Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 558 insertions, 0 deletions

diff --git a/third_party/rust/futures-io/src/lib.rs b/third_party/rust/futures-io/src/lib.rs
new file mode 100644
index 0000000000..e91eb78492
--- /dev/null
+++ b/third_party/rust/futures-io/src/lib.rs
@@ -0,0 +1,558 @@
+//! Asynchronous I/O
+//!
+//! This crate contains the `AsyncRead`, `AsyncWrite`, `AsyncSeek`, and
+//! `AsyncBufRead` traits, the asynchronous analogs to
+//! `std::io::{Read, Write, Seek, BufRead}`. The primary difference is
+//! that these traits integrate with the asynchronous task system.
+//!
+//! All items of this library are only available when the `std` feature of this
+//! library is activated, and it is activated by default.
+
+#![cfg_attr(not(feature = "std"), no_std)]
+#![warn(missing_debug_implementations, missing_docs, rust_2018_idioms, unreachable_pub)]
+// It cannot be included in the published code because this lints have false positives in the minimum required version.
+#![cfg_attr(test, warn(single_use_lifetimes))]
+#![doc(test(
+    no_crate_inject,
+    attr(
+        deny(warnings, rust_2018_idioms, single_use_lifetimes),
+        allow(dead_code, unused_assignments, unused_variables)
+    )
+))]
+#![cfg_attr(docsrs, feature(doc_cfg))]
+
+#[cfg(feature = "std")]
+mod if_std {
+    use std::io;
+    use std::ops::DerefMut;
+    use std::pin::Pin;
+    use std::task::{Context, Poll};
+
+    // Re-export some types from `std::io` so that users don't have to deal
+    // with conflicts when `use`ing `futures::io` and `std::io`.
+    #[allow(unreachable_pub)] // https://github.com/rust-lang/rust/issues/57411
+    #[doc(no_inline)]
+    pub use io::{Error, ErrorKind, IoSlice, IoSliceMut, Result, SeekFrom};
+
+    /// Read bytes asynchronously.
+    ///
+    /// This trait is analogous to the `std::io::Read` trait, but integrates
+    /// with the asynchronous task system. In particular, the `poll_read`
+    /// method, unlike `Read::read`, will automatically queue the current task
+    /// for wakeup and return if data is not yet available, rather than blocking
+    /// the calling thread.
+    pub trait AsyncRead {
+        /// Attempt to read from the `AsyncRead` into `buf`.
+        ///
+        /// On success, returns `Poll::Ready(Ok(num_bytes_read))`.
+        ///
+        /// If no data is available for reading, the method returns
+        /// `Poll::Pending` and arranges for the current task (via
+        /// `cx.waker().wake_by_ref()`) to receive a notification when the object becomes
+        /// readable or is closed.
+        ///
+        /// # Implementation
+        ///
+        /// This function may not return errors of kind `WouldBlock` or
+        /// `Interrupted`.  Implementations must convert `WouldBlock` into
+        /// `Poll::Pending` and either internally retry or convert
+        /// `Interrupted` into another error kind.
+        fn poll_read(
+            self: Pin<&mut Self>,
+            cx: &mut Context<'_>,
+            buf: &mut [u8],
+        ) -> Poll<Result<usize>>;
+
+        /// Attempt to read from the `AsyncRead` into `bufs` using vectored
+        /// IO operations.
+        ///
+        /// This method is similar to `poll_read`, but allows data to be read
+        /// into multiple buffers using a single operation.
+        ///
+        /// On success, returns `Poll::Ready(Ok(num_bytes_read))`.
+        ///
+        /// If no data is available for reading, the method returns
+        /// `Poll::Pending` and arranges for the current task (via
+        /// `cx.waker().wake_by_ref()`) to receive a notification when the object becomes
+        /// readable or is closed.
+        /// By default, this method delegates to using `poll_read` on the first
+        /// nonempty buffer in `bufs`, or an empty one if none exists. Objects which
+        /// support vectored IO should override this method.
+        ///
+        /// # Implementation
+        ///
+        /// This function may not return errors of kind `WouldBlock` or
+        /// `Interrupted`.  Implementations must convert `WouldBlock` into
+        /// `Poll::Pending` and either internally retry or convert
+        /// `Interrupted` into another error kind.
