ids)
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key = (event.type, event.state_key)
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context.current_state_ids[key] = event.event_id
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else:
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context.current_state_ids = context.prev_state_ids
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else:
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context.current_state_ids = {}
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context.prev_state_ids = {}
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context.prev_state_events = []
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context.state_group = self.store.get_next_state_group()
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defer.returnValue(context)
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if old_state:
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context = EventContext()
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context.prev_state_ids = {
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(s.type, s.state_key): s.event_id for s in old_state
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}
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context.state_group = self.store.get_next_state_group()
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if event.is_state():
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key = (event.type, event.state_key)
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if key in context.prev_state_ids:
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replaces = context.prev_state_ids[key]
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if replaces != event.event_id: # Paranoia check
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event.unsigned["replaces_state"] = replaces
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context.current_state_ids = dict(context.prev_state_ids)
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context.current_state_ids[key] = event.event_id
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else:
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context.current_state_ids = context.prev_state_ids
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context.prev_state_events = []
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defer.returnValue(context)
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logger.debug("calling resolve_state_groups from compute_event_context")
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entry = yield self.resolve_state_groups(
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event.room_id, [e for e, _ in event.prev_events],
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)
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curr_state = entry.state
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context = EventContext()
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context.prev_state_ids = curr_state
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if event.is_state():
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context.state_group = self.store.get_next_state_group()
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key = (event.type, event.state_key)
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if key in context.prev_state_ids:
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replaces = context.prev_state_ids[key]
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event.unsigned["replaces_state"] = replaces
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context.current_state_ids = dict(context.prev_state_ids)
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context.current_state_ids[key] = event.event_id
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if entry.state_group:
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context.prev_group = entry.state_group
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context.delta_ids = {
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key: event.event_id
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}
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elif entry.prev_group:
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context.prev_group = entry.prev_group
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context.delta_ids = dict(entry.delta_ids)
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context.delta_ids[key] = event.event_id
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else:
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if entry.state_group is None:
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entry.state_group = self.store.get_next_state_group()
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entry.state_id = entry.state_group
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context.state_group = entry.state_group
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context.current_state_ids = context.prev_state_ids
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context.prev_group = entry.prev_group
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context.delta_ids = entry.delta_ids
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context.prev_state_events = []
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defer.returnValue(context)
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@defer.inlineCallbacks
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@log_function
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def resolve_state_groups(self, room_id, event_ids):
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""" Given a list of event_ids this method fetches the state at each
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event, resolves conflicts between them and returns them.
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Returns:
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a Deferred tuple of (`state_group`, `state`, `prev_state`).
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`state_group` is the name of a state group if one and only one is
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involved. `state` is a map from (type, state_key) to event, and
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`prev_state` is a list of event ids.
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"""
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logger.debug("resolve_state_groups event_ids %s", event_ids)
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state_groups_ids = yield self.store.get_state_groups_ids(
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room_id, event_ids
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)
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logger.debug(
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"resolve_state_groups state_groups %s",
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state_groups_ids.keys()
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)
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group_names = frozenset(state_groups_ids.keys())
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if len(group_names) == 1:
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name, state_list = state_groups_ids.items().pop()
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prev_group, delta_ids = yield self.store.get_state_group_delta(name)
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defer.returnValue(_StateCacheEntry(
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state=state_list,
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state_group=name,
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prev_group=prev_group,
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delta_ids=delta_ids,
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))
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with (yield self.resolve_linearizer.queue(group_names)):
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if self._state_cache is not None:
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cache = self._state_cache.get(group_names, None)
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if cache:
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defer.returnValue(cache)
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logger.info(
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"Resolving state for %s with %d groups", room_id, len(state_groups_ids)
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)
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state = {}
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for st in state_groups_ids.values():
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for key, e_id in st.items():
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state.setdefault(key, set()).add(e_id)
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conflicted_state = {
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k: list(v)
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for k, v in state.items()
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if len(v) > 1
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}
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if conflicted_state:
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logger.info("Resolving conflicted state for %r", room_id)
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with Measure(self.clock, "state._resolve_events"):
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new_state = yield resolve_events(
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state_groups_ids.values(),
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state_map_factory=lambda ev_ids: self.store.get_events(
