feat(client): introduce lower-level Connection API

Closes #1449

benches/end_to_end.rs

@@ -8,14 +8,13 @@ extern crate tokio_core;
 
 use std::net::SocketAddr;
 
-use futures::{future, Future, Stream};
+use futures::{Future, Stream};
 use tokio_core::reactor::{Core, Handle};
 use tokio_core::net::TcpListener;
 
 use hyper::client;
 use hyper::header::{ContentLength, ContentType};
 use hyper::Method;
-use hyper::server::{self, Service};
 
 
 #[bench]
@@ -42,13 +41,15 @@ fn get_one_at_a_time(b: &mut test::Bencher) {
 
 #[bench]
 fn post_one_at_a_time(b: &mut test::Bencher) {
+    extern crate pretty_env_logger;
+    let _ = pretty_env_logger::try_init();
     let mut core = Core::new().unwrap();
     let handle = core.handle();
     let addr = spawn_hello(&handle);
 
     let client = hyper::Client::new(&handle);
 
-    let url: hyper::Uri = format!("http://{}/get", addr).parse().unwrap();
+    let url: hyper::Uri = format!("http://{}/post", addr).parse().unwrap();
 
     let post = "foo bar baz quux";
     b.bytes = 180 * 2 + post.len() as u64 + PHRASE.len() as u64;
@@ -69,35 +70,32 @@ fn post_one_at_a_time(b: &mut test::Bencher) {
 
 static PHRASE: &'static [u8] = include_bytes!("../CHANGELOG.md"); //b"Hello, World!";
 
-#[derive(Clone, Copy)]
-struct Hello;
-
-impl Service for Hello {
-    type Request = server::Request;
-    type Response = server::Response;
-    type Error = hyper::Error;
-    type Future = future::FutureResult<Self::Response, hyper::Error>;
-    fn call(&self, _req: Self::Request) -> Self::Future {
-        future::ok(
-            server::Response::new()
-                .with_header(ContentLength(PHRASE.len() as u64))
-                .with_header(ContentType::plaintext())
-                .with_body(PHRASE)
-        )
-    }
-
-}
-
 fn spawn_hello(handle: &Handle) -> SocketAddr {
+    use hyper::server::{const_service, service_fn, NewService, Request, Response};
     let addr = "127.0.0.1:0".parse().unwrap();
     let listener = TcpListener::bind(&addr, handle).unwrap();
     let addr = listener.local_addr().unwrap();
 
     let handle2 = handle.clone();
     let http = hyper::server::Http::<hyper::Chunk>::new();
+
+    let service = const_service(service_fn(|req: Request| {
+        req.body()
+            .concat2()
+            .map(|_| {
+                Response::<hyper::Body>::new()
+                    .with_header(ContentLength(PHRASE.len() as u64))
+                    .with_header(ContentType::plaintext())
+                    .with_body(PHRASE)
+            })
+    }));
+
+    let mut conns = 0;
     handle.spawn(listener.incoming().for_each(move |(socket, _addr)| {
+        conns += 1;
+        assert_eq!(conns, 1, "should only need 1 connection");
         handle2.spawn(
-            http.serve_connection(socket, Hello)
+            http.serve_connection(socket, service.new_service()?)
                 .map(|_| ())
                 .map_err(|_| ())
         );