如何在Rust中使用hyper、tokio和futures设置HTTP请求的超时时间？

Question

如何在使用异步Hyper（>=0.11）时为HTTP请求设置超时时间？

以下为没有超时时间的代码示例：

extern crate hyper;
extern crate tokio_core;
extern crate futures;

use futures::Future;
use hyper::Client;
use tokio_core::reactor::Core;

fn main() {
    let mut core = Core::new().unwrap();
    let client = Client::new(&core.handle());

    let uri = "http://stackoverflow.com".parse().unwrap();
    let work = client.get(uri).map(|res| {
        res.status()
    });

    match core.run(work) {
        Ok(status) => println!("Status: {}", status),
        Err(e) => println!("Error: {:?}", e)
    }
}

- Sergey Potapov

Answer 1

根据seanmonstar提供的链接到Hyper Guide / General Timeout，我用一个可行的代码示例回答了自己的问题：

extern crate hyper;
extern crate tokio_core;
extern crate futures;

use futures::Future;
use futures::future::Either;
use hyper::Client;
use tokio_core::reactor::Core;
use std::time::Duration;
use std::io;

fn main() {
    let mut core = Core::new().unwrap();
    let handle = core.handle();
    let client = Client::new(&handle);

    let uri: hyper::Uri = "http://stackoverflow.com".parse().unwrap();
    let request = client.get(uri.clone()).map(|res| res.status());

    let timeout = tokio_core::reactor::Timeout::new(Duration::from_millis(170), &handle).unwrap();

    let work = request.select2(timeout).then(|res| match res {
        Ok(Either::A((got, _timeout))) => Ok(got),
        Ok(Either::B((_timeout_error, _get))) => {
            Err(hyper::Error::Io(io::Error::new(
                io::ErrorKind::TimedOut,
                "Client timed out while connecting",
            )))
        }
        Err(Either::A((get_error, _timeout))) => Err(get_error),
        Err(Either::B((timeout_error, _get))) => Err(From::from(timeout_error)),
    });

    match core.run(work) {
        Ok(status) => println!("OK: {:?}", status),
        Err(e) => println!("Error: {:?}", e)
    }
}

- Sergey Potapov

Answer 2

< p>仅供参考，自Tokyo版本1.0起，这变得更加容易，因为现在有一个专门的timeout包装器，可以应用于未来（例如请求），并将原始未来类型包装在一个Result中，其中Ok 是原始未来类型，Err 是超时错误。

因此，您在问题中的代码现在可以按以下方式处理超时：

extern crate tokio; // 1.7.1, full features

use hyper::Client;
use std::time::Duration;

#[tokio::main]
async fn main() {
    let client = Client::new();


    let uri = "http://stackoverflow.com".parse().unwrap();
    let work = client.get(uri);

    match tokio::time::timeout(Duration::from_millis(10), work).await {
        Ok(result) => match result {
            Ok(response) => println!("Status: {}", response.status()),
            Err(e) => println!("Network error: {:?}", e),
        },
        Err(_) => println!("Timeout: no response in 10 milliseconds."),
    };
}

（当然，这段代码始终会让您超时。要查看来自网络的预期301响应，请尝试转到200毫秒。）

- brotskydotcom