629 lines
23 KiB
Python
629 lines
23 KiB
Python
# -*- coding: utf-8 -*-
|
|
# Copyright 2014-2016 OpenMarket Ltd
|
|
# 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 collections import namedtuple
|
|
|
|
from six import iteritems, itervalues
|
|
|
|
from frozendict import frozendict
|
|
|
|
from twisted.internet import defer
|
|
|
|
from synapse.api.constants import EventTypes, RoomVersions
|
|
from synapse.events.snapshot import EventContext
|
|
from synapse.state import v1
|
|
from synapse.util.async_helpers import Linearizer
|
|
from synapse.util.caches import get_cache_factor_for
|
|
from synapse.util.caches.expiringcache import ExpiringCache
|
|
from synapse.util.logutils import log_function
|
|
from synapse.util.metrics import Measure
|
|
|
|
logger = logging.getLogger(__name__)
|
|
|
|
|
|
KeyStateTuple = namedtuple("KeyStateTuple", ("context", "type", "state_key"))
|
|
|
|
|
|
SIZE_OF_CACHE = 100000 * get_cache_factor_for("state_cache")
|
|
EVICTION_TIMEOUT_SECONDS = 60 * 60
|
|
|
|
|
|
_NEXT_STATE_ID = 1
|
|
|
|
POWER_KEY = (EventTypes.PowerLevels, "")
|
|
|
|
|
|
def _gen_state_id():
|
|
global _NEXT_STATE_ID
|
|
s = "X%d" % (_NEXT_STATE_ID,)
|
|
_NEXT_STATE_ID += 1
|
|
return s
|
|
|
|
|
|
class _StateCacheEntry(object):
|
|
__slots__ = ["state", "state_group", "state_id", "prev_group", "delta_ids"]
|
|
|
|
def __init__(self, state, state_group, prev_group=None, delta_ids=None):
|
|
# dict[(str, str), str] map from (type, state_key) to event_id
|
|
self.state = frozendict(state)
|
|
|
|
# the ID of a state group if one and only one is involved.
|
|
# otherwise, None otherwise?
|
|
self.state_group = state_group
|
|
|
|
self.prev_group = prev_group
|
|
self.delta_ids = frozendict(delta_ids) if delta_ids is not None else None
|
|
|
|
# The `state_id` is a unique ID we generate that can be used as ID for
|
|
# this collection of state. Usually this would be the same as the
|
|
# state group, but on worker instances we can't generate a new state
|
|
# group each time we resolve state, so we generate a separate one that
|
|
# isn't persisted and is used solely for caches.
|
|
# `state_id` is either a state_group (and so an int) or a string. This
|
|
# ensures we don't accidentally persist a state_id as a stateg_group
|
|
if state_group:
|
|
self.state_id = state_group
|
|
else:
|
|
self.state_id = _gen_state_id()
|
|
|
|
def __len__(self):
|
|
return len(self.state)
|
|
|
|
|
|
class StateHandler(object):
|
|
"""Fetches bits of state from the stores, and does state resolution
|
|
where necessary
|
|
"""
|
|
|
|
def __init__(self, hs):
|
|
self.clock = hs.get_clock()
|
|
self.store = hs.get_datastore()
|
|
self.hs = hs
|
|
self._state_resolution_handler = hs.get_state_resolution_handler()
|
|
|
|
def start_caching(self):
|
|
# TODO: remove this shim
|
|
self._state_resolution_handler.start_caching()
|
|
|
|
@defer.inlineCallbacks
|
|
def get_current_state(self, room_id, event_type=None, state_key="",
|
|
latest_event_ids=None):
|
|
""" Retrieves the current state for the room. This is done by
|
|
calling `get_latest_events_in_room` to get the leading edges of the
|
|
event graph and then resolving any of the state conflicts.
|
|
|
|
This is equivalent to getting the state of an event that were to send
|
|
next before receiving any new events.
|
|
|
|
If `event_type` is specified, then the method returns only the one
|
|
event (or None) with that `event_type` and `state_key`.
