use crate::codec::decoder::Decoder;
use crate::codec::encoder::Encoder;
use crate::codec::framed_impl::{FramedImpl, RWFrames, ReadFrame, WriteFrame};
use futures_core::Stream;
use tokio::io::{AsyncRead, AsyncWrite};
use bytes::BytesMut;
use futures_sink::Sink;
use pin_project_lite::pin_project;
use std::fmt;
use std::io;
use std::pin::Pin;
use std::task::{Context, Poll};
pin_project! {
/// A unified [`Stream`] and [`Sink`] interface to an underlying I/O object, using
/// the `Encoder` and `Decoder` traits to encode and decode frames.
///
/// You can create a `Framed` instance by using the [`Decoder::framed`] adapter, or
/// by using the `new` function seen below.
///
/// [`Stream`]: futures_core::Stream
/// [`Sink`]: futures_sink::Sink
/// [`AsyncRead`]: tokio::io::AsyncRead
/// [`Decoder::framed`]: crate::codec::Decoder::framed()
pub struct Framed<T, U> {
#[pin]
inner: FramedImpl<T, U, RWFrames>
}
}
impl<T, U> Framed<T, U>
where
T: AsyncRead + AsyncWrite,
{
/// Provides a [`Stream`] and [`Sink`] interface for reading and writing to this
/// I/O object, using [`Decoder`] and [`Encoder`] to read and write the raw data.
///
/// Raw I/O objects work with byte sequences, but higher-level code usually
/// wants to batch these into meaningful chunks, called "frames". This
/// method layers framing on top of an I/O object, by using the codec
/// traits to handle encoding and decoding of messages frames. Note that
/// the incoming and outgoing frame types may be distinct.
///
/// This function returns a *single* object that is both [`Stream`] and
/// [`Sink`]; grouping this into a single object is often useful for layering
/// things like gzip or TLS, which require both read and write access to the
/// underlying object.
///
/// If you want to work more directly with the streams and sink, consider
/// calling [`split`] on the `Framed` returned by this method, which will
/// break them into separate objects, allowing them to interact more easily.
///
/// Note that, for some byte sources, the stream can be resumed after an EOF
/// by reading from it, even after it has returned `None`. Repeated attempts
/// to do so, without new data available, continue to return `None` without
/// creating more (closing) frames.
///
/// [`Stream`]: futures_core::Stream
/// [`Sink`]: futures_sink::Sink
/// [`Decode`]: crate::codec::Decoder
/// [`Encoder`]: crate::codec::Encoder
/// [`split`]: https://docs.rs/futures/0.3/futures/stream/trait.StreamExt.html#method.split
pub fn new(inner: T, codec: U) -> Framed<T, U> {
Framed {
inner: FramedImpl {
inner,
codec,
state: Default::default(),
},
}
}
/// Provides a [`Stream`] and [`Sink`] interface for reading and writing to this
/// I/O object, using [`Decoder`] and [`Encoder`] to read and write the raw data,
/// with a specific read buffer initial capacity.
///
/// Raw I/O objects work with byte sequences, but higher-level code usually
/// wants to batch these into meaningful chunks, called "frames". This
/// method layers framing on top of an I/O object, by using the codec
/// traits to handle encoding and decoding of messages frames. Note that
/// the incoming and outgoing frame types may be distinct.
///
/// This function returns a *single* object that is both [`Stream`] and
/// [`Sink`]; grouping this into a single object is often useful for layering
/// things like gzip or TLS, which require both read and write access to the
/// underlying object.
///
/// If you want to work more directly with the streams and sink, consider
/// calling [`split`] on the `Framed` returned by this method, which will
/// break them into separate objects, allowing them to interact more easily.
///
/// [`Stream`]: futures_core::Stream
/// [`Sink`]: futures_sink::Sink
/// [`Decode`]: crate::codec::Decoder
/// [`Encoder`]: crate::codec::Encoder
/// [`split`]: https://docs.rs/futures/0.3/futures/stream/trait.StreamExt.html#method.split
pub fn with_capacity(inner: T, codec: U, capacity: usize) -> Framed<T, U> {
Framed {
inner: FramedImpl {
inner,
codec,
state: RWFrames {
read: ReadFrame {
eof: false,
is_readable: false,
buffer: BytesMut::with_capacity(capacity),
has_errored: false,
},
write: WriteFrame::default(),
},
},
}
}
}
impl<T, U> Framed<T, U> {
/// Provides a [`Stream`] and [`Sink`] interface for reading and writing to this
/// I/O object, using [`Decoder`] and [`Encoder`] to read and write the raw data.
///
/// Raw I/O objects work with byte sequences, but higher-level code usually
/// wants to batch these into meaningful chunks, called "frames". This
/// method layers framing on top of an I/O object, by using the `Codec`
/// traits to handle encoding and decoding of messages frames. Note that
/// the incoming and outgoing frame types may be distinct.
///
/// This function returns a *single* object that is both [`Stream`] and
/// [`Sink`]; grouping this into a single object is often useful for layering
/// things like gzip or TLS, which require both read and write access to the
/// underlying object.
///
/// This objects takes a stream and a readbuffer and a writebuffer. These field
/// can be obtained from an existing `Framed` with the [`into_parts`] method.
///
/// If you want to work more directly with the streams and sink, consider
/// calling [`split`] on the `Framed` returned by this method, which will
/// break them into separate objects, allowing them to interact more easily.
