Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1

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

1 files changed, 267 insertions, 0 deletions

diff --git a/vendor/tokio/src/io/mod.rs b/vendor/tokio/src/io/mod.rs
new file mode 100644
index 000000000..14a4a6304
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+++ b/vendor/tokio/src/io/mod.rs
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+#![cfg_attr(loom, allow(dead_code, unreachable_pub))]
+
+//! Traits, helpers, and type definitions for asynchronous I/O functionality.
+//!
+//! This module is the asynchronous version of `std::io`. Primarily, it
+//! defines two traits, [`AsyncRead`] and [`AsyncWrite`], which are asynchronous
+//! versions of the [`Read`] and [`Write`] traits in the standard library.
+//!
+//! # AsyncRead and AsyncWrite
+//!
+//! Like the standard library's [`Read`] and [`Write`] traits, [`AsyncRead`] and
+//! [`AsyncWrite`] provide the most general interface for reading and writing
+//! input and output. Unlike the standard library's traits, however, they are
+//! _asynchronous_ — meaning that reading from or writing to a `tokio::io`
+//! type will _yield_ to the Tokio scheduler when IO is not ready, rather than
+//! blocking. This allows other tasks to run while waiting on IO.
+//!
+//! Another difference is that `AsyncRead` and `AsyncWrite` only contain
+//! core methods needed to provide asynchronous reading and writing
+//! functionality. Instead, utility methods are defined in the [`AsyncReadExt`]
+//! and [`AsyncWriteExt`] extension traits. These traits are automatically
+//! implemented for all values that implement `AsyncRead` and `AsyncWrite`
+//! respectively.
+//!
+//! End users will rarely interact directly with `AsyncRead` and
+//! `AsyncWrite`. Instead, they will use the async functions defined in the
+//! extension traits. Library authors are expected to implement `AsyncRead`
+//! and `AsyncWrite` in order to provide types that behave like byte streams.
+//!
+//! Even with these differences, Tokio's `AsyncRead` and `AsyncWrite` traits
+//! can be used in almost exactly the same manner as the standard library's
+//! `Read` and `Write`. Most types in the standard library that implement `Read`
+//! and `Write` have asynchronous equivalents in `tokio` that implement
+//! `AsyncRead` and `AsyncWrite`, such as [`File`] and [`TcpStream`].
+//!
+//! For example, the standard library documentation introduces `Read` by
+//! [demonstrating][std_example] reading some bytes from a [`std::fs::File`]. We
+//! can do the same with [`tokio::fs::File`][`File`]:
+//!
+//! ```no_run
+//! use tokio::io::{self, AsyncReadExt};
+//! use tokio::fs::File;
+//!
+//! #[tokio::main]
+//! async fn main() -> io::Result<()> {
+//!     let mut f = File::open("foo.txt").await?;
+//!     let mut buffer = [0; 10];
+//!
+//!     // read up to 10 bytes
+//!     let n = f.read(&mut buffer).await?;
+//!
+//!     println!("The bytes: {:?}", &buffer[..n]);
+//!     Ok(())
+//! }
+//! ```
+//!
+//! [`File`]: crate::fs::File
+//! [`TcpStream`]: crate::net::TcpStream
+//! [`std::fs::File`]: std::fs::File
+//! [std_example]: std::io#read-and-write
+//!
+//! ## Buffered Readers and Writers
+//!
+//! Byte-based interfaces are unwieldy and can be inefficient, as we'd need to be
+//! making near-constant calls to the operating system. To help with this,
+//! `std::io` comes with [support for _buffered_ readers and writers][stdbuf],
+//! and therefore, `tokio::io` does as well.
+//!
+//! Tokio provides an async version of the [`std::io::BufRead`] trait,
+//! [`AsyncBufRead`]; and async [`BufReader`] and [`BufWriter`] structs, which
+//! wrap readers and writers. These wrappers use a buffer, reducing the number
+//! of calls and providing nicer methods for accessing exactly what you want.
