perf(client): change HttpConnecting to hold Arc<Config> instead of inlined fields

benches/connect.rs

@@ -0,0 +1,34 @@
+#![feature(test)]
+#![deny(warnings)]
+
+extern crate test;
+
+use tokio::net::TcpListener;
+use tokio::runtime::current_thread::Runtime;
+use hyper::client::connect::{Destination, HttpConnector};
+use hyper::service::Service;
+use http::Uri;
+
+#[bench]
+fn http_connector(b: &mut test::Bencher) {
+    let _ = pretty_env_logger::try_init();
+    let mut rt = Runtime::new().unwrap();
+    let mut listener = rt.block_on(TcpListener::bind("127.0.0.1:0")).expect("bind");
+    let addr = listener.local_addr().expect("local_addr");
+    let uri: Uri = format!("http://{}/", addr).parse().expect("uri parse");
+    let dst = Destination::try_from_uri(uri).expect("destination");
+    let mut connector = HttpConnector::new();
+
+    rt.spawn(async move {
+        loop {
+            let _ = listener.accept().await;
+        }
+    });
+
+
+    b.iter(|| {
+        rt.block_on(async {
+            connector.call(dst.clone()).await.expect("connect");
+        });
+    });
+}