如何在同一结构中使用多个通道

Question

在我的代码中，我想执行以下操作：

1. 从输入接收数据event和message

2. 根据接收到的数据格式化event

我想使用与 OOP 中的方法接近的东西，但看起来我搞砸了。

我写的是：

// Define the structs that contains the channels

type sseData struct {

    event, message string

}

type DataPasser struct {

    data       chan sseData

    logs       chan string

    connection chan struct{} // To control maximum allowed clients connections

}

// DEfine the struct's reciever that do the formating based on the input date

func (p *DataPasser) Format() {

    data := <-p.data

    switch {

    case len(data.event) > 0:

        p.logs <- fmt.Sprintf("event: %v\ndata: %v\n\n", data.event, data.message)

    case len(data.event) == 0:

        p.logs <- fmt.Sprintf("data: %v\n\n", data.message)

    }

}

然后我有以下内容：

func (p *DataPasser) HandleSignal(w http.ResponseWriter, r *http.Request) {

    w.Header().Set("Content-Type", "text/event-stream; charset=utf-8")

    w.Header().Set("Cache-Control", "no-cache")

    w.Header().Set("Connection", "keep-alive")

    setupCORS(&w, r)

    fmt.Println("Client connected from IP:", r.RemoteAddr)

    p.connection <- struct{}{}

    flusher, ok := w.(http.Flusher)

    if !ok {

        http.Error(w, "Internal error", 500)

        return

    }

    fmt.Fprint(w, "event: notification\ndata: Connection to WhatsApp server ...\n\n")

    flusher.Flush()

    // Connect to the WhatsApp client

    go Connect()

    // Prepare dataParser `p` to recieve data through its sseData channel

    go p.Format()

    for {

        select {

        case c := <-p.logs:

            fmt.Fprint(w, c)

            flusher.Flush()

        case <-r.Context().Done():

            <-p.connection

            fmt.Println("Connection closed")

            return

        }

    }

}

Answer 1

当您passer.data从go connect()例程向其发送数据时，例程go p.Format()不在监听。因为您使用的是无缓冲通道parser.data但没有接收器正在监听，所以您的代码被卡住了。要么使用缓冲通道，parser.data要么确保您的例程监听来自数据通道的传入消息已启动，并在实际将数据发送到通道之前进行监听。在你的情况下，我想在Format例程之前开始例程Connect就足够了。

Answer 2

我通过写解决了它：&nbsp; &nbsp; // Connect to the WhatsApp client&nbsp; &nbsp; go Connect()&nbsp; &nbsp; for {&nbsp; &nbsp; &nbsp; &nbsp; select {&nbsp; &nbsp; &nbsp; &nbsp; case data := <-p.data:&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; fmt.Println("recieved")&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; switch {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; case len(data.event) > 0:&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; fmt.Fprintf(w, "event: %v\ndata: %v\n\n", data.event, data.message)&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; case len(data.event) == 0:&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; fmt.Fprintf(w, "data: %v\n\n", data.message)&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; flusher.Flush()&nbsp; &nbsp; &nbsp; &nbsp; case <-r.Context().Done():&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <-p.connection&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; fmt.Println("Connection closed")&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; }但我仍然对拆分操作和使用接收器感兴趣，我不能接受这个作为答案，因为它是问题的解决方案，但不是问题的答案。任何想法？