rust - 我可以在 Rocket 中重复使用 Tokio Core 和 Hyper Client 吗？

Question

在收到用户的传入请求后，我想使用 Hyper 0.11 发出客户端请求，我使用火箭处理并使用尽可能少的资源。如果我不能重用 Core 或 Client，我将不得不在每次 Rocket 发出请求时创建它们。每次服务器响应请求时，这将在高性能环境中占用太多资源来创建 Core 和 Client。所以我使用 State 使对象可用于所有“点火”。在 Hyper 0.10.13 中它可以工作，但在带有 Tokio 的 Hyper 0.11 中我收到大量错误消息。

cargo .toml:

rocket = "0.3.3"
rocket_codegen = "0.3.3"
hyper = "0.11"
futures = "0.1"
tokio-core = "0.1"

主要.rs

#![feature(plugin, decl_macro)]
#![plugin(rocket_codegen)]
extern crate futures;
extern crate hyper;
extern crate rocket;
extern crate tokio_core;
use rocket::State;
use hyper::*;
use hyper::header::{ContentLength, ContentType};
use futures::{Future, Stream};
use tokio_core::reactor::Core;

fn main() {
    let mut core = Core::new().unwrap();
    let client = Client::new(&core.handle());
    rocket::ignite()
        .mount("/", routes![index])
        .manage(client.clone())
        .launch();
}

#[post("/", data = "<var>")]
fn index(var: String, client: State<hyper::Client<tokio_core::reactor::Handle>>) -> &'static str {
    let json = r#"{"library":"hyper"}"#;
    let uri = "http://xxx.xxx.xxx.xxx".parse().unwrap();
    let mut req = Request::new(Method::Post, uri);
    req.headers_mut().set(ContentType::json());
    req.headers_mut().set(ContentLength(json.len() as u64));
    req.set_body(json);
    let post = client.request(req).and_then(|res| {
        //println!("POST: {}", res.status());
        res.body().concat2()
    });
}

我收到如下错误消息:

error[E0277]: the trait bound `std::rc::Weak<std::cell::RefCell<tokio_core::reactor::Inner>>: std::marker::Send` is not satisfied in `hyper::Client<tokio_core::reactor::Handle>`
  --> src/main.rs:23:1
   |
23 | / fn index(var: String, client: State<hyper::Client<tokio_core::reactor::Handle>>) -> &'static str {
24 | |     let json = r#"{"library":"hyper"}"#;
25 | |     let uri = "http://xxx.xxx.xxx.xxx".parse().unwrap();
26 | |     let mut req = Request::new(Method::Post, uri);
...  |
33 | |     });
34 | | }
   | |_^ `std::rc::Weak<std::cell::RefCell<tokio_core::reactor::Inner>>` cannot be sent between threads safely
   |
   = help: within `hyper::Client<tokio_core::reactor::Handle>`, the trait `std::marker::Send` is not implemented for `std::rc::Weak<std::cell::RefCell<tokio_core::reactor::Inner>>`
   = note: required because it appears within the type `tokio_core::reactor::Handle`
   = note: required because it appears within the type `hyper::Client<tokio_core::reactor::Handle>`
   = note: required by `rocket::State`

error[E0277]: the trait bound `std::rc::Weak<std::cell::RefCell<tokio_core::reactor::Inner>>: std::marker::Sync` is not satisfied in `hyper::Client<tokio_core::reactor::Handle>`
  --> src/main.rs:23:1
   |
23 | / fn index(var: String, client: State<hyper::Client<tokio_core::reactor::Handle>>) -> &'static str {
24 | |     let json = r#"{"library":"hyper"}"#;
25 | |     let uri = "http://xxx.xxx.xxx.xxx".parse().unwrap();
26 | |     let mut req = Request::new(Method::Post, uri);
...  |
33 | |     });
34 | | }
   | |_^ `std::rc::Weak<std::cell::RefCell<tokio_core::reactor::Inner>>` cannot be shared between threads safely
   |
   = help: within `hyper::Client<tokio_core::reactor::Handle>`, the trait `std::marker::Sync` is not implemented for `std::rc::Weak<std::cell::RefCell<tokio_core::reactor::Inner>>`
   = note: required because it appears within the type `tokio_core::reactor::Handle`
   = note: required because it appears within the type `hyper::Client<tokio_core::reactor::Handle>`
   = note: required by `rocket::State`

