Merge pull request #67 from iamjpotts/20240319-improve-example

Examples: Add additional logging of accepted connections

examples/server.rs

@@ -1,9 +1,9 @@
 use hyper::{service::service_fn, Response};
 use hyper_util::rt::TokioIo;
-use std::{error::Error, fs, path::Path};
+use std::{error::Error, fs, io::ErrorKind, path::Path};
 use tokio::net::UnixListener;
 
-const PHRASE: &str = "It's a Unix system. I know this.";
+const PHRASE: &str = "It's a Unix system. I know this.\n";
 
 // Adapted from https://hyper.rs/guides/1/server/hello-world/
 #[tokio::main]
@@ -16,16 +16,25 @@ async fn main() -> Result<(), Box<dyn Error + Send + Sync>> {
 
     let listener = UnixListener::bind(path)?;
 
+    println!("Listening for connections at {}.", path.display());
+
     loop {
         let (stream, _) = listener.accept().await?;
         let io = TokioIo::new(stream);
 
+        println!("Accepting connection.");
+
         tokio::task::spawn(async move {
             let svc_fn = service_fn(|_req| async {
                 let body = PHRASE.to_string();
                 Ok::<_, hyper::Error>(Response::new(body))
             });
 
+            // On linux, serve_connection will return right away with Result::Ok.
+            //
+            // On OSX, serve_connection will block until the client disconnects,
+            // and return Result::Err(hyper::Error) with a source (inner/cause)
+            // socket error indicating the client connection is no longer open.
             match hyper::server::conn::http1::Builder::new()
                 .serve_connection(io, svc_fn)
                 .await
@@ -34,7 +43,17 @@ async fn main() -> Result<(), Box<dyn Error + Send + Sync>> {
                     println!("Accepted connection.");
                 }
                 Err(err) => {
-                    eprintln!("Failed to accept connection: {err:?}");
+                    let source: Option<&std::io::Error> =
+                        err.source().and_then(|s| s.downcast_ref());
+
+                    match source {
+                        Some(io_err) if io_err.kind() == ErrorKind::NotConnected => {
+                            println!("Client disconnected.");
+                        }
+                        _ => {
+                            eprintln!("Failed to accept connection: {err:?}");
+                        }
+                    }
                 }
             };
         });