Merge pull request #237 from ahmedcharles/example

daniel-abramov · web-flow · commit a960ccbf58b0 · 2022-08-02T17:35:29.000+02:00
Add an example of using tungstenite with a custom accept.
diff --git a/Cargo.toml b/Cargo.toml
@@ -65,6 +65,7 @@ version = "0.22.1"
 
 [dev-dependencies]
 futures-channel = "0.3"
+hyper = { version = "0.14", default-features = false, features = ["http1", "server", "tcp"] }
 tokio = { version = "1.0.0", default-features = false, features = ["io-std", "macros", "net", "rt-multi-thread", "time"] }
 url = "2.0.0"
 env_logger = "0.9"
diff --git a/examples/server-custom-accept.rs b/examples/server-custom-accept.rs
@@ -0,0 +1,169 @@
+//! A chat server that broadcasts a message to all connections.
+//!
+//! This is a simple line-based server which accepts WebSocket connections,
+//! reads lines from those connections, and broadcasts the lines to all other
+//! connected clients.
+//!
+//! You can test this out by running:
+//!
+//!     cargo run --example server 127.0.0.1:12345
+//!
+//! And then in another window run:
+//!
+//!     cargo run --example client ws://127.0.0.1:12345/socket
+//!
+//! You can run the second command in multiple windows and then chat between the
+//! two, seeing the messages from the other client as they're received. For all
+//! connected clients they'll all join the same room and see everyone else's
+//! messages.
+
+use std::{
+    collections::HashMap,
+    convert::Infallible,
+    env,
+    net::SocketAddr,
+    sync::{Arc, Mutex},
+};
+
+use hyper::{
+    header::{
+        HeaderValue, CONNECTION, SEC_WEBSOCKET_ACCEPT, SEC_WEBSOCKET_KEY, SEC_WEBSOCKET_VERSION,
+        UPGRADE,
+    },
+    server::conn::AddrStream,
+    service::{make_service_fn, service_fn},
+    upgrade::Upgraded,
+    Body, Method, Request, Response, Server, StatusCode, Version,
+};
+
+use futures_channel::mpsc::{unbounded, UnboundedSender};
+use futures_util::{future, pin_mut, stream::TryStreamExt, StreamExt};
+
+use tokio_tungstenite::WebSocketStream;
+use tungstenite::{
+    handshake::derive_accept_key,
+    protocol::{Message, Role},
+};
+
+type Tx = UnboundedSender<Message>;
+type PeerMap = Arc<Mutex<HashMap<SocketAddr, Tx>>>;
+
+async fn handle_connection(
+    peer_map: PeerMap,
+    ws_stream: WebSocketStream<Upgraded>,
+    addr: SocketAddr,
+) {
+    println!("WebSocket connection established: {}", addr);
+
+    // Insert the write part of this peer to the peer map.
+    let (tx, rx) = unbounded();
+    peer_map.lock().unwrap().insert(addr, tx);
+
+    let (outgoing, incoming) = ws_stream.split();
+
+    let broadcast_incoming = incoming.try_for_each(|msg| {
+        println!("Received a message from {}: {}", addr, msg.to_text().unwrap());
+        let peers = peer_map.lock().unwrap();
+
+        // We want to broadcast the message to everyone except ourselves.
+        let broadcast_recipients =
+            peers.iter().filter(|(peer_addr, _)| peer_addr != &&addr).map(|(_, ws_sink)| ws_sink);
+
+        for recp in broadcast_recipients {
+            recp.unbounded_send(msg.clone()).unwrap();
+        }
+
+        future::ok(())
+    });
+
+    let receive_from_others = rx.map(Ok).forward(outgoing);
+
+    pin_mut!(broadcast_incoming, receive_from_others);
+    future::select(broadcast_incoming, receive_from_others).await;
+
+    println!("{} disconnected", &addr);
+    peer_map.lock().unwrap().remove(&addr);
+}
+
+async fn handle_request(
+    peer_map: PeerMap,
+    mut req: Request<Body>,
+    addr: SocketAddr,
+) -> Result<Response<Body>, Infallible> {
+    println!("Received a new, potentially ws handshake");
+    println!("The request's path is: {}", req.uri().path());
+    println!("The request's headers are:");
+    for (ref header, _value) in req.headers() {
+        println!("* {}", header);
+    }
+    let upgrade = HeaderValue::from_static("Upgrade");
+    let websocket = HeaderValue::from_static("websocket");
+    let headers = req.headers();
+    let key = headers.get(SEC_WEBSOCKET_KEY);
+    let derived = key.map(|k| derive_accept_key(k.as_bytes()));
+    if req.method() != Method::GET
+        || req.version() < Version::HTTP_11
+        || !headers
+            .get(CONNECTION)
+            .and_then(|h| h.to_str().ok())
+            .map(|h| {
+                h.split(|c| c == ' ' || c == ',')
+                    .any(|p| p.eq_ignore_ascii_case(upgrade.to_str().unwrap()))
+            })
+            .unwrap_or(false)
+        || !headers
+            .get(UPGRADE)
+            .and_then(|h| h.to_str().ok())
+            .map(|h| h.eq_ignore_ascii_case("websocket"))
+            .unwrap_or(false)
+        || !headers.get(SEC_WEBSOCKET_VERSION).map(|h| h == "13").unwrap_or(false)
+        || key.is_none()
+        || req.uri() != "/socket"
+    {
+        return Ok(Response::new(Body::from("Hello World!")));
+    }
+    let ver = req.version();
+    tokio::task::spawn(async move {
+        match hyper::upgrade::on(&mut req).await {
+            Ok(upgraded) => {
+                handle_connection(
+                    peer_map,
+                    WebSocketStream::from_raw_socket(upgraded, Role::Server, None).await,
+                    addr,
+                )
+                .await;
+            }
+            Err(e) => println!("upgrade error: {}", e),
+        }
+    });
+    let mut res = Response::new(Body::empty());
+    *res.status_mut() = StatusCode::SWITCHING_PROTOCOLS;
+    *res.version_mut() = ver;
+    res.headers_mut().append(CONNECTION, upgrade);
+    res.headers_mut().append(UPGRADE, websocket);
+    res.headers_mut().append(SEC_WEBSOCKET_ACCEPT, derived.unwrap().parse().unwrap());
+    // Let's add an additional header to our response to the client.
+    res.headers_mut().append("MyCustomHeader", ":)".parse().unwrap());
+    res.headers_mut().append("SOME_TUNGSTENITE_HEADER", "header_value".parse().unwrap());
+    Ok(res)
+}
+
+#[tokio::main]
+async fn main() -> Result<(), hyper::Error> {
+    let state = PeerMap::new(Mutex::new(HashMap::new()));
+
+    let addr = env::args().nth(1).unwrap_or_else(|| "127.0.0.1:8080".to_string()).parse().unwrap();
+
+    let make_svc = make_service_fn(move |conn: &AddrStream| {
+        let remote_addr = conn.remote_addr();
+        let state = state.clone();
+        let service = service_fn(move |req| handle_request(state.clone(), req, remote_addr));
+        async { Ok::<_, Infallible>(service) }
+    });
+
+    let server = Server::bind(&addr).serve(make_svc);
+
+    server.await?;
+
+    Ok::<_, hyper::Error>(())
+}
