Files
hyper/examples/send_file.rs
Sean McArthur 2dc6202fe7 feat(service): introduce hyper-specific Service
This introduces the `hyper::service` module, which replaces
`tokio-service`.

Since the trait is specific to hyper, its associated
types have been adjusted. It didn't make sense to need to define
`Service<Request=http::Request>`, since we already know the context is
HTTP. Instead, the request and response bodies are associated types now,
and slightly stricter bounds have been placed on `Error`.

The helpers `service_fn` and `service_fn_ok` should be sufficient for
now to ease creating `Service`s.

The `NewService` trait now allows service creation to also be
asynchronous.

These traits are similar to `tower` in nature, and possibly will be
replaced completely by it in the future. For now, hyper defining its own
allows the traits to have better context, and prevents breaking changes
in `tower` from affecting hyper.

Closes #1461

BREAKING CHANGE: The `Service` trait has changed: it has some changed
  associated types, and `call` is now bound to `&mut self`.

  The `NewService` trait has changed: it has some changed associated
  types, and `new_service` now returns a `Future`.

  `Client` no longer implements `Service` for now.

  `hyper::server::conn::Serve` now returns `Connecting` instead of
  `Connection`s, since `new_service` can now return a `Future`. The
  `Connecting` is a future wrapping the new service future, returning
  a `Connection` afterwards. In many cases, `Future::flatten` can be
  used.
2018-04-17 17:09:15 -07:00

145 lines
5.0 KiB
Rust

#![deny(warnings)]
extern crate futures;
extern crate hyper;
extern crate pretty_env_logger;
extern crate tokio;
use futures::{future, Future};
use futures::sync::oneshot;
use hyper::{Body, Method, Request, Response, Server, StatusCode};
use hyper::service::service_fn;
use std::fs::File;
use std::io::{self, copy/*, Read*/};
use std::thread;
static NOTFOUND: &[u8] = b"Not Found";
static INDEX: &str = "examples/send_file_index.html";
fn main() {
pretty_env_logger::init();
let addr = "127.0.0.1:1337".parse().unwrap();
let server = Server::bind(&addr)
.serve(|| service_fn(response_examples))
.map_err(|e| eprintln!("server error: {}", e));
println!("Listening on http://{}", addr);
tokio::run(server);
}
type ResponseFuture = Box<Future<Item=Response<Body>, Error=io::Error> + Send>;
fn response_examples(req: Request<Body>) -> ResponseFuture {
match (req.method(), req.uri().path()) {
(&Method::GET, "/") | (&Method::GET, "/index.html") => {
simple_file_send(INDEX)
},
(&Method::GET, "/big_file.html") => {
// Stream a large file in chunks. This requires a
// little more overhead with two channels, (one for
// the response future, and a second for the response
// body), but can handle arbitrarily large files.
//
// We use an artificially small buffer, since we have
// a small test file.
let (tx, rx) = oneshot::channel();
thread::spawn(move || {
let _file = match File::open(INDEX) {
Ok(f) => f,
Err(_) => {
tx.send(Response::builder()
.status(StatusCode::NOT_FOUND)
.body(NOTFOUND.into())
.unwrap())
.expect("Send error on open");
return;
},
};
let (_tx_body, rx_body) = Body::channel();
let res = Response::new(rx_body.into());
tx.send(res).expect("Send error on successful file read");
/* TODO: fix once we have futures 0.2 Sink working
let mut buf = [0u8; 16];
loop {
match file.read(&mut buf) {
Ok(n) => {
if n == 0 {
// eof
tx_body.close().expect("panic closing");
break;
} else {
let chunk: Chunk = buf[0..n].to_vec().into();
match tx_body.send_data(chunk).wait() {
Ok(t) => { tx_body = t; },
Err(_) => { break; }
};
}
},
Err(_) => { break; }
}
}
*/
});
Box::new(rx.map_err(|e| io::Error::new(io::ErrorKind::Other, e)))
},
(&Method::GET, "/no_file.html") => {
// Test what happens when file cannot be be found
simple_file_send("this_file_should_not_exist.html")
},
_ => {
Box::new(future::ok(Response::builder()
.status(StatusCode::NOT_FOUND)
.body(Body::empty())
.unwrap()))
}
}
}
fn simple_file_send(f: &str) -> ResponseFuture {
// Serve a file by reading it entirely into memory. As a result
// this is limited to serving small files, but it is somewhat
// simpler with a little less overhead.
//
// On channel errors, we panic with the expect method. The thread
// ends at that point in any case.
let filename = f.to_string(); // we need to copy for lifetime issues
let (tx, rx) = oneshot::channel();
thread::spawn(move || {
let mut file = match File::open(filename) {
Ok(f) => f,
Err(_) => {
tx.send(Response::builder()
.status(StatusCode::NOT_FOUND)
.body(NOTFOUND.into())
.unwrap())
.expect("Send error on open");
return;
},
};
let mut buf: Vec<u8> = Vec::new();
match copy(&mut file, &mut buf) {
Ok(_) => {
let res = Response::new(buf.into());
tx.send(res).expect("Send error on successful file read");
},
Err(_) => {
tx.send(Response::builder()
.status(StatusCode::INTERNAL_SERVER_ERROR)
.body(Body::empty())
.unwrap())
.expect("Send error on error reading file");
},
};
});
Box::new(rx.map_err(|e| io::Error::new(io::ErrorKind::Other, e)))
}