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use crate::future::poll_fn;
use crate::io::{AsyncRead, AsyncWrite, PollEvented, ReadBuf};
use crate::net::unix::split::{split, ReadHalf, WriteHalf};
use crate::net::unix::split_owned::{split_owned, OwnedReadHalf, OwnedWriteHalf};
use crate::net::unix::ucred::{self, UCred};
use crate::net::unix::SocketAddr;
use std::convert::TryFrom;
use std::fmt;
use std::io::{self, Read, Write};
use std::net::Shutdown;
use std::os::unix::io::{AsRawFd, RawFd};
use std::os::unix::net;
use std::path::Path;
use std::pin::Pin;
use std::task::{Context, Poll};
cfg_net_unix! {
/// A structure representing a connected Unix socket.
///
/// This socket can be connected directly with `UnixStream::connect` or accepted
/// from a listener with `UnixListener::incoming`. Additionally, a pair of
/// anonymous Unix sockets can be created with `UnixStream::pair`.
pub struct UnixStream {
io: PollEvented<mio::net::UnixStream>,
}
}
impl UnixStream {
/// Connects to the socket named by `path`.
///
/// This function will create a new Unix socket and connect to the path
/// specified, associating the returned stream with the default event loop's
/// handle.
pub async fn connect<P>(path: P) -> io::Result<UnixStream>
where
P: AsRef<Path>,
{
let stream = mio::net::UnixStream::connect(path)?;
let stream = UnixStream::new(stream)?;
poll_fn(|cx| stream.io.poll_write_ready(cx)).await?;
Ok(stream)
}
/// Consumes a `UnixStream` in the standard library and returns a
/// nonblocking `UnixStream` from this crate.
///
/// The returned stream will be associated with the given event loop
/// specified by `handle` and is ready to perform I/O.
///
/// # Panics
///
/// This function panics if thread-local runtime is not set.
///
/// The runtime is usually set implicitly when this function is called
/// from a future driven by a tokio runtime, otherwise runtime can be set
/// explicitly with [`Runtime::enter`](crate::runtime::Runtime::enter) function.
pub fn from_std(stream: net::UnixStream) -> io::Result<UnixStream> {
let stream = mio::net::UnixStream::from_std(stream);
let io = PollEvented::new(stream)?;
Ok(UnixStream { io })
}
/// Creates an unnamed pair of connected sockets.
///
/// This function will create a pair of interconnected Unix sockets for
/// communicating back and forth between one another. Each socket will
/// be associated with the default event loop's handle.
pub fn pair() -> io::Result<(UnixStream, UnixStream)> {
let (a, b) = mio::net::UnixStream::pair()?;
let a = UnixStream::new(a)?;
let b = UnixStream::new(b)?;
Ok((a, b))
}
pub(crate) fn new(stream: mio::net::UnixStream) -> io::Result<UnixStream> {
let io = PollEvented::new(stream)?;
Ok(UnixStream { io })
}
/// Returns the socket address of the local half of this connection.
pub fn local_addr(&self) -> io::Result<SocketAddr> {
self.io.get_ref().local_addr().map(SocketAddr)
}
/// Returns the socket address of the remote half of this connection.
pub fn peer_addr(&self) -> io::Result<SocketAddr> {
self.io.get_ref().peer_addr().map(SocketAddr)
}
/// Returns effective credentials of the process which called `connect` or `pair`.
pub fn peer_cred(&self) -> io::Result<UCred> {
ucred::get_peer_cred(self)
}
/// Returns the value of the `SO_ERROR` option.
pub fn take_error(&self) -> io::Result<Option<io::Error>> {
self.io.get_ref().take_error()
}
/// Shuts down the read, write, or both halves of this connection.
///
/// This function will cause all pending and future I/O calls on the
/// specified portions to immediately return with an appropriate value
/// (see the documentation of `Shutdown`).
pub fn shutdown(&self, how: Shutdown) -> io::Result<()> {
self.io.get_ref().shutdown(how)
}
// These lifetime markers also appear in the generated documentation, and make
// it more clear that this is a *borrowed* split.
#[allow(clippy::needless_lifetimes)]
/// Split a `UnixStream` into a read half and a write half, which can be used
/// to read and write the stream concurrently.
///
/// This method is more efficient than [`into_split`], but the halves cannot be
/// moved into independently spawned tasks.
///
/// [`into_split`]: Self::into_split()
pub fn split<'a>(&'a mut self) -> (ReadHalf<'a>, WriteHalf<'a>) {
split(self)
}
/// Splits a `UnixStream` into a read half and a write half, which can be used
/// to read and write the stream concurrently.
///
/// Unlike [`split`], the owned halves can be moved to separate tasks, however
/// this comes at the cost of a heap allocation.
///
/// **Note:** Dropping the write half will shut down the write half of the
/// stream. This is equivalent to calling [`shutdown(Write)`] on the `UnixStream`.
///
/// [`split`]: Self::split()
/// [`shutdown(Write)`]: fn@Self::shutdown
pub fn into_split(self) -> (OwnedReadHalf, OwnedWriteHalf) {
split_owned(self)
}
}
impl TryFrom<net::UnixStream> for UnixStream {
type Error = io::Error;
/// Consumes stream, returning the tokio I/O object.
///
/// This is equivalent to
/// [`UnixStream::from_std(stream)`](UnixStream::from_std).
fn try_from(stream: net::UnixStream) -> io::Result<Self> {
Self::from_std(stream)
}
}
impl AsyncRead for UnixStream {
fn poll_read(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &mut ReadBuf<'_>,
) -> Poll<io::Result<()>> {
self.poll_read_priv(cx, buf)
}
}
impl AsyncWrite for UnixStream {
fn poll_write(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
buf: &[u8],
) -> Poll<io::Result<usize>> {
self.poll_write_priv(cx, buf)
}
fn poll_flush(self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<io::Result<()>> {
Poll::Ready(Ok(()))
}
fn poll_shutdown(self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<io::Result<()>> {
self.shutdown(std::net::Shutdown::Write)?;
Poll::Ready(Ok(()))
}
}
impl UnixStream {
// == Poll IO functions that takes `&self` ==
//
// They are not public because (taken from the doc of `PollEvented`):
//
// While `PollEvented` is `Sync` (if the underlying I/O type is `Sync`), the
// caller must ensure that there are at most two tasks that use a
// `PollEvented` instance concurrently. One for reading and one for writing.
// While violating this requirement is "safe" from a Rust memory model point
// of view, it will result in unexpected behavior in the form of lost
// notifications and tasks hanging.
pub(crate) fn poll_read_priv(
&self,
cx: &mut Context<'_>,
buf: &mut ReadBuf<'_>,
) -> Poll<io::Result<()>> