diff --git a/synapse/storage/events.py b/synapse/storage/events.py
index eb8bbe13ab..76cfbc90fe 100644
--- a/synapse/storage/events.py
+++ b/synapse/storage/events.py
@@ -565,6 +565,7 @@ class EventsStore(EventsWorkerStore):
# map from state_group to ((type, key) -> event_id) state map
state_groups_map = {}
+ # Map from (prev state group, new state group) -> delta state dict
state_group_deltas = {}
for ev, ctx in events_context:
@@ -631,23 +632,24 @@ class EventsStore(EventsWorkerStore):
if old_state_groups == new_state_groups:
defer.returnValue((None, None))
- if len(new_state_groups) == 1:
- # If there is only one state group, then we know what the current
- # state is.
- if len(old_state_groups) == 1:
- new_state_group = next(iter(new_state_groups))
- old_state_group = next(iter(old_state_groups))
+ if len(new_state_groups) == 1 and len(old_state_groups) == 1:
+ # If we're going from one state group to another, lets check if
+ # we have a delta for that transition. If we do then we can just
+ # return that.
- delta_ids = state_group_deltas.get(
- (old_state_group, new_state_group,), None
- )
- if delta_ids is not None:
- # We have a delta from the existing to new current state,
- # so lets just return that. If we happen to already have
- # the current state in memory then lets also return that,
- # but it doesn't matter if we don't.
- new_state = state_groups_map.get(new_state_group)
- defer.returnValue((new_state, delta_ids))
+ new_state_group = next(iter(new_state_groups))
+ old_state_group = next(iter(old_state_groups))
+
+ delta_ids = state_group_deltas.get(
+ (old_state_group, new_state_group,), None
+ )
+ if delta_ids is not None:
+ # We have a delta from the existing to new current state,
+ # so lets just return that. If we happen to already have
+ # the current state in memory then lets also return that,
+ # but it doesn't matter if we don't.
+ new_state = state_groups_map.get(new_state_group)
+ defer.returnValue((new_state, delta_ids))
# Now that we have calculated new_state_groups we need to get
# their state IDs so we can resolve to a single state set.
@@ -657,6 +659,8 @@ class EventsStore(EventsWorkerStore):
state_groups_map.update(group_to_state)
if len(new_state_groups) == 1:
+ # If there is only one state group, then we know what the current
+ # state is.
defer.returnValue((state_groups_map[new_state_groups.pop()], None))
# Ok, we need to defer to the state handler to resolve our state sets.
|
