add actorless websocket echo example

Cargo.lock

@@ -571,6 +571,19 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "actix-ws"
+version = "0.2.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "535aec173810be3ca6f25dd5b4d431ae7125d62000aa3cbae1ec739921b02cf3"
+dependencies = [
+ "actix-codec",
+ "actix-http",
+ "actix-web",
+ "futures-core",
+ "tokio 1.19.2",
+]
+
 [[package]]
 name = "actix_derive"
 version = "0.6.0"
@@ -7034,6 +7047,21 @@ dependencies = [
  "rand 0.8.5",
 ]
 
+[[package]]
+name = "websocket-echo-actorless-example"
+version = "1.0.0"
+dependencies = [
+ "actix-files",
+ "actix-web",
+ "actix-ws",
+ "awc",
+ "env_logger 0.9.0",
+ "futures-util",
+ "log",
+ "tokio 1.19.2",
+ "tokio-stream",
+]
+
 [[package]]
 name = "websocket-example"
 version = "1.0.0"

Cargo.toml

@@ -56,6 +56,7 @@ members = [
    "websockets/chat-broker",
    "websockets/chat-tcp",
    "websockets/chat",
+   "websockets/echo-actorless",
    "websockets/echo",
 ]
 exclude = [

templating/fluent/src/lang_choice.rs

@@ -18,7 +18,6 @@ impl LangChoice {
         let lang = req
             .get_header::<AcceptLanguage>()
             .and_then(|lang| lang.preference().into_item())
-            .map(|lang| lang.to_string())
             .map_or_else(|| "en".to_owned(), |lang| lang.to_string());
 
         Self(lang)

websockets/echo-actorless/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "websocket-echo-actorless-example"
+version = "1.0.0"
+edition = "2021"
+
+[dependencies]
+actix-files = "0.6"
+actix-web = "4"
+actix-ws = "0.2.5"
+awc = "3"
+
+env_logger = "0.9"
+futures-util = { version = "0.3.7", default-features = false, features = ["std", "sink"] }
+log = "0.4"
+tokio = { version = "1.13.1", features = ["full"] }
+tokio-stream = "0.1.8"

websockets/echo-actorless/README.md

@@ -0,0 +1,26 @@
+# Echo WebSocket (actor-less)
+
+Simple echo websocket server using [`actix-ws`].
+
+## Usage
+
+### Server
+
+```sh
+cd websockets/echo-actorless
+cargo run
+# starting HTTP server at http://localhost:8080
+```
+
+### Web Client
+
+Go to <http://localhost:8080/> in a browser.
+
+### CLI Client
+
+```sh
+# using `websocat` (https://github.com/vi/websocat)
+websocat -v --ping-interval=2 ws://127.0.0.1:8080/ws
+```
+
+[`actix-ws`]: https://crates.io/crates/actix-ws

