add client::Builder to configure Clients

src/client.rs

@@ -4,21 +4,20 @@ use frame::Reason::*;
 use proto::{self, Connection, WindowSize};
 
 use bytes::{Bytes, IntoBuf};
-use futures::{AndThen, Async, AsyncSink, Future, MapErr, Poll, Sink};
+use futures::{Async, Future, MapErr, Poll};
 use http::{HeaderMap, Request, Response};
 use tokio_io::{AsyncRead, AsyncWrite};
 use tokio_io::io::WriteAll;
 
 use std::fmt;
-use std::io::Error as IoError;
+use std::io;
+use std::marker::PhantomData;
 
 /// In progress H2 connection binding
 pub struct Handshake<T: AsyncRead + AsyncWrite, B: IntoBuf = Bytes> {
-    inner: AndThen<
-        MapErr<WriteAll<T, &'static [u8]>, fn(IoError) -> ::Error>,
-        Result<Client<T, B>, ::Error>,
-        fn((T, &'static [u8])) -> Result<Client<T, B>, ::Error>,
-    >,
+    inner: MapErr<WriteAll<T, &'static [u8]>, fn(io::Error) -> ::Error>,
+    settings: Settings,
+    _marker: PhantomData<B>,
 }
 
 /// Marker type indicating a client peer
@@ -36,6 +35,12 @@ pub struct Body<B: IntoBuf> {
     inner: proto::StreamRef<B::Buf, Peer>,
 }
 
+/// Build a Client.
+#[derive(Debug, Default)]
+pub struct Builder {
+    settings: Settings,
+}
+
 #[derive(Debug)]
 pub(crate) struct Peer;
 
@@ -43,16 +48,7 @@ impl<T> Client<T, Bytes>
 where
     T: AsyncRead + AsyncWrite,
 {
-    pub fn handshake(io: T) -> Handshake<T, Bytes> {
-        Client::handshake2(io)
-    }
-}
 
-impl<T, B> Client<T, B>
-where
-    T: AsyncRead + AsyncWrite,
-    B: IntoBuf,
-{
     /// Bind an H2 client connection.
     ///
     /// Returns a future which resolves to the connection value once the H2
@@ -60,41 +56,35 @@ where
     ///
     /// It's important to note that this does not **flush** the outbound
     /// settings to the wire.
-    pub fn handshake2(io: T) -> Handshake<T, B> {
+    pub fn handshake(io: T) -> Handshake<T, Bytes> {
+        Builder::default().handshake(io)
+    }
+}
+
+impl Client<(), Bytes> {
+    /// Creates a Client Builder to customize a Client before binding.
+    pub fn builder() -> Builder {
+        Builder::default()
+    }
+}
+
+impl<T, B> Client<T, B>
+where T: AsyncRead + AsyncWrite,
+      B: IntoBuf
+{
+    fn handshake2(io: T, settings: Settings) -> Handshake<T, B> {
         use tokio_io::io;
 
         debug!("binding client connection");
 
-        let bind: fn((T, &'static [u8]))
-            -> Result<Client<T, B>, ::Error> = |(io, _)| {
-            debug!("client connection bound");
-
-            // Create the codec
-            let mut codec = Codec::new(io);
-
-            // Create the initial SETTINGS frame
-            let settings = Settings::default();
-
-            // Send initial settings frame
-            match codec.start_send(settings.into()) {
-                Ok(AsyncSink::Ready) => {
-                    let connection = Connection::new(codec);
-                    Ok(Client {
-                        connection,
-                    })
-                },
-                Ok(_) => unreachable!(),
-                Err(e) => Err(::Error::from(e)),
-            }
-        };
-
         let msg: &'static [u8] = b"PRI * HTTP/2.0\r\n\r\nSM\r\n\r\n";
         let handshake = io::write_all(io, msg)
-            .map_err(::Error::from as fn(IoError) -> ::Error)
-            .and_then(bind);
+            .map_err(::Error::from as _);
 
         Handshake {
             inner: handshake,
+            settings: settings,
+            _marker: PhantomData,
         }
     }
 