+        fn poll_read_vectored(
+            self: Pin<&mut Self>,
+            cx: &mut Context<'_>,
+            bufs: &mut [IoSliceMut<'_>],
+        ) -> Poll<Result<usize>> {
+            for b in bufs {
+                if !b.is_empty() {
+                    return self.poll_read(cx, b);
+                }
+            }
+
+            self.poll_read(cx, &mut [])
+        }
+    }
+
+    /// Write bytes asynchronously.
+    ///
+    /// This trait is analogous to the `std::io::Write` trait, but integrates
+    /// with the asynchronous task system. In particular, the `poll_write`
+    /// method, unlike `Write::write`, will automatically queue the current task
+    /// for wakeup and return if the writer cannot take more data, rather than blocking
+    /// the calling thread.
+    pub trait AsyncWrite {
+        /// Attempt to write bytes from `buf` into the object.
+        ///
+        /// On success, returns `Poll::Ready(Ok(num_bytes_written))`.
+        ///
+        /// If the object is not ready for writing, the method returns
+        /// `Poll::Pending` and arranges for the current task (via
+        /// `cx.waker().wake_by_ref()`) to receive a notification when the object becomes
+        /// writable or is closed.
+        ///
+        /// # Implementation
+        ///
+        /// This function may not return errors of kind `WouldBlock` or
+        /// `Interrupted`.  Implementations must convert `WouldBlock` into
+        /// `Poll::Pending` and either internally retry or convert
+        /// `Interrupted` into another error kind.
+        ///
+        /// `poll_write` must try to make progress by flushing the underlying object if
+        /// that is the only way the underlying object can become writable again.
+        fn poll_write(
+            self: Pin<&mut Self>,
+            cx: &mut Context<'_>,
+            buf: &[u8],
+        ) -> Poll<Result<usize>>;
+
+        /// Attempt to write bytes from `bufs` into the object using vectored
+        /// IO operations.
+        ///
+        /// This method is similar to `poll_write`, but allows data from multiple buffers to be written
+        /// using a single operation.
+        ///
+        /// On success, returns `Poll::Ready(Ok(num_bytes_written))`.
+        ///
+        /// If the object is not ready for writing, the method returns
+        /// `Poll::Pending` and arranges for the current task (via
+        /// `cx.waker().wake_by_ref()`) to receive a notification when the object becomes
+        /// writable or is closed.
+        ///
+        /// By default, this method delegates to using `poll_write` on the first
+        /// nonempty buffer in `bufs`, or an empty one if none exists. Objects which
+        /// support vectored IO should override this method.
+        ///
+        /// # Implementation
+        ///
+        /// This function may not return errors of kind `WouldBlock` or
+        /// `Interrupted`.  Implementations must convert `WouldBlock` into
+        /// `Poll::Pending` and either internally retry or convert
+        /// `Interrupted` into another error kind.
+        fn poll_write_vectored(
+            self: Pin<&mut Self>,
+            cx: &mut Context<'_>,
+            bufs: &[IoSlice<'_>],
+        ) -> Poll<Result<usize>> {
+            for b in bufs {
+                if !b.is_empty() {
+                    return self.poll_write(cx, b);
+                }
+            }
+
+            self.poll_write(cx, &[])
+        }
+
+        /// Attempt to flush the object, ensuring that any buffered data reach
+        /// their destination.
+        ///
+        /// On success, returns `Poll::Ready(Ok(()))`.
+        ///
+        /// If flushing cannot immediately complete, this method returns
+        /// `Poll::Pending` and arranges for the current task (via
+        /// `cx.waker().wake_by_ref()`) to receive a notification when the object can make
+        /// progress towards flushing.
+        ///
+        /// # Implementation
+        ///
+        /// This function may not return errors of kind `WouldBlock` or
+        /// `Interrupted`.  Implementations must convert `WouldBlock` into
+        /// `Poll::Pending` and either internally retry or convert
+        /// `Interrupted` into another error kind.
+        ///
+        /// It only makes sense to do anything here if you actually buffer data.
+        fn poll_flush(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<()>>;
+
+        /// Attempt to close the object.
+        ///
+        /// On success, returns `Poll::Ready(Ok(()))`.
+        ///
+        /// If closing cannot immediately complete, this function returns
+        /// `Poll::Pending` and arranges for the current task (via
+        /// `cx.waker().wake_by_ref()`) to receive a notification when the object can make
+        /// progress towards closing.