|
|
|
|
Returns:
|
|
map from (type, state_key) to event
|
|
"""
|
|
if not latest_event_ids:
|
|
latest_event_ids = yield self.store.get_latest_event_ids_in_room(room_id)
|
|
|
|
logger.debug("calling resolve_state_groups from get_current_state")
|
|
ret = yield self.resolve_state_groups_for_events(room_id, latest_event_ids)
|
|
state = ret.state
|
|
|
|
if event_type:
|
|
event_id = state.get((event_type, state_key))
|
|
event = None
|
|
if event_id:
|
|
event = yield self.store.get_event(event_id, allow_none=True)
|
|
defer.returnValue(event)
|
|
return
|
|
|
|
state_map = yield self.store.get_events(list(state.values()),
|
|
get_prev_content=False)
|
|
state = {
|
|
key: state_map[e_id] for key, e_id in iteritems(state) if e_id in state_map
|
|
}
|
|
|
|
defer.returnValue(state)
|
|
|
|
@defer.inlineCallbacks
|
|
def get_current_state_ids(self, room_id, latest_event_ids=None):
|
|
"""Get the current state, or the state at a set of events, for a room
|
|
|
|
Args:
|
|
room_id (str):
|
|
|
|
latest_event_ids (iterable[str]|None): if given, the forward
|
|
extremities to resolve. If None, we look them up from the
|
|
database (via a cache)
|
|
|
|
Returns:
|
|
Deferred[dict[(str, str), str)]]: the state dict, mapping from
|
|
(event_type, state_key) -> event_id
|
|
"""
|
|
if not latest_event_ids:
|
|
latest_event_ids = yield self.store.get_latest_event_ids_in_room(room_id)
|
|
|
|
logger.debug("calling resolve_state_groups from get_current_state_ids")
|
|
ret = yield self.resolve_state_groups_for_events(room_id, latest_event_ids)
|
|
state = ret.state
|
|
|
|
defer.returnValue(state)
|
|
|
|
@defer.inlineCallbacks
|
|
def get_current_user_in_room(self, room_id, latest_event_ids=None):
|
|
if not latest_event_ids:
|
|
latest_event_ids = yield self.store.get_latest_event_ids_in_room(room_id)
|
|
logger.debug("calling resolve_state_groups from get_current_user_in_room")
|
|
entry = yield self.resolve_state_groups_for_events(room_id, latest_event_ids)
|
|
joined_users = yield self.store.get_joined_users_from_state(room_id, entry)
|
|
defer.returnValue(joined_users)
|
|
|
|
@defer.inlineCallbacks
|
|
def get_current_hosts_in_room(self, room_id, latest_event_ids=None):
|
|
if not latest_event_ids:
|
|
latest_event_ids = yield self.store.get_latest_event_ids_in_room(room_id)
|
|
logger.debug("calling resolve_state_groups from get_current_hosts_in_room")
|
|
entry = yield self.resolve_state_groups_for_events(room_id, latest_event_ids)
|
|
joined_hosts = yield self.store.get_joined_hosts(room_id, entry)
|
|
defer.returnValue(joined_hosts)
|
|
|
|
@defer.inlineCallbacks
|
|
def compute_event_context(self, event, old_state=None):
|
|
"""Build an EventContext structure for the event.
|
|
|
|
This works out what the current state should be for the event, and
|
|
generates a new state group if necessary.
|
|
|
|
Args:
|
|
event (synapse.events.EventBase):
|
|
old_state (dict|None): The state at the event if it can't be
|
|
calculated from existing events. This is normally only specified
|
|
when receiving an event from federation where we don't have the
|
|
prev events for, e.g. when backfilling.