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ev_ids, get_prev_content=False, check_redacted=False,
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),
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)
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else:
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new_state = {
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key: e_ids.pop() for key, e_ids in state.items()
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}
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state_group = None
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new_state_event_ids = frozenset(new_state.values())
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for sg, events in state_groups_ids.items():
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if new_state_event_ids == frozenset(e_id for e_id in events):
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state_group = sg
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break
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# TODO: We want to create a state group for this set of events, to
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# increase cache hits, but we need to make sure that it doesn't
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# end up as a prev_group without being added to the database
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prev_group = None
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delta_ids = None
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for old_group, old_ids in state_groups_ids.iteritems():
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if not set(new_state) - set(old_ids):
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n_delta_ids = {
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k: v
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for k, v in new_state.iteritems()
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if old_ids.get(k) != v
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}
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if not delta_ids or len(n_delta_ids) < len(delta_ids):
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prev_group = old_group
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delta_ids = n_delta_ids
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cache = _StateCacheEntry(
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state=new_state,
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state_group=state_group,
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prev_group=prev_group,
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delta_ids=delta_ids,
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)
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if self._state_cache is not None:
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self._state_cache[group_names] = cache
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defer.returnValue(cache)
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def resolve_events(self, state_sets, event):
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logger.info(
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"Resolving state for %s with %d groups", event.room_id, len(state_sets)
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)
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state_set_ids = [{
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(ev.type, ev.state_key): ev.event_id
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for ev in st
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} for st in state_sets]
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state_map = {
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ev.event_id: ev
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for st in state_sets
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for ev in st
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}
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with Measure(self.clock, "state._resolve_events"):
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new_state = resolve_events(state_set_ids, state_map)
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new_state = {
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key: state_map[ev_id] for key, ev_id in new_state.items()
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}
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return new_state
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def _ordered_events(events):
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def key_func(e):
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return -int(e.depth), hashlib.sha1(e.event_id).hexdigest()
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return sorted(events, key=key_func)
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def resolve_events(state_sets, state_map_factory):
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"""
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Args:
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state_sets(list): List of dicts of (type, state_key) -> event_id,
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which are the different state groups to resolve.
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state_map_factory(dict|callable): If callable, then will be called
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with a list of event_ids that are needed, and should return with
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a Deferred of dict of event_id to event. Otherwise, should be
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a dict from event_id to event of all events in state_sets.
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Returns
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dict[(str, str), synapse.events.FrozenEvent] is a map from
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(type, state_key) to event.
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"""
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if len(state_sets) == 1:
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return state_sets[0]
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unconflicted_state, conflicted_state = _seperate(
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state_sets,
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)
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if callable(state_map_factory):
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return _resolve_with_state_fac(
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unconflicted_state, conflicted_state, state_map_factory
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)
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state_map = state_map_factory
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auth_events = _create_auth_events_from_maps(
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unconflicted_state, conflicted_state, state_map
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)
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return _resolve_with_state(
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unconflicted_state, conflicted_state, auth_events, state_map
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)
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def _seperate(state_sets):
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"""Takes the state_sets and figures out which keys are conflicted and
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which aren't. i.e., which have multiple different event_ids associated
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with them in different state sets.
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"""
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unconflicted_state = dict(state_sets[0])
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conflicted_state = {}
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for state_set in state_sets[1:]:
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for key, value in state_set.iteritems():
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# Check if there is an unconflicted entry for the state key.
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unconflicted_value = unconflicted_state.get(key)
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if unconflicted_value is None:
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# There isn't an unconflicted entry so check if there is a
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# conflicted entry.
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ls = conflicted_state.get(key)
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if ls is None:
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# There wasn't a conflicted entry so haven't seen this key before.
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# Therefore it isn't conflicted yet.
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unconflicted_state[key] = value
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else:
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# This key is already conflicted, add our value to the conflict set.
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ls.add(value)
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elif unconflicted_value != value:
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# If the unconflicted value is not the same as our value then we
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# have a new conflict. So move the key from the unconflicted_state
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# to the conflicted state.
