流式异步HTTP 1.1解析器。

HTTP本质上是一个有状态的RPC协议，客户端和服务器通过编码和解码消息进行通信。

• client 编码HTTP请求，解码HTTP响应。
• server 解码HTTP请求，编码HTTP响应。

客户端始终启动HTTP连接。HTTP连接的生存期如下

1. encode            2. decode
        \            /
        -> request  ->
 client                server
        <- response <-
        /            \
4. decode            3. encode

另请参阅 async-tls，async-std。

示例

HTTP客户端

use async_std::net::TcpStream;
use http_types::{Method, Request, Url};

#[async_std::main]
async fn main() -> http_types::Result<()> {
    let stream = TcpStream::connect("127.0.0.1:8080").await?;

    let peer_addr = stream.peer_addr()?;
    println!("connecting to {}", peer_addr);
    let url = Url::parse(&format!("http://{}/foo", peer_addr))?;

    let req = Request::new(Method::Get, url);
    let res = async_h1::connect(stream.clone(), req).await?;
    println!("{:?}", res);

    Ok(())
}

HTTP服务器

use async_std::net::{TcpStream, TcpListener};
use async_std::prelude::*;
use async_std::task;
use http_types::{Response, StatusCode};

#[async_std::main]
async fn main() -> http_types::Result<()> {
    // Open up a TCP connection and create a URL.
    let listener = TcpListener::bind(("127.0.0.1", 8080)).await?;
    let addr = format!("http://{}", listener.local_addr()?);
    println!("listening on {}", addr);

    // For each incoming TCP connection, spawn a task and call `accept`.
    let mut incoming = listener.incoming();
    while let Some(stream) = incoming.next().await {
        let stream = stream?;
        task::spawn(async {
            if let Err(err) = accept(stream).await {
                eprintln!("{}", err);
            }
        });
    }
    Ok(())
}

// Take a TCP stream, and convert it into sequential HTTP request / response pairs.
async fn accept(stream: TcpStream) -> http_types::Result<()> {
    println!("starting new connection from {}", stream.peer_addr()?);
    async_h1::accept(stream.clone(), |_req| async move {
        let mut res = Response::new(StatusCode::Ok);
        res.insert_header("Content-Type", "text/plain");
        res.set_body("Hello");
        Ok(res)
    })
    .await?;
    Ok(())
}