error[E0277]: the trait bound `std::rc::Rc<std::cell::RefCell<hyper::client::pool::PoolInner<tokio_proto::util::client_proxy::ClientProxy<tokio_proto::streaming::message::Message<hyper::proto::MessageHead<hyper::proto::RequestLine>, hyper::Body>, tokio_proto::streaming::message::Message<hyper::proto::MessageHead<hyper::proto::RawStatus>, tokio_proto::streaming::body::Body<hyper::Chunk, hyper::Error>>, hyper::Error>>>>: std::marker::Send` is not satisfied in `hyper::Client<tokio_core::reactor::Handle>`
  --> src/main.rs:23:1
   |
23 | / fn index(var: String, client: State<hyper::Client<tokio_core::reactor::Handle>>) -> &'static str {
24 | |     let json = r#"{"library":"hyper"}"#;
25 | |     let uri = "http://xxx.xxx.xxx.xxx".parse().unwrap();
26 | |     let mut req = Request::new(Method::Post, uri);
...  |
33 | |     });
34 | | }
   | |_^ `std::rc::Rc<std::cell::RefCell<hyper::client::pool::PoolInner<tokio_proto::util::client_proxy::ClientProxy<tokio_proto::streaming::message::Message<hyper::proto::MessageHead<hyper::proto::RequestLine>, hyper::Body>, tokio_proto::streaming::message::Message<hyper::proto::MessageHead<hyper::proto::RawStatus>, tokio_proto::streaming::body::Body<hyper::Chunk, hyper::Error>>, hyper::Error>>>>` cannot be sent between threads safely
   |
   = help: within `hyper::Client<tokio_core::reactor::Handle>`, the trait `std::marker::Send` is not implemented for `std::rc::Rc<std::cell::RefCell<hyper::client::pool::PoolInner<tokio_proto::util::client_proxy::ClientProxy<tokio_proto::streaming::message::Message<hyper::proto::MessageHead<hyper::proto::RequestLine>, hyper::Body>, tokio_proto::streaming::message::Message<hyper::proto::MessageHead<hyper::proto::RawStatus>, tokio_proto::streaming::body::Body<hyper::Chunk, hyper::Error>>, hyper::Error>>>>`
   = note: required because it appears within the type `hyper::client::pool::Pool<tokio_proto::util::client_proxy::ClientProxy<tokio_proto::streaming::message::Message<hyper::proto::MessageHead<hyper::proto::RequestLine>, hyper::Body>, tokio_proto::streaming::message::Message<hyper::proto::MessageHead<hyper::proto::RawStatus>, tokio_proto::streaming::body::Body<hyper::Chunk, hyper::Error>>, hyper::Error>>`
   = note: required because it appears within the type `hyper::client::Dispatch<hyper::Body>`
   = note: required because it appears within the type `hyper::Client<tokio_core::reactor::Handle>`
   = note: required by `rocket::State`