|
|
Returns:
|
|
synapse.events.snapshot.EventContext:
|
|
"""
|
|
|
|
if event.internal_metadata.is_outlier():
|
|
# If this is an outlier, then we know it shouldn't have any current
|
|
# state. Certainly store.get_current_state won't return any, and
|
|
# persisting the event won't store the state group.
|
|
if old_state:
|
|
prev_state_ids = {
|
|
(s.type, s.state_key): s.event_id for s in old_state
|
|
}
|
|
if event.is_state():
|
|
current_state_ids = dict(prev_state_ids)
|
|
key = (event.type, event.state_key)
|
|
current_state_ids[key] = event.event_id
|
|
else:
|
|
current_state_ids = prev_state_ids
|
|
else:
|
|
current_state_ids = {}
|
|
prev_state_ids = {}
|
|
|
|
# We don't store state for outliers, so we don't generate a state
|
|
# group for it.
|
|
context = EventContext.with_state(
|
|
state_group=None,
|
|
current_state_ids=current_state_ids,
|
|
prev_state_ids=prev_state_ids,
|
|
)
|
|
|
|
defer.returnValue(context)
|
|
|
|
if old_state:
|
|
# We already have the state, so we don't need to calculate it.
|
|
# Let's just correctly fill out the context and create a
|
|
# new state group for it.
|
|
|
|
prev_state_ids = {
|
|
(s.type, s.state_key): s.event_id for s in old_state
|
|
}
|
|
|
|
if event.is_state():
|
|
key = (event.type, event.state_key)
|
|
if key in prev_state_ids:
|
|
replaces = prev_state_ids[key]
|
|
if replaces != event.event_id: # Paranoia check
|
|
event.unsigned["replaces_state"] = replaces
|
|
current_state_ids = dict(prev_state_ids)
|
|
current_state_ids[key] = event.event_id
|
|
else:
|
|
current_state_ids = prev_state_ids
|
|
|
|
state_group = yield self.store.store_state_group(
|
|
event.event_id,
|
|
event.room_id,
|
|
prev_group=None,
|
|
delta_ids=None,
|
|
current_state_ids=current_state_ids,
|
|
)
|
|
|
|
context = EventContext.with_state(
|
|
state_group=state_group,
|
|
current_state_ids=current_state_ids,
|
|
prev_state_ids=prev_state_ids,
|
|
)
|
|
|
|
defer.returnValue(context)
|
|
|
|
logger.debug("calling resolve_state_groups from compute_event_context")
|
|
|
|
entry = yield self.resolve_state_groups_for_events(
|
|
event.room_id, [e for e, _ in event.prev_events],
|
|
)
|
|
|
|
prev_state_ids = entry.state
|
|
prev_group = None
|
|
delta_ids = None
|
|
|
|
if event.is_state():
|
|
# If this is a state event then we need to create a new state
|
|
# group for the state after this event.
|
|
|
|
key = (event.type, event.state_key)
|
|
if key in prev_state_ids:
|
|
replaces = prev_state_ids[key]
|
|
event.unsigned["replaces_state"] = replaces
|
|
|
|
current_state_ids = dict(prev_state_ids)
|
|
current_state_ids[key] = event.event_id
|
|
|
|
if entry.state_group:
|
|
# If the state at the event has a state group assigned then
|
|
# we can use that as the prev group
|
|
prev_group = entry.state_group
|
|
delta_ids = {
|
|
key: event.event_id
|
|
}
|
|
elif entry.prev_group:
