diff --git a/changelog.d/11776.misc b/changelog.d/11776.misc
new file mode 100644
index 0000000000..572ccda847
--- /dev/null
+++ b/changelog.d/11776.misc
@@ -0,0 +1 @@
+Add some comments and type annotations for `_update_outliers_txn`.
diff --git a/synapse/storage/databases/main/events.py b/synapse/storage/databases/main/events.py
index 7278002322..1ae1ebe108 100644
--- a/synapse/storage/databases/main/events.py
+++ b/synapse/storage/databases/main/events.py
@@ -1254,20 +1254,22 @@ class PersistEventsStore:
for room_id, depth in depth_updates.items():
self._update_min_depth_for_room_txn(txn, room_id, depth)
- def _update_outliers_txn(self, txn, events_and_contexts):
+ def _update_outliers_txn(
+ self,
+ txn: LoggingTransaction,
+ events_and_contexts: List[Tuple[EventBase, EventContext]],
+ ) -> List[Tuple[EventBase, EventContext]]:
"""Update any outliers with new event info.
- This turns outliers into ex-outliers (unless the new event was
- rejected).
+ This turns outliers into ex-outliers (unless the new event was rejected), and
+ also removes any other events we have already seen from the list.
Args:
- txn (twisted.enterprise.adbapi.Connection): db connection
- events_and_contexts (list[(EventBase, EventContext)]): events
- we are persisting
+ txn: db connection
+ events_and_contexts: events we are persisting
Returns:
- list[(EventBase, EventContext)] new list, without events which
- are already in the events table.
+ new list, without events which are already in the events table.
"""
txn.execute(
"SELECT event_id, outlier FROM events WHERE event_id in (%s)"
@@ -1275,7 +1277,9 @@ class PersistEventsStore:
[event.event_id for event, _ in events_and_contexts],
)
- have_persisted = {event_id: outlier for event_id, outlier in txn}
+ have_persisted: Dict[str, bool] = {
+ event_id: outlier for event_id, outlier in txn
+ }
to_remove = set()
for event, context in events_and_contexts:
@@ -1285,15 +1289,22 @@ class PersistEventsStore:
to_remove.add(event)
if context.rejected:
- # If the event is rejected then we don't care if the event
- # was an outlier or not.
+ # If the incoming event is rejected then we don't care if the event
+ # was an outlier or not - what we have is at least as good.
continue
outlier_persisted = have_persisted[event.event_id]
if not event.internal_metadata.is_outlier() and outlier_persisted:
# We received a copy of an event that we had already stored as
- # an outlier in the database. We now have some state at that
+ # an outlier in the database. We now have some state at that event
# so we need to update the state_groups table with that state.
+ #
+ # Note that we do not update the stream_ordering of the event in this
+ # scenario. XXX: does this cause bugs? It will mean we won't send such
+ # events down /sync. In general they will be historical events, so that
+ # doesn't matter too much, but that is not always the case.
+
+ logger.info("Updating state for ex-outlier event %s", event.event_id)
# insert into event_to_state_groups.
try:
|
