package pool import ( "strings" "sync/atomic" "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/session" lru "github.com/hashicorp/golang-lru/v2" ) type sessionCache struct { cache *lru.Cache[string, *cacheValue] currentEpoch uint64 } type cacheValue struct { token session.Object } func newCache() (*sessionCache, error) { cache, err := lru.New[string, *cacheValue](100) if err != nil { return nil, err } return &sessionCache{cache: cache}, nil } // Get returns a copy of the session token from the cache without signature // and context related fields. Returns nil if token is missing in the cache. // It is safe to modify and re-sign returned session token. func (c *sessionCache) Get(key string) (session.Object, bool) { value, ok := c.cache.Get(key) if !ok { return session.Object{}, false } if c.expired(value) { c.cache.Remove(key) return session.Object{}, false } return value.token, true } func (c *sessionCache) Put(key string, token session.Object) bool { return c.cache.Add(key, &cacheValue{ token: token, }) } func (c *sessionCache) DeleteByPrefix(prefix string) { for _, key := range c.cache.Keys() { if strings.HasPrefix(key, prefix) { c.cache.Remove(key) } } } func (c *sessionCache) updateEpoch(newEpoch uint64) { epoch := atomic.LoadUint64(&c.currentEpoch) if newEpoch > epoch { atomic.StoreUint64(&c.currentEpoch, newEpoch) } } func (c *sessionCache) expired(val *cacheValue) bool { epoch := atomic.LoadUint64(&c.currentEpoch) // use epoch+1 (clear cache beforehand) to prevent 'expired session token' error right after epoch tick return val.token.ExpiredAt(epoch + 1) }