+//!
+//! For example, [`BufReader`] works with the [`AsyncBufRead`] trait to add
+//! extra methods to any async reader:
+//!
+//! ```no_run
+//! use tokio::io::{self, BufReader, AsyncBufReadExt};
+//! use tokio::fs::File;
+//!
+//! #[tokio::main]
+//! async fn main() -> io::Result<()> {
+//!     let f = File::open("foo.txt").await?;
+//!     let mut reader = BufReader::new(f);
+//!     let mut buffer = String::new();
+//!
+//!     // read a line into buffer
+//!     reader.read_line(&mut buffer).await?;
+//!
+//!     println!("{}", buffer);
+//!     Ok(())
+//! }
+//! ```
+//!
+//! [`BufWriter`] doesn't add any new ways of writing; it just buffers every call
+//! to [`write`](crate::io::AsyncWriteExt::write). However, you **must** flush
+//! [`BufWriter`] to ensure that any buffered data is written.
+//!
+//! ```no_run
+//! use tokio::io::{self, BufWriter, AsyncWriteExt};
+//! use tokio::fs::File;
+//!
+//! #[tokio::main]
+//! async fn main() -> io::Result<()> {
+//!     let f = File::create("foo.txt").await?;
+//!     {
+//!         let mut writer = BufWriter::new(f);
+//!
+//!         // Write a byte to the buffer.
+//!         writer.write(&[42u8]).await?;
+//!
+//!         // Flush the buffer before it goes out of scope.
+//!         writer.flush().await?;
+//!
+//!     } // Unless flushed or shut down, the contents of the buffer is discarded on drop.
+//!
+//!     Ok(())
+//! }
+//! ```
+//!
+//! [stdbuf]: std::io#bufreader-and-bufwriter
+//! [`std::io::BufRead`]: std::io::BufRead
+//! [`AsyncBufRead`]: crate::io::AsyncBufRead
+//! [`BufReader`]: crate::io::BufReader
+//! [`BufWriter`]: crate::io::BufWriter
+//!
+//! ## Implementing AsyncRead and AsyncWrite
+//!
+//! Because they are traits, we can implement [`AsyncRead`] and [`AsyncWrite`] for
+//! our own types, as well. Note that these traits must only be implemented for
+//! non-blocking I/O types that integrate with the futures type system. In
+//! other words, these types must never block the thread, and instead the
+//! current task is notified when the I/O resource is ready.
+//!
+//! ## Conversion to and from Sink/Stream
+//!
+//! It is often convenient to encapsulate the reading and writing of
+//! bytes and instead work with a [`Sink`] or [`Stream`] of some data
+//! type that is encoded as bytes and/or decoded from bytes. Tokio
+//! provides some utility traits in the [tokio-util] crate that
+//! abstract the asynchronous buffering that is required and allows
+//! you to write [`Encoder`] and [`Decoder`] functions working with a
+//! buffer of bytes, and then use that ["codec"] to transform anything
+//! that implements [`AsyncRead`] and [`AsyncWrite`] into a `Sink`/`Stream` of
+//! your structured data.
+//!
+//! [tokio-util]: https://docs.rs/tokio-util/0.6/tokio_util/codec/index.html
+//!
+//! # Standard input and output
+//!
+//! Tokio provides asynchronous APIs to standard [input], [output], and [error].
+//! These APIs are very similar to the ones provided by `std`, but they also
+//! implement [`AsyncRead`] and [`AsyncWrite`].
+//!
+//! Note that the standard input / output APIs  **must** be used from the
+//! context of the Tokio runtime, as they require Tokio-specific features to
+//! function. Calling these functions outside of a Tokio runtime will panic.
+//!
+//! [input]: fn@stdin
+//! [output]: fn@stdout
+//! [error]: fn@stderr
+//!
+//! # `std` re-exports
+//!
