forked/hyper
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

docs(examples): update echo example to use async/await

Browse Source
This commit is contained in:
Fuyang Liu
2019-07-12 19:39:08 +02:00
committed by Sean McArthur
parent 22142943f4
commit 7ff8fccced
1 changed files with 38 additions and 38 deletions
Download Patch File Download Diff File Expand all files Collapse all files

76
examples/echo.rs
View File

@@ -1,80 +1,80 @@
#![feature(async_await)]
#![deny(warnings)]
extern crate futures;
extern crate hyper;
use futures::future;
use hyper::rt::{Future, Stream};
use hyper::service::service_fn;
use hyper::{Body, Method, Request, Response, Server, StatusCode};
/// We need to return different futures depending on the route matched,
/// and we can do that with an enum, such as `futures::Either`, or with
/// trait objects.
///
/// A boxed Future (trait object) is used as it is easier to understand
/// and extend with more types. Advanced users could switch to `Either`.
type BoxFut = Box<dyn Future<Item = Response<Body>, Error = hyper::Error> + Send>;
use hyper::service::{make_service_fn, service_fn};
use futures_util::TryStreamExt;
/// This is our service handler. It receives a Request, routes on its
/// path, and returns a Future of a Response.
fn echo(req: Request<Body>) -> BoxFut {
let mut response = Response::new(Body::empty());
async fn echo(req: Request<Body>) -> Result<Response<Body>, hyper::Error> {
match (req.method(), req.uri().path()) {
// Serve some instructions at /
(&Method::GET, "/") => {
*response.body_mut() = Body::from("Try POSTing data to /echo");
Ok(Response::new(Body::from("Try POSTing data to /echo such as: `curl localhost:3000/echo -XPOST -d 'hello world'`")))
}
// Simply echo the body back to the client.
(&Method::POST, "/echo") => {
*response.body_mut() = req.into_body();
Ok(Response::new(req.into_body()))
}
// Convert to uppercase before sending back to client.
// Convert to uppercase before sending back to client using a stream.
(&Method::POST, "/echo/uppercase") => {
let mapping = req.into_body().map(|chunk| {
let chunk_stream = req.into_body().map_ok(|chunk| {
chunk
.iter()
.map(|byte| byte.to_ascii_uppercase())
.collect::<Vec<u8>>()
});
*response.body_mut() = Body::wrap_stream(mapping);
Ok(Response::new(Body::wrap_stream(chunk_stream)))
}
// Reverse the entire body before sending back to the client.
//
// Since we don't know the end yet, we can't simply stream
// the chunks as they arrive. So, this returns a different
// future, waiting on concatenating the full body, so that
// it can be reversed. Only then can we return a `Response`.
// the chunks as they arrive as we did with the above uppercase endpoint.
// So here we do `.await` on the future, waiting on concatenating the full body,
// then afterwards the content can be reversed. Only then can we return a `Response`.
(&Method::POST, "/echo/reversed") => {
let reversed = req.into_body().concat2().map(move |chunk| {
let body = chunk.iter().rev().cloned().collect::<Vec<u8>>();
*response.body_mut() = Body::from(body);
response
});
let whole_chunk = req.into_body().try_concat().await;
return Box::new(reversed);
let reversed_chunk = whole_chunk.map(move |chunk| {
chunk.iter().rev().cloned().collect::<Vec<u8>>()
})?;
Ok(Response::new(Body::from(reversed_chunk)))
}
// The 404 Not Found route...
// Return the 404 Not Found for other routes.
_ => {
*response.status_mut() = StatusCode::NOT_FOUND;
let mut not_found = Response::default();
*not_found.status_mut() = StatusCode::NOT_FOUND;
Ok(not_found)
}
};
Box::new(future::ok(response))
}
}
fn main() {
#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
let addr = ([127, 0, 0, 1], 3000).into();
let service = make_service_fn(|_| {
async {
Ok::<_, hyper::Error>(service_fn(echo))
}
});
let server = Server::bind(&addr)
.serve(|| service_fn(echo))
.map_err(|e| eprintln!("server error: {}", e));
.serve(service);
println!("Listening on http://{}", addr);
hyper::rt::run(server);
server.await?;
Ok(())
}