Update examples to async/await

examples/proxy.rs

@@ -0,0 +1,48 @@
+#![feature(async_await)]
+#![deny(warnings)]
+
+use hyper::{Client, Error, Server};
+use hyper::service::{make_service_fn, service_fn};
+use std::net::SocketAddr;
+
+#[hyper::rt::main]
+async fn main() {
+    pretty_env_logger::init();
+
+    let in_addr = ([127, 0, 0, 1], 3001).into();
+    let out_addr: SocketAddr = ([127, 0, 0, 1], 3000).into();
+
+    let client_main = Client::new();
+
+    let out_addr_clone = out_addr.clone();
+
+    // The closure inside `make_service_fn` is run for each connection,
+    // creating a 'service' to handle requests for that specific connection.
+    let make_service = make_service_fn(move |_| {
+        let client = client_main.clone();
+
+        async move {
+            // This is the `Service` that will handle the connection.
+            // `service_fn` is a helper to convert a function that
+            // returns a Response into a `Service`.
+            Ok::<_, Error>(service_fn(move |mut req| {
+                let uri_string = format!("http://{}/{}",
+                                         out_addr_clone,
+                                         req.uri().path_and_query().map(|x| x.as_str()).unwrap_or(""));
+                let uri = uri_string.parse().unwrap();
+                *req.uri_mut() = uri;
+                client.request(req)
+            }))
+        }
+    });
+
+    let server = Server::bind(&in_addr)
+        .serve(make_service);
+
+    println!("Listening on http://{}", in_addr);
+    println!("Proxying on http://{}", out_addr);
+
+    if let Err(e) = server.await {
+        eprintln!("server error: {}", e);
+    }
+}

examples/single_threaded.rs

@@ -0,0 +1,55 @@
+#![feature(async_await)]
+#![deny(warnings)]
+
+use std::cell::Cell;
+use std::rc::Rc;
+
+use hyper::{Body, Error, Response, Server};
+use hyper::service::{make_service_fn, service_fn};
+use tokio::runtime::current_thread;
+
+// Configure a runtime that runs everything on the current thread,
+// which means it can spawn !Send futures...
+#[hyper::rt::main(single_thread)]
+async fn main() {
+    pretty_env_logger::init();
+
+    let addr = ([127, 0, 0, 1], 3000).into();
+
+    // Using a !Send request counter is fine on 1 thread...
+    let counter = Rc::new(Cell::new(0));
+
+    let make_service = make_service_fn(move |_| {
+        // For each connection, clone the counter to use in our service...
+        let cnt = counter.clone();
+
+        async move {
+            Ok::<_, Error>(service_fn(move |_| {
+                let prev = cnt.get();
+                cnt.set(prev + 1);
+                let value = cnt.get();
+                async move {
+                    Ok::<_, Error>(Response::new(Body::from(
+                        format!("Request #{}", value)
+                    )))
+                }
+            }))
+        }
+    });
+
+    // Since the Server needs to spawn some background tasks, we needed
+    // to configure an Executor that can spawn !Send futures...
+    let exec = current_thread::TaskExecutor::current();
+
+    let server = Server::bind(&addr)
+        .executor(exec)
+        .serve(make_service);
+
+    println!("Listening on http://{}", addr);
+
+    // The server would block on current thread to await !Send futures.
+    if let Err(e) = server.await {
+        eprintln!("server error: {}", e);
+    }
+}
+

examples/state.rs

@@ -0,0 +1,56 @@
+#![feature(async_await)]
+#![deny(warnings)]
+
+use std::sync::{Arc, atomic::{AtomicUsize, Ordering}};
+
+use hyper::{Body, Error, Response, Server};
+use hyper::service::{make_service_fn, service_fn};
+
+#[hyper::rt::main]
+async fn main() {
+    pretty_env_logger::init();
+
+    let addr = ([127, 0, 0, 1], 3000).into();
+
+    // For the most basic of state, we just share a counter, that increments
+    // with each request, and we send its value back in the response.
+    let counter = Arc::new(AtomicUsize::new(0));
+
+    // The closure inside `make_service_fn` is run for each connection,
+    // creating a 'service' to handle requests for that specific connection.
+    let make_service = make_service_fn(move |_| {
+        // While the state was moved into the make_service closure,
+        // we need to clone it here because this closure is called
+        // once for every connection.
+        //
+        // Each connection could send multiple requests, so
+        // the `Service` needs a clone to handle later requests.
+        let counter = counter.clone();
+
+        async move {
+            // This is the `Service` that will handle the connection.
+            // `service_fn` is a helper to convert a function that
+            // returns a Response into a `Service`.
+            Ok::<_, Error>(service_fn(move |_req| {
+                // Get the current count, and also increment by 1, in a single
+                // atomic operation.
+                let count = counter.fetch_add(1, Ordering::AcqRel);
+                async move {
+                    Ok::<_, Error>(
+                        Response::new(Body::from(format!("Request #{}", count)))
+                    )
+                }
+            }))
+        }
+    });
+
+    let server = Server::bind(&addr)
+        .serve(make_service);
+
+    println!("Listening on http://{}", addr);
+
+    if let Err(e) = server.await {
+        eprintln!("server error: {}", e);
+    }
+}
+

