diff options
Diffstat (limited to 'synapse/state.py')
| -rw-r--r-- | synapse/state.py | 308 |
1 files changed, 216 insertions, 92 deletions
diff --git a/synapse/state.py b/synapse/state.py index 9e624b4937..cc93bbcb6b 100644 --- a/synapse/state.py +++ b/synapse/state.py @@ -58,7 +58,11 @@ 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 @@ -81,31 +85,19 @@ class _StateCacheEntry(object): class StateHandler(object): - """ Responsible for doing state conflict resolution. + """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 - - # dict of set of event_ids -> _StateCacheEntry. - self._state_cache = None - self.resolve_linearizer = Linearizer(name="state_resolve_lock") + self._state_resolution_handler = hs.get_state_resolution_handler() 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() + # TODO: remove this shim + self._state_resolution_handler.start_caching() @defer.inlineCallbacks def get_current_state(self, room_id, event_type=None, state_key="", @@ -127,7 +119,7 @@ class StateHandler(object): 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(room_id, latest_event_ids) + ret = yield self.resolve_state_groups_for_events(room_id, latest_event_ids) state = ret.state if event_type: @@ -146,19 +138,27 @@ class StateHandler(object): defer.returnValue(state) @defer.inlineCallbacks - def get_current_state_ids(self, room_id, event_type=None, state_key="", - latest_event_ids=None): + 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(room_id, latest_event_ids) + ret = yield self.resolve_state_groups_for_events(room_id, latest_event_ids) state = ret.state - if event_type: - defer.returnValue(state.get((event_type, state_key))) - return - defer.returnValue(state) @defer.inlineCallbacks @@ -166,7 +166,7 @@ class StateHandler(object): 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(room_id, latest_event_ids) + 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) @@ -175,7 +175,7 @@ class StateHandler(object): 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(room_id, latest_event_ids) + 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) @@ -183,8 +183,15 @@ class StateHandler(object): 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: """ @@ -208,15 +215,22 @@ class StateHandler(object): context.current_state_ids = {} context.prev_state_ids = {} context.prev_state_events = [] - context.state_group = self.store.get_next_state_group() + + # We don't store state for outliers, so we don't generate a state + # froup for it. + context.state_group = None + 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. + context = EventContext() context.prev_state_ids = { (s.type, s.state_key): s.event_id for s in old_state } - context.state_group = self.store.get_next_state_group() if event.is_state(): key = (event.type, event.state_key) @@ -229,11 +243,19 @@ class StateHandler(object): else: context.current_state_ids = context.prev_state_ids + context.state_group = yield self.store.store_state_group( + event.event_id, + event.room_id, + prev_group=None, + delta_ids=None, + current_state_ids=context.current_state_ids, + ) + context.prev_state_events = [] defer.returnValue(context) logger.debug("calling resolve_state_groups from compute_event_context") - entry = yield self.resolve_state_groups( + entry = yield self.resolve_state_groups_for_events( event.room_id, [e for e, _ in event.prev_events], ) @@ -242,7 +264,8 @@ class StateHandler(object): context = EventContext() context.prev_state_ids = curr_state if event.is_state(): - context.state_group = self.store.get_next_state_group() + # 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 context.prev_state_ids: @@ -253,38 +276,57 @@ class StateHandler(object): context.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 context.prev_group = entry.state_group context.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. context.prev_group = entry.prev_group context.delta_ids = dict(entry.delta_ids) context.delta_ids[key] = event.event_id + + context.state_group = yield self.store.store_state_group( + event.event_id, + event.room_id, + prev_group=context.prev_group, + delta_ids=context.delta_ids, + current_state_ids=context.current_state_ids, + ) else: + context.current_state_ids = context.prev_state_ids + context.prev_group = entry.prev_group + context.delta_ids = entry.delta_ids + if entry.state_group is None: - entry.state_group = self.store.get_next_state_group() + 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=context.current_state_ids, + ) entry.state_id = entry.state_group context.state_group = entry.state_group - context.current_state_ids = context.prev_state_ids - context.prev_group = entry.prev_group - context.delta_ids = entry.delta_ids context.prev_state_events = [] defer.returnValue(context) @defer.inlineCallbacks - @log_function - def resolve_state_groups(self, room_id, event_ids): + 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]): + Returns: - a Deferred tuple of (`state_group`, `state`, `prev_state`). - `state_group` is