Wire in PushPromise

src/frame/headers.rs

@@ -320,6 +320,14 @@ impl PushPromise {
             flags: flags,
         })
     }
+
+    pub fn stream_id(&self) -> StreamId {
+        self.stream_id
+    }
+
+    pub fn promised_id(&self) -> StreamId {
+        self.promised_id
+    }
 }
 
 impl<T> From<PushPromise> for Frame<T> {

src/proto/connection.rs

@@ -155,11 +155,8 @@ impl<T, P, B> Connection<T, P, B>
                     */
                 }
                 Some(PushPromise(frame)) => {
-                    // TODO: implement
-                    /*
                     trace!("recv PUSH_PROMISE; frame={:?}", frame);
-                    try!(self.streams.recv_push_promise(frame));
+                    self.streams.recv_push_promise(frame)?;
-                    */
                 }
                 Some(Settings(frame)) => {
                     trace!("recv SETTINGS; frame={:?}", frame);

src/proto/streams/prioritize.rs

@@ -2,24 +2,18 @@ use super::*;
 
 #[derive(Debug)]
 pub(super) struct Prioritize<B> {
-    pending_send: Option<Indices>,
+    pending_send: store::List<B>,
 
     /// Holds frames that are waiting to be written to the socket
     buffer: Buffer<B>,
 }
 
-#[derive(Debug, Clone, Copy)]
-struct Indices {
-    head: store::Key,
-    tail: store::Key,
-}
-
 impl<B> Prioritize<B>
     where B: Buf,
 {
     pub fn new() -> Prioritize<B> {
         Prioritize {
-            pending_send: None,
+            pending_send: store::List::new(),
             buffer: Buffer::new(),
         }
     }
@@ -32,7 +26,7 @@ impl<B> Prioritize<B>
         stream.pending_send.push_back(&mut self.buffer, frame);
 
         if stream.is_pending_send {
-            debug_assert!(self.pending_send.is_some());
+            debug_assert!(!self.pending_send.is_empty());
 
             // Already queued to have frame processed.
             return;
@@ -84,44 +78,20 @@ impl<B> Prioritize<B>
     }
 
     fn push_sender(&mut self, stream: &mut store::Ptr<B>) {
-        // The next pointer shouldn't be set
+        debug_assert!(!stream.is_pending_send);
-        debug_assert!(stream.next_pending_send.is_none());
 
-        // Queue the stream
+        self.pending_send.push(stream);
-        match self.pending_send {
-            Some(ref mut idxs) => {
-                // Update the current tail node to point to `stream`
-                stream.resolve(idxs.tail).next_pending_send = Some(stream.key());
-
-                // Update the tail pointer
-                idxs.tail = stream.key();
-            }
-            None => {
-                self.pending_send = Some(Indices {
-                    head: stream.key(),
-                    tail: stream.key(),
-                });
-            }
-        }
 
         stream.is_pending_send = true;
     }
 
     fn pop_sender<'a>(&mut self, store: &'a mut Store<B>) -> Option<store::Ptr<'a, B>> {
-        if let Some(mut idxs) = self.pending_send {
+        match self.pending_send.pop(store) {
-            let mut stream = store.resolve(idxs.head);
+            Some(mut stream) => {
-
+                stream.is_pending_send = false;
-            if idxs.head == idxs.tail {
+                Some(stream)
-                assert!(stream.next_pending_send.is_none());
+            }
-                self.pending_send = None;
+            None => None,
-            } else {
-                idxs.head = stream.next_pending_send.take().unwrap();
-                self.pending_send = Some(idxs);
         }
-
-            return Some(stream);
-        }
-
-        None
     }
 }

src/proto/streams/recv.rs

@@ -21,6 +21,8 @@ pub(super) struct Recv<P, B> {
     /// Connection level flow control governing received data
     flow_control: FlowControl,
 
+    /// Streams that have pending window updates
+    /// TODO: don't use a VecDeque
     pending_window_updates: VecDeque<StreamId>,
 
     /// Holds frames that are waiting to be read
@@ -38,6 +40,12 @@ pub(super) struct Chunk {
     pub pending_recv: buffer::Deque<Bytes>,
 }
 