error[E0277]: the trait bound `std::rc::Rc<std::cell::RefCell<hyper::client::pool::PoolInner<std::cell::RefCell<futures::sync::mpsc::Sender<(hyper::proto::MessageHead<hyper::proto::RequestLine>, std::option::Option<hyper::Body>, futures::Sender<std::result::Result<hyper::Response, hyper::Error>>)>>>>>: std::marker::Send` is not satisfied in `hyper::Client<tokio_core::reactor::Handle>`
  --> src/main.rs:23:1
   |
23 | / fn index(var: String, client: State<hyper::Client<tokio_core::reactor::Handle>>) -> &'static str {
24 | |     let json = r#"{"library":"hyper"}"#;
25 | |     let uri = "http://xxx.xxx.xxx.xxx".parse().unwrap();
26 | |     let mut req = Request::new(Method::Post, uri);
...  |
33 | |     });
34 | | }
   | |_^ `std::rc::Rc<std::cell::RefCell<hyper::client::pool::PoolInner<std::cell::RefCell<futures::sync::mpsc::Sender<(hyper::proto::MessageHead<hyper::proto::RequestLine>, std::option::Option<hyper::Body>, futures::Sender<std::result::Result<hyper::Response, hyper::Error>>)>>>>>` cannot be sent between threads safely
   |
   = help: within `hyper::Client<tokio_core::reactor::Handle>`, the trait `std::marker::Send` is not implemented for `std::rc::Rc<std::cell::RefCell<hyper::client::pool::PoolInner<std::cell::RefCell<futures::sync::mpsc::Sender<(hyper::proto::MessageHead<hyper::proto::RequestLine>, std::option::Option<hyper::Body>, futures::Sender<std::result::Result<hyper::Response, hyper::Error>>)>>>>>`
   = note: required because it appears within the type `hyper::client::pool::Pool<std::cell::RefCell<futures::sync::mpsc::Sender<(hyper::proto::MessageHead<hyper::proto::RequestLine>, std::option::Option<hyper::Body>, futures::Sender<std::result::Result<hyper::Response, hyper::Error>>)>>>`
   = note: required because it appears within the type `hyper::client::Dispatch<hyper::Body>`
   = note: required because it appears within the type `hyper::Client<tokio_core::reactor::Handle>`
   = note: required by `rocket::State`

error[E0277]: the trait bound `std::rc::Rc<std::cell::RefCell<hyper::client::pool::PoolInner<tokio_proto::util::client_proxy::ClientProxy<tokio_proto::streaming::message::Message<hyper::proto::MessageHead<hyper::proto::RequestLine>, hyper::Body>, tokio_proto::streaming::message::Message<hyper::proto::MessageHead<hyper::proto::RawStatus>, tokio_proto::streaming::body::Body<hyper::Chunk, hyper::Error>>, hyper::Error>>>>: std::marker::Sync` is not satisfied in `hyper::Client<tokio_core::reactor::Handle>`
  --> src/main.rs:23:1
   |
23 | / fn index(var: String, client: State<hyper::Client<tokio_core::reactor::Handle>>) -> &'static str {
24 | |     let json = r#"{"library":"hyper"}"#;
25 | |     let uri = "http://xxx.xxx.xxx.xxx".parse().unwrap();
26 | |     let mut req = Request::new(Method::Post, uri);
...  |
33 | |     });
34 | | }
   | |_^ `std::rc::Rc<std::cell::RefCell<hyper::client::pool::PoolInner<tokio_proto::util::client_proxy::ClientProxy<tokio_proto::streaming::message::Message<hyper::proto::MessageHead<hyper::proto::RequestLine>, hyper::Body>, tokio_proto::streaming::message::Message<hyper::proto::MessageHead<hyper::proto::RawStatus>, tokio_proto::streaming::body::Body<hyper::Chunk, hyper::Error>>, hyper::Error>>>>` cannot be shared between threads safely
   |
   = help: within `hyper::Client<tokio_core::reactor::Handle>`, the trait `std::marker::Sync` is not implemented for `std::rc::Rc<std::cell::RefCell<hyper::client::pool::PoolInner<tokio_proto::util::client_proxy::ClientProxy<tokio_proto::streaming::message::Message<hyper::proto::MessageHead<hyper::proto::RequestLine>, hyper::Body>, tokio_proto::streaming::message::Message<hyper::proto::MessageHead<hyper::proto::RawStatus>, tokio_proto::streaming::body::Body<hyper::Chunk, hyper::Error>>, hyper::Error>>>>`
   = note: required because it appears within the type `hyper::client::pool::Pool<tokio_proto::util::client_proxy::ClientProxy<tokio_proto::streaming::message::Message<hyper::proto::MessageHead<hyper::proto::RequestLine>, hyper::Body>, tokio_proto::streaming::message::Message<hyper::proto::MessageHead<hyper::proto::RawStatus>, tokio_proto::streaming::body::Body<hyper::Chunk, hyper::Error>>, hyper::Error>>`
   = note: required because it appears within the type `hyper::client::Dispatch<hyper::Body>`
   = note: required because it appears within the type `hyper::Client<tokio_core::reactor::Handle>`
   = note: required by `rocket::State`