the name of a state group if one and only one is - involved. `state` is a map from (type, state_key) to event, and - `prev_state` is a list of event ids. + Deferred[_StateCacheEntry]: resolved state """ logger.debug("resolve_state_groups event_ids %s", event_ids) @@ -295,13 +337,7 @@ class StateHandler(object): room_id, event_ids ) - logger.debug( - "resolve_state_groups state_groups %s", - state_groups_ids.keys() - ) - - group_names = frozenset(state_groups_ids.keys()) - if len(group_names) == 1: + if len(state_groups_ids) == 1: name, state_list = state_groups_ids.items().pop() prev_group, delta_ids = yield self.store.get_state_group_delta(name) @@ -313,6 +349,92 @@ class StateHandler(object): delta_ids=delta_ids, )) + result = yield self._state_resolution_handler.resolve_state_groups( + room_id, state_groups_ids, 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, + ) + + def resolve_events(self, 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 = resolve_events_with_state_map(state_set_ids, state_map) + + new_state = { + key: state_map[ev_id] for key, ev_id in new_state.items() + } + + return 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, state_groups_ids, 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) + 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: + 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) @@ -341,17 +463,19 @@ class StateHandler(object): if conflicted_state: logger.info("Resolving conflicted state for %r", room_id) with Measure(self.clock, "state._resolve_events"): - new_state = yield resolve_events( + new_state = yield resolve_events_with_factory( state_groups_ids.values(), - state_map_factory=lambda ev_ids: self.store.get_events( - ev_ids, get_prev_content=False, check_redacted=False, - ), + state_map_factory=state_map_factory, ) else: new_state = { key: e_ids.pop() for key, e_ids in state.items() } + # 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. state_group = None new_state_event_ids = frozenset(new_state.values()) for sg, events in state_groups_ids.items(): @@ -388,30 +512,6 @@ class StateHandler(object): defer.returnValue(cache) - def resolve_events(self, 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 = resolve_events(state_set_ids, state_map) - - new_state = { - key: state_map[ev_id] for key, ev_id in new_state.items() - } - - return new_state - def _ordered_events(events): def key_func(e): @@ -420,19 +520,17 @@ def _ordered_events(events): return sorted(events, key=key_func) -def resolve_events(state_sets, state_map_factory): +def resolve_events_with_state_map(state_sets, state_map): """ Args: state_sets(list): List of dicts of (type, state_key) -> event_id, which are the different state groups to resolve. - state_map_factory(dict|callable): If callable, then 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. Otherwise, should be - a dict from event_id to event of all events in state_sets. + state_map(dict): a dict from event_id to event, for all events in + state_sets. Returns - dict[(str, str), synapse.events.FrozenEvent] is a map from - (type, state_key) to event. + dict[(str, str), str]: + a map from (type, state_key) to event_id. """ if len(state_sets) == 1: return state_sets[0] @@ -441,13 +539,6 @@ def resolve_events(state_sets, state_map_factory): state_sets, ) - if callable(state_map_factory): - return _resolve_with_state_fac( - unconflicted_state, conflicted_state, state_map_factory - ) - - state_map = state_map_factory - auth_events = _create_auth_events_from_maps( unconflicted_state, conflicted_state, state_map ) @@ -461,6 +552,21 @@ def _seperate(state_sets): """Takes the state_sets and figures out which keys are conflicted and which aren't. i.e., which have multiple different event_ids associated with them in different state sets. + + Args: + state_sets(list[dict[(str, str), str]]): + List of dicts of (type, state_key) -> event_id, which are the + different state groups to resolve. + + Returns: + (dict[(str, str), str], dict[(str, str), set[str]]): + A tuple of (unconflicted_state, conflicted_state), where: + + unconflicted_state is a dict mapping (type, state_key)->event_id + for unconflicted state keys. + + conflicted_state is a dict mapping (type, state_key) to a set of + event ids for conflicted state keys. """ unconflicted_state = dict(state_sets[0]) conflicted_state = {} @@ -491,8 +597,26 @@ def _seperate(state_sets): @defer.inlineCallbacks -def _resolve_with_state_fac(unconflicted_state, conflicted_state, - state_map_factory): +def resolve_events_with_factory(state_sets, state_map_factory): + """ + Args: + state_sets(list): List of dicts of (type, state_key) -> event_id, + which are the different state groups to resolve. + 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 len(state_sets) == 1: + defer.returnValue(state_sets[0]) + + unconflicted_state, conflicted_state = _seperate( + state_sets, + ) + needed_events = set( event_id for event_ids in conflicted_state.itervalues() |