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conflicted_state[key] = {value, unconflicted_value}
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unconflicted_state.pop(key, None)
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return unconflicted_state, conflicted_state
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@defer.inlineCallbacks
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def _resolve_with_state_fac(unconflicted_state, conflicted_state,
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state_map_factory):
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needed_events = set(
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event_id
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for event_ids in conflicted_state.itervalues()
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for event_id in event_ids
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)
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logger.info("Asking for %d conflicted events", len(needed_events))
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state_map = yield state_map_factory(needed_events)
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auth_events = _create_auth_events_from_maps(
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unconflicted_state, conflicted_state, state_map
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)
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new_needed_events = set(auth_events.itervalues())
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new_needed_events -= needed_events
|
|
|
|
logger.info("Asking for %d auth events", len(new_needed_events))
|
|
|
|
state_map_new = yield state_map_factory(new_needed_events)
|
|
state_map.update(state_map_new)
|
|
|
|
defer.returnValue(_resolve_with_state(
|
|
unconflicted_state, conflicted_state, auth_events, state_map
|
|
))
|
|
|
|
|
|
def _create_auth_events_from_maps(unconflicted_state, conflicted_state, state_map):
|
|
auth_events = {}
|
|
for event_ids in conflicted_state.itervalues():
|
|
for event_id in event_ids:
|
|
if event_id in state_map:
|
|
keys = event_auth.auth_types_for_event(state_map[event_id])
|
|
for key in keys:
|
|
if key not in auth_events:
|
|
event_id = unconflicted_state.get(key, None)
|
|
if event_id:
|
|
auth_events[key] = event_id
|
|
return auth_events
|
|
|
|
|
|
def _resolve_with_state(unconflicted_state_ids, conflicted_state_ds, auth_event_ids,
|
|
state_map):
|
|
conflicted_state = {}
|
|
for key, event_ids in conflicted_state_ds.iteritems():
|
|
events = [state_map[ev_id] for ev_id in event_ids if ev_id in state_map]
|
|
if len(events) > 1:
|
|
conflicted_state[key] = events
|
|
elif len(events) == 1:
|
|
unconflicted_state_ids[key] = events[0].event_id
|
|
|
|
auth_events = {
|
|
key: state_map[ev_id]
|
|
for key, ev_id in auth_event_ids.items()
|
|
if ev_id in state_map
|
|
}
|
|
|
|
try:
|
|
resolved_state = _resolve_state_events(
|
|
conflicted_state, auth_events
|
|
)
|
|
except:
|
|
logger.exception("Failed to resolve state")
|
|
raise
|
|
|
|
new_state = unconflicted_state_ids
|
|
for key, event in resolved_state.iteritems():
|
|
new_state[key] = event.event_id
|
|
|
|
return new_state
|
|
|
|
|
|
def _resolve_state_events(conflicted_state, auth_events):
|
|
""" This is where we actually decide which of the conflicted state to
|
|
use.
|
|
|
|
We resolve conflicts in the following order:
|
|
1. power levels
|
|
2. join rules
|
|
3. memberships
|
|
4. other events.
|
|
"""
|
|
resolved_state = {}
|
|
if POWER_KEY in conflicted_state:
|
|
events = conflicted_state[POWER_KEY]
|
|
logger.debug("Resolving conflicted power levels %r", events)
|
|
resolved_state[POWER_KEY] = _resolve_auth_events(
|
|
events, auth_events)
|
|
|
|
auth_events.update(resolved_state)
|
|
|
|
for key, events in conflicted_state.items():
|
|
if key[0] == EventTypes.JoinRules:
|
|
logger.debug("Resolving conflicted join rules %r", events)
|
|
resolved_state[key] = _resolve_auth_events(
|
|
events,
|
|
auth_events
|
|
)
|
|
|
|
auth_events.update(resolved_state)
|
|
|
|
for key, events in conflicted_state.items():
|
|
if key[0] == EventTypes.Member:
|
|
logger.debug("Resolving conflicted member lists %r", events)
|
|
resolved_state[key] = _resolve_auth_events(
|
|
events,
|
|
auth_events
|
|
)
|
|
|
|
auth_events.update(resolved_state)
|
|
|
|
for key, events in conflicted_state.items():
|
|
if key not in resolved_state:
|
|
logger.debug("Resolving conflicted state %r:%r", key, events)
|
|
resolved_state[key] = _resolve_normal_events(
|
|
events, auth_events
|
|
)
|
|
|
|
return resolved_state
|
|
|
|
|
|
def _resolve_auth_events(events, auth_events):
|
|
reverse = [i for i in reversed(_ordered_events(events))]
|
|
|
|
auth_keys = set(
|
|
key
|
|
for event in events
|
|
for key in event_auth.auth_types_for_event(event)
|
|
)
|
|
|
|
new_auth_events = {}
|
|
for key in auth_keys:
|
|
auth_event = auth_events.get(key, None)
|
|
if auth_event:
|
|
new_auth_events[key] = auth_event
|
|
|
|
auth_events = new_auth_events
|
|
|
|
prev_event = reverse[0]
|
|
for event in reverse[1:]:
|
|
auth_events[(prev_event.type, prev_event.state_key)] = prev_event
|
|
try:
|
|
# The signatures have already been checked at this point
|
|
event_auth.check(event, auth_events, do_sig_check=False, do_size_check=False)
|
|
prev_event = event
|
|
except AuthError:
|
|
return prev_event
|
|
|
|
return event
|
|
|
|
|
|
def _resolve_normal_events(events, auth_events):
|
|
for event in _ordered_events(events):
|
|
try:
|
|
# The signatures have already been checked at this point
|
|
event_auth.check(event, auth_events, do_sig_check=False, do_size_check=False)
|
|
return event
|
|
except AuthError:
|
|
pass
|
|
|
|
# Use the last event (the one with the least depth) if they all fail
|
|
# the auth check.
|
|
return event
|