blob: 91640778b2e404111ca3a6a7a61429e2bd290944 [file] [log] [blame]
use futures_core::future::{FusedFuture, Future};
use futures_core::stream::{FusedStream, Stream};
use futures_io::{
self as io, AsyncBufRead, AsyncRead, AsyncSeek, AsyncWrite, IoSlice, IoSliceMut, SeekFrom,
};
use futures_sink::Sink;
use pin_project::pin_project;
use std::{
pin::Pin,
task::{Context, Poll},
};
/// Wrapper that interleaves [`Poll::Pending`] in calls to poll.
///
/// See the `interleave_pending` methods on:
/// * [`FutureTestExt`](crate::future::FutureTestExt::interleave_pending)
/// * [`StreamTestExt`](crate::stream::StreamTestExt::interleave_pending)
/// * [`SinkTestExt`](crate::sink::SinkTestExt::interleave_pending_sink)
/// * [`AsyncReadTestExt`](crate::io::AsyncReadTestExt::interleave_pending)
/// * [`AsyncWriteTestExt`](crate::io::AsyncWriteTestExt::interleave_pending_write)
#[pin_project]
#[derive(Debug)]
pub struct InterleavePending<T> {
#[pin]
inner: T,
pended: bool,
}
impl<T> InterleavePending<T> {
pub(crate) fn new(inner: T) -> Self {
Self { inner, pended: false }
}
/// Acquires a reference to the underlying I/O object that this adaptor is
/// wrapping.
pub fn get_ref(&self) -> &T {
&self.inner
}
/// Acquires a mutable reference to the underlying I/O object that this
/// adaptor is wrapping.
pub fn get_mut(&mut self) -> &mut T {
&mut self.inner
}
/// Acquires a pinned mutable reference to the underlying I/O object that
/// this adaptor is wrapping.
pub fn get_pin_mut(self: Pin<&mut Self>) -> Pin<&mut T> {
self.project().inner
}
/// Consumes this adaptor returning the underlying I/O object.
pub fn into_inner(self) -> T {
self.inner
}
fn poll_with<'a, U>(
self: Pin<&'a mut Self>,
cx: &mut Context<'_>,
f: impl FnOnce(Pin<&'a mut T>, &mut Context<'_>) -> Poll<U>,
) -> Poll<U> {
let this = self.project();
if *this.pended {
let next = f(this.inner, cx);
if next.is_ready() {
*this.pended = false;
}
next
} else {
cx.waker().wake_by_ref();
*this.pended = true;
Poll::Pending
}
}
}
impl<Fut: Future> Future for InterleavePending<Fut> {
type Output = Fut::Output;
fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
self.poll_with(cx, Fut::poll)
}
}
impl<Fut: FusedFuture> FusedFuture for InterleavePending<Fut> {
fn is_terminated(&self) -> bool {
self.inner.is_terminated()
}
}
impl<St: Stream> Stream for InterleavePending<St> {
type Item = St::Item;
fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
self.poll_with(cx, St::poll_next)
}
fn size_hint(&self) -> (usize, Option<usize>) {
self.inner.size_hint()
}
}
impl<St: FusedStream> FusedStream for InterleavePending<St> {
fn is_terminated(&self) -> bool {
self.inner.is_terminated()
}
}
impl<Si: Sink<Item>, Item> Sink<Item> for InterleavePending<Si> {
type Error = Si::Error;
fn poll_ready(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
self.poll_with(cx, Si::poll_ready)
}
fn start_send(self: Pin<&mut Self>, item: Item) -> Result<(), Self::Error> {
self.project().inner.start_send(item)
}
fn poll_flush(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
self.poll_with(cx, Si::poll_flush)
}
fn poll_close(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
self.poll_with(cx, Si::poll_close)
}
}
impl<R: AsyncRead> AsyncRead for InterleavePending<R> {
fn poll_read(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &mut [u8],
) -> Poll<io::Result<usize>> {
self.poll_with(cx, |r, cx| r.poll_read(cx, buf))
}
fn poll_read_vectored(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
bufs: &mut [IoSliceMut<'_>],
) -> Poll<io::Result<usize>> {
self.poll_with(cx, |r, cx| r.poll_read_vectored(cx, bufs))
}
}
impl<W: AsyncWrite> AsyncWrite for InterleavePending<W> {
fn poll_write(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &[u8],
) -> Poll<io::Result<usize>> {
self.poll_with(cx, |w, cx| w.poll_write(cx, buf))
}
fn poll_write_vectored(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
bufs: &[IoSlice<'_>],
) -> Poll<io::Result<usize>> {
self.poll_with(cx, |w, cx| w.poll_write_vectored(cx, bufs))
}
fn poll_flush(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
self.poll_with(cx, W::poll_flush)
}
fn poll_close(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
self.poll_with(cx, W::poll_close)
}
}
impl<S: AsyncSeek> AsyncSeek for InterleavePending<S> {
fn poll_seek(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
pos: SeekFrom,
) -> Poll<io::Result<u64>> {
self.poll_with(cx, |s, cx| s.poll_seek(cx, pos))
}
}
impl<R: AsyncBufRead> AsyncBufRead for InterleavePending<R> {
fn poll_fill_buf(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<&[u8]>> {
self.poll_with(cx, R::poll_fill_buf)
}
fn consume(self: Pin<&mut Self>, amount: usize) {
self.project().inner.consume(amount)
}
}