|
|
# If the state at the event only has a prev group, then we can
|
|
# use that as a prev group too.
|
|
prev_group = entry.prev_group
|
|
delta_ids = dict(entry.delta_ids)
|
|
delta_ids[key] = event.event_id
|
|
|
|
state_group = yield self.store.store_state_group(
|
|
event.event_id,
|
|
event.room_id,
|
|
prev_group=prev_group,
|
|
delta_ids=delta_ids,
|
|
current_state_ids=current_state_ids,
|
|
)
|
|
else:
|
|
current_state_ids = prev_state_ids
|
|
prev_group = entry.prev_group
|
|
delta_ids = entry.delta_ids
|
|
|
|
if entry.state_group is None:
|
|
entry.state_group = yield self.store.store_state_group(
|
|
event.event_id,
|
|
event.room_id,
|
|
prev_group=entry.prev_group,
|
|
delta_ids=entry.delta_ids,
|
|
current_state_ids=current_state_ids,
|
|
)
|
|
entry.state_id = entry.state_group
|
|
|
|
state_group = entry.state_group
|
|
|
|
context = EventContext.with_state(
|
|
state_group=state_group,
|
|
current_state_ids=current_state_ids,
|
|
prev_state_ids=prev_state_ids,
|
|
prev_group=prev_group,
|
|
delta_ids=delta_ids,
|
|
)
|
|
|
|
defer.returnValue(context)
|
|
|
|
@defer.inlineCallbacks
|
|
def resolve_state_groups_for_events(self, room_id, event_ids):
|
|
""" Given a list of event_ids this method fetches the state at each
|
|
event, resolves conflicts between them and returns them.
|
|
|
|
Args:
|
|
room_id (str)
|
|
event_ids (list[str])
|
|
explicit_room_version (str|None): If set uses the the given room
|
|
version to choose the resolution algorithm. If None, then
|
|
checks the database for room version.
|
|
|
|
Returns:
|
|
Deferred[_StateCacheEntry]: resolved state
|
|
"""
|
|
logger.debug("resolve_state_groups event_ids %s", event_ids)
|
|
|
|
# map from state group id to the state in that state group (where
|
|
# 'state' is a map from state key to event id)
|
|
# dict[int, dict[(str, str), str]]
|
|
state_groups_ids = yield self.store.get_state_groups_ids(
|
|
room_id, event_ids
|
|
)
|
|
|
|
if len(state_groups_ids) == 0:
|
|
defer.returnValue(_StateCacheEntry(
|
|
state={},
|
|
state_group=None,
|
|
))
|
|
elif len(state_groups_ids) == 1:
|
|
name, state_list = list(state_groups_ids.items()).pop()
|
|
|
|
prev_group, delta_ids = yield self.store.get_state_group_delta(name)
|
|
|
|
defer.returnValue(_StateCacheEntry(
|
|
state=state_list,
|
|
state_group=name,
|
|
prev_group=prev_group,
|
|
delta_ids=delta_ids,
|
|
))
|
|
|
|
room_version = yield self.store.get_room_version(room_id)
|
|
|
|
result = yield self._state_resolution_handler.resolve_state_groups(
|
|
room_id, room_version, state_groups_ids, None,
|
|
self._state_map_factory,
|
|
)
|
|
defer.returnValue(result)
|
|
|
|
def _state_map_factory(self, ev_ids):
|
|
return self.store.get_events(
|
|
ev_ids, get_prev_content=False, check_redacted=False,
|
|
)
|
|
|
|
@defer.inlineCallbacks
|
|
def resolve_events(self, room_version, state_sets, event):
|
|
logger.info(
|
|
"Resolving state for %s with %d groups", event.room_id, len(state_sets)
|
|
)
|
|
state_set_ids = [{
|
|
(ev.type, ev.state_key): ev.event_id
|
|
for ev in st
|
|
} for st in state_sets]
|
|
|
|
state_map = {
|
|
ev.event_id: ev
|
|
for st in state_sets
|
|
for ev in st
|
|
}
|
|
|
|
with Measure(self.clock, "state._resolve_events"):
|
|
new_state = yield resolve_events_with_factory(
|
|
room_version, state_set_ids,
|
|
event_map=state_map,
|
|
state_map_factory=self._state_map_factory
|
|
)
|
|
|
|
new_state = {
|
|
key: state_map[ev_id] for key, ev_id in iteritems(new_state)
|
|
}
|
|
|
|
defer.returnValue(new_state)
|
|
|
|
|
|
class StateResolutionHandler(object):
|
|
"""Responsible for doing state conflict resolution.
|
|
|
|
Note that the storage layer depends on this handler, so all functions must
|
|
be storage-independent.
