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use futures_01::executor::{
spawn as spawn01, Notify as Notify01, NotifyHandle as NotifyHandle01, Spawn as Spawn01,
UnsafeNotify as UnsafeNotify01,
};
use futures_01::{Async as Async01, Future as Future01, Stream as Stream01};
#[cfg(feature = "sink")]
use futures_01::{AsyncSink as AsyncSink01, Sink as Sink01};
use futures_core::{future::Future as Future03, stream::Stream as Stream03, task as task03};
#[cfg(feature = "sink")]
use futures_sink::Sink as Sink03;
use std::pin::Pin;
use std::task::Context;
#[cfg(feature = "io-compat")]
#[cfg_attr(docsrs, doc(cfg(feature = "io-compat")))]
pub use io::{AsyncRead01CompatExt, AsyncWrite01CompatExt};
/// Converts a futures 0.1 Future, Stream, AsyncRead, or AsyncWrite
/// object to a futures 0.3-compatible version,
#[derive(Debug)]
#[must_use = "futures do nothing unless you `.await` or poll them"]
pub struct Compat01As03<T> {
pub(crate) inner: Spawn01<T>,
}
impl<T> Unpin for Compat01As03<T> {}
impl<T> Compat01As03<T> {
/// Wraps a futures 0.1 Future, Stream, AsyncRead, or AsyncWrite
/// object in a futures 0.3-compatible wrapper.
pub fn new(object: T) -> Self {
Self { inner: spawn01(object) }
}
fn in_notify<R>(&mut self, cx: &mut Context<'_>, f: impl FnOnce(&mut T) -> R) -> R {
let notify = &WakerToHandle(cx.waker());
self.inner.poll_fn_notify(notify, 0, f)
}
/// Get a reference to 0.1 Future, Stream, AsyncRead, or AsyncWrite object contained within.
pub fn get_ref(&self) -> &T {
self.inner.get_ref()
}
/// Get a mutable reference to 0.1 Future, Stream, AsyncRead or AsyncWrite object contained
/// within.
pub fn get_mut(&mut self) -> &mut T {
self.inner.get_mut()
}
/// Consume this wrapper to return the underlying 0.1 Future, Stream, AsyncRead, or
/// AsyncWrite object.
pub fn into_inner(self) -> T {
self.inner.into_inner()
}
}
/// Extension trait for futures 0.1 [`Future`](futures_01::future::Future)
pub trait Future01CompatExt: Future01 {
/// Converts a futures 0.1
/// [`Future<Item = T, Error = E>`](futures_01::future::Future)
/// into a futures 0.3
/// [`Future<Output = Result<T, E>>`](futures_core::future::Future).
///
/// ```
/// # futures::executor::block_on(async {
/// # // TODO: These should be all using `futures::compat`, but that runs up against Cargo
/// # // feature issues
/// use futures_util::compat::Future01CompatExt;
///
/// let future = futures_01::future::ok::<u32, ()>(1);
/// assert_eq!(future.compat().await, Ok(1));
/// # });
/// ```
fn compat(self) -> Compat01As03<Self>
where
Self: Sized,
{
Compat01As03::new(self)
}
}
impl<Fut: Future01> Future01CompatExt for Fut {}
/// Extension trait for futures 0.1 [`Stream`](futures_01::stream::Stream)
pub trait Stream01CompatExt: Stream01 {
/// Converts a futures 0.1
/// [`Stream<Item = T, Error = E>`](futures_01::stream::Stream)
/// into a futures 0.3
/// [`Stream<Item = Result<T, E>>`](futures_core::stream::Stream).
