add ping query

pkg/models/client.go

@@ -17,14 +17,24 @@ type ClientCommand struct {
 
 // Represents a single client
 type WebsocketClient struct {
-	Conn   *websocket.Conn
+	Conn     *websocket.Conn
-	RealIP string
+	LastPong time.Time
+	RealIP   string
 }
 
 // Sends a message to the websocket.
 // Automatically locks and unlocks the client mutex, to ensure that only one goroutine can write at a time.
 func (c *WebsocketClient) SendMessage(messageType int, data []byte) error {
+	c.Conn.SetPongHandler(func(appData string) error {
+		c.LastPong = time.Now()
+		return nil
+	})
 	c.Conn.SetWriteDeadline(time.Now().Add(TIMEOUT * time.Second))
-	err := c.Conn.WriteMessage(messageType, data)
+	err := c.Conn.WriteMessage(websocket.PingMessage, nil)
-	return err
+	if err != nil {
+		return err
+	}
+
+	c.Conn.SetWriteDeadline(time.Now().Add(TIMEOUT * time.Second))
+	return c.Conn.WriteMessage(messageType, data)
 }