Move tokio-io into the git repository. (#96)

The crates remain separate, but are now developed in the same git
repository using cargo workspaces.

This facilitates making coordinated changes.

tokio-io/src/framed_write.rs

@@ -0,0 +1,256 @@
+use std::io::{self, Read};
+use std::fmt;
+
+use {AsyncRead, AsyncWrite};
+use codec::Decoder;
+use framed::Fuse;
+
+use futures::{Async, AsyncSink, Poll, Stream, Sink, StartSend};
+use bytes::BytesMut;
+
+/// Trait of helper objects to write out messages as bytes, for use with
+/// `FramedWrite`.
+pub trait Encoder {
+    /// The type of items consumed by the `Encoder`
+    type Item;
+
+    /// The type of encoding errors.
+    ///
+    /// `FramedWrite` requires `Encoder`s errors to implement `From<io::Error>`
+    /// in the interest letting it return `Error`s directly.
+    type Error: From<io::Error>;
+
+    /// Encodes a frame into the buffer provided.
+    ///
+    /// This method will encode `item` into the byte buffer provided by `dst`.
+    /// The `dst` provided is an internal buffer of the `Framed` instance and
+    /// will be written out when possible.
+    fn encode(&mut self, item: Self::Item, dst: &mut BytesMut)
+              -> Result<(), Self::Error>;
+}
+
+/// A `Sink` of frames encoded to an `AsyncWrite`.
+pub struct FramedWrite<T, E> {
+    inner: FramedWrite2<Fuse<T, E>>,
+}
+
+pub struct FramedWrite2<T> {
+    inner: T,
+    buffer: BytesMut,
+}
+
+const INITIAL_CAPACITY: usize = 8 * 1024;
+const BACKPRESSURE_BOUNDARY: usize = INITIAL_CAPACITY;
+
+impl<T, E> FramedWrite<T, E>
+    where T: AsyncWrite,
+          E: Encoder,
+{
+    /// Creates a new `FramedWrite` with the given `encoder`.
+    pub fn new(inner: T, encoder: E) -> FramedWrite<T, E> {
+        FramedWrite {
+            inner: framed_write2(Fuse(inner, encoder)),
+        }
+    }
+}
+
+impl<T, E> FramedWrite<T, E> {
+    /// Returns a reference to the underlying I/O stream wrapped by
+    /// `FramedWrite`.
+    ///
+    /// Note that care should be taken to not tamper with the underlying stream
+    /// of data coming in as it may corrupt the stream of frames otherwise
+    /// being worked with.
+    pub fn get_ref(&self) -> &T {
+        &self.inner.inner.0
+    }
+
+    /// Returns a mutable reference to the underlying I/O stream wrapped by
+    /// `FramedWrite`.
+    ///
+    /// Note that care should be taken to not tamper with the underlying stream
+    /// of data coming in as it may corrupt the stream of frames otherwise
+    /// being worked with.
+    pub fn get_mut(&mut self) -> &mut T {
+        &mut self.inner.inner.0
+    }
+
+    /// Consumes the `FramedWrite`, returning its underlying I/O stream.
+    ///
+    /// Note that care should be taken to not tamper with the underlying stream
+    /// of data coming in as it may corrupt the stream of frames otherwise
+    /// being worked with.
+    pub fn into_inner(self) -> T {
+        self.inner.inner.0
+    }
+
+    /// Returns a reference to the underlying decoder.
+    pub fn encoder(&self) -> &E {
+        &self.inner.inner.1
+    }
+
+    /// Returns a mutable reference to the underlying decoder.
+    pub fn encoder_mut(&mut self) -> &mut E {
+        &mut self.inner.inner.1
+    }
+}
+
+impl<T, E> Sink for FramedWrite<T, E>
+    where T: AsyncWrite,
+          E: Encoder,
+{
+    type SinkItem = E::Item;
+    type SinkError = E::Error;
+
+    fn start_send(&mut self, item: E::Item) -> StartSend<E::Item, E::Error> {
+        self.inner.start_send(item)
+    }
+
+    fn poll_complete(&mut self) -> Poll<(), Self::SinkError> {
+        self.inner.poll_complete()
+    }
+
+    fn close(&mut self) -> Poll<(), Self::SinkError> {
+        Ok(try!(self.inner.close()))
+    }
+}
+
+impl<T, D> Stream for FramedWrite<T, D>
+    where T: Stream,
+{
+    type Item = T::Item;
+    type Error = T::Error;
+
+    fn poll(&mut self) -> Poll<Option<Self::Item>, Self::Error> {
+        self.inner.inner.0.poll()
+    }
+}
+
+impl<T, U> fmt::Debug for FramedWrite<T, U>
+    where T: fmt::Debug,
+          U: fmt::Debug,
+{
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_struct("FramedWrite")
+         .field("inner", &self.inner.get_ref().0)
+         .field("encoder", &self.inner.get_ref().1)
+         .field("buffer", &self.inner.buffer)
+         .finish()
+    }
+}
+
+// ===== impl FramedWrite2 =====
+
+pub fn framed_write2<T>(inner: T) -> FramedWrite2<T> {
+    FramedWrite2 {
+        inner: inner,
+        buffer: BytesMut::with_capacity(INITIAL_CAPACITY),
+    }
+}
+
+pub fn framed_write2_with_buffer<T>(inner: T, mut buf: BytesMut) -> FramedWrite2<T> {
+    if buf.capacity() < INITIAL_CAPACITY {
+        let bytes_to_reserve = INITIAL_CAPACITY - buf.capacity();
+        buf.reserve(bytes_to_reserve);
+    }
+    FramedWrite2 {
+        inner: inner,
+        buffer: buf,
+    }
+}
+
+impl<T> FramedWrite2<T> {
+    pub fn get_ref(&self) -> &T {
+        &self.inner
+    }
+
+    pub fn into_inner(self) -> T {
+        self.inner
+    }
+
+    pub fn into_parts(self) -> (T, BytesMut) {
+        (self.inner, self.buffer)
+    }
+
+    pub fn get_mut(&mut self) -> &mut T {
+        &mut self.inner
+    }
+}
+
+impl<T> Sink for FramedWrite2<T>
+    where T: AsyncWrite + Encoder,
+{
+    type SinkItem = T::Item;
+    type SinkError = T::Error;
+
+    fn start_send(&mut self, item: T::Item) -> StartSend<T::Item, T::Error> {
+        // If the buffer is already over 8KiB, then attempt to flush it. If after flushing it's
+        // *still* over 8KiB, then apply backpressure (reject the send).
+        if self.buffer.len() >= BACKPRESSURE_BOUNDARY {
+            try!(self.poll_complete());
+
+            if self.buffer.len() >= BACKPRESSURE_BOUNDARY {
+                return Ok(AsyncSink::NotReady(item));
+            }
+        }
+
+        try!(self.inner.encode(item, &mut self.buffer));
+
+        Ok(AsyncSink::Ready)
+    }
+
+    fn poll_complete(&mut self) -> Poll<(), Self::SinkError> {
+        trace!("flushing framed transport");
+
+        while !self.buffer.is_empty() {
+            trace!("writing; remaining={}", self.buffer.len());
+
+            let n = try_nb!(self.inner.write(&self.buffer));
+
+            if n == 0 {
+                return Err(io::Error::new(io::ErrorKind::WriteZero, "failed to
+                                          write frame to transport").into());
+            }
+
+            // TODO: Add a way to `bytes` to do this w/o returning the drained
+            // data.
+            let _ = self.buffer.split_to(n);
+        }
+
+        // Try flushing the underlying IO
+        try_nb!(self.inner.flush());
+
+        trace!("framed transport flushed");
+        return Ok(Async::Ready(()));
+    }
+
+    fn close(&mut self) -> Poll<(), Self::SinkError> {
+        try_ready!(self.poll_complete());
+        Ok(try!(self.inner.shutdown()))
+    }
+}
+
+impl<T: Decoder> Decoder for FramedWrite2<T> {
+    type Item = T::Item;
+    type Error = T::Error;
+
+    fn decode(&mut self, src: &mut BytesMut) -> Result<Option<T::Item>, T::Error> {
+        self.inner.decode(src)
+    }
+
+    fn decode_eof(&mut self, src: &mut BytesMut) -> Result<Option<T::Item>, T::Error> {
+        self.inner.decode_eof(src)
+    }
+}
+
+impl<T: Read> Read for FramedWrite2<T> {
+    fn read(&mut self, dst: &mut [u8]) -> io::Result<usize> {
+        self.inner.read(dst)
+    }
+}
+
+impl<T: AsyncRead> AsyncRead for FramedWrite2<T> {
+    unsafe fn prepare_uninitialized_buffer(&self, buf: &mut [u8]) -> bool {
+        self.inner.prepare_uninitialized_buffer(buf)
+    }
+}