+#[derive(Debug, Clone, Copy)]
+struct Indices {
+    head: store::Key,
+    tail: store::Key,
+}
+
 impl<P, B> Recv<P, B>
     where P: Peer,
           B: Buf,
@@ -63,15 +71,10 @@ impl<P, B> Recv<P, B>
 
         try!(self.ensure_can_open(id));
 
-        if let Some(max) = self.max_streams {
+        if !self.can_inc_num_streams() {
-            if max <= self.num_streams {
             self.refused = Some(id);
             return Ok(None);
         }
-        }
-
-        // Increment the number of remote initiated streams
-        self.num_streams += 1;
 
         Ok(Some(Stream::new(id)))
     }
@@ -82,7 +85,16 @@ impl<P, B> Recv<P, B>
                         stream: &mut store::Ptr<B>)
         -> Result<Option<frame::Headers>, ConnectionError>
     {
-        stream.state.recv_open(self.init_window_sz, frame.is_end_stream())?;
+        let is_initial = stream.state.recv_open(self.init_window_sz, frame.is_end_stream())?;
+
+        if is_initial {
+            if !self.can_inc_num_streams() {
+                unimplemented!();
+            }
+
+            // Increment the number of concurrent streams
+            self.inc_num_streams();
+        }
 
         // Only servers can receive a headers frame that initiates the stream.
         // This is verified in `Streams` before calling this function.
@@ -105,7 +117,7 @@ impl<P, B> Recv<P, B>
 
     pub fn recv_data(&mut self,
                      frame: frame::Data,
-                     stream: &mut Stream<B>)
+                     stream: &mut store::Ptr<B>)
         -> Result<(), ConnectionError>
     {
         let sz = frame.payload().len();
@@ -143,6 +155,48 @@ impl<P, B> Recv<P, B>
         Ok(())
     }
 
+    pub fn recv_push_promise(&mut self, frame: frame::PushPromise, stream: &mut store::Ptr<B>)
+        -> Result<(), ConnectionError>
+    {
+        // First, make sure that the values are legit
+        self.ensure_can_reserve(frame.promised_id())?;
+
+        // Make sure that the stream state is valid
+        stream.state.ensure_recv_open()?;
+
+        // TODO: Streams in the reserved states do not count towards the concurrency
+        // limit. However, it seems like there should be a cap otherwise this
+        // could grow in memory indefinitely.
+
+        /*
+        if !self.inc_num_streams() {
+            self.refused = Some(frame.promised_id());
+            return Ok(());
+        }
+        */
+
+        // TODO: All earlier stream IDs should be implicitly closed.
+
+        // Now, create a new entry for the stream
+        let mut new_stream = Stream::new(frame.promised_id());
+        new_stream.state.reserve_remote();
+
+        let mut ppp = stream.pending_push_promises.take();
+
+        {
+            // Store the stream
+            let mut new_stream = stream.store()
+                .insert(frame.promised_id(), new_stream);
+
+            ppp.push(&mut new_stream);
+        }
+
+        stream.pending_push_promises = ppp;
+        stream.notify_recv();
+
+        Ok(())
+    }
+
     pub fn recv_err(&mut self, err: &ConnectionError, stream: &mut Stream<B>) {
         // Receive an error
         stream.state.recv_err(err);
@@ -151,6 +205,26 @@ impl<P, B> Recv<P, B>
         stream.notify_recv();
     }
 
+    /// Returns true if the current stream concurrency can be incremetned
+    fn can_inc_num_streams(&self) -> bool {
+        if let Some(max) = self.max_streams {
+            max > self.num_streams
+        } else {
+            true
+        }
+    }
+
+    /// Increments the number of concurrenty streams. Panics on failure as this
+    /// should have been validated before hand.
+    fn inc_num_streams(&mut self) {
+        if !self.can_inc_num_streams() {
+            panic!();
+        }
+
+        // Increment the number of remote initiated streams
+        self.num_streams += 1;
+    }
+
     pub fn dec_num_streams(&mut self) {
         self.num_streams -= 1;
     }
@@ -171,6 +245,21 @@ impl<P, B> Recv<P, B>
         Ok(())
     }
 