///
/// [`Stream`]: futures_core::Stream
/// [`Sink`]: futures_sink::Sink
/// [`Decoder`]: crate::codec::Decoder
/// [`Encoder`]: crate::codec::Encoder
/// [`into_parts`]: crate::codec::Framed::into_parts()
/// [`split`]: https://docs.rs/futures/0.3/futures/stream/trait.StreamExt.html#method.split
pub fn from_parts(parts: FramedParts<T, U>) -> Framed<T, U> {
Framed {
inner: FramedImpl {
inner: parts.io,
codec: parts.codec,
state: RWFrames {
read: parts.read_buf.into(),
write: parts.write_buf.into(),
},
},
}
}
/// Returns a reference to the underlying I/O stream wrapped by
/// `Framed`.
///
/// 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
}
/// Returns a mutable reference to the underlying I/O stream wrapped by
/// `Framed`.
///
/// 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
}
/// Returns a pinned mutable reference to the underlying I/O stream wrapped by
/// `Framed`.
///
/// 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_pin_mut(self: Pin<&mut Self>) -> Pin<&mut T> {
self.project().inner.project().inner
}
/// Returns a reference to the underlying codec wrapped by
/// `Framed`.
///
/// Note that care should be taken to not tamper with the underlying codec
/// as it may corrupt the stream of frames otherwise being worked with.
pub fn codec(&self) -> &U {
&self.inner.codec
}
/// Returns a mutable reference to the underlying codec wrapped by
/// `Framed`.
///
/// Note that care should be taken to not tamper with the underlying codec
/// as it may corrupt the stream of frames otherwise being worked with.
pub fn codec_mut(&mut self) -> &mut U {
&mut self.inner.codec
}
/// Maps the codec `U` to `C`, preserving the read and write buffers
/// wrapped by `Framed`.
///
/// Note that care should be taken to not tamper with the underlying codec
/// as it may corrupt the stream of frames otherwise being worked with.
pub fn map_codec<C, F>(self, map: F) -> Framed<T, C>
where
F: FnOnce(U) -> C,
{
// This could be potentially simplified once rust-lang/rust#86555 hits stable
let parts = self.into_parts();
Framed::from_parts(FramedParts {
io: parts.io,
codec: map(parts.codec),
read_buf: parts.read_buf,
write_buf: parts.write_buf,
_priv: (),
})
}
/// Returns a mutable reference to the underlying codec wrapped by
/// `Framed`.
///
/// Note that care should be taken to not tamper with the underlying codec
/// as it may corrupt the stream of frames otherwise being worked with.
pub fn codec_pin_mut(self: Pin<&mut Self>) -> &mut U {
self.project().inner.project().codec
}
/// Returns a reference to the read buffer.
pub fn read_buffer(&self) -> &BytesMut {
&self.inner.state.read.buffer
}
/// Returns a mutable reference to the read buffer.
pub fn read_buffer_mut(&mut self) -> &mut BytesMut {
&mut self.inner.state.read.buffer
}
/// Returns a reference to the write buffer.
pub fn write_buffer(&self) -> &BytesMut {
&self.inner.state.write.buffer
}
/// Returns a mutable reference to the write buffer.
pub fn write_buffer_mut(&mut self) -> &mut BytesMut {
&mut self.inner.state.write.buffer
}
/// Consumes the `Framed`, 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
}
/// Consumes the `Framed`, returning its underlying I/O stream, the buffer
/// with unprocessed data, and the codec.
///
/// 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_parts(self) -> FramedParts<T, U> {
FramedParts {
io: self.inner.inner,
codec: self.inner.codec,
read_buf: self.inner.state.read.buffer,
write_buf: self.inner.state.write.buffer,
_priv: (),
}
}
}
// This impl just defers to the underlying FramedImpl
impl<T, U> Stream for Framed<T, U>
where
T: AsyncRead,
U: Decoder,
{
type Item = Result<U::Item, U::Error>;
fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
self.project().inner.poll_next(cx)
}
}
// This impl just defers to the underlying FramedImpl
impl<T, I, U> Sink<I> for Framed<T, U>
where
T: AsyncWrite,
U: Encoder<I>,
U::Error: From<io::Error>,
{
type Error = U::Error;
fn poll_ready(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
self.project().inner.poll_ready(cx)
}
fn start_send(self: Pin<&mut Self>, item: I) -> Result<(), Self::Error> {
self.project().inner.start_send(item)
}
fn poll_flush(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
self.project().inner.poll_flush(cx)
}
fn poll_close(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
self.project().inner.poll_close(cx)
}
}
impl<T, U> fmt::Debug for Framed<T, U>
where
T: fmt::Debug,
U: fmt::Debug,
{
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("Framed")
.field("io", self.get_ref())
.field("codec", self.codec())
.finish()
}
}
/// `FramedParts` contains an export of the data of a Framed transport.
/// It can be used to construct a new [`Framed`] with a different codec.
/// It contains all current buffers and the inner transport.
///
/// [`Framed`]: crate::codec::Framed
#[derive(Debug)]
#[allow(clippy::manual_non_exhaustive)]
pub struct FramedParts<T, U> {
/// The inner transport used to read bytes to and write bytes to
pub io: T,
/// The codec
pub codec: U,
/// The buffer with read but unprocessed data.
pub read_buf: BytesMut,
/// A buffer with unprocessed data which are not written yet.
pub write_buf: BytesMut,
/// This private field allows us to add additional fields in the future in a
/// backwards compatible way.
_priv: (),
}
impl<T, U> FramedParts<T, U> {
/// Create a new, default, `FramedParts`
pub fn new<I>(io: T, codec: U) -> FramedParts<T, U>
where
U: Encoder<I>,
{
FramedParts {
io,
codec,
read_buf: BytesMut::new(),
write_buf: BytesMut::new(),
_priv: (),
}
}
}