英文:
how to set timeout on bufio.ReadBytes()
问题
我正在编写一段代码，用于从网络中读取数据并设置超时。最初我写了这段代码（为简化起见，省略了错误检查）：
func read_msg(conn net.Conn, ch chan []byte) {
b := bufio.NewReader(conn)
msg,_ := b.ReadBytes(byte('\n'))
ch <- msg
close(ch)
}
func main() {
ln,_ := net.Listen("tcp", ":12345")
conn,_ := ln.Accept()
for {
ch := make(chan []byte)
go read_msg(conn,ch)
select {
case msg := <-ch:
fmt.Println("message received: ", msg)
case <-time.After(time.Duration(1)*time.Second):
fmt.Println("timeout")
}
}
}
当超时发生时，goroutine 会保持活动状态，等待 bufio.ReadBytes()。有没有办法在 bufio 上设置超时呢？
英文:
I am writing a code, which reads data from network with timeouts. Initially I wrote this (much simplified skipped error checks too)
func read_msg(conn net.Conn, ch chan []byte) {
b := bufio.NewReader(conn)
msg,_ := b.ReadBytes(byte('\n'))
ch <- msg
close(ch)
}
func main() {
ln,_ := net.Listen("tcp", ":12345")
conn,_ := ln.Accept()
for {
ch := make(chan []byte)
go read_msg(conn,ch)
select {
case msg := <-ch:
fmt.Println("message received: ", msg)
case <-time.After(time.Duration(1)*time.Second):
fmt.Println("timeout")
}
}
}
When the timeout happens, the goroutine stays active, waiting on the bufio.ReadBytes(). Is there anyway to set a timeout on the bufio itself?
答案1
得分: 3
不，bufio包没有这个功能（你可以在这里阅读文档）。
更合适的解决方案是使用net.Conn值的SetReadDeadline方法。
// 截止时间是一个绝对时间，在此之后，I/O操作将失败而不是阻塞。截止时间适用于所有未来和挂起的I/O操作，而不仅仅是紧接着的Read或Write调用。
...
// SetReadDeadline设置未来Read调用和任何当前阻塞的Read调用的截止时间。
// t的零值表示Read不会超时。
例如：
conn.SetReadDeadline(time.Now().Add(time.Second))
英文:
No, bufio does not have this feature (you can read the docs here).
The more appropriate solution is to use the SetReadDeadline method of the net.Conn value.
// A deadline is an absolute time after which I/O operations
// fail instead of blocking. The deadline applies to all future
// and pending I/O, not just the immediately following call to
// Read or Write.
...
// SetReadDeadline sets the deadline for future Read calls
// and any currently-blocked Read call.
// A zero value for t means Read will not time out.
For example:
conn.SetReadDeadline(time.Now().Add(time.Second))
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