+    /// Returns true if the remote peer can reserve a stream with the given ID.
+    fn ensure_can_reserve(&self, promised_id: StreamId) -> Result<(), ConnectionError> {
+        // TODO: Are there other rules?
+        if P::is_server() {
+            // The remote is a client and cannot reserve
+            return Err(ProtocolError.into());
+        }
+
+        if !promised_id.is_server_initiated() {
+            return Err(ProtocolError.into());
+        }
+
+        Ok(())
+    }
+
     /// Send any pending refusals.
     pub fn send_pending_refusal<T>(&mut self, dst: &mut Codec<T, B>)
         -> Poll<(), ConnectionError>
@@ -206,7 +295,7 @@ impl<P, B> Recv<P, B>
     pub fn expand_stream_window(&mut self,
                                 id: StreamId,
                                 sz: WindowSize,
-                                stream: &mut Stream<B>)
+                                stream: &mut store::Ptr<B>)
         -> Result<(), ConnectionError>
     {
         // TODO: handle overflow
@@ -276,7 +365,7 @@ impl<P, B> Recv<P, B>
     {
         while let Some(id) = self.pending_window_updates.pop_front() {
             let flow = streams.find_mut(&id)
-                .and_then(|stream| stream.recv_flow_control());
+                .and_then(|stream| stream.into_mut().recv_flow_control());
 
 
             if let Some(flow) = flow {

src/proto/streams/send.rs

@@ -177,7 +177,7 @@ impl<P, B> Send<P, B>
         let update = self.pending_window_updates.pop_front()
             .and_then(|id| {
                 streams.find_mut(&id)
-                    .and_then(|stream| stream.send_flow_control())
+                    .and_then(|stream| stream.into_mut().send_flow_control())
                     .and_then(|flow| flow.apply_window_update())
                     .map(|incr| WindowUpdate::new(id, incr))
             });
@@ -209,7 +209,7 @@ impl<P, B> Send<P, B>
 
     pub fn recv_stream_window_update(&mut self,
                                      frame: frame::WindowUpdate,
-                                     stream: &mut Stream<B>)
+                                     stream: &mut store::Ptr<B>)
         -> Result<(), ConnectionError>
     {
         if let Some(flow) = stream.send_flow_control() {

src/proto/streams/state.rs

@@ -58,7 +58,7 @@ enum Inner {
     Idle,
     // TODO: these states shouldn't count against concurrency limits:
     //ReservedLocal,
-    //ReservedRemote,
+    ReservedRemote,
     Open {
         local: Peer,
         remote: Peer,
@@ -126,11 +126,16 @@ impl State {
 
     /// Open the receive have of the stream, this action is taken when a HEADERS
     /// frame is received.
-    pub fn recv_open(&mut self, sz: WindowSize, eos: bool) -> Result<(), ConnectionError> {
+    ///
+    /// Returns true if this transitions the state to Open
+    pub fn recv_open(&mut self, sz: WindowSize, eos: bool) -> Result<bool, ConnectionError> {
         let remote = Peer::streaming(sz);
+        let mut initial = false;
 
         self.inner = match self.inner {
             Idle => {
+                initial = true;
+
                 if eos {
                     HalfClosedRemote(AwaitingHeaders)
                 } else {
@@ -140,6 +145,18 @@ impl State {
                     }
                 }
             }
+            ReservedRemote => {
+                initial = true;
+
+                if eos {
+                    Closed(None)
+                } else {
+                    Open {
+                        local: AwaitingHeaders,
+                        remote,
+                    }
+                }
+            }
             Open { local, remote: AwaitingHeaders } => {
                 if eos {
                     HalfClosedRemote(local)
@@ -163,7 +180,18 @@ impl State {
             }
         };
 
-        return Ok(());
+        return Ok(initial);
+    }
+
+    /// Transition from Idle -> ReservedRemote
+    pub fn reserve_remote(&mut self) -> Result<(), ConnectionError> {
+        match self.inner {
+            Idle => {
+                self.inner = ReservedRemote;
+                Ok(())
+            }
+            _ => Err(ProtocolError.into()),
+        }
     }
 
