diff options
Diffstat (limited to 'synapse')
| -rw-r--r-- | synapse/state.py | 134 |
1 files changed, 84 insertions, 50 deletions
diff --git a/synapse/state.py b/synapse/state.py index 8144fa02b4..081bc31bb5 100644 --- a/synapse/state.py +++ b/synapse/state.py @@ -19,6 +19,7 @@ from twisted.internet import defer from synapse.util.logutils import log_function from synapse.util.async import run_on_reactor from synapse.api.constants import EventTypes +from synapse.api.errors import AuthError from synapse.events.snapshot import EventContext from collections import namedtuple @@ -36,12 +37,16 @@ def _get_state_key_from_event(event): KeyStateTuple = namedtuple("KeyStateTuple", ("context", "type", "state_key")) +AuthEventTypes = (EventTypes.Create, EventTypes.Member, EventTypes.PowerLevels,) + + class StateHandler(object): """ Responsible for doing state conflict resolution. """ def __init__(self, hs): self.store = hs.get_datastore() + self.hs = hs @defer.inlineCallbacks def get_current_state(self, room_id, event_type=None, state_key=""): @@ -210,64 +215,93 @@ class StateHandler(object): else: prev_states = [] + auth_events = { + k: e for k, e in unconflicted_state.items() + if k[0] in AuthEventTypes + } + try: - new_state = {} - new_state.update(unconflicted_state) - for key, events in conflicted_state.items(): - new_state[key] = self._resolve_state_events(events) + resolved_state = self._resolve_state_events( + conflicted_state, auth_events + ) except: logger.exception("Failed to resolve state") raise - defer.returnValue((None, new_state, prev_states)) - - def _get_power_level_from_event_state(self, event, user_id): - if hasattr(event, "old_state_events") and event.old_state_events: - key = (EventTypes.PowerLevels, "", ) - power_level_event = event.old_state_events.get(key) - level = None - if power_level_event: - level = power_level_event.content.get("users", {}).get( - user_id - ) - if not level: - level = power_level_event.content.get("users_default", 0) + new_state = unconflicted_state + new_state.update(resolved_state) - return level - else: - return 0 + defer.returnValue((None, new_state, prev_states)) @log_function - def _resolve_state_events(self, events): - curr_events = events - - new_powers = [ - self._get_power_level_from_event_state(e, e.user_id) - for e in curr_events - ] - - new_powers = [ - int(p) if p else 0 for p in new_powers - ] + def _resolve_state_events(self, 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. memberships + 3. other events. + """ + resolved_state = {} + power_key = (EventTypes.PowerLevels, "") + if power_key in conflicted_state.items(): + power_levels = conflicted_state[power_key] + resolved_state[power_key] = self._resolve_auth_events(power_levels) + + auth_events.update(resolved_state) + + for key, events in conflicted_state.items(): + if key[0] == EventTypes.Member: + resolved_state[key] = self._resolve_auth_events( + events, + auth_events + ) - max_power = max(new_powers) + auth_events.update(resolved_state) - curr_events = [ - z[0] for z in zip(curr_events, new_powers) - if z[1] == max_power - ] + for key, events in conflicted_state.items(): + if key not in resolved_state: + resolved_state[key] = self._resolve_normal_events( + events, auth_events + ) - if not curr_events: - raise RuntimeError("Max didn't get a max?") - elif len(curr_events) == 1: - return curr_events[0] - - # TODO: For now, just choose the one with the largest event_id. - return ( - sorted( - curr_events, - key=lambda e: hashlib.sha1( - e.event_id + e.user_id + e.room_id + e.type - ).hexdigest() - )[0] - ) + return resolved_state + + def _resolve_auth_events(self, events, auth_events): + reverse = [i for i in reversed(self._ordered_events(events))] + + auth_events = dict(auth_events) + + prev_event = reverse[0] + for event in reverse[1:]: + auth_events[(prev_event.type, prev_event.state_key)] = prev_event + try: + # FIXME: hs.get_auth() is bad style, but we need to do it to + # get around circular deps. + self.hs.get_auth().check(event, auth_events) + prev_event = event + except AuthError: + return prev_event + + return event + + def _resolve_normal_events(self, events, auth_events): + for event in self._ordered_events(events): + try: + # FIXME: hs.get_auth() is bad style, but we need to do it to + # get around circular deps. + self.hs.get_auth().check(event, auth_events) + return event + except AuthError: + pass + + # Use the last event (the one with the least depth) if they all fail + # the auth check. + return event + + def _ordered_events(self, events): + def key_func(e): + return -int(e.depth), hashlib.sha1(e.event_id).hexdigest() + + return sorted(events, key=key_func) |