Try update example echo - WIP

Fuyang Liu · Fuyang Liu · commit 5fddaa2b061c · 2019-07-10T22:37:26.000+02:00
diff --git a/examples/echo.rs b/examples/echo.rs
@@ -1,23 +1,17 @@
+#![feature(async_await)]
 #![deny(warnings)]
-extern crate futures;
+
 extern crate hyper;
 
-use futures::future;
-use hyper::rt::{Future, Stream};
-use hyper::service::service_fn;
-use hyper::{Body, Method, Request, Response, Server, StatusCode};
+use futures_util::stream::StreamExt; // TODO: is this correct or?
 
-/// We need to return different futures depending on the route matched,
-/// and we can do that with an enum, such as `futures::Either`, or with
-/// trait objects.
-///
-/// A boxed Future (trait object) is used as it is easier to understand
-/// and extend with more types. Advanced users could switch to `Either`.
-type BoxFut = Box<dyn Future<Item = Response<Body>, Error = hyper::Error> + Send>;
+use hyper::{Body, Method, Request, Response, Server, StatusCode};
+use hyper::service::{make_service_fn, service_fn};
+use hyper::body::Chunk;
 
 /// This is our service handler. It receives a Request, routes on its
 /// path, and returns a Future of a Response.
-fn echo(req: Request<Body>) -> BoxFut {
+async fn echo(req: Request<Body>) -> Result<Response<Body>, hyper::Error> {
     let mut response = Response::new(Body::empty());
 
     match (req.method(), req.uri().path()) {
@@ -34,13 +28,15 @@ fn echo(req: Request<Body>) -> BoxFut {
         // Convert to uppercase before sending back to client.
         (&Method::POST, "/echo/uppercase") => {
             let mapping = req.into_body().map(|chunk| {
-                chunk
+                let chunk= chunk.unwrap();
+                let x = chunk
                     .iter()
                     .map(|byte| byte.to_ascii_uppercase())
-                    .collect::<Vec<u8>>()
-            });
+                    .collect::<Vec<_>>();
+                x
+            }).collect::<Vec<_>>().await;
 
-            *response.body_mut() = Body::wrap_stream(mapping);
+            *response.body_mut() = Body::from(mapping);
         }
 
         // Reverse the entire body before sending back to the client.
@@ -49,32 +45,42 @@ fn echo(req: Request<Body>) -> BoxFut {
         // the chunks as they arrive. So, this returns a different
         // future, waiting on concatenating the full body, so that
         // it can be reversed. Only then can we return a `Response`.
-        (&Method::POST, "/echo/reversed") => {
-            let reversed = req.into_body().concat2().map(move |chunk| {
-                let body = chunk.iter().rev().cloned().collect::<Vec<u8>>();
-                *response.body_mut() = Body::from(body);
-                response
-            });
-
-            return Box::new(reversed);
-        }
+//        (&Method::POST, "/echo/reversed") => {
+//            let reversed = req.into_body().concat2().map(move |chunk| {
+//                let body = chunk.iter().rev().cloned().collect::<Vec<u8>>();
+//                *response.body_mut() = Body::from(body);
+//                response
+//            });
+//
+//            return Ok(reversed);
+//        }
 
         // The 404 Not Found route...
         _ => {
             *response.status_mut() = StatusCode::NOT_FOUND;
         }
     };
 
-    Box::new(future::ok(response))
+    Ok(response)
 }
 
-fn main() {
+
+#[tokio::main]
+async fn main() -> Result<(), Box<dyn std::error::Error>> {
     let addr = ([127, 0, 0, 1], 3000).into();
 
+    let service = make_service_fn(|_| {
+        async {
+            Ok::<_, hyper::Error>(service_fn(echo))
+        }
+    });
+
     let server = Server::bind(&addr)
-        .serve(|| service_fn(echo))
-        .map_err(|e| eprintln!("server error: {}", e));
+        .serve(service);
 
     println!("Listening on http://{}", addr);
-    hyper::rt::run(server);
+
+    server.await?;
+
+    Ok(())
 }
