src/bin/h2client.rs: switch to async

Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>

src/bin/h2client.rs

@@ -1,10 +1,14 @@
+use std::future::Future;
+use std::pin::Pin;
+use std::task::{Context, Poll};
+
 use failure::*;
-use futures::*;
+use futures::future::TryFutureExt;
+use futures::stream::Stream;
+use tokio::net::TcpStream;
 
 // Simple H2 client to test H2 download speed using h2server.rs
 
-use tokio::net::TcpStream;
-
 struct Process {
     body: h2::RecvStream,
     trailers: bool,
@@ -12,28 +16,32 @@ struct Process {
 }
 
 impl Future for Process {
-    type Item = usize;
-    type Error = Error;
+    type Output = Result<usize, Error>;
+
+    fn poll(self: Pin<&mut Self>, cx: &mut Context) -> Poll<Self::Output> {
+        let this = self.get_mut();
 
-    fn poll(&mut self) -> Poll<usize, Error> {
         loop {
-            if self.trailers {
-                let trailers = try_ready!(self.body.poll_trailers());
-                if let Some(trailers) = trailers {
-                    println!("trailers: {:?}", trailers);
+            if this.trailers {
+                match futures::ready!(this.body.poll_trailers(cx)) {
+                    Ok(Some(trailers)) => println!("trailers: {:?}", trailers),
+                    Ok(None) => (),
+                    Err(err) => return Poll::Ready(Err(Error::from(err))),
                 }
-                println!("Received {} bytes", self.bytes);
 
-                return Ok(Async::Ready(self.bytes));
+                println!("Received {} bytes", this.bytes);
+
+                return Poll::Ready(Ok(this.bytes));
             } else {
-                match try_ready!(self.body.poll()) {
-                    Some(chunk) => {
-                        self.body.release_capacity().release_capacity(chunk.len())?;
-                        self.bytes += chunk.len();
+                match futures::ready!(Pin::new(&mut this.body).poll_next(cx)) {
+                    Some(Ok(chunk)) => {
+                        this.body.release_capacity().release_capacity(chunk.len())?;
+                        this.bytes += chunk.len();
                         // println!("GOT FRAME {}", chunk.len());
                     },
+                    Some(Err(err)) => return Poll::Ready(Err(Error::from(err))),
                     None => {
-                        self.trailers = true;
+                        this.trailers = true;
                     },
                 }
             }
@@ -41,7 +49,9 @@ impl Future for Process {
     }
 }
 
-fn send_request(mut client: h2::client::SendRequest<bytes::Bytes>) -> impl Future<Item=usize, Error=Error> {
+fn send_request(
+    mut client: h2::client::SendRequest<bytes::Bytes>,
+) -> impl Future<Output = Result<usize, Error>> {
 
     println!("sending request");
 
@@ -59,52 +69,37 @@ fn send_request(mut client: h2::client::SendRequest<bytes::Bytes>) -> impl Futur
         })
 }
 
-pub fn main() -> Result<(), Error> {
-
-    let tcp_stream = TcpStream::connect(&"127.0.0.1:8008".parse().unwrap());
+#[tokio::main]
+async fn main() -> Result<(), Error> {
 
     let start = std::time::SystemTime::now();
 
-    let tcp = tcp_stream
-        .map_err(Error::from)
-        .and_then(|c| {
-            h2::client::Builder::new()
+    let conn = TcpStream::connect(&"127.0.0.1:8008".parse().unwrap())
+        .await?;
+
+    let (client, h2) = h2::client::Builder::new()
         .initial_connection_window_size(1024*1024*1024)
         .initial_window_size(1024*1024*1024)
         .max_frame_size(4*1024*1024)
-                .handshake(c)
-                .map_err(Error::from)
-        })
-        .and_then(|(client, h2)| {
+        .handshake(conn)
+        .await?;
 
-            // Spawn a task to run the conn...
-            tokio::spawn(h2.map_err(|e| println!("GOT ERR={:?}", e)));
-
-            futures::stream::repeat(())
-                .take(2000)
-                .and_then(move |_| send_request(client.clone()))
-                .fold(0, move |mut acc, size| {
-                    acc += size;
-                    Ok::<_, Error>(acc)
-                })
-        })
-        .then(move |result| {
-            match result {
-                Err(err) => {
-                    println!("ERROR {}", err);
+    tokio::spawn(async move {
+        if let Err(err) = h2.await {
+            println!("GOT ERR={:?}", err);
         }
-                Ok(bytes) => {
+    });
+
+    let mut bytes = 0;
+    for _ in 0..2000 {
+        bytes += send_request(client.clone()).await?;
+    }
+
     let elapsed = start.elapsed().unwrap();
     let elapsed = (elapsed.as_secs() as f64) +
         (elapsed.subsec_millis() as f64)/1000.0;
 
     println!("Downloaded {} bytes, {} MB/s", bytes, (bytes as f64)/(elapsed*1024.0*1024.0));
-                }
-            }
-            Ok(())
-        });
-
-    tokio::run(tcp);
 
     Ok(())
 }