add serial cache

main.go

@@ -26,7 +26,7 @@ func init() {
 }
 
 var tlog = log.New("main", "main.go")
-
+var serial string
 // @title Golang Gin API
 // @version 1.0
 // @description An example of gin
@@ -82,10 +82,16 @@ func main() {
 func broadcast()  {
 	var pai pai_service.Pai
 	send := "hello world"
-	ok := pai.GetConfig()
-	if ok {
-		send = pai.Serial
+	if serial != "" {
+		send = serial
+	} else {
+		ok := pai.GetConfig()
+		if ok {
+			send = pai.Serial
+			serial = pai.Serial
+		}
 	}
+
 	//ip 会变化
 	ip,err := util.GetLocalIP()
 	if err != nil {