///
/// ```
/// # futures::executor::block_on(async {
/// use futures::stream::StreamExt;
/// use futures_util::compat::Stream01CompatExt;
///
/// let stream = futures_01::stream::once::<u32, ()>(Ok(1));
/// let mut stream = stream.compat();
/// assert_eq!(stream.next().await, Some(Ok(1)));
/// assert_eq!(stream.next().await, None);
/// # });
/// ```
fn compat(self) -> Compat01As03<Self>
where
Self: Sized,
{
Compat01As03::new(self)
}
}
impl<St: Stream01> Stream01CompatExt for St {}
/// Extension trait for futures 0.1 [`Sink`](futures_01::sink::Sink)
#[cfg(feature = "sink")]
#[cfg_attr(docsrs, doc(cfg(feature = "sink")))]
pub trait Sink01CompatExt: Sink01 {
/// Converts a futures 0.1
/// [`Sink<SinkItem = T, SinkError = E>`](futures_01::sink::Sink)
/// into a futures 0.3
/// [`Sink<T, Error = E>`](futures_sink::Sink).
///
/// ```
/// # futures::executor::block_on(async {
/// use futures::{sink::SinkExt, stream::StreamExt};
/// use futures_util::compat::{Stream01CompatExt, Sink01CompatExt};
///
/// let (tx, rx) = futures_01::unsync::mpsc::channel(1);
/// let (mut tx, mut rx) = (tx.sink_compat(), rx.compat());
///
/// tx.send(1).await.unwrap();
/// drop(tx);
/// assert_eq!(rx.next().await, Some(Ok(1)));
/// assert_eq!(rx.next().await, None);
/// # });
/// ```
fn sink_compat(self) -> Compat01As03Sink<Self, Self::SinkItem>
where
Self: Sized,
{
Compat01As03Sink::new(self)
}
}
#[cfg(feature = "sink")]
impl<Si: Sink01> Sink01CompatExt for Si {}
fn poll_01_to_03<T, E>(x: Result<Async01<T>, E>) -> task03::Poll<Result<T, E>> {
match x? {
Async01::Ready(t) => task03::Poll::Ready(Ok(t)),
Async01::NotReady => task03::Poll::Pending,
}
}
impl<Fut: Future01> Future03 for Compat01As03<Fut> {
type Output = Result<Fut::Item, Fut::Error>;
fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> task03::Poll<Self::Output> {
poll_01_to_03(self.in_notify(cx, Future01::poll))
}
}
impl<St: Stream01> Stream03 for Compat01As03<St> {
type Item = Result<St::Item, St::Error>;
fn poll_next(
mut self: Pin<&mut Self>,
cx: &mut Context<'_>,
) -> task03::Poll<Option<Self::Item>> {
match self.in_notify(cx, Stream01::poll)? {
Async01::Ready(Some(t)) => task03::Poll::Ready(Some(Ok(t))),
Async01::Ready(None) => task03::Poll::Ready(None),
Async01::NotReady => task03::Poll::Pending,
}
}
}
/// Converts a futures 0.1 Sink object to a futures 0.3-compatible version
#[cfg(feature = "sink")]
#[cfg_attr(docsrs, doc(cfg(feature = "sink")))]
#[derive(Debug)]
#[must_use = "sinks do nothing unless polled"]
pub struct Compat01As03Sink<S, SinkItem> {
pub(crate) inner: Spawn01<S>,
pub(crate) buffer: Option<SinkItem>,
pub(crate) close_started: bool,
}
#[cfg(feature = "sink")]
impl<S, SinkItem> Unpin for Compat01As03Sink<S, SinkItem> {}
#[cfg(feature = "sink")]
impl<S, SinkItem> Compat01As03Sink<S, SinkItem> {
/// Wraps a futures 0.1 Sink object in a futures 0.3-compatible wrapper.
pub fn new(inner: S) -> Self {
Self { inner: spawn01(inner), buffer: None, close_started: false }
}
fn in_notify<R>(&mut self, cx: &mut Context<'_>, f: impl FnOnce(&mut S) -> R) -> R {
let notify = &WakerToHandle(cx.waker());
self.inner.poll_fn_notify(notify, 0, f)
}
/// Get a reference to 0.1 Sink object contained within.
pub fn get_ref(&self) -> &S {
self.inner.get_ref()
}
/// Get a mutable reference to 0.1 Sink contained within.
pub fn get_mut(&mut self) -> &mut S {
self.inner.get_mut()
}
/// Consume this wrapper to return the underlying 0.1 Sink.