+//! Additionally, [`Error`], [`ErrorKind`], [`Result`], and [`SeekFrom`] are
+//! re-exported from `std::io` for ease of use.
+//!
+//! [`AsyncRead`]: trait@AsyncRead
+//! [`AsyncWrite`]: trait@AsyncWrite
+//! [`AsyncReadExt`]: trait@AsyncReadExt
+//! [`AsyncWriteExt`]: trait@AsyncWriteExt
+//! ["codec"]: https://docs.rs/tokio-util/0.6/tokio_util/codec/index.html
+//! [`Encoder`]: https://docs.rs/tokio-util/0.6/tokio_util/codec/trait.Encoder.html
+//! [`Decoder`]: https://docs.rs/tokio-util/0.6/tokio_util/codec/trait.Decoder.html
+//! [`Error`]: struct@Error
+//! [`ErrorKind`]: enum@ErrorKind
+//! [`Result`]: type@Result
+//! [`Read`]: std::io::Read
+//! [`SeekFrom`]: enum@SeekFrom
+//! [`Sink`]: https://docs.rs/futures/0.3/futures/sink/trait.Sink.html
+//! [`Stream`]: https://docs.rs/futures/0.3/futures/stream/trait.Stream.html
+//! [`Write`]: std::io::Write
+cfg_io_blocking! {
+    pub(crate) mod blocking;
+}
+
+mod async_buf_read;
+pub use self::async_buf_read::AsyncBufRead;
+
+mod async_read;
+pub use self::async_read::AsyncRead;
+
+mod async_seek;
+pub use self::async_seek::AsyncSeek;
+
+mod async_write;
+pub use self::async_write::AsyncWrite;
+
+mod read_buf;
+pub use self::read_buf::ReadBuf;
+
+// Re-export some types from `std::io` so that users don't have to deal
+// with conflicts when `use`ing `tokio::io` and `std::io`.
+#[doc(no_inline)]
+pub use std::io::{Error, ErrorKind, Result, SeekFrom};
+
+cfg_io_driver_impl! {
+    pub(crate) mod driver;
+
+    cfg_net! {
+        pub use driver::{Interest, Ready};
+    }
+
+    mod poll_evented;
+
+    #[cfg(not(loom))]
+    pub(crate) use poll_evented::PollEvented;
+}
+
+cfg_net_unix! {
+    mod async_fd;
+
+    pub mod unix {
+        //! Asynchronous IO structures specific to Unix-like operating systems.
+        pub use super::async_fd::{AsyncFd, AsyncFdReadyGuard, AsyncFdReadyMutGuard, TryIoError};
+    }
+}
+
+cfg_io_std! {
+    mod stdio_common;
+
+    mod stderr;
+    pub use stderr::{stderr, Stderr};
+
+    mod stdin;
+    pub use stdin::{stdin, Stdin};
+
+    mod stdout;
+    pub use stdout::{stdout, Stdout};
+}
+
+cfg_io_util! {
+    mod split;
+    pub use split::{split, ReadHalf, WriteHalf};
+
+    pub(crate) mod seek;
+    pub(crate) mod util;
+    pub use util::{
+        copy, copy_bidirectional, copy_buf, duplex, empty, repeat, sink, AsyncBufReadExt, AsyncReadExt, AsyncSeekExt, AsyncWriteExt,
+        BufReader, BufStream, BufWriter, DuplexStream, Empty, Lines, Repeat, Sink, Split, Take,
+    };
+}
+
+cfg_not_io_util! {
+    cfg_process! {
+        pub(crate) mod util;
+    }
+}
+
+cfg_io_blocking! {
+    /// Types in this module can be mocked out in tests.
+    mod sys {
+        // TODO: don't rename
+        pub(crate) use crate::blocking::spawn_blocking as run;
+        pub(crate) use crate::blocking::JoinHandle as Blocking;
+    }
+}