简单网络通信

在本章节中，我们将从一个简单的 HTTP 客户端以及服务器示例开始。然后在下个章节中，我们会介绍更为复杂的非阻塞示例。

HTTP 客户端的如下。

使用如下命令来编译 Rust 程序。

使用如下命令在 WasmEdge 中运行程序。

wasmedge target/wasm32-wasi/release/http_client.wasm

HTTP 服务器的源代码如下。

use bytecodec::DecodeExt;
use httpcodec::{HttpVersion, ReasonPhrase, Request, RequestDecoder, Response, StatusCode};
use std::io::{Read, Write};
#[cfg(feature = "std")]
use std::net::{Shutdown, TcpListener, TcpStream};
#[cfg(not(feature = "std"))]
use wasmedge_wasi_socket::{Shutdown, TcpListener, TcpStream};
fn handle_http(req: Request<String>) -> bytecodec::Result<Response<String>> {
  Ok(Response::new(
    HttpVersion::V1_0,
    StatusCode::new(200)?,
    ReasonPhrase::new("")?,
    format!("echo: {}", req.body()),
  ))
}
fn handle_client(mut stream: TcpStream) -> std::io::Result<()> {
  let mut buff = [0u8; 1024];
    let n = stream.read(&mut buff)?;
    data.extend_from_slice(&buff[0..n]);
    if n < 1024 {
      break;
    }
  }
  let mut decoder =
    RequestDecoder::<httpcodec::BodyDecoder<bytecodec::bytes::Utf8Decoder>>::default();
  let req = match decoder.decode_from_bytes(data.as_slice()) {
    Ok(req) => handle_http(req),
    Err(e) => Err(e),
  };
  let r = match req {
    Ok(r) => r,
    Err(e) => {
      let err = format!("{:?}", e);
        HttpVersion::V1_0,
        StatusCode::new(500).unwrap(),
        err.clone(),
      )
    }
  };
  let write_buf = r.to_string();
  stream.write(write_buf.as_bytes())?;
  stream.shutdown(Shutdown::Both)?;
  Ok(())
}
fn main() -> std::io::Result<()> {
  let port = std::env::var("PORT").unwrap_or(1234.to_string());
  println!("new connection at {}", port);
  let listener = TcpListener::bind(format!("0.0.0.0:{}", port))?;
  loop {
    let _ = handle_client(listener.accept()?.0);
  }

cargo build --target wasm32-wasi --release

使用如下命令在 WasmEdge 中运行程序。

$ wasmedge target/wasm32-wasi/release/http_server.wasm new connection at 1234

3.1.4. 简单的 HTTP 客户端和服务器

简单网络通信