Cache all the things

roomserver/storage/shared/storage.go

@@ -68,12 +68,25 @@ func (d *Database) eventTypeNIDs(
 	ctx context.Context, txn *sql.Tx, eventTypes []string,
 ) (map[string]types.EventTypeNID, error) {
 	result := make(map[string]types.EventTypeNID)
-	nids, err := d.EventTypesTable.BulkSelectEventTypeNID(ctx, txn, eventTypes)
-	if err != nil {
-		return nil, err
+	// first try the cache
+	fetchEventTypes := make([]string, 0, len(eventTypes))
+	for _, eventType := range eventTypes {
+		eventTypeNID, ok := d.Cache.GetEventTypeKey(eventType)
+		if ok {
+			result[eventType] = eventTypeNID
+			continue
+		}
+		fetchEventTypes = append(fetchEventTypes, eventType)
 	}
-	for eventType, nid := range nids {
-		result[eventType] = nid
+	if len(fetchEventTypes) > 0 {
+		nids, err := d.EventTypesTable.BulkSelectEventTypeNID(ctx, txn, fetchEventTypes)
+		if err != nil {
+			return nil, err
+		}
+		for eventType, nid := range nids {
+			result[eventType] = nid
+			d.Cache.StoreEventTypeKey(nid, eventType)
+		}
 	}
 	return result, nil
 }
@@ -90,13 +103,15 @@ func (d *Database) EventStateKeys(
 			fetch = append(fetch, nid)
 		}
 	}
-	fromDB, err := d.EventStateKeysTable.BulkSelectEventStateKey(ctx, nil, fetch)
-	if err != nil {
-		return nil, err
-	}
-	for nid, key := range fromDB {
-		result[nid] = key
-		d.Cache.StoreEventStateKey(nid, key)
+	if len(fetch) > 0 {
+		fromDB, err := d.EventStateKeysTable.BulkSelectEventStateKey(ctx, nil, fetch)
+		if err != nil {
+			return nil, err
+		}
+		for nid, key := range fromDB {
+			result[nid] = key
+			d.Cache.StoreEventStateKey(nid, key)
+		}
 	}
 	return result, nil
 }
@@ -130,6 +145,7 @@ func (d *Database) eventStateKeyNIDs(
 		}
 		for eventStateKey, nid := range nids {
 			result[eventStateKey] = nid
+			d.Cache.StoreEventStateKey(nid, eventStateKey)
 		}
 	}