|
|
"""
|
|
def __init__(self, hs):
|
|
self.clock = hs.get_clock()
|
|
|
|
# dict of set of event_ids -> _StateCacheEntry.
|
|
self._state_cache = None
|
|
self.resolve_linearizer = Linearizer(name="state_resolve_lock")
|
|
|
|
def start_caching(self):
|
|
logger.debug("start_caching")
|
|
|
|
self._state_cache = ExpiringCache(
|
|
cache_name="state_cache",
|
|
clock=self.clock,
|
|
max_len=SIZE_OF_CACHE,
|
|
expiry_ms=EVICTION_TIMEOUT_SECONDS * 1000,
|
|
iterable=True,
|
|
reset_expiry_on_get=True,
|
|
)
|
|
|
|
self._state_cache.start()
|
|
|
|
@defer.inlineCallbacks
|
|
@log_function
|
|
def resolve_state_groups(
|
|
self, room_id, room_version, state_groups_ids, event_map, state_map_factory,
|
|
):
|
|
"""Resolves conflicts between a set of state groups
|
|
|
|
Always generates a new state group (unless we hit the cache), so should
|
|
not be called for a single state group
|
|
|
|
Args:
|
|
room_id (str): room we are resolving for (used for logging)
|
|
room_version (str): version of the room
|
|
state_groups_ids (dict[int, dict[(str, str), str]]):
|
|
map from state group id to the state in that state group
|
|
(where 'state' is a map from state key to event id)
|
|
|
|
event_map(dict[str,FrozenEvent]|None):
|
|
a dict from event_id to event, for any events that we happen to
|
|
have in flight (eg, those currently being persisted). This will be
|
|
used as a starting point fof finding the state we need; any missing
|
|
events will be requested via state_map_factory.
|
|
|
|
If None, all events will be fetched via state_map_factory.
|
|
|
|
Returns:
|
|
Deferred[_StateCacheEntry]: resolved state
|
|
"""
|
|
logger.debug(
|
|
"resolve_state_groups state_groups %s",
|
|
state_groups_ids.keys()
|
|
)
|
|
|
|
group_names = frozenset(state_groups_ids.keys())
|
|
|
|
with (yield self.resolve_linearizer.queue(group_names)):
|
|
if self._state_cache is not None:
|
|
cache = self._state_cache.get(group_names, None)
|
|
if cache:
|
|
defer.returnValue(cache)
|
|
|
|
logger.info(
|
|
"Resolving state for %s with %d groups", room_id, len(state_groups_ids)
|
|
)
|
|
|
|
# start by assuming we won't have any conflicted state, and build up the new
|
|
# state map by iterating through the state groups. If we discover a conflict,
|
|
# we give up and instead use `resolve_events_with_factory`.
|
|
#
|
|
# XXX: is this actually worthwhile, or should we just let
|
|
# resolve_events_with_factory do it?
|
|
new_state = {}
|
|
conflicted_state = False
|
|
for st in itervalues(state_groups_ids):
|
|
for key, e_id in iteritems(st):
|
|
if key in new_state:
|
|
conflicted_state = True
|
|
break
|
|
new_state[key] = e_id
|
|
if conflicted_state:
|
|
break
|
|
|
|
if conflicted_state:
|
|
logger.info("Resolving conflicted state for %r", room_id)
|
|
with Measure(self.clock, "state._resolve_events"):
|
|
new_state = yield resolve_events_with_factory(
|
|
room_version,
|
|
list(itervalues(state_groups_ids)),
|
|
event_map=event_map,
|
|
state_map_factory=state_map_factory,
|
|
)
|
|
|
|
# if the new state matches any of the input state groups, we can
|
|
# use that state group again. Otherwise we will generate a state_id
|
|
# which will be used as a cache key for future resolutions, but
|
|
# not get persisted.
|
|
|
|
with Measure(self.clock, "state.create_group_ids"):
|
|
cache = _make_state_cache_entry(new_state, state_groups_ids)
|
|
|
|
if self._state_cache is not None:
|
|
self._state_cache[group_names] = cache
|
|
|
|
defer.returnValue(cache)
|
|
|
|
|
|
def _make_state_cache_entry(
|
|
new_state,
|
|
state_groups_ids,
|
|
):
|
|
"""Given a resolved state, and a set of input state groups, pick one to base
|
|
a new state group on (if any), and return an appropriately-constructed
|
|
_StateCacheEntry.