     /// Indicates that the remote side will not send more data to the local.

src/proto/streams/store.rs

@@ -4,6 +4,7 @@ use slab;
 
 use std::ops;
 use std::collections::{HashMap, hash_map};
+use std::marker::PhantomData;
 
 /// Storage for streams
 #[derive(Debug)]
@@ -22,6 +23,19 @@ pub(super) struct Ptr<'a, B: 'a> {
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub(super) struct Key(usize);
 
+#[derive(Debug)]
+pub(super) struct List<B> {
+    indices: Option<store::Indices>,
+    _p: PhantomData<B>,
+}
+
+/// A linked list
+#[derive(Debug, Clone, Copy)]
+struct Indices {
+    pub head: Key,
+    pub tail: Key,
+}
+
 pub(super) enum Entry<'a, B: 'a> {
     Occupied(OccupiedEntry<'a, B>),
     Vacant(VacantEntry<'a, B>),
@@ -54,9 +68,12 @@ impl<B> Store<B> {
         }
     }
 
-    pub fn find_mut(&mut self, id: &StreamId) -> Option<&mut Stream<B>> {
+    pub fn find_mut(&mut self, id: &StreamId) -> Option<Ptr<B>> {
-        if let Some(handle) = self.ids.get(id) {
+        if let Some(&key) = self.ids.get(id) {
-            Some(&mut self.slab[*handle])
+            Some(Ptr {
+                key: Key(key),
+                store: self,
+            })
         } else {
             None
         }
@@ -100,6 +117,68 @@ impl<B> Store<B> {
     }
 }
 
+// ===== impl List =====
+
+impl<B> List<B> {
+    pub fn new() -> Self {
+        List {
+            indices: None,
+            _p: PhantomData,
+        }
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.indices.is_none()
+    }
+
+    pub fn take(&mut self) -> Self {
+        List {
+            indices: self.indices.take(),
+            _p: PhantomData,
+        }
+    }
+
+    pub fn push(&mut self, stream: &mut store::Ptr<B>) {
+        // The next pointer shouldn't be set
+        debug_assert!(stream.next.is_none());
+
+        // Queue the stream
+        match self.indices {
+            Some(ref mut idxs) => {
+                // Update the current tail node to point to `stream`
+                stream.resolve(idxs.tail).next = Some(stream.key());
+
+                // Update the tail pointer
+                idxs.tail = stream.key();
+            }
+            None => {
+                self.indices = Some(store::Indices {
+                    head: stream.key(),
+                    tail: stream.key(),
+                });
+            }
+        }
+    }
+
+    pub fn pop<'a>(&mut self, store: &'a mut Store<B>) -> Option<store::Ptr<'a, B>> {
+        if let Some(mut idxs) = self.indices {
+            let mut stream = store.resolve(idxs.head);
+
+            if idxs.head == idxs.tail {
+                assert!(stream.next.is_none());
+                self.indices = None;
+            } else {
+                idxs.head = stream.next.take().unwrap();
+                self.indices = Some(idxs);
+            }
+
+            return Some(stream);
+        }
+
+        None
+    }
+}
+
 // ===== impl Ptr =====
 
 impl<'a, B: 'a> Ptr<'a, B> {
@@ -107,12 +186,20 @@ impl<'a, B: 'a> Ptr<'a, B> {
         self.key
     }
 
+    pub fn store(&mut self) -> &mut Store<B> {
+        &mut self.store
+    }
+
     pub fn resolve(&mut self, key: Key) -> Ptr<B> {
         Ptr {
             key: key,
             store: self.store,
         }
     }
+
+    pub fn into_mut(self) -> &'a mut Stream<B> {
+        &mut self.store.slab[self.key.0]
+    }
 }
 
 impl<'a, B: 'a> ops::Deref for Ptr<'a, B> {

src/proto/streams/stream.rs

@@ -17,8 +17,14 @@ pub(super) struct Stream<B> {
     /// Frames pending for this stream being sent to the socket
     pub pending_send: buffer::Deque<B>,
 
