Erik JohnstonandClaude Opus 5.5 47367a14a2 Make the Rust event cache EventsWorkerStore's event cache ...

`EventsWorkerStore._get_event_cache` is now the Rust `EventCache` that the
sync handler and state resolution read, so each event is held once.

The cache keeps Rust `CachedEvent` values. Python gets them through
`RustEventCache`, a `RustCache` subclass with the `AsyncLruCache` names the
rest of Synapse uses, and each hit wraps the cached event in a new `Event`
object. The wrapper shares the cached event's internal metadata, unsigned
data and signatures, so a change Python makes, such as adding
`prev_content` or flipping `outlier`, lands in the one copy the Rust
readers see. Python's `_event_ref` weak map is checked before the cache,
so while anything holds an event, a lookup returns that same object, as
before. A hit there marks the cache entry as read, and puts the event back
if it was evicted.

- The cache is sized from `caches.event_cache_size` and named
  `*getEvent*`, so its metrics and `per_cache_factors` keep their names.
  The Rust loader now counts its misses too.
- Invalidating an event drops its chain position as well, and a room
  purge drops the room's events through the room index, plus the chain
  cover and state group caches, as `RustStore.invalidate_event` and
  `clear_event_cache` did. Those two calls are gone.
- `EventsWorkerStore` and `RustWorkerStore` run their `__init__` bodies
  in a different order in `DataStore` and `GenericWorkerStore`, as they
  sit differently in each MRO. So whichever runs first builds the
  `RustStore`. A datastore without `RustWorkerStore`, such as the port
  script's, gets a standalone `RustEventCache`.
- The external cache stubs (`get_external`, `set_external`,
  `_invalidate_async_get_event_cache` and its room variant) are dropped.
  They were documented no-ops.
- The sync shadow diff still ignores `prev_content` on state events.
  Python keeps the objects it holds after the cache evicts them, so a Rust
  reader can still load a second copy without it. Trial's cache of one
  event makes that routine.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VpBQxvqZTUvHCMm3u6CR7J

2026-10-15 12:14:54 +00:00

..

main

Make the Rust event cache EventsWorkerStore's event cache

2026-10-15 12:14:54 +00:00

__init__.py

Correctly mention previous copyright (#16820)

2024-01-23 11:26:48 +00:00