websockets/echo-actorless/src/handler.rs

@@ -0,0 +1,116 @@
+use std::time::{Duration, Instant};
+
+use actix_web::rt;
+use actix_ws::Message;
+use futures_util::stream::StreamExt as _;
+use tokio::select;
+
+/// How often heartbeat pings are sent
+const HEARTBEAT_INTERVAL: Duration = Duration::from_secs(5);
+
+/// How long before lack of client response causes a timeout
+const CLIENT_TIMEOUT: Duration = Duration::from_secs(10);
+
+/// Echo text & binary messages received from the client, respond to ping messages, and monitor
+/// connection health to detect network issues and free up resources.
+pub async fn echo_heartbeat_ws(
+    mut session: actix_ws::Session,
+    mut msg_stream: actix_ws::MessageStream,
+) {
+    log::info!("connected");
+
+    let mut last_heartbeat = Instant::now();
+
+    let mut interval = rt::time::interval(HEARTBEAT_INTERVAL);
+
+    loop {
+        select! {
+            Some(Ok(msg)) = msg_stream.next() => {
+                log::debug!("msg: {msg:?}");
+
+                match msg {
+                    Message::Ping(bytes) => {
+                        last_heartbeat = Instant::now();
+                        let _ = session.pong(&bytes).await;
+                    }
+
+                    Message::Pong(_) => {
+                        last_heartbeat = Instant::now();
+                    }
+
+                    Message::Text(text) => {
+                        session.text(text).await.unwrap();
+                    }
+
+                    Message::Binary(bin) => {
+                        session.binary(bin).await.unwrap();
+                    }
+
+                    Message::Close(reason) => {
+                        let _ = session.close(reason).await;
+                        break;
+                    }
+
+                    _ => {
+                        let _ = session.close(None).await;
+                        break;
+                    }
+                }
+            }
+
+            _ = interval.tick() => {
+                // if no heartbeat ping/pong received recently, close the connection
+                if Instant::now().duration_since(last_heartbeat) > CLIENT_TIMEOUT {
+                    log::info!("client has not sent heartbeat in over {CLIENT_TIMEOUT:?}; disconnecting");
+                    let _ = session.close(None).await;
+                    break;
+                }
+
+                // send heartbeat ping
+                let _ = session.ping(b"").await;
+
+                // reset interval duration
+                interval.reset();
+            }
+        };
+    }
+}
+
+/// Echo text & binary messages received from the client and respond to ping messages.
+///
+/// This example is just for demonstration of simplicity. In reality, you likely want to include
+/// some handling of heartbeats for connection health tracking to free up server resources when
+/// connections die or network issues arise.
+pub async fn echo_ws(mut session: actix_ws::Session, mut msg_stream: actix_ws::MessageStream) {
+    log::info!("connected");
+
+    while let Some(Ok(msg)) = msg_stream.next().await {
+        log::debug!("msg: {msg:?}");
+
+        match msg {
+            Message::Ping(bytes) => {
+                let _ = session.pong(&bytes).await;
+            }
+
+            Message::Pong(_) => {}
+
+            Message::Text(text) => {
+                session.text(text).await.unwrap();
+            }
+
+            Message::Binary(bin) => {
+                session.binary(bin).await.unwrap();
+            }
+
+            Message::Close(reason) => {
+                let _ = session.close(reason).await;
+                break;
+            }
+
+            _ => {
+                let _ = session.close(None).await;
+                break;
+            }
+        }
+    }
+}

websockets/echo-actorless/src/main.rs

@@ -0,0 +1,60 @@
+//! Simple echo websocket server.
+//!
+//! Open `http://localhost:8080/` in browser to test.
+
+use actix_files::NamedFile;
+use actix_web::{
+    middleware, rt, web, App, Error, HttpRequest, HttpResponse, HttpServer, Responder,
+};
+
+mod handler;
+
+async fn index() -> impl Responder {
+    NamedFile::open_async("./static/index.html").await.unwrap()
+}
+
+/// Handshake and start WebSocket handler with heartbeats.
+async fn echo_heartbeat_ws(req: HttpRequest, stream: web::Payload) -> Result<HttpResponse, Error> {
+    let (res, session, msg_stream) = actix_ws::handle(&req, stream)?;
+
+    // spawn websocket handler (and don't await it) so that the response is returned immediately
+    rt::spawn(handler::echo_heartbeat_ws(session, msg_stream));
+
+    Ok(res)
+}
+
+/// Handshake and start basic WebSocket handler.
+///
+/// This example is just for demonstration of simplicity. In reality, you likely want to include
+/// some handling of heartbeats for connection health tracking to free up server resources when
+/// connections die or network issues arise.
+async fn echo_ws(req: HttpRequest, stream: web::Payload) -> Result<HttpResponse, Error> {
+    let (res, session, msg_stream) = actix_ws::handle(&req, stream)?;
+
+    // spawn websocket handler (and don't await it) so that the response is returned immediately
+    rt::spawn(handler::echo_ws(session, msg_stream));
+
+    Ok(res)
+}
+
+#[actix_web::main]
+async fn main() -> std::io::Result<()> {
+    env_logger::init_from_env(env_logger::Env::new().default_filter_or("info"));
+
+    log::info!("starting HTTP server at http://localhost:8080");
+
+    HttpServer::new(|| {
+        App::new()
+            // WebSocket UI HTML file
+            .service(web::resource("/").to(index))
+            // websocket routes
+            .service(web::resource("/ws").route(web::get().to(echo_heartbeat_ws)))
+            .service(web::resource("/ws-basic").route(web::get().to(echo_ws)))
+            // enable logger
+            .wrap(middleware::Logger::default())
+    })
+    .workers(2)
+    .bind(("127.0.0.1", 8080))?
+    .run()
+    .await
+}

websockets/echo-actorless/static/index.html

@@ -0,0 +1 @@
+../../echo/static/index.html