diff options
Diffstat (limited to 'third_party/rust/futures-util/src/compat/compat01as03.rs')
| -rw-r--r-- | third_party/rust/futures-util/src/compat/compat01as03.rs | 454 |
1 files changed, 454 insertions, 0 deletions
diff --git a/third_party/rust/futures-util/src/compat/compat01as03.rs b/third_party/rust/futures-util/src/compat/compat01as03.rs new file mode 100644 index 0000000000..36de1da98d --- /dev/null +++ b/third_party/rust/futures-util/src/compat/compat01as03.rs @@ -0,0 +1,454 @@ +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")))] +#[allow(unreachable_pub)] // https://github.com/rust-lang/rust/issues/57411 +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). + /// + /// ``` + /// # if cfg!(miri) { return; } // https://github.com/rust-lang/futures-rs/issues/2514 + /// # 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). + /// + /// ``` + /// # if cfg!(miri) { return; } // https://github.com/rust-lang/futures-rs/issues/2514 + /// # 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). + /// + /// ``` + /// # if cfg!(miri) { return; } // https://github.com/rust-lang/futures-rs/issues/2514 + /// # 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). + /// + /// ``` + /// # if cfg!(miri) { return; } // https://github.com/rust-lang/futures-rs/issues/2514 + /// # 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). + /// + /// ``` + /// # if cfg!(miri) { return; } // https://github.com/rust-lang/futures-rs/issues/2514 + /// # 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)) + } + } +} |