feat: add recovery middleware and use negative error codes for system errors

- Added a new recovery middleware
- Use the negative error codes.

middlewares/recovery.go

@@ -0,0 +1,25 @@
+package middlewares
+
+import (
+	"runtime/debug"
+
+	"github.com/wonli/aqi/logger"
+	"github.com/wonli/aqi/ws"
+)
+
+func Recovery() ws.HandlerFunc {
+	return func(a *ws.Context) {
+		defer func() {
+			if err := recover(); err != nil {
+				// 获取 panic 发生的堆栈跟踪
+				stack := debug.Stack()
+				logger.SugarLog.Errorf("Panic happened: %s \n %s\n", err, stack)
+
+				a.SendCode(-30, "服务维护中")
+				a.Abort()
+			}
+		}()
+
+		a.Next()
+	}
+}

ws/dispatcher.go

@@ -20,14 +20,14 @@ func Dispatcher(c *Client, request string) {
 	if c.User != nil {
 		isBanned, bandTime := c.User.IsBanned()
 		if isBanned {
-			c.SendRawMsg(21, "sys.ban", "You have been ban", bandTime)
+			c.SendRawMsg(-11, "sys.ban", "You have been ban", bandTime)
 			return
 		}
 	}
 
 	//请求频率限制5毫秒
 	if t.Sub(c.LastRequestTime).Microseconds() <= 5 {
-		c.SendRawMsg(23, "sys.requestLimit", "Your requests are too frequent", nil)
+		c.SendRawMsg(-13, "sys.requestLimit", "Your requests are too frequent", nil)
 		return
 	} else {
 		//更新最后请求时间
@@ -42,7 +42,7 @@ func Dispatcher(c *Client, request string) {
 
 	handlers := InitManager().Handlers(action)
 	if handlers == nil || len(handlers) == 0 {
-		c.SendRawMsg(25, action, "Request not supported", nil)
+		c.SendRawMsg(-15, action, "Request not supported", nil)
 		return
 	}