@@ -172,6 +162,30 @@ where
     }
 }
 
+// ===== impl Builder =====
+
+impl Builder {
+    /// Set the initial window size of the remote peer.
+    pub fn initial_window_size(&mut self, size: u32) -> &mut Self {
+        self.settings.set_initial_window_size(Some(size));
+        self
+    }
+
+    /// Bind an H2 client connection.
+    ///
+    /// Returns a future which resolves to the connection value once the H2
+    /// handshake has been completed.
+    ///
+    /// It's important to note that this does not **flush** the outbound
+    /// settings to the wire.
+    pub fn handshake<T, B>(&self, io: T) -> Handshake<T, B>
+        where T: AsyncRead + AsyncWrite,
+              B: IntoBuf
+    {
+        Client::handshake2(io, self.settings.clone())
+    }
+}
+
 // ===== impl Handshake =====
 
 impl<T, B: IntoBuf> Future for Handshake<T, B>
@@ -182,7 +196,21 @@ where
     type Error = ::Error;
 
     fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
-        self.inner.poll()
+        let (io, _) = try_ready!(self.inner.poll());
+
+        debug!("client connection bound");
+
+        // Create the codec
+        let mut codec = Codec::new(io);
+
+        // Send initial settings frame
+        codec.buffer(self.settings.clone().into())
+           .expect("invalid SETTINGS frame");
+
+        let connection = Connection::new(codec, &self.settings);
+        Ok(Async::Ready(Client {
+            connection,
+        }))
     }
 }
 

src/frame/settings.rs

@@ -66,6 +66,10 @@ impl Settings {
         self.initial_window_size
     }
 
+    pub fn set_initial_window_size(&mut self, size: Option<u32>) {
+        self.initial_window_size = size;
+    }
+
     pub fn max_concurrent_streams(&self) -> Option<u32> {
         self.max_concurrent_streams
     }

src/proto/connection.rs

@@ -58,13 +58,15 @@ where
     P: Peer,
     B: IntoBuf,
 {
-    pub fn new(codec: Codec<T, Prioritized<B::Buf>>) -> Connection<T, P, B> {
+    pub fn new(codec: Codec<T, Prioritized<B::Buf>>, settings: &frame::Settings) -> Connection<T, P, B> {
         // TODO: Actually configure
         let streams = Streams::new(streams::Config {
             max_remote_initiated: None,
             init_remote_window_sz: DEFAULT_INITIAL_WINDOW_SIZE,
             max_local_initiated: None,
-            init_local_window_sz: DEFAULT_INITIAL_WINDOW_SIZE,
+            init_local_window_sz: settings
+                .initial_window_size()
+                .unwrap_or(DEFAULT_INITIAL_WINDOW_SIZE),
         });
 
         Connection {

src/server.rs

@@ -1,5 +1,5 @@
 use codec::{Codec, RecvError};
-use frame::{self, Reason, StreamId};
+use frame::{self, Reason, Settings, StreamId};
 use frame::Reason::*;
 use proto::{self, Connection, WindowSize};
 
@@ -82,19 +82,18 @@ where
         let mut codec = Codec::new(io);
 
         // Create the initial SETTINGS frame
-        let settings = frame::Settings::default();
+        let settings = Settings::default();
 
         // Send initial settings frame
         codec
             .buffer(settings.into())
-            .ok()
             .expect("invalid SETTINGS frame");
 
         // Flush pending settings frame and then wait for the client preface
         let handshake = Flush::new(codec)
             .and_then(ReadPreface::new)
             .map(move |codec| {
-                let connection = Connection::new(codec);
+                let connection = Connection::new(codec, &Settings::default());
                 Server {
                     connection,
                 }

tests/stream_states.rs

@@ -62,7 +62,10 @@ fn send_recv_data() {
         ])
         .build();
 
-    let mut h2 = Client::handshake2(mock).wait().unwrap();
+    let mut h2 = Client::builder()
+        .handshake(mock)
+        .wait()
+        .unwrap();
 
     let request = Request::builder()
         .method(Method::POST)