|
|
|
|
Args:
|
|
new_state (dict[(str, str), str]): resolved state map (mapping from
|
|
(type, state_key) to event_id)
|
|
|
|
state_groups_ids (dict[int, dict[(str, str), str]]):
|
|
map from state group id to the state in that state group
|
|
(where 'state' is a map from state key to event id)
|
|
|
|
Returns:
|
|
_StateCacheEntry
|
|
"""
|
|
# if the new state matches any of the input state groups, we can
|
|
# use that state group again. Otherwise we will generate a state_id
|
|
# which will be used as a cache key for future resolutions, but
|
|
# not get persisted.
|
|
|
|
# first look for exact matches
|
|
new_state_event_ids = set(itervalues(new_state))
|
|
for sg, state in iteritems(state_groups_ids):
|
|
if len(new_state_event_ids) != len(state):
|
|
continue
|
|
|
|
old_state_event_ids = set(itervalues(state))
|
|
if new_state_event_ids == old_state_event_ids:
|
|
# got an exact match.
|
|
return _StateCacheEntry(
|
|
state=new_state,
|
|
state_group=sg,
|
|
)
|
|
|
|
# TODO: We want to create a state group for this set of events, to
|
|
# increase cache hits, but we need to make sure that it doesn't
|
|
# end up as a prev_group without being added to the database
|
|
|
|
# failing that, look for the closest match.
|
|
prev_group = None
|
|
delta_ids = None
|
|
|
|
for old_group, old_state in iteritems(state_groups_ids):
|
|
n_delta_ids = {
|
|
k: v
|
|
for k, v in iteritems(new_state)
|
|
if old_state.get(k) != v
|
|
}
|
|
if not delta_ids or len(n_delta_ids) < len(delta_ids):
|
|
prev_group = old_group
|
|
delta_ids = n_delta_ids
|
|
|
|
return _StateCacheEntry(
|
|
state=new_state,
|
|
state_group=None,
|
|
prev_group=prev_group,
|
|
delta_ids=delta_ids,
|
|
)
|
|
|
|
|
|
def resolve_events_with_factory(room_version, state_sets, event_map, state_map_factory):
|
|
"""
|
|
Args:
|
|
room_version(str): Version of the room
|
|
|
|
state_sets(list): List of dicts of (type, state_key) -> event_id,
|
|
which are the different state groups to resolve.
|
|
|
|
event_map(dict[str,FrozenEvent]|None):
|
|
a dict from event_id to event, for any events that we happen to
|
|
have in flight (eg, those currently being persisted). This will be
|
|
used as a starting point fof finding the state we need; any missing
|
|
events will be requested via state_map_factory.
|
|
|
|
If None, all events will be fetched via state_map_factory.
|
|
|
|
state_map_factory(func): will be called
|
|
with a list of event_ids that are needed, and should return with
|
|
a Deferred of dict of event_id to event.
|
|
|
|
Returns
|
|
Deferred[dict[(str, str), str]]:
|
|
a map from (type, state_key) to event_id.
|
|
"""
|
|
if room_version in (RoomVersions.V1, RoomVersions.VDH_TEST,):
|
|
return v1.resolve_events_with_factory(
|
|
state_sets, event_map, state_map_factory,
|
|
)
|
|
else:
|
|
# This should only happen if we added a version but forgot to add it to
|
|
# the list above.
|
|
raise Exception(
|
|
"No state resolution algorithm defined for version %r" % (room_version,)
|
|
)
|