wip

src/frame/window_update.rs

@@ -14,6 +14,13 @@ pub struct WindowUpdate {
 }
 
 impl WindowUpdate {
+    pub fn new(stream_id: StreamId, increment: Increment) -> WindowUpdate {
+        WindowUpdate {
+            stream_id,
+            increment,
+        }
+    }
+
     pub fn stream_id(&self) -> StreamId {
         self.stream_id
     }
@@ -22,13 +29,13 @@ impl WindowUpdate {
         self.increment
     }
 
-        /// Builds a `Ping` frame from a raw frame.
+    /// Builds a `WindowUpdate` frame from a raw frame.
     pub fn load(head: Head, bytes: &[u8]) -> Result<WindowUpdate, Error> {
         debug_assert_eq!(head.kind(), ::frame::Kind::WindowUpdate);
         Ok(WindowUpdate {
             stream_id: head.stream_id(),
-            // Clear the most significant bit, as that is reserved and MUST be ignored when
+            // Clear the most significant bit, as that is reserved and MUST be ignored
-            // received.
+            // when received.
             increment: NetworkEndian::read_u32(bytes) & !INCREMENT_MASK,
         })
     }

src/proto/connection.rs

@@ -1,8 +1,8 @@
 use {Frame, ConnectionError, Peer, StreamId};
 use client::Client;
 use frame::{Frame as WireFrame};
+use proto::{self, FlowController, ReadySink, PeerState, State, WindowUpdate};
 use server::Server;
-use proto::{self, ReadySink, State, WindowUpdate};
 
 use tokio_io::{AsyncRead, AsyncWrite};
 
@@ -13,49 +13,11 @@ use futures::*;
 use ordermap::OrderMap;
 use fnv::FnvHasher;
 
-use std::marker::PhantomData;
+use std::collections::VecDeque;
 use std::hash::BuildHasherDefault;
+use std::marker::PhantomData;
 
-pub struct FlowControlViolation;
+// TODO get window size from `inner`.
-
-#[derive(Debug)]
-struct FlowController {
-    window_size: u32,
-    underflow: u32,
-}
-
-impl FlowController {
-    pub fn new(window_size: u32) -> FlowController {
-        FlowController {
-            window_size,
-            underflow: 0,
-        }
-    }
-
-    pub fn shrink(&mut self, mut sz: u32) {
-        self.underflow += sz;
-    }
-
-    pub fn consume(&mut self, mut sz: u32) -> Result<(), FlowControlViolation> {
-        if sz < self.window_size {
-            self.underflow -= sz;
-            return Err(FlowControlViolation);
-        }
-
-        self.window_size -= sz;
-        Ok(())
-    }
-
-    pub fn increment(&mut self, mut sz: u32) {
-        if sz <= self.underflow {
-            self.underflow -= sz;
-            return;
-        }
-
-        sz -= self.underflow;
-        self.window_size += sz;
-    }
-}
 
 /// An H2 connection
 #[derive(Debug)]
@@ -63,13 +25,24 @@ pub struct Connection<T, P> {
     inner: proto::Inner<T>,
     streams: StreamMap<State>,
     peer: PhantomData<P>,
+
+    /// Tracks connection-level flow control.
     local_flow_controller: FlowController,
+    initial_local_window_size: u32,
+    pending_local_window_updates: VecDeque<WindowUpdate>,
+
     remote_flow_controller: FlowController,
+    initial_remote_window_size: u32,
+    pending_remote_window_updates: VecDeque<WindowUpdate>,
+    blocked_remote_window_update: Option<task::Task>
 }
 
 type StreamMap<T> = OrderMap<StreamId, T, BuildHasherDefault<FnvHasher>>;
 
