英文:
getting channel value from a webscoket client
问题
你的问题是在将响应从客户端传递到主文件中的通道时遇到了问题。目前，该通道只返回一个空值，然后不再返回任何内容。在将值传递给通道时似乎存在问题。你想知道如何解决这个问题。
根据你提供的代码，问题可能出在以下几个地方：
-
在
PubListen函数中，你将res的值发送到通道ch之后立即打印res和ch的值。这可能导致打印出空值，因为在发送到通道之前，res可能还没有被赋值。你可以尝试在发送到通道之前打印res的值，看看是否有值。 -
你在
main函数中创建了一个goroutine来接收通道ch的值并打印它们。但是，你没有等待该goroutine完成，就立即调用了cancel()函数和wg.Wait()函数。这可能导致在goroutine还没有完成时就关闭了通道，从而导致无法接收到所有的值。你可以尝试在调用cancel()和wg.Wait()之前等待该goroutine完成。
请尝试根据上述建议进行修改，并检查是否解决了问题。如果问题仍然存在，请提供更多的信息和错误消息，以便我可以更好地帮助你。
英文:
I'm running a websocket client and want to pass the response(s) from the client to a channel that i can work with in my main file. Currently, the channel just returns a nil value once and then nothing else. I seem to have an issue when passing a value to the channel. Any help? Here is what I've done so far
package main
import (
"context"
"fmt"
"kraken_client/stored_data"
"kraken_client/ws_client"
"os"
"os/signal"
"strings"
"sync"
"syscall"
)
func main() {
// check if in production or testing mode & find base curency
var testing bool = true
args := os.Args
isTesting(args, &testing, &stored_data.Base_currency)
// go routine handler
comms := make(chan os.Signal, 1)
signal.Notify(comms, os.Interrupt, syscall.SIGTERM)
ctx := context.Background()
ctx, cancel := context.WithCancel(ctx)
var wg sync.WaitGroup
// set ohlc interval and pairs
OHLCinterval := 5
pairs := []string{"BTC/" + stored_data.Base_currency, "EOS/" + stored_data.Base_currency}
// create ws connections
pubSocket, err := ws_client.ConnectToServer("public", testing)
if err != nil {
fmt.Println(err)
os.Exit(1)
}
// listen to websocket connections
ch := make(chan interface{})
wg.Add(1)
go pubSocket.PubListen(ctx, &wg, ch, testing)
// subscribe to a stream
pubSocket.SubscribeToOHLC(pairs, OHLCinterval)
go func() {
for c := range ch {
fmt.Println(c)
}
}()
<-comms
cancel()
wg.Wait()
defer close(ch)
}
Here is how the PubListen function works
func (socket *Socket) PubListen(ctx context.Context, wg *sync.WaitGroup, ch chan interface{}, testing bool) {
defer wg.Done()
defer socket.Close()
var res interface{}
socket.OnTextMessage = func(message string, socket Socket) {
//log.Println(message)
res = pubJsonDecoder(message, testing) // this function decodes the message and returns an interface
log.Println(res) // this is printing the correctly decoded value.
}
ch <- res
log.Println(res) // does not print a value
log.Println(ch) // does not print a value
<-ctx.Done()
log.Println("closing public socket")
return
}
What am I doing wrong?
答案1
得分: 1
问题中的代码在PubListen函数中执行了一次ch <- res语句，而在res被OnTextMessage函数设置之前。
要在每个消息中向ch发送一个值，将ch <- res这一行移到OnTextMessage函数中。该函数会为每个消息调用一次。
func (socket *Socket) PubListen(ctx context.Context, wg *sync.WaitGroup, ch chan interface{}, testing bool) {
defer wg.Done()
defer socket.Close()
socket.OnTextMessage = func(message string, socket Socket) {
res := pubJsonDecoder(message, testing)
ch <- res
log.Println(res)
}
<-ctx.Done()
log.Println("closing public socket")
return
}
英文:
The code in the question executes the statement ch <- res once from PubListen before the res is set by the OnTextMessage function.
To send a value to ch on each message, move the line ch <- res to the OnTextMessage function. That function is called once for each message.
func (socket *Socket) PubListen(ctx context.Context, wg *sync.WaitGroup, ch chan interface{}, testing bool) {
defer wg.Done()
defer socket.Close()
socket.OnTextMessage = func(message string, socket Socket) {
res := pubJsonDecoder(message, testing)
ch <- res
log.Println(res)
}
<-ctx.Done()
log.Println("closing public socket")
return
}
通过集体智慧和协作来改善编程学习和解决问题的方式。致力于成为全球开发者共同参与的知识库，让每个人都能够通过互相帮助和分享经验来进步。
评论