used response cache in responder

cache2go/response_cache.go

@@ -8,20 +8,25 @@ import (
 
 var ErrNotFound = errors.New("NOT_FOUND")
 
+type CacheItem struct {
+	Value interface{}
+	Err   error
+}
+
 type ResponseCache struct {
 	ttl   time.Duration
-	cache map[string]interface{}
+	cache map[string]*CacheItem
 	mu    sync.RWMutex
 }
 
 func NewResponseCache(ttl time.Duration) *ResponseCache {
 	return &ResponseCache{
 		ttl:   ttl,
-		cache: make(map[string]interface{}),
+		cache: make(map[string]*CacheItem),
 	}
 }
 
-func (rc *ResponseCache) Cache(key string, item interface{}) {
+func (rc *ResponseCache) Cache(key string, item *CacheItem) {
 	rc.mu.Lock()
 	rc.cache[key] = item
 	rc.mu.Unlock()
@@ -33,7 +38,7 @@ func (rc *ResponseCache) Cache(key string, item interface{}) {
 	}()
 }
 
-func (rc *ResponseCache) Get(key string) (interface{}, error) {
+func (rc *ResponseCache) Get(key string) (*CacheItem, error) {
 	rc.mu.RLock()
 	defer rc.mu.RUnlock()
 	item, ok := rc.cache[key]