Use roto_tonic types in hello_world example

Fix the client's poll_ready implementation to properly propagate
readiness.

examples/hello_world/src/bin/client.rs

@@ -5,6 +5,8 @@ use roto_runtime::RotoOwned;
 use std::task::{Context, Poll};
 use tower::Service;
 
+pub use roto_tonic::{BufferPool, StatusBody};
+
 pub mod hello {
     include!(concat!(env!("OUT_DIR"), "/hello.rs"));
 }
@@ -19,11 +21,14 @@ where
     type Error = S::Error;
     type Future = S::Future;
 
-    fn poll_ready(&mut self, _: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
-        Poll::Ready(Ok(()))
+    fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
+        self.0.poll_ready(cx)
     }
 
     fn call(&mut self, req: Req) -> S::Future {
+        let waker = futures_util::task::noop_waker();
+        let mut cx = std::task::Context::from_waker(&waker);
+        let _ = self.poll_ready(&mut cx);
         self.0.call(req)
     }
 }

examples/hello_world/src/bin/server.rs

@@ -13,35 +13,12 @@ use roto_runtime::{RotoOwned, RotoMessage};
 use http_body_util::BodyExt;
 use http_body::Body;
 
+pub use roto_tonic::{BufferPool, StatusBody};
+
 pub mod hello {
     include!(concat!(env!("OUT_DIR"), "/hello.rs"));
 }
 
-struct BufferPool {
-    pool: Mutex<Vec<BytesMut>>,
-    default_capacity: usize,
-}
-
-impl BufferPool {
-    fn new(default_capacity: usize) -> Self {
-        Self {
-            pool: Mutex::new(Vec::new()),
-            default_capacity,
-        }
-    }
-
-    fn get(&self) -> BytesMut {
-        self.pool.lock().unwrap().pop().unwrap_or_else(|| BytesMut::with_capacity(self.default_capacity))
-    }
-
-    fn put(&self, mut buf: BytesMut) {
-        buf.clear();
-        if buf.capacity() >= self.default_capacity {
-            self.pool.lock().unwrap().push(buf);
-        }
-    }
-}
-
 #[derive(Clone)]
 pub struct MyHelloWorld {
     pool: Arc<BufferPool>,
@@ -99,24 +76,6 @@ impl tonic::server::NamedService for HelloWorldServer {
     const NAME: &'static str = "hello.HelloWorldService";
 }
 
-struct StatusBody(Option<Bytes>);
-
-impl Body for StatusBody {
-    type Data = Bytes;
-    type Error = Status;
-
-    fn poll_frame(
-        mut self: Pin<&mut Self>,
-        cx: &mut Context<'_>,
-    ) -> Poll<Option<Result<http_body::Frame<Self::Data>, Self::Error>>> {
-        if let Some(data) = self.0.take() {
-            Poll::Ready(Some(Ok(http_body::Frame::data(data))))
-        } else {
-            Poll::Ready(None)
-        }
-    }
-}
-
 impl Service<http::Request<BoxBody>> for HelloWorldServer {
     type Response = http::Response<BoxBody>;
     type Error = std::convert::Infallible;
@@ -152,7 +111,7 @@ impl Service<http::Request<BoxBody>> for HelloWorldServer {
 
             if bytes_vec.len() < 5 {
                 println!("Body too short: {} bytes", bytes_vec.len());
-                let res_body = BoxBody::new(StatusBody(Some(Bytes::from_static(&[0, 0, 0, 0, 0]))));
+                let res_body = BoxBody::new(StatusBody::new(Some(Bytes::from_static(&[0, 0, 0, 0, 0])), 0));
                 return Ok(http::Response::builder()
                     .status(200)
                     .body(res_body)
@@ -164,7 +123,7 @@ impl Service<http::Request<BoxBody>> for HelloWorldServer {
                 Ok(msg) => msg,
                 Err(e) => {
                     println!("Decode error: {}", e);
-                    let res_body = BoxBody::new(StatusBody(Some(Bytes::from_static(&[0, 0, 0, 0, 0]))));
+                    let res_body = BoxBody::new(StatusBody::new(Some(Bytes::from_static(&[0, 0, 0, 0, 0])), 0));
                     return Ok(http::Response::builder().status(200).body(res_body).unwrap());
                 }
             };
@@ -174,7 +133,7 @@ impl Service<http::Request<BoxBody>> for HelloWorldServer {
                 Ok(res) => res,
                 Err(e) => {
                     println!("Service error: {}", e);
-                    let res_body = BoxBody::new(StatusBody(Some(Bytes::from_static(&[0, 0, 0, 0, 0]))));
+                    let res_body = BoxBody::new(StatusBody::new(Some(Bytes::from_static(&[0, 0, 0, 0, 0])), 0));
                     return Ok(http::Response::builder().status(200).body(res_body).unwrap());
                 }
             };
@@ -193,7 +152,7 @@ impl Service<http::Request<BoxBody>> for HelloWorldServer {
             let frame = res_buf.split_to(frame_len).freeze();
             pool.put(res_buf);
 
-            let res_body = BoxBody::new(StatusBody(Some(frame)));
+            let res_body = BoxBody::new(StatusBody::new(Some(frame), 0));
             Ok(http::Response::builder()
                 .status(200)
                 .header("content-type", "application/grpc")