optimize code of websocket close handler

handler/real_time_data_pull.go

@@ -60,6 +60,15 @@ func PullRealTimeDataHandler(c *gin.Context) {
 	ctx, cancel := context.WithCancel(c.Request.Context())
 	defer cancel()
 
+	conn.SetCloseHandler(func(code int, text string) error {
+		logger.Info(c.Request.Context(), "websocket processor shutdown trigger",
+			"clientID", clientID, "code", code, "reason", text)
+
+		// call cancel to notify other goroutines to stop working
+		cancel()
+		return nil
+	})
+
 	// TODO[BACKPRESSURE-ISSUE] 先期使用固定大容量对扇入模型进行定义 #1
 	fanInChan := make(chan network.RealTimePullTarget, constants.FanInChanMaxSize)
 	sendChan := make(chan []network.RealTimePullTarget, constants.SendChanBufferSize)