fix traffic counting

core/hy2/hook.go

@@ -12,15 +12,19 @@ type HookServer struct {
 }
 
 func (h *HookServer) Log(id string, tx, rx uint64) (ok bool) {
-	if c, ok := h.Counter.Load(h.Tag); ok {
-		c.(*counter.TrafficCounter).Rx(id, int(rx))
-		c.(*counter.TrafficCounter).Tx(id, int(rx))
-		return true
-	} else {
-		c := counter.NewTrafficCounter()
+	var c interface{}
+	var exists bool
+
+	if c, exists = h.Counter.Load(h.Tag); !exists {
+		c = counter.NewTrafficCounter()
 		h.Counter.Store(h.Tag, c)
-		c.Rx(id, int(rx))
-		c.Tx(id, int(rx))
+	}
+
+	if tc, ok := c.(*counter.TrafficCounter); ok {
+		tc.Rx(id, int(rx))
+		tc.Tx(id, int(tx))
 		return true
 	}
+
+	return false
 }