启动线程池中的线程并通过通道发送数据块。渠道实现Stream
和一个超级Body
可以由Stream
using wrap_stream:
use futures::{channel::mpsc, executor::ThreadPool, task::SpawnExt, SinkExt, Stream}; // 0.3.1, features = ["thread-pool"]
use hyper::{
service::{make_service_fn, service_fn},
Body, Response, Server,
}; // 0.13.1
use std::{convert::Infallible, io, thread, time::Duration};
use tokio; // 0.2.6, features = ["macros"]
struct SlowData;
impl SlowData {
fn new(_initial: &str) -> SlowData {
thread::sleep(Duration::from_secs(1));
Self
}
fn next_block(&self) -> io::Result<&[u8]> {
thread::sleep(Duration::from_secs(1));
Ok(b"data")
}
}
fn stream(pool: ThreadPool) -> impl Stream<Item = io::Result<Vec<u8>>> {
let (mut tx, rx) = mpsc::channel(10);
pool.spawn(async move {
let sd = SlowData::new("dummy");
for _ in 0..3 {
let block = sd.next_block().map(|b| b.to_vec());
tx.send(block).await.expect("Unable to send block");
}
})
.expect("Unable to spawn thread");
rx
}
#[tokio::main]
async fn main() {
// Construct our SocketAddr to listen on...
let addr = ([127, 0, 0, 1], 3000).into();
// Create a threadpool (cloning is cheap)...
let pool = ThreadPool::new().unwrap();
// Handle each connection...
let make_service = make_service_fn(|_socket| {
let pool = pool.clone();
async {
// Handle each request...
let svc_fn = service_fn(move |_request| {
let pool = pool.clone();
async {
let data = stream(pool);
let resp = Response::new(Body::wrap_stream(data));
Result::<_, Infallible>::Ok(resp)
}
});
Result::<_, Infallible>::Ok(svc_fn)
}
});
// Bind and serve...
let server = Server::bind(&addr).serve(make_service);
// Finally, run the server
if let Err(e) = server.await {
eprintln!("server error: {}", e);
}
}
创建线程时,无法避免将切片复制到Vec
.
也可以看看:
- 这个答案适用于 hyper 0.12 和 future 0.1
- 如何通过 io::Write 特征写入来通过 futures Stream 发送数据?
- Rust 中 async/await 的目的是什么?
- 在 future-rs 中封装阻塞 I/O 的最佳方法是什么?
- 如何使用 futures.rs 和 Redis PubSub 实现阻塞调用的 future 流?