rust - UnixStream 写入/读取完整字符串

Question

我有一个问题的这个小示例版本:

#[test]
fn streams() {
    use std::io::prelude::*;
    use std::net::Shutdown;
    use std::os::unix::net::UnixStream;
    use std::time::Duration;

    let (mut s1, mut s2) = UnixStream::pair().unwrap();
    s1.write_all(b"hello world").unwrap();
    // Problem is that if not calling shutdown message never arrives
    s1.shutdown(Shutdown::Write).unwrap();
    let mut response = String::new();
    s2.read_to_string(&mut response).unwrap();
    assert_eq!("hello world".to_string(), response);
}

Playground link

我需要关闭连接，否则消息永远不会到达。我认为问题在于 write_all 不写入 EOF，因此在使用 read_to_string 时挂起。

例如在 python 中我会简单地使用:

socket.sendall(message.encode())
data = socket.recv(1024)

发送和接收回复。

我怎样才能用 Rust 实现同样的效果？

提前谢谢你。

Answer 1

read_to_string的语义是:

Read all bytes until EOF in this source, appending them to buf.

If successful, this function returns the number of bytes which were read and appended to buf.

所以如果你不关闭流它就会挂起。您想改用 read:

    let (mut s1, mut s2) = UnixStream::pair().unwrap();
    s1.write_all(b"hello world").unwrap();
    let mut buf = [0; 1024];
    let count = s2.read(&mut buf).unwrap();
    let response = String::from_utf8(buf[..count].to_vec()).unwrap();
    assert_eq!("hello world".to_string(), response);