pub fn into_inner(self) -> S {
self.inner.into_inner()
}
}
#[cfg(feature = "sink")]
impl<S, SinkItem> Stream03 for Compat01As03Sink<S, SinkItem>
where
S: Stream01,
{
type Item = Result<S::Item, S::Error>;
fn poll_next(
mut self: Pin<&mut Self>,
cx: &mut Context<'_>,
) -> task03::Poll<Option<Self::Item>> {
match self.in_notify(cx, Stream01::poll)? {
Async01::Ready(Some(t)) => task03::Poll::Ready(Some(Ok(t))),
Async01::Ready(None) => task03::Poll::Ready(None),
Async01::NotReady => task03::Poll::Pending,
}
}
}
#[cfg(feature = "sink")]
impl<S, SinkItem> Sink03<SinkItem> for Compat01As03Sink<S, SinkItem>
where
S: Sink01<SinkItem = SinkItem>,
{
type Error = S::SinkError;
fn start_send(mut self: Pin<&mut Self>, item: SinkItem) -> Result<(), Self::Error> {
debug_assert!(self.buffer.is_none());
self.buffer = Some(item);
Ok(())
}
fn poll_ready(
mut self: Pin<&mut Self>,
cx: &mut Context<'_>,
) -> task03::Poll<Result<(), Self::Error>> {
match self.buffer.take() {
Some(item) => match self.in_notify(cx, |f| f.start_send(item))? {
AsyncSink01::Ready => task03::Poll::Ready(Ok(())),
AsyncSink01::NotReady(i) => {
self.buffer = Some(i);
task03::Poll::Pending
}
},
None => task03::Poll::Ready(Ok(())),
}
}
fn poll_flush(
mut self: Pin<&mut Self>,
cx: &mut Context<'_>,
) -> task03::Poll<Result<(), Self::Error>> {
let item = self.buffer.take();
match self.in_notify(cx, |f| match item {
Some(i) => match f.start_send(i)? {
AsyncSink01::Ready => f.poll_complete().map(|i| (i, None)),
AsyncSink01::NotReady(t) => Ok((Async01::NotReady, Some(t))),
},
None => f.poll_complete().map(|i| (i, None)),
})? {
(Async01::Ready(_), _) => task03::Poll::Ready(Ok(())),
(Async01::NotReady, item) => {
self.buffer = item;
task03::Poll::Pending
}
}
}
fn poll_close(
mut self: Pin<&mut Self>,
cx: &mut Context<'_>,
) -> task03::Poll<Result<(), Self::Error>> {
let item = self.buffer.take();
let close_started = self.close_started;
let result = self.in_notify(cx, |f| {
if !close_started {
if let Some(item) = item {
if let AsyncSink01::NotReady(item) = f.start_send(item)? {
return Ok((Async01::NotReady, Some(item), false));
}
}
if let Async01::NotReady = f.poll_complete()? {
return Ok((Async01::NotReady, None, false));
}
}
Ok((<S as Sink01>::close(f)?, None, true))
});
match result? {
(Async01::Ready(_), _, _) => task03::Poll::Ready(Ok(())),
(Async01::NotReady, item, close_started) => {
self.buffer = item;
self.close_started = close_started;
task03::Poll::Pending
}
}
}
}
struct NotifyWaker(task03::Waker);
#[allow(missing_debug_implementations)] // false positive: this is private type
#[derive(Clone)]
struct WakerToHandle<'a>(&'a task03::Waker);
impl From<WakerToHandle<'_>> for NotifyHandle01 {
fn from(handle: WakerToHandle<'_>) -> Self {
let ptr = Box::new(NotifyWaker(handle.0.clone()));
unsafe { Self::new(Box::into_raw(ptr)) }
}
}
impl Notify01 for NotifyWaker {
fn notify(&self, _: usize) {
self.0.wake_by_ref();
}
}
unsafe impl UnsafeNotify01 for NotifyWaker {
unsafe fn clone_raw(&self) -> NotifyHandle01 {
WakerToHandle(&self.0).into()
}
unsafe fn drop_raw(&self) {
let ptr: *const dyn UnsafeNotify01 = self;
drop(Box::from_raw(ptr as *mut dyn UnsafeNotify01));
}
}
#[cfg(feature = "io-compat")]
#[cfg_attr(docsrs, doc(cfg(feature = "io-compat")))]
mod io {
use super::*;
use futures_io::{AsyncRead as AsyncRead03, AsyncWrite as AsyncWrite03};
use std::io::Error;
use tokio_io::{AsyncRead as AsyncRead01, AsyncWrite as AsyncWrite01};
/// Extension trait for tokio-io [`AsyncRead`](tokio_io::AsyncRead)
#[cfg_attr(docsrs, doc(cfg(feature = "io-compat")))]
pub trait AsyncRead01CompatExt: AsyncRead01 {
/// Converts a tokio-io [`AsyncRead`](tokio_io::AsyncRead) into a futures-io 0.3
/// [`AsyncRead`](futures_io::AsyncRead).
