diff options
| -rw-r--r-- | changelog.d/3995.bug | 1 | ||||
| -rw-r--r-- | synapse/storage/events.py | 111 |
2 files changed, 79 insertions, 33 deletions
diff --git a/changelog.d/3995.bug b/changelog.d/3995.bug new file mode 100644 index 0000000000..2adc36756b --- /dev/null +++ b/changelog.d/3995.bug @@ -0,0 +1 @@ +Fix bug in event persistence logic which caused 'NoneType is not iterable' \ No newline at end of file diff --git a/synapse/storage/events.py b/synapse/storage/events.py index e7487311ce..046174edb3 100644 --- a/synapse/storage/events.py +++ b/synapse/storage/events.py @@ -38,6 +38,7 @@ from synapse.storage.background_updates import BackgroundUpdateStore from synapse.storage.event_federation import EventFederationStore from synapse.storage.events_worker import EventsWorkerStore from synapse.types import RoomStreamToken, get_domain_from_id +from synapse.util import batch_iter from synapse.util.async_helpers import ObservableDeferred from synapse.util.caches.descriptors import cached, cachedInlineCallbacks from synapse.util.frozenutils import frozendict_json_encoder @@ -386,12 +387,10 @@ class EventsStore(EventFederationStore, EventsWorkerStore, BackgroundUpdateStore ) for room_id, ev_ctx_rm in iteritems(events_by_room): - # Work out new extremities by recursively adding and removing - # the new events. latest_event_ids = yield self.get_latest_event_ids_in_room( room_id ) - new_latest_event_ids = yield self._calculate_new_extremeties( + new_latest_event_ids = yield self._calculate_new_extremities( room_id, ev_ctx_rm, latest_event_ids ) @@ -400,6 +399,12 @@ class EventsStore(EventFederationStore, EventsWorkerStore, BackgroundUpdateStore # No change in extremities, so no change in state continue + # there should always be at least one forward extremity. + # (except during the initial persistence of the send_join + # results, in which case there will be no existing + # extremities, so we'll `continue` above and skip this bit.) + assert new_latest_event_ids, "No forward extremities left!" + new_forward_extremeties[room_id] = new_latest_event_ids len_1 = ( @@ -517,44 +522,88 @@ class EventsStore(EventFederationStore, EventsWorkerStore, BackgroundUpdateStore ) @defer.inlineCallbacks - def _calculate_new_extremeties(self, room_id, event_contexts, latest_event_ids): - """Calculates the new forward extremeties for a room given events to + def _calculate_new_extremities(self, room_id, event_contexts, latest_event_ids): + """Calculates the new forward extremities for a room given events to persist. Assumes that we are only persisting events for one room at a time. """ - new_latest_event_ids = set(latest_event_ids) - # First, add all the new events to the list - new_latest_event_ids.update( - event.event_id for event, ctx in event_contexts + + # we're only interested in new events which aren't outliers and which aren't + # being rejected. + new_events = [ + event for event, ctx in event_contexts if not event.internal_metadata.is_outlier() and not ctx.rejected + ] + + # start with the existing forward extremities + result = set(latest_event_ids) + + # add all the new events to the list + result.update( + event.event_id for event in new_events ) - # Now remove all events that are referenced by the to-be-added events - new_latest_event_ids.difference_update( + + # Now remove all events which are prev_events of any of the new events + result.difference_update( e_id - for event, ctx in event_contexts + for event in new_events for e_id, _ in event.prev_events - if not event.internal_metadata.is_outlier() and not ctx.rejected ) - # And finally remove any events that are referenced by previously added - # events. - rows = yield self._simple_select_many_batch( - table="event_edges", - column="prev_event_id", - iterable=list(new_latest_event_ids), - retcols=["prev_event_id"], - keyvalues={ - "is_state": False, - }, - desc="_calculate_new_extremeties", - ) + # Finally, remove any events which are prev_events of any existing events. + existing_prevs = yield self._get_events_which_are_prevs(result) + result.difference_update(existing_prevs) - new_latest_event_ids.difference_update( - row["prev_event_id"] for row in rows - ) + if not result: + logger.warn( + "Forward extremity list A+B-C-D is now empty in %s. " + "Old extremities (A): %s, new events (B): %s, " + "existing events which are reffed by new events (C): %s, " + "new events which are reffed by existing events (D): %s", + room_id, latest_event_ids, new_events, + [e_id for event in new_events for e_id, _ in event.prev_events], + existing_prevs, + ) + defer.returnValue(result) - defer.returnValue(new_latest_event_ids) + @defer.inlineCallbacks + def _get_events_which_are_prevs(self, event_ids): + """Filter the supplied list of event_ids to get those which are prev_events of + existing (non-outlier) events. + + Args: + event_ids (Iterable[str]): event ids to filter + + Returns: + Deferred[List[str]]: filtered event ids + """ + results = [] + + def _get_events(txn, batch): + sql = """ + SELECT prev_event_id + FROM event_edges + INNER JOIN events USING (event_id) + LEFT JOIN rejections USING (event_id) + WHERE + prev_event_id IN (%s) + AND rejections.event_id IS NULL + """ % ( + ",".join("?" for _ in batch), + ) + + txn.execute(sql, batch) + results.extend(r[0] for r in txn) + + for chunk in batch_iter(event_ids, 100): + yield self.runInteraction( + "_get_events_which_are_prevs", + _get_events, + chunk, + ) + + defer.returnValue(results) @defer.inlineCallbacks def _get_new_state_after_events(self, room_id, events_context, old_latest_event_ids, @@ -586,10 +635,6 @@ class EventsStore(EventFederationStore, EventsWorkerStore, BackgroundUpdateStore the new current state is only returned if we've already calculated it. """ - - if not new_latest_event_ids: - return - # map from state_group to ((type, key) -> event_id) state map state_groups_map = {} |