+        ///
+        /// # Implementation
+        ///
+        /// This function may not return errors of kind `WouldBlock` or
+        /// `Interrupted`.  Implementations must convert `WouldBlock` into
+        /// `Poll::Pending` and either internally retry or convert
+        /// `Interrupted` into another error kind.
+        fn poll_close(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<()>>;
+    }
+
+    /// Seek bytes asynchronously.
+    ///
+    /// This trait is analogous to the `std::io::Seek` trait, but integrates
+    /// with the asynchronous task system. In particular, the `poll_seek`
+    /// method, unlike `Seek::seek`, will automatically queue the current task
+    /// for wakeup and return if data is not yet available, rather than blocking
+    /// the calling thread.
+    pub trait AsyncSeek {
+        /// Attempt to seek to an offset, in bytes, in a stream.
+        ///
+        /// A seek beyond the end of a stream is allowed, but behavior is defined
+        /// by the implementation.
+        ///
+        /// If the seek operation completed successfully,
+        /// this method returns the new position from the start of the stream.
+        /// That position can be used later with [`SeekFrom::Start`].
+        ///
+        /// # Errors
+        ///
+        /// Seeking to a negative offset is considered an error.
+        ///
+        /// # Implementation
+        ///
+        /// This function may not return errors of kind `WouldBlock` or
+        /// `Interrupted`.  Implementations must convert `WouldBlock` into
+        /// `Poll::Pending` and either internally retry or convert
+        /// `Interrupted` into another error kind.
+        fn poll_seek(
+            self: Pin<&mut Self>,
+            cx: &mut Context<'_>,
+            pos: SeekFrom,
+        ) -> Poll<Result<u64>>;
+    }
+
+    /// Read bytes asynchronously.
+    ///
+    /// This trait is analogous to the `std::io::BufRead` trait, but integrates
+    /// with the asynchronous task system. In particular, the `poll_fill_buf`
+    /// method, unlike `BufRead::fill_buf`, will automatically queue the current task
+    /// for wakeup and return if data is not yet available, rather than blocking
+    /// the calling thread.
+    pub trait AsyncBufRead: AsyncRead {
+        /// Attempt to return the contents of the internal buffer, filling it with more data
+        /// from the inner reader if it is empty.
+        ///
+        /// On success, returns `Poll::Ready(Ok(buf))`.
+        ///
+        /// If no data is available for reading, the method returns
+        /// `Poll::Pending` and arranges for the current task (via
+        /// `cx.waker().wake_by_ref()`) to receive a notification when the object becomes
+        /// readable or is closed.
+        ///
+        /// This function is a lower-level call. It needs to be paired with the
+        /// [`consume`] method to function properly. When calling this
+        /// method, none of the contents will be "read" in the sense that later
+        /// calling [`poll_read`] may return the same contents. As such, [`consume`] must
+        /// be called with the number of bytes that are consumed from this buffer to
+        /// ensure that the bytes are never returned twice.
+        ///
+        /// [`poll_read`]: AsyncRead::poll_read
+        /// [`consume`]: AsyncBufRead::consume
+        ///
+        /// An empty buffer returned indicates that the stream has reached EOF.
+        ///
+        /// # Implementation
+        ///
+        /// This function may not return errors of kind `WouldBlock` or
+        /// `Interrupted`.  Implementations must convert `WouldBlock` into
+        /// `Poll::Pending` and either internally retry or convert
+        /// `Interrupted` into another error kind.
+        fn poll_fill_buf(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<&[u8]>>;
+
+        /// Tells this buffer that `amt` bytes have been consumed from the buffer,
+        /// so they should no longer be returned in calls to [`poll_read`].
+        ///
+        /// This function is a lower-level call. It needs to be paired with the
+        /// [`poll_fill_buf`] method to function properly. This function does
+        /// not perform any I/O, it simply informs this object that some amount of
+        /// its buffer, returned from [`poll_fill_buf`], has been consumed and should
+        /// no longer be returned. As such, this function may do odd things if
+        /// [`poll_fill_buf`] isn't called before calling it.
+        ///
+        /// The `amt` must be `<=` the number of bytes in the buffer returned by
+        /// [`poll_fill_buf`].
