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use futures_core::task::{Context, Poll};
use futures_io::{AsyncBufRead, AsyncRead, AsyncSeek, AsyncWrite, IoSlice, IoSliceMut, SeekFrom};
use std::pin::Pin;
use std::{fmt, io};
/// A simple wrapper type which allows types which implement only
/// implement `std::io::Read` or `std::io::Write`
/// to be used in contexts which expect an `AsyncRead` or `AsyncWrite`.
///
/// If these types issue an error with the kind `io::ErrorKind::WouldBlock`,
/// it is expected that they will notify the current task on readiness.
/// Synchronous `std` types should not issue errors of this kind and
/// are safe to use in this context. However, using these types with
/// `AllowStdIo` will cause the event loop to block, so they should be used
/// with care.
#[derive(Debug, Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
pub struct AllowStdIo<T>(T);
impl<T> Unpin for AllowStdIo<T> {}
macro_rules! try_with_interrupt {
($e:expr) => {
loop {
match $e {
Ok(e) => {
break e;
}
Err(ref e) if e.kind() == ::std::io::ErrorKind::Interrupted => {
continue;
}
Err(e) => {
return Poll::Ready(Err(e));
}
}
}
};
}
impl<T> AllowStdIo<T> {
/// Creates a new `AllowStdIo` from an existing IO object.
pub fn new(io: T) -> Self {
Self(io)
}
/// Returns a reference to the contained IO object.
pub fn get_ref(&self) -> &T {
&self.0
}
/// Returns a mutable reference to the contained IO object.
pub fn get_mut(&mut self) -> &mut T {
&mut self.0
}
/// Consumes self and returns the contained IO object.
pub fn into_inner(self) -> T {
self.0
}
}
impl<T> io::Write for AllowStdIo<T>
where
T: io::Write,
{
fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
self.0.write(buf)
}
fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
self.0.write_vectored(bufs)
}
fn flush(&mut self) -> io::Result<()> {
self.0.flush()
}
fn write_all(&mut self, buf: &[u8]) -> io::Result<()> {
self.0.write_all(buf)
}
fn write_fmt(&mut self, fmt: fmt::Arguments<'_>) -> io::Result<()> {
self.0.write_fmt(fmt)
}
}
impl<T> AsyncWrite for AllowStdIo<T>
where
T: io::Write,
{
fn poll_write(
mut self: Pin<&mut Self>,
_: &mut Context<'_>,
buf: &[u8],
) -> Poll<io::Result<usize>> {
Poll::Ready(Ok(try_with_interrupt!(self.0.write(buf))))
}
fn poll_write_vectored(
mut self: Pin<&mut Self>,
_: &mut Context<'_>,
bufs: &[IoSlice<'_>],
) -> Poll<io::Result<usize>> {
Poll::Ready(Ok(try_with_interrupt!(self.0.write_vectored(bufs))))
}
fn poll_flush(mut self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<io::Result<()>> {
try_with_interrupt!(self.0.flush());
Poll::Ready(Ok(()))
}
fn poll_close(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
self.poll_flush(cx)
}
}
impl<T> io::Read for AllowStdIo<T>
where
T: io::Read,
{
fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
self.0.read(buf)
}
fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
self.0.read_vectored(bufs)
}
fn read_to_end(&mut self, buf: &mut Vec<u8>) -> io::Result<usize> {
self.0.read_to_end(buf)
}
fn read_to_string(&mut self, buf: &mut String) -> io::Result<usize> {
self.0.read_to_string(buf)
}
fn read_exact(&mut self, buf: &mut [u8]) -> io::Result<()> {
self.0.read_exact(buf)
}
}
impl<T> AsyncRead for AllowStdIo<T>
where
T: io::Read,
{
fn poll_read(
mut self: Pin<&mut Self>,
_: &mut Context<'_>,
buf: &mut [u8],
) -> Poll<io::Result<usize>> {
Poll::Ready(Ok(try_with_interrupt!(self.0.read(buf))))
}
fn poll_read_vectored(
mut self: Pin<&mut Self>,
_: &mut Context<'_>,
bufs: &mut [IoSliceMut<'_>],
) -> Poll<io::Result<usize>> {
Poll::Ready(Ok(try_with_interrupt!(self.0.read_vectored(bufs))))
}
}
impl<T> io::Seek for AllowStdIo<T>
where
T: io::Seek,
{
fn seek(&mut self, pos: SeekFrom) -> io::Result<u64> {
self.0.seek(pos)
}
}
impl<T> AsyncSeek for AllowStdIo<T>
where
T: io::Seek,
{
fn poll_seek(
mut self: Pin<&mut Self>,
_: &mut Context<'_>,
pos: SeekFrom,
) -> Poll<io::Result<u64>> {
Poll::Ready(Ok(try_with_interrupt!(self.0.seek(pos))))
}
}
impl<T> io::BufRead for AllowStdIo<T>
where
T: io::BufRead,
{
fn fill_buf(&mut self) -> io::Result<&[u8]> {
self.0.fill_buf()
}
fn consume(&mut self, amt: usize) {
self.0.consume(amt)
}
}
impl<T> AsyncBufRead for AllowStdIo<T>
where
T: io::BufRead,
{
fn poll_fill_buf(mut self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<io::Result<&[u8]>> {
let this: *mut Self = &mut *self as *mut _;
Poll::Ready(Ok(try_with_interrupt!(unsafe { &mut *this }.0.fill_buf())))
}
fn consume(mut self: Pin<&mut Self>, amt: usize) {
self.0.consume(amt)
}
}