error[E0277]: the trait bound `std::rc::Rc<std::cell::RefCell<hyper::client::pool::PoolInner<std::cell::RefCell<futures::sync::mpsc::Sender<(hyper::proto::MessageHead<hyper::proto::RequestLine>, std::option::Option<hyper::Body>, futures::Sender<std::result::Result<hyper::Response, hyper::Error>>)>>>>>: std::marker::Sync` is not satisfied in `hyper::Client<tokio_core::reactor::Handle>`
  --> src/main.rs:23:1
   |
23 | / fn index(var: String, client: State<hyper::Client<tokio_core::reactor::Handle>>) -> &'static str {
24 | |     let json = r#"{"library":"hyper"}"#;
25 | |     let uri = "http://xxx.xxx.xxx.xxx".parse().unwrap();
26 | |     let mut req = Request::new(Method::Post, uri);
...  |
33 | |     });
34 | | }
   | |_^ `std::rc::Rc<std::cell::RefCell<hyper::client::pool::PoolInner<std::cell::RefCell<futures::sync::mpsc::Sender<(hyper::proto::MessageHead<hyper::proto::RequestLine>, std::option::Option<hyper::Body>, futures::Sender<std::result::Result<hyper::Response, hyper::Error>>)>>>>>` cannot be shared between threads safely
   |
   = help: within `hyper::Client<tokio_core::reactor::Handle>`, the trait `std::marker::Sync` is not implemented for `std::rc::Rc<std::cell::RefCell<hyper::client::pool::PoolInner<std::cell::RefCell<futures::sync::mpsc::Sender<(hyper::proto::MessageHead<hyper::proto::RequestLine>, std::option::Option<hyper::Body>, futures::Sender<std::result::Result<hyper::Response, hyper::Error>>)>>>>>`
   = note: required because it appears within the type `hyper::client::pool::Pool<std::cell::RefCell<futures::sync::mpsc::Sender<(hyper::proto::MessageHead<hyper::proto::RequestLine>, std::option::Option<hyper::Body>, futures::Sender<std::result::Result<hyper::Response, hyper::Error>>)>>>`
   = note: required because it appears within the type `hyper::client::Dispatch<hyper::Body>`
   = note: required because it appears within the type `hyper::Client<tokio_core::reactor::Handle>`
   = note: required by `rocket::State`

我的状态有问题吗？请不要为答案付出太多努力。如果你能给我指出正确的方向，我可以自己工作。另一种解决方案如何使用另一种设置来解决这个问题也非常受欢迎。

Answer 1

不，您不能在线程之间共享 hyper::Client。但是，您可以共享一个 tokio_core Remote :

#![feature(plugin, decl_macro)]
#![plugin(rocket_codegen)]
extern crate futures;
extern crate hyper;
extern crate rocket;
extern crate tokio_core;

use rocket::State;
use futures::{Future, Stream};
use tokio_core::reactor::Core;

fn main() {
    let core = Core::new().unwrap();
    rocket::ignite()
        .mount("/", routes![index])
        .manage(core.remote())
        .launch();
}

#[post("/", data = "<var>")]
fn index(var: String, remote: State<tokio_core::reactor::Remote>) -> String {
    remote.spawn(|handle| {
        use hyper::{Client, Request, Method};
        use hyper::header::{ContentLength, ContentType};

        let client = Client::new(handle);

        let json = r#"{"library":"hyper"}"#;
        let uri = "http://xxx.xxx.xxx.xxx".parse().unwrap();
        let mut req = Request::new(Method::Post, uri);
        req.headers_mut().set(ContentType::json());
        req.headers_mut().set(ContentLength(json.len() as u64));
        req.set_body(json);

        client.request(req)
            .and_then(|res| res.body().concat2())
            .map(|_| ())
            .map_err(|_| ())
    });

    var
}

然后问题转向你的另一个断言:

I would have to create them each time Rocket ignites a request. This would take too many resources in an high performance environment

我不确定您做出这样的决定的依据是什么。 Constructing a Client doesn't do much .