+        ///
+        /// [`poll_read`]: AsyncRead::poll_read
+        /// [`poll_fill_buf`]: AsyncBufRead::poll_fill_buf
+        fn consume(self: Pin<&mut Self>, amt: usize);
+    }
+
+    macro_rules! deref_async_read {
+        () => {
+            fn poll_read(
+                mut self: Pin<&mut Self>,
+                cx: &mut Context<'_>,
+                buf: &mut [u8],
+            ) -> Poll<Result<usize>> {
+                Pin::new(&mut **self).poll_read(cx, buf)
+            }
+
+            fn poll_read_vectored(
+                mut self: Pin<&mut Self>,
+                cx: &mut Context<'_>,
+                bufs: &mut [IoSliceMut<'_>],
+            ) -> Poll<Result<usize>> {
+                Pin::new(&mut **self).poll_read_vectored(cx, bufs)
+            }
+        };
+    }
+
+    impl<T: ?Sized + AsyncRead + Unpin> AsyncRead for Box<T> {
+        deref_async_read!();
+    }
+
+    impl<T: ?Sized + AsyncRead + Unpin> AsyncRead for &mut T {
+        deref_async_read!();
+    }
+
+    impl<P> AsyncRead for Pin<P>
+    where
+        P: DerefMut + Unpin,
+        P::Target: AsyncRead,
+    {
+        fn poll_read(
+            self: Pin<&mut Self>,
+            cx: &mut Context<'_>,
+            buf: &mut [u8],
+        ) -> Poll<Result<usize>> {
+            self.get_mut().as_mut().poll_read(cx, buf)
+        }
+
+        fn poll_read_vectored(
+            self: Pin<&mut Self>,
+            cx: &mut Context<'_>,
+            bufs: &mut [IoSliceMut<'_>],
+        ) -> Poll<Result<usize>> {
+            self.get_mut().as_mut().poll_read_vectored(cx, bufs)
+        }
+    }
+
+    macro_rules! delegate_async_read_to_stdio {
+        () => {
+            fn poll_read(
+                mut self: Pin<&mut Self>,
+                _: &mut Context<'_>,
+                buf: &mut [u8],
+            ) -> Poll<Result<usize>> {
+                Poll::Ready(io::Read::read(&mut *self, buf))
+            }
+
+            fn poll_read_vectored(
+                mut self: Pin<&mut Self>,
+                _: &mut Context<'_>,
+                bufs: &mut [IoSliceMut<'_>],
+            ) -> Poll<Result<usize>> {
+                Poll::Ready(io::Read::read_vectored(&mut *self, bufs))
+            }
+        };
+    }
+
+    impl AsyncRead for &[u8] {
+        delegate_async_read_to_stdio!();
+    }
+
+    macro_rules! deref_async_write {
+        () => {
+            fn poll_write(
+                mut self: Pin<&mut Self>,
+                cx: &mut Context<'_>,
+                buf: &[u8],
+            ) -> Poll<Result<usize>> {
+                Pin::new(&mut **self).poll_write(cx, buf)
+            }
+
+            fn poll_write_vectored(
+                mut self: Pin<&mut Self>,
+                cx: &mut Context<'_>,
+                bufs: &[IoSlice<'_>],
+            ) -> Poll<Result<usize>> {
+                Pin::new(&mut **self).poll_write_vectored(cx, bufs)
+            }
+
+            fn poll_flush(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<()>> {
+                Pin::new(&mut **self).poll_flush(cx)
+            }
+
+            fn poll_close(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<()>> {
+                Pin::new(&mut **self).poll_close(cx)
+            }
+        };
+    }
+
+    impl<T: ?Sized + AsyncWrite + Unpin> AsyncWrite for Box<T> {
+        deref_async_write!();
+    }
+
+    impl<T: ?Sized + AsyncWrite + Unpin> AsyncWrite for &mut T {
+        deref_async_write!();
+    }
+
+    impl<P> AsyncWrite for Pin<P>
+    where
+        P: DerefMut + Unpin,
+        P::Target: AsyncWrite,
+    {
+        fn poll_write(
+            self: Pin<&mut Self>,
+            cx: &mut Context<'_>,
+            buf: &[u8],
+        ) -> Poll<Result<usize>> {
+            self.get_mut().as_mut().poll_write(cx, buf)
+        }
+
+        fn poll_write_vectored(
+            self: Pin<&mut Self>,
+            cx: &mut Context<'_>,
