0
0
Fork 0
mirror of https://github.com/matrix-org/dendrite synced 2024-12-15 09:53:53 +01:00
dendrite/common/caching/immutableinmemorylru.go
Neil Alexander a466e9e9cc
LRU cache for room versions in RS query API (#976)
* Experimental LRU cache for room versions

* Don't accidentally try to type-assert nil

* Also reduce hits on query API

* Use hashicorp implementation which mutexes for us

* Define const for max cache entries

* Rename to be specifically immutable, panic if we try to mutate a cache entry

* Review comments

* Remove nil guards, give roomserver integration test a cache

* go mod tidy
2020-04-22 13:00:05 +01:00

43 lines
1.2 KiB
Go

package caching
import (
"fmt"
lru "github.com/hashicorp/golang-lru"
"github.com/matrix-org/gomatrixserverlib"
)
type ImmutableInMemoryLRUCache struct {
roomVersions *lru.Cache
}
func NewImmutableInMemoryLRUCache() (*ImmutableInMemoryLRUCache, error) {
roomVersionCache, rvErr := lru.New(RoomVersionMaxCacheEntries)
if rvErr != nil {
return nil, rvErr
}
return &ImmutableInMemoryLRUCache{
roomVersions: roomVersionCache,
}, nil
}
func checkForInvalidMutation(cache *lru.Cache, key string, value interface{}) {
if peek, ok := cache.Peek(key); ok && peek != value {
panic(fmt.Sprintf("invalid use of immutable cache tries to mutate existing value of %q", key))
}
}
func (c *ImmutableInMemoryLRUCache) GetRoomVersion(roomID string) (gomatrixserverlib.RoomVersion, bool) {
val, found := c.roomVersions.Get(roomID)
if found && val != nil {
if roomVersion, ok := val.(gomatrixserverlib.RoomVersion); ok {
return roomVersion, true
}
}
return "", false
}
func (c *ImmutableInMemoryLRUCache) StoreRoomVersion(roomID string, roomVersion gomatrixserverlib.RoomVersion) {
checkForInvalidMutation(c.roomVersions, roomID, roomVersion)
c.roomVersions.Add(roomID, roomVersion)
}