examples/upgrades.rs

@@ -0,0 +1,154 @@
+#![feature(async_await)]
+#![deny(warnings)]
+
+// Note: `hyper::upgrade` docs link to this upgrade.
+use std::str;
+
+use tokio::sync::oneshot;
+use tokio::io::{AsyncReadExt, AsyncWriteExt};
+
+use hyper::{Body, Client, Request, Response, Server, StatusCode};
+use hyper::header::{UPGRADE, HeaderValue};
+use hyper::service::{make_service_fn, service_fn};
+use hyper::upgrade::Upgraded;
+use std::net::SocketAddr;
+
+// A simple type alias so as to DRY.
+type Result<T> = std::result::Result<T, Box<dyn std::error::Error + Send + Sync>>;
+
+/// Handle server-side I/O after HTTP upgraded.
+async fn server_upgraded_io(mut upgraded: Upgraded) -> Result<()> {
+    // we have an upgraded connection that we can read and
+    // write on directly.
+    //
+    // since we completely control this example, we know exactly
+    // how many bytes the client will write, so just read exact...
+    let mut vec = vec![0; 7];
+    upgraded.read_exact(&mut vec).await?;
+    println!("server[foobar] recv: {:?}", str::from_utf8(&vec));
+
+    // and now write back the server 'foobar' protocol's
+    // response...
+    upgraded.write_all(b"barr=foo").await?;
+    println!("server[foobar] sent");
+    Ok(())
+}
+
+/// Our server HTTP handler to initiate HTTP upgrades.
+async fn server_upgrade(req: Request<Body>) -> Result<Response<Body>> {
+    let mut res = Response::new(Body::empty());
+
+    // Send a 400 to any request that doesn't have
+    // an `Upgrade` header.
+    if !req.headers().contains_key(UPGRADE) {
+        *res.status_mut() = StatusCode::BAD_REQUEST;
+        return Ok(res);
+    }
+
+    // Setup a future that will eventually receive the upgraded
+    // connection and talk a new protocol, and spawn the future
+    // into the runtime.
+    //
+    // Note: This can't possibly be fulfilled until the 101 response
+    // is returned below, so it's better to spawn this future instead
+    // waiting for it to complete to then return a response.
+    hyper::rt::spawn(async move {
+        match req.into_body().on_upgrade().await {
+            Ok(upgraded) => {
+                if let Err(e) = server_upgraded_io(upgraded).await {
+                    eprintln!("server foobar io error: {}", e)
+                };
+            }
+            Err(e) => eprintln!("upgrade error: {}", e)
+        }
+    });
+
+    // Now return a 101 Response saying we agree to the upgrade to some
+    // made-up 'foobar' protocol.
+    *res.status_mut() = StatusCode::SWITCHING_PROTOCOLS;
+    res.headers_mut().insert(UPGRADE, HeaderValue::from_static("foobar"));
+    Ok(res)
+}
+
+/// Handle client-side I/O after HTTP upgraded.
+async fn client_upgraded_io(mut upgraded: Upgraded) -> Result<()> {
+    // We've gotten an upgraded connection that we can read
+    // and write directly on. Let's start out 'foobar' protocol.
+    upgraded.write_all(b"foo=bar").await?;
+    println!("client[foobar] sent");
+
+    let mut vec = Vec::new();
+    upgraded.read_to_end(&mut vec).await?;
+    println!("client[foobar] recv: {:?}", str::from_utf8(&vec));
+
+    Ok(())
+}
+
+/// Our client HTTP handler to initiate HTTP upgrades.
+async fn client_upgrade_request(addr: SocketAddr) -> Result<()> {
+    let req = Request::builder()
+        .uri(format!("http://{}/", addr))
+        .header(UPGRADE, "foobar")
+        .body(Body::empty())
+        .unwrap();
+
+    let res = Client::new().request(req).await?;
+    if res.status() != StatusCode::SWITCHING_PROTOCOLS {
+        panic!("Our server didn't upgrade: {}", res.status());
+    }
+
+    match res.into_body().on_upgrade().await {
+        Ok(upgraded) => {
+            if let Err(e) = client_upgraded_io(upgraded).await {
+                eprintln!("client foobar io error: {}", e)
+            };
+        }
+        Err(e) => eprintln!("upgrade error: {}", e)
+    }
+
+    Ok(())
+}
+
+#[hyper::rt::main]
+async fn main() {
+    // For this example, we just make a server and our own client to talk to
+    // it, so the exact port isn't important. Instead, let the OS give us an
+    // unused port.
+    let addr = ([127, 0, 0, 1], 0).into();
+
+    let make_service = make_service_fn(|_| async {
+        Ok::<_, hyper::Error>(service_fn(server_upgrade))
+    });
+
+    let server = Server::bind(&addr)
+        .serve(make_service);
+
+    // We need the assigned address for the client to send it messages.
+    let addr = server.local_addr();
+
+    // For this example, a oneshot is used to signal that after 1 request,
+    // the server should be shutdown.
+    let (tx, rx) = oneshot::channel::<()>();
+    let server = server
+        .with_graceful_shutdown(async {
+            rx.await.ok();
+        });
+
+    // Spawn server on the default executor,
+    // which is usually a thread-pool from tokio default runtime.
+    hyper::rt::spawn(async {
+        if let Err(e) = server.await {
+            eprintln!("server error: {}", e);
+        }
+    });
+
+    // Client requests a HTTP connection upgrade.
+    let request = client_upgrade_request(addr.clone());
+    if let Err(e) = request.await {
+        eprintln!("client error: {}", e);
+    }
+
+    // Complete the oneshot so that the server stops
+    // listening and the process can close down.
+    let _ = tx.send(());
+}