-    /// Next stream pending send
+    /// Next node in the `Stream` linked list.
-    pub next_pending_send: Option<store::Key>,
+    ///
+    /// This field is used in different linked lists depending on the stream
+    /// state.
+    pub next: Option<store::Key>,
+
+    /// The stream's pending push promises
+    pub pending_push_promises: store::List<B>,
 
     /// True if the stream is currently pending send
     pub is_pending_send: bool,
@@ -32,7 +38,8 @@ impl<B> Stream<B> {
             pending_recv: buffer::Deque::new(),
             recv_task: None,
             pending_send: buffer::Deque::new(),
-            next_pending_send: None,
+            next: None,
+            pending_push_promises: store::List::new(),
             is_pending_send: false,
         }
     }

src/proto/streams/streams.rs

@@ -119,14 +119,14 @@ impl<P, B> Streams<P, B>
         let mut me = self.inner.lock().unwrap();
         let me = &mut *me;
 
-        let stream = match me.store.find_mut(&id) {
+        let mut stream = match me.store.find_mut(&id) {
             Some(stream) => stream,
             None => return Err(ProtocolError.into()),
         };
 
         // Ensure there's enough capacity on the connection before acting on the
         // stream.
-        try!(me.actions.recv.recv_data(frame, stream));
+        try!(me.actions.recv.recv_data(frame, &mut stream));
 
         if stream.state.is_closed() {
             me.actions.dec_num_streams(id);
@@ -160,18 +160,28 @@ impl<P, B> Streams<P, B>
         } else {
             // The remote may send window updates for streams that the local now
             // considers closed. It's ok...
-            if let Some(state) = me.store.find_mut(&id) {
+            if let Some(mut stream) = me.store.find_mut(&id) {
-                try!(me.actions.send.recv_stream_window_update(frame, state));
+                try!(me.actions.send.recv_stream_window_update(frame, &mut stream));
             }
         }
 
         Ok(())
     }
 
-    pub fn recv_push_promise(&mut self, _frame: frame::PushPromise)
+    pub fn recv_push_promise(&mut self, frame: frame::PushPromise)
         -> Result<(), ConnectionError>
     {
-        unimplemented!();
+        let mut me = self.inner.lock().unwrap();
+        let me = &mut *me;
+
+        let id = frame.stream_id();
+
+        let mut stream = match me.store.find_mut(&id) {
+            Some(stream) => stream,
+            None => return Err(ProtocolError.into()),
+        };
+
+        me.actions.recv.recv_push_promise(frame, &mut stream)
     }
 
     pub fn send_headers(&mut self, headers: frame::Headers)
@@ -208,31 +218,6 @@ impl<P, B> Streams<P, B>
         */
     }
 
-    /*
-    pub fn send_data(&mut self, frame: &frame::Data<B>)
-        -> Result<(), ConnectionError>
-    {
-        let id = frame.stream_id();
-        let mut me = self.inner.lock().unwrap();
-        let me = &mut *me;
-
-        let stream = match me.store.find_mut(&id) {
-            Some(stream) => stream,
-            None => return Err(UnexpectedFrameType.into()),
-        };
-
-        // Ensure there's enough capacity on the connection before acting on the
-        // stream.
-        try!(me.actions.send.send_data(frame, stream));
-
-        if stream.state.is_closed() {
-            me.actions.dec_num_streams(id);
-        }
-
-        Ok(())
-    }
-    */
-
     pub fn poll_window_update(&mut self)
         -> Poll<WindowUpdate, ConnectionError>
     {
@@ -250,8 +235,8 @@ impl<P, B> Streams<P, B>
         if id.is_zero() {
             try!(me.actions.recv.expand_connection_window(sz));
         } else {
-            if let Some(state) = me.store.find_mut(&id) {
+            if let Some(mut stream) = me.store.find_mut(&id) {
-                try!(me.actions.recv.expand_stream_window(id, sz, state));
+                try!(me.actions.recv.expand_stream_window(id, sz, &mut stream));
             }
         }