///
/// ```
/// # futures::executor::block_on(async {
/// use futures::io::AsyncReadExt;
/// use futures_util::compat::AsyncRead01CompatExt;
///
/// let input = b"Hello World!";
/// let reader /* : impl tokio_io::AsyncRead */ = std::io::Cursor::new(input);
/// let mut reader /* : impl futures::io::AsyncRead + Unpin */ = reader.compat();
///
/// let mut output = Vec::with_capacity(12);
/// reader.read_to_end(&mut output).await.unwrap();
/// assert_eq!(output, input);
/// # });
/// ```
fn compat(self) -> Compat01As03<Self>
where
Self: Sized,
{
Compat01As03::new(self)
}
}
impl<R: AsyncRead01> AsyncRead01CompatExt for R {}
/// Extension trait for tokio-io [`AsyncWrite`](tokio_io::AsyncWrite)
#[cfg_attr(docsrs, doc(cfg(feature = "io-compat")))]
pub trait AsyncWrite01CompatExt: AsyncWrite01 {
/// Converts a tokio-io [`AsyncWrite`](tokio_io::AsyncWrite) into a futures-io 0.3
/// [`AsyncWrite`](futures_io::AsyncWrite).
///
/// ```
/// # futures::executor::block_on(async {
/// use futures::io::AsyncWriteExt;
/// use futures_util::compat::AsyncWrite01CompatExt;
///
/// let input = b"Hello World!";
/// let mut cursor = std::io::Cursor::new(Vec::with_capacity(12));
///
/// let mut writer = (&mut cursor).compat();
/// writer.write_all(input).await.unwrap();
///
/// assert_eq!(cursor.into_inner(), input);
/// # });
/// ```
fn compat(self) -> Compat01As03<Self>
where
Self: Sized,
{
Compat01As03::new(self)
}
}
impl<W: AsyncWrite01> AsyncWrite01CompatExt for W {}
impl<R: AsyncRead01> AsyncRead03 for Compat01As03<R> {
fn poll_read(
mut self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &mut [u8],
) -> task03::Poll<Result<usize, Error>> {
poll_01_to_03(self.in_notify(cx, |x| x.poll_read(buf)))
}
}
impl<W: AsyncWrite01> AsyncWrite03 for Compat01As03<W> {
fn poll_write(
mut self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &[u8],
) -> task03::Poll<Result<usize, Error>> {
poll_01_to_03(self.in_notify(cx, |x| x.poll_write(buf)))
}
fn poll_flush(
mut self: Pin<&mut Self>,
cx: &mut Context<'_>,
) -> task03::Poll<Result<(), Error>> {
poll_01_to_03(self.in_notify(cx, AsyncWrite01::poll_flush))
}
fn poll_close(
mut self: Pin<&mut Self>,
cx: &mut Context<'_>,
) -> task03::Poll<Result<(), Error>> {
poll_01_to_03(self.in_notify(cx, AsyncWrite01::shutdown))
}
}
}