codec: update to use std-future (#1214)

Strategy was to - copy the old codec code that was temporarily being stashed in `tokio-io` - modify all the type signatures to use Pin, as literal a translation as possible - fix up the tests likewise This is intended just to get things compiling and passing tests. Beyond that there is surely lots of refactoring that can be done to make things more idiomatic. The docs are unchanged. Closes #1189
2026-08-26 00:00:16 +02:00 · 2019-06-27 10:10:29 -07:00
parent ed4d4a5353
commit 6b9e7bdace
16 changed files with 1256 additions and 100 deletions
@@ -0,0 +1,308 @@
+#![allow(deprecated)]
+
+use std::fmt;
+use std::io::{self, Read, Write};
+use std::pin::Pin;
+use std::task::{Context, Poll};
+
+use crate::decoder::Decoder;
+use crate::encoder::Encoder;
+use crate::framed_read::{framed_read2, framed_read2_with_buffer, FramedRead2};
+use crate::framed_write::{framed_write2, framed_write2_with_buffer, FramedWrite2};
+use tokio_futures::{Sink, Stream};
+use tokio_io::{AsyncRead, AsyncWrite};
+
+use bytes::BytesMut;
+
+/// 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 `AsyncRead::framed` adapter.
+pub struct Framed<T, U> {
+    inner: FramedRead2<FramedWrite2<Fuse<T, U>>>,
+}
+
+pub struct Fuse<T, U>(pub T, pub U);
+
+impl<T, U> Framed<T, U>
+where
+    T: AsyncRead + AsyncWrite,
+    U: Decoder + Encoder,
+{
+    /// Provides a `Stream` and `Sink` interface for reading and writing to this
+    /// `Io` object, using `Decode` and `Encode` 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.
+    pub fn new(inner: T, codec: U) -> Framed<T, U> {
+        Framed {
+            inner: framed_read2(framed_write2(Fuse(inner, codec))),
+        }
+    }
+}
+
+impl<T, U> Framed<T, U> {
+    /// Provides a `Stream` and `Sink` interface for reading and writing to this
+    /// `Io` object, using `Decode` and `Encode` 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.
+    pub fn from_parts(parts: FramedParts<T, U>) -> Framed<T, U> {
+        Framed {
+            inner: framed_read2_with_buffer(
+                framed_write2_with_buffer(Fuse(parts.io, parts.codec), parts.write_buf),
+                parts.read_buf,
+            ),
+        }
+    }
+
+    /// Returns a reference to the underlying I/O stream wrapped by
+    /// `Frame`.
+    ///
+    /// 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.get_ref().get_ref().0
+    }
+
+    /// Returns a mutable reference to the underlying I/O stream wrapped by
+    /// `Frame`.
+    ///
+    /// 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.get_mut().get_mut().0
+    }
+
+    /// Returns a reference to the underlying codec wrapped by
+    /// `Frame`.
+    ///
+    /// 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.get_ref().get_ref().1
+    }
+
+    /// Returns a mutable reference to the underlying codec wrapped by
+    /// `Frame`.
+    ///
+    /// 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.get_mut().get_mut().1
+    }
+
+    /// Consumes the `Frame`, 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.into_inner().into_inner().0
+    }
+
+    /// Consumes the `Frame`, 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> {
+        let (inner, read_buf) = self.inner.into_parts();
+        let (inner, write_buf) = inner.into_parts();
+
+        FramedParts {
+            io: inner.0,
+            codec: inner.1,
+            read_buf: read_buf,
+            write_buf: write_buf,
+            _priv: (),
+        }
+    }
+}
+
+impl<T, U> Stream for Framed<T, U>
+where
+    T: AsyncRead + Unpin,
+    U: Decoder + Unpin,
+{
+    type Item = Result<U::Item, U::Error>;
+
+    fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
+        pin!(self.get_mut().inner).poll_next(cx)
+    }
+}
+
+impl<T, I, U> Sink<I> for Framed<T, U>
+where
+    T: AsyncWrite + Unpin,
+    U: Encoder<Item = I> + Unpin,
+    U::Error: From<io::Error>,
+{
+    type Error = U::Error;
+
+    fn poll_ready(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
+        Pin::new(Pin::get_mut(self).inner.get_mut()).poll_ready(cx)
+    }
+
+    fn start_send(self: Pin<&mut Self>, item: I) -> Result<(), Self::Error> {
+        Pin::new(Pin::get_mut(self).inner.get_mut()).start_send(item)
+    }
+
+    fn poll_flush(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
+        Pin::new(Pin::get_mut(self).inner.get_mut()).poll_flush(cx)
+    }
+
+    fn poll_close(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
+        Pin::new(Pin::get_mut(self).inner.get_mut()).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.inner.get_ref().get_ref().0)
+            .field("codec", &self.inner.get_ref().get_ref().1)
+            .finish()
+    }
+}
+
+// ===== impl Fuse =====
+
+impl<T: Read, U> Read for Fuse<T, U> {
+    fn read(&mut self, dst: &mut [u8]) -> io::Result<usize> {
+        self.0.read(dst)
+    }
+}
+
+impl<T: AsyncRead + Unpin, U: Unpin> AsyncRead for Fuse<T, U> {
+    unsafe fn prepare_uninitialized_buffer(&self, buf: &mut [u8]) -> bool {
+        self.0.prepare_uninitialized_buffer(buf)
+    }
+
+    fn poll_read(
+        self: Pin<&mut Self>,
+        cx: &mut Context<'_>,
+        buf: &mut [u8],
+    ) -> Poll<Result<usize, io::Error>> {
+        pin!(self.get_mut().0).poll_read(cx, buf)
+    }
+}
+
+impl<T: Write, U> Write for Fuse<T, U> {
+    fn write(&mut self, src: &[u8]) -> io::Result<usize> {
+        self.0.write(src)
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        self.0.flush()
+    }
+}
+
+impl<T: AsyncWrite + Unpin, U: Unpin> AsyncWrite for Fuse<T, U> {
+    fn poll_write(
+        self: Pin<&mut Self>,
+        cx: &mut Context<'_>,
+        buf: &[u8],
+    ) -> Poll<Result<usize, io::Error>> {
+        pin!(self.get_mut().0).poll_write(cx, buf)
+    }
+
+    fn poll_flush(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), io::Error>> {
+        pin!(self.get_mut().0).poll_flush(cx)
+    }
+
+    fn poll_shutdown(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), io::Error>> {
+        pin!(self.get_mut().0).poll_shutdown(cx)
+    }
+}
+
+impl<T, U: Decoder> Decoder for Fuse<T, U> {
+    type Item = U::Item;
+    type Error = U::Error;
+
+    fn decode(&mut self, buffer: &mut BytesMut) -> Result<Option<Self::Item>, Self::Error> {
+        self.1.decode(buffer)
+    }
+
+    fn decode_eof(&mut self, buffer: &mut BytesMut) -> Result<Option<Self::Item>, Self::Error> {
+        self.1.decode_eof(buffer)
+    }
+}
+
+impl<T, U: Encoder> Encoder for Fuse<T, U> {
+    type Item = U::Item;
+    type Error = U::Error;
+
+    fn encode(&mut self, item: Self::Item, dst: &mut BytesMut) -> Result<(), Self::Error> {
+        self.1.encode(item, dst)
+    }
+}
+
+/// `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.
+#[derive(Debug)]
+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(io: T, codec: U) -> FramedParts<T, U> {
+        FramedParts {
+            io,
+            codec,
+            read_buf: BytesMut::new(),
+            write_buf: BytesMut::new(),
+            _priv: (),
+        }
+    }
+}