-pub fn new<T, P>(transport: proto::Inner<T>, initial_local_window_size: u32, initial_remote_window_size: u32) -> Connection<T, P>
+pub fn new<T, P>(transport: proto::Inner<T>,
+                 initial_local_window_size: u32,
+                 initial_remote_window_size: u32)
+    -> Connection<T, P>
     where T: AsyncRead + AsyncWrite,
           P: Peer,
 {
@@ -77,35 +50,70 @@ pub fn new<T, P>(transport: proto::Inner<T>, initial_local_window_size: u32, ini
         inner: transport,
         streams: StreamMap::default(),
         peer: PhantomData,
+
         local_flow_controller: FlowController::new(initial_local_window_size),
+        initial_local_window_size,
+        pending_local_window_updates: VecDeque::default(),
+
         remote_flow_controller: FlowController::new(initial_remote_window_size),
+        initial_remote_window_size,
+        pending_remote_window_updates: VecDeque::default(),
+        blocked_remote_window_update: None,
     }
 }
 
 impl<T, P> Connection<T, P> {
-    /// Publishes stream window updates to the remote.
+    /// Publishes local stream window updates to the remote.
     ///
-    /// Connection window updates (StreamId=0) and stream window updates are published
+    /// Connection window updates (StreamId=0) and stream window must be published
     /// distinctly.
     pub fn increment_local_window(&mut self, up: WindowUpdate) {
-        let incr = up.increment();
+        let added = match &up {
-        let flow = match up {
+            &WindowUpdate::Connection { increment } => {
-            WindowUpdate::Connection { .. } => Some(&self.local_flow_controller),
+                if increment == 0 {
-            WindowUpdate::Stream { id, .. } => {
+                    false
-                self.streams.get(&id).map(|s| s.local_flow_controller())
+                } else {
+                    self.local_flow_controller.increment(increment);
+                    true
+                }
+            }
+            &WindowUpdate::Stream { id, increment } => {
+                if increment == 0 {
+                    false
+                } else {
+                    match self.streams.get_mut(&id) {
+                        Some(&mut State::Open { local: PeerState::Data(ref mut fc), .. }) |
+                        Some(&mut State::HalfClosedRemote(PeerState::Data(ref mut fc))) => {
+                            fc.increment(increment);
+                            true
+                        }
+                        _ => false,
+                    }
+                }
             }
         };
-        if let Some(flow) = flow {
+
-            flow.increment(incr);
+        if added {
+            self.pending_local_window_updates.push_back(up);
         }
-        unimplemented!()
     }
 
-    /// Advertises stream window updates from the remote.
+    /// Advertises the remote's stream window updates.
     ///
     /// Connection window updates (StreamId=0) and stream window updates are advertised
     /// distinctly.
-    pub fn poll_remote_window(&mut self) -> Poll<WindowUpdate, ()> {
+    fn increment_remote_window(&mut self, id: StreamId, incr: u32) {
+        if id.is_zero() {
+            self.remote_flow_controller.increment(incr);
+        } else {
+            match self.streams.get_mut(&id) {
+                Some(&mut State::Open { remote: PeerState::Data(ref mut fc), .. }) |
+                Some(&mut State::HalfClosedLocal(PeerState::Data(ref mut fc))) => {
+                    fc.increment(incr);
+                }
+                _ => {}
+            }
+        }
         unimplemented!()
     }
 }
@@ -154,6 +162,7 @@ impl<T, P> Stream for Connection<T, P>
     fn poll(&mut self) -> Poll<Option<Self::Item>, ConnectionError> {
         trace!("Connection::poll");
 
+    loop {
             let frame = match try!(self.inner.poll()) {
                 Async::Ready(f) => f,
                 Async::NotReady => {
@@ -172,9 +181,12 @@ impl<T, P> Stream for Connection<T, P>
                     let stream_id = v.stream_id();
                     let end_of_stream = v.is_end_stream();
 
+                    // TODO load window size from settings.
+                    let init_window_size = 65_535;
+
                     let stream_initialized = try!(self.streams.entry(stream_id)
                         .or_insert(State::default())
-                     .recv_headers::<P>(end_of_stream));
+                        .recv_headers::<P>(end_of_stream, init_window_size));
 
                     if stream_initialized {
                         // TODO: Ensure available capacity for a new stream
@@ -204,11 +216,16 @@ impl<T, P> Stream for Connection<T, P>
                         end_of_stream: end_of_stream,
                     }
                 }
+                Some(WireFrame::WindowUpdate(v)) => {
+                    self.increment_remote_window(v.stream_id(), v.increment());
+                    continue;
+                }
                 Some(frame) => panic!("unexpected frame; frame={:?}", frame),
                 None => return Ok(Async::Ready(None)),
             };
 