+            bufs: &[IoSlice<'_>],
+        ) -> Poll<Result<usize>> {
+            self.get_mut().as_mut().poll_write_vectored(cx, bufs)
+        }
+
+        fn poll_flush(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<()>> {
+            self.get_mut().as_mut().poll_flush(cx)
+        }
+
+        fn poll_close(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<()>> {
+            self.get_mut().as_mut().poll_close(cx)
+        }
+    }
+
+    macro_rules! delegate_async_write_to_stdio {
+        () => {
+            fn poll_write(
+                mut self: Pin<&mut Self>,
+                _: &mut Context<'_>,
+                buf: &[u8],
+            ) -> Poll<Result<usize>> {
+                Poll::Ready(io::Write::write(&mut *self, buf))
+            }
+
+            fn poll_write_vectored(
+                mut self: Pin<&mut Self>,
+                _: &mut Context<'_>,
+                bufs: &[IoSlice<'_>],
+            ) -> Poll<Result<usize>> {
+                Poll::Ready(io::Write::write_vectored(&mut *self, bufs))
+            }
+
+            fn poll_flush(mut self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<Result<()>> {
+                Poll::Ready(io::Write::flush(&mut *self))
+            }
+
+            fn poll_close(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<()>> {
+                self.poll_flush(cx)
+            }
+        };
+    }
+
+    impl AsyncWrite for Vec<u8> {
+        delegate_async_write_to_stdio!();
+    }
+
+    macro_rules! deref_async_seek {
+        () => {
+            fn poll_seek(
+                mut self: Pin<&mut Self>,
+                cx: &mut Context<'_>,
+                pos: SeekFrom,
+            ) -> Poll<Result<u64>> {
+                Pin::new(&mut **self).poll_seek(cx, pos)
+            }
+        };
+    }
+
+    impl<T: ?Sized + AsyncSeek + Unpin> AsyncSeek for Box<T> {
+        deref_async_seek!();
+    }
+
+    impl<T: ?Sized + AsyncSeek + Unpin> AsyncSeek for &mut T {
+        deref_async_seek!();
+    }
+
+    impl<P> AsyncSeek for Pin<P>
+    where
+        P: DerefMut + Unpin,
+        P::Target: AsyncSeek,
+    {
+        fn poll_seek(
+            self: Pin<&mut Self>,
+            cx: &mut Context<'_>,
+            pos: SeekFrom,
+        ) -> Poll<Result<u64>> {
+            self.get_mut().as_mut().poll_seek(cx, pos)
+        }
+    }
+
+    macro_rules! deref_async_buf_read {
+        () => {
+            fn poll_fill_buf(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<&[u8]>> {
+                Pin::new(&mut **self.get_mut()).poll_fill_buf(cx)
+            }
+
+            fn consume(mut self: Pin<&mut Self>, amt: usize) {
+                Pin::new(&mut **self).consume(amt)
+            }
+        };
+    }
+
+    impl<T: ?Sized + AsyncBufRead + Unpin> AsyncBufRead for Box<T> {
+        deref_async_buf_read!();
+    }
+
+    impl<T: ?Sized + AsyncBufRead + Unpin> AsyncBufRead for &mut T {
+        deref_async_buf_read!();
+    }
+
+    impl<P> AsyncBufRead for Pin<P>
+    where
+        P: DerefMut + Unpin,
+        P::Target: AsyncBufRead,
+    {
+        fn poll_fill_buf(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<&[u8]>> {
+            self.get_mut().as_mut().poll_fill_buf(cx)
+        }
+
+        fn consume(self: Pin<&mut Self>, amt: usize) {
+            self.get_mut().as_mut().consume(amt)
+        }
+    }
+
+    macro_rules! delegate_async_buf_read_to_stdio {
+        () => {
+            fn poll_fill_buf(self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<Result<&[u8]>> {
+                Poll::Ready(io::BufRead::fill_buf(self.get_mut()))
+            }
+
+            fn consume(self: Pin<&mut Self>, amt: usize) {
+                io::BufRead::consume(self.get_mut(), amt)
+            }
+        };
+    }
+
+    impl AsyncBufRead for &[u8] {
+        delegate_async_buf_read_to_stdio!();
+    }
+}
+
+#[cfg(feature = "std")]
+pub use self::if_std::*;