1 files changed, 200 insertions, 0 deletions
diff --git a/third_party/rust/futures-util/src/io/allow_std.rs b/third_party/rust/futures-util/src/io/allow_std.rs
new file mode 100644
index 0000000000..ec30ee31e5
--- /dev/null
+++ b/third_party/rust/futures-util/src/io/allow_std.rs
@@ -0,0 +1,200 @@
+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)
+    }
+}