-        Ok(Async::Ready(Some(frame)))
+            return Ok(Async::Ready(Some(frame)));
+        }
     }
 }
 
@@ -229,13 +246,15 @@ impl<T, P> Sink for Connection<T, P>
 
         match item {
             Frame::Headers { id, headers, end_of_stream } => {
+                // TODO load window size from settings.
+                let init_window_size = 65_535;
+
                 // Transition the stream state, creating a new entry if needed
-                //
                 // TODO: Response can send multiple headers frames before body
                 // (1xx responses).
                 let stream_initialized = try!(self.streams.entry(id)
                      .or_insert(State::default())
-                     .send_headers::<P>(end_of_stream));
+                     .send_headers::<P>(end_of_stream, init_window_size));
 
                 if stream_initialized {
                     // TODO: Ensure available capacity for a new stream

src/proto/flow_control.rs

@@ -0,0 +1,40 @@
+#[derive(Clone, Copy, Debug)]
+pub struct WindowUnderflow;
+
+#[derive(Copy, Clone, Debug)]
+pub struct FlowController {
+    window_size: u32,
+    underflow: u32,
+}
+
+impl FlowController {
+    pub fn new(window_size: u32) -> FlowController {
+        FlowController {
+            window_size,
+            underflow: 0,
+        }
+    }
+
+    pub fn shrink(&mut self, sz: u32) {
+        self.underflow += sz;
+    }
+
+    pub fn consume(&mut self, sz: u32) -> Result<(), WindowUnderflow> {
+        if self.window_size < sz {
+            return Err(WindowUnderflow);
+        }
+
+        self.window_size -= sz;
+        Ok(())
+    }
+
+    pub fn increment(&mut self, sz: u32) {
+        if sz <= self.underflow {
+            self.underflow -= sz;
+            return;
+        }
+
+        self.window_size += sz - self.underflow;
+        self.underflow = 0;
+    }
+}

src/proto/mod.rs

@@ -1,4 +1,5 @@
 mod connection;
+mod flow_control;
 mod framed_read;
 mod framed_write;
 mod ping_pong;
@@ -7,13 +8,14 @@ mod settings;
 mod state;
 mod window_update;
 
-pub use self::connection::{Connection};
+pub use self::connection::Connection;
+pub use self::flow_control::FlowController;
 pub use self::framed_read::FramedRead;
 pub use self::framed_write::FramedWrite;
 pub use self::ping_pong::PingPong;
 pub use self::ready::ReadySink;
 pub use self::settings::Settings;
-pub use self::state::State;
+pub use self::state::{PeerState, State};
 pub use self::window_update::WindowUpdate;
 
 use {frame, Peer};

src/proto/state.rs

@@ -1,4 +1,5 @@
 use {ConnectionError, Reason, Peer};
+use proto::FlowController;
 
 /// Represents the state of an H2 stream
 ///
@@ -40,7 +41,7 @@ use {ConnectionError, Reason, Peer};
 ///        ES: END_STREAM flag
 ///        R:  RST_STREAM frame
 /// ```
-#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+#[derive(Debug, Copy, Clone)]
 pub enum State {
     Idle,
     ReservedLocal,
@@ -54,18 +55,35 @@ pub enum State {
     Closed,
 }
 
