Return and log the GC crash error instead of panic

session.go

@@ -43,9 +43,14 @@ func New(cfg Config) *Session {
 		cfg.DecodeFunc = Base64Decode
 	}
 
+	if cfg.Logger == nil {
+		cfg.Logger = log.New(log.Writer(), "session-manager", log.Flags())
+	}
+
 	session := &Session{
 		config: cfg,
 		cookie: newCookie(),
+		log:    cfg.Logger,
 		storePool: &sync.Pool{
 			New: func() interface{} {
 				return NewStore()
@@ -74,7 +79,7 @@ func (s *Session) startGC() {
 		case <-time.After(s.config.GCLifetime):
 			err := s.provider.GC()
 			if err != nil {
-				log.Printf("session GC crash: %v", err)
+				s.log.Printf("session GC crash: %v", err)
 			}
 		case <-s.stopGCChan:
 			return

session_test.go

@@ -117,18 +117,19 @@ func TestSession_SetProvider(t *testing.T) {
 }
 
 func TestSession_startGC(t *testing.T) {
+	output := &bytes.Buffer{}
+	logger := log.New(output, "test", log.Flags())
+
 	s := New(Config{
 		GCLifetime: 100 * time.Millisecond,
+		Logger:     logger,
 	})
 	provider := &mockProvider{
 		needGCValue: true,
 		errGC:       errors.New("mock error"),
 	}
 	s.provider = provider
 
-	output := &bytes.Buffer{}
-	log.SetOutput(output)
-
 	go s.startGC()
 	time.Sleep(s.config.GCLifetime + 100*time.Millisecond)
 

types.go

@@ -58,6 +58,9 @@ type Config struct {
 	// DecodeFunc session value unSerialize func
 	DecodeFunc func(dst *Dict, src []byte) error
 
+	// Logger
+	Logger Logger
+
 	// value cookie length
 	cookieLen uint32
 }
@@ -67,6 +70,7 @@ type Session struct {
 	provider Provider
 	config   Config
 	cookie   *cookie
+	log      Logger
 
 	storePool  *sync.Pool
 	stopGCChan chan struct{}
@@ -87,6 +91,11 @@ type Store struct {
 
 type cookie struct{}
 
+type Logger interface {
+	Print(v ...interface{})
+	Printf(format string, v ...interface{})
+}
+
 // Provider interface implemented by providers
 type Provider interface {
 	Get(id []byte) ([]byte, error)