Ristretto cache (#2563)

* Try Ristretto cache

* Tweak

* It's beautiful

* Update GMSL

* More strict keyable interface

* Fix that some more

* Make less panicky

* Don't enforce mutability checks for now

* Determine mutability using deep equality

* Tweaks

* Namespace keys

* Make federation caches mutable

* Update cost estimation, add metric

* Update GMSL

* Estimate cost for metrics better

* Reduce counters a bit

* Try caching events

* Some guards

* Try again

* Try this

* Use separate caches for hopefully better hash distribution

* Fix bug with admitting events into cache

* Try to fix bugs

* Check nil

* Try that again

* Preserve order jeezo this is messy

* thanks VS Code for doing exactly the wrong thing

* Try this again

* Be more specific

* aaaaargh

* One more time

* That might be better

* Stronger sorting

* Cache expiries, async publishing of EDUs

* Put it back

* Use a shared cache again

* Cost estimation fixes

* Update ristretto

* Reduce counters a bit

* Clean up a bit

* Update GMSL

* 1GB

* Configurable cache sizees

* Tweaks

* Add `config.DataUnit` for specifying friendly cache sizes

* Various tweaks

* Update GMSL

* Add back some lazy loading caching

* Include key in cost

* Include key in cost

* Tweak max age handling, config key name

* Only register prometheus metrics if requested

* Review comments @S7evinK

* Don't return errors when creating caches (it is better just to crash since otherwise we'll `nil`-pointer exception everywhere)

* Review comments

* Update sample configs

* Update GHA Workflow

* Update Complement images to Go 1.18

* Remove the cache test from the federation API as we no longer guarantee immediate cache admission

* Don't check the caches in the renewal test

* Possibly fix the upgrade tests

* Update to matrix-org/gomatrixserverlib#322

* Update documentation to refer to Go 1.18

roomserver/internal/input/input_events.go

@@ -319,11 +319,9 @@ func (r *Inputer) processRoomEvent(
 
 	// if storing this event results in it being redacted then do so.
 	if !isRejected && redactedEventID == event.EventID() {
-		r, rerr := eventutil.RedactEvent(redactionEvent, event)
-		if rerr != nil {
+		if err = eventutil.RedactEvent(redactionEvent, event); err != nil {
 			return fmt.Errorf("eventutil.RedactEvent: %w", rerr)
 		}
-		event = r
 	}
 
 	// For outliers we can stop after we've stored the event itself as it

roomserver/internal/input/input_test.go

@@ -48,10 +48,6 @@ func TestSingleTransactionOnInput(t *testing.T) {
 		Kind:  api.KindOutlier, // don't panic if we generate an output event
 		Event: event.Headered(gomatrixserverlib.RoomVersionV6),
 	}
-	cache, err := caching.NewInMemoryLRUCache(false)
-	if err != nil {
-		t.Fatal(err)
-	}
 	db, err := storage.Open(
 		nil,
 		&config.DatabaseOptions{
@@ -59,7 +55,7 @@ func TestSingleTransactionOnInput(t *testing.T) {
 			MaxOpenConnections: 1,
 			MaxIdleConnections: 1,
 		},
-		cache,
+		caching.NewRistrettoCache(8*1024*1024, time.Hour, false),
 	)
 	if err != nil {
 		t.Logf("PostgreSQL not available (%s), skipping", err)

roomserver/internal/perform/perform_backfill.go

@@ -593,12 +593,11 @@ func persistEvents(ctx context.Context, db storage.Database, events []*gomatrixs
 		// redacted, which we don't care about since we aren't returning it in this backfill.
 		if redactedEventID == ev.EventID() {
 			eventToRedact := ev.Unwrap()
-			redactedEvent, err := eventutil.RedactEvent(redactionEvent, eventToRedact)
-			if err != nil {
+			if err := eventutil.RedactEvent(redactionEvent, eventToRedact); err != nil {
 				logrus.WithError(err).WithField("event_id", ev.EventID()).Error("Failed to redact event")
 				continue
 			}
-			ev = redactedEvent.Headered(ev.RoomVersion)
+			ev = eventToRedact.Headered(ev.RoomVersion)
 			events[j] = ev
 		}
 		backfilledEventMap[ev.EventID()] = types.Event{