This repository was archived by the owner on Apr 26, 2024. It is now read-only.
This repository was archived by the owner on Apr 26, 2024. It is now read-only.
caching on have_seen_event is somewhat broken #13865
Description
As discovered in #13863 (comment) and discussed in #synapse-dev. Part of #13856
The cache on have_seen_event uses a TreeCache, which means the cache is structured as {room_id: {event_id: result}}. However, _have_seen_events_dict tries to use it with @cachedList, which stores entries as {(room_id, event_id): result}. As a result, caching is inefficient, and cache invalidation is unreliable.