gjs如何使用g_data_input_stream_read_line_async在Gnome Shell Extension中读取套接字流 [英] gjs How to read a socket stream in Gnome Shell Extension using g_data_input_stream_read_line_async

问题描述

我正在尝试编写一个Gnome-Shell扩展，该扩展通过Socket Server与Arduino通信. Server和Arduino运行良好，但是我被扩展代码侦听Server传入的消息.

I'm trying to write a Gnome-Shell extension that communicates with Arduino through a Socket Server. The Server and Arduino are running fine, but I'm stuck at the extension code that listens for incoming Server messages.

由于我需要一种非阻塞方法，因此请使用 read_line_async 似乎很完美.

Since I need a non blocking approach, using read_line_async seems perfect.

但是我无法使其正常工作.这是我到目前为止(相关部分)的内容:

However I can't manage to get it to work. Here's what i got so far (relevant part):

    let sockClient, sockConnection, output_reader, receivedline;

// connect to socket
    sockClient = new Gio.SocketClient();
    sockConnection = sockClient.connect_to_host("127.0.0.1:21567", null, null);


// read server socket

    output_reader = new Gio.DataInputStream({ base_stream: sockConnection.get_input_stream() });

    output_reader.read_line_async(0, null, _SocketRead, null);


// callback

    function _SocketRead() {

        let [lineout, charlength, error] = output_reader.read_line_finish();

        receivedline = lineout;
        // process received data

    }

异步功能可以很好地启动，并且当从服务器接收到一行时，也会调用_SocketRead，但是它无法使用read_line_finish()读取数据.

The async function is started just fine and also _SocketRead gets called, when there's a line received from the server, but it fails to read the data with read_line_finish().

我对gio和Extension开发完全陌生，所以我可能会错过一些显而易见的东西.

I'm completely new to gio and Extension development so I might just miss something obvious.

在我看来，read_line_finish()可能丢失了它的 GAsyncResult 参数，但是我不知道如何实现它.

To me it seems like read_line_finish() may be missing it's GAsyncResult parameter, but i've got no clue on how to implement it.

回调函数和read_line_finish()缺少其参数. 多亏了Gerd的回答，我才得以使它发挥作用.帮助我找出说明"下 GIO参考中链接的示例.因此，这是用于比较的工作代码:

The Callback function and read_line_finish() were missing their parameters. Thanks to Gerd's answer I was able to make it work. Helped me to figure out the example linked in the GIO Reference under "Description". So here is the working code for comparison:

    let sockClient, sockConnection, output_reader, receivedline;

// connect to socket
    sockClient = new Gio.SocketClient();
    sockConnection = sockClient.connect_to_host("127.0.0.1:21567", null, null);


// read server socket

    output_reader = new Gio.DataInputStream({ base_stream: sockConnection.get_input_stream() });

    output_reader.read_line_async(0, null, _SocketRead, null);


// callback

    function _SocketRead(gobject, async_res, user_data) {

        let [lineout, charlength, error] = gobject.read_line_finish(async_res);

        receivedline = lineout;
        // process received data

    }

推荐答案

我对GJS还是陌生的，但是对编程语言的深刻理解使我想到了以下部分解决方案:根据

I am also new to GJS but a solid understanding of programming language led me to the following partial solution: According to the Gio DataStream reference You have to provide all required parameters to the method, e.g.,

let asyncResult = new Gio.SimpleAsyncResult();
let length;
let lineout = output_reader.read_line_finish(asyncResult, length);

HTH， 格尔德

HTH, Gerd

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