-#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+#[derive(Debug, Copy, Clone)]
 pub enum PeerState {
     Headers,
-    Data,
+    Data(FlowController),
 }
 
 impl State {
+    pub fn increment_local_window_size(&mut self, incr: u32) {
+        use self::State::*;
+        use self::PeerState::*;
+
+        *self = match *self {
+            Open { local: Data(mut local), remote } => {
+                local.increment(incr);
+                Open { local: Data(local), remote }
+            }
+            HalfClosedRemote(Data(mut local)) => {
+                local.increment(incr);
+                HalfClosedRemote(Data(local))
+            }
+            s => s,
+        }
+    }
+
     /// Transition the state to represent headers being received.
     ///
     /// Returns true if this state transition results in iniitializing the
     /// stream id. `Err` is returned if this is an invalid state transition.
-    pub fn recv_headers<P: Peer>(&mut self, eos: bool) -> Result<bool, ConnectionError> {
+    pub fn recv_headers<P: Peer>(&mut self, eos: bool, remote_window_size: u32) -> Result<bool, ConnectionError> {
         use self::State::*;
         use self::PeerState::*;
 
@@ -76,7 +94,7 @@ impl State {
                 } else {
                     Open {
                         local: Headers,
-                        remote: Data,
+                        remote: Data(FlowController::new(remote_window_size)),
                     }
                 };
 
@@ -88,7 +106,7 @@ impl State {
                 *self = if eos {
                     HalfClosedRemote(local)
                 } else {
-                    let remote = Data;
+                    let remote = Data(FlowController::new(remote_window_size));
                     Open { local, remote }
                 };
 
@@ -100,7 +118,7 @@ impl State {
                 *self = if eos {
                     Closed
                 } else {
-                    HalfClosedLocal(Data)
+                    HalfClosedLocal(Data(FlowController::new(remote_window_size)))
                 };
 
                 Ok(false)
@@ -116,7 +134,7 @@ impl State {
     ///
     /// Returns true if this state transition results in initializing the stream
     /// id. `Err` is returned if this is an invalid state transition.
-    pub fn send_headers<P: Peer>(&mut self, eos: bool) -> Result<bool, ConnectionError> {
+    pub fn send_headers<P: Peer>(&mut self, eos: bool, local_window_size: u32) -> Result<bool, ConnectionError> {
         use self::State::*;
         use self::PeerState::*;
 
@@ -126,7 +144,7 @@ impl State {
                     HalfClosedLocal(Headers)
                 } else {
                     Open {
-                        local: Data,
+                        local: Data(FlowController::new(local_window_size)),
                         remote: Headers,
                     }
                 };
@@ -139,7 +157,7 @@ impl State {
                 *self = if eos {
                     HalfClosedLocal(remote)
                 } else {
-                    let local = Data;
+                    let local = Data(FlowController::new(local_window_size));
                     Open { local, remote }
                 };
 
@@ -151,7 +169,7 @@ impl State {
                 *self = if eos {
                     Closed
                 } else {
-                    HalfClosedRemote(Data)
+                    HalfClosedRemote(Data(FlowController::new(local_window_size)))
                 };
 
                 Ok(false)

src/proto/window_update.rs

@@ -1,16 +1,36 @@
 use StreamId;
+use frame;
 
 #[derive(Debug)]
 pub enum WindowUpdate {
-    Connection { increment: usize },
+    Connection { increment: u32 },
-    Stream { id: StreamId, increment: usize },
+    Stream { id: StreamId, increment: u32 },
 }
 
 impl WindowUpdate {
-    pub fn increment(&self) -> usize {
+    pub fn increment(&self) -> u32 {
         match *self {
             WindowUpdate::Connection { increment } |
             WindowUpdate::Stream { increment, .. } => increment
         }
     }
 }
+
+impl From<WindowUpdate> for frame::WindowUpdate {
+    fn from(src: WindowUpdate) -> Self {
+        match src {
+            WindowUpdate::Connection { increment } => {
+                frame::WindowUpdate::new(StreamId::zero(), increment)
+            }
+            WindowUpdate::Stream { id, increment } => {
+                frame::WindowUpdate::new(id, increment)
+            }
+        }
+    }
+}
+
+impl From<WindowUpdate> for frame::Frame {
+    fn from(src: WindowUpdate) -> Self {
+        frame::Frame::WindowUpdate(src.into())
+    }
+}