examples/send_file.rs

#![deny(warnings)]
extern crate futures;
extern crate hyper;
extern crate pretty_env_logger;
extern crate tokio_fs;
extern crate tokio_io;

use futures::{future, Future};

use hyper::{Body, Method, Request, Response, Server, StatusCode};
use hyper::service::service_fn;

use std::io;

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);

    hyper::rt::run(server);
}

type ResponseFuture = Box<dyn 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") | (&Method::GET, "/big_file.html") => {
            simple_file_send(INDEX)
        },
        (&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 asynchronously reading it entirely into memory.
    // Uses tokio_fs to open file asynchronously, then tokio_io to read into
    // memory asynchronously.
    let filename = f.to_string(); // we need to copy for lifetime issues
    Box::new(tokio_fs::file::File::open(filename)
        .and_then(|file| {
            let buf: Vec<u8> = Vec::new();
            tokio_io::io::read_to_end(file, buf)
                .and_then(|item| {
                    Ok(Response::new(item.1.into()))
                })
                .or_else(|_| {
                    Ok(Response::builder()
                        .status(StatusCode::INTERNAL_SERVER_ERROR)
                        .body(Body::empty())
                        .unwrap())
                })
        })
        .or_else(|_| {
            Ok(Response::builder()
                .status(StatusCode::NOT_FOUND)
                .body(NOTFOUND.into())
                .unwrap())
        }))
}