blob: 8ba75092db268e4c82875cd64d74469b0f2dd025 [file] [log] [blame]
#![allow(deprecated)]
use std::io::{self, Read};
use std::fmt;
use {AsyncRead, AsyncWrite};
use codec::{Decoder, Encoder};
use super::framed::Fuse;
use futures::{Async, AsyncSink, Poll, Stream, Sink, StartSend};
use bytes::BytesMut;
/// 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_ready!(self.inner.poll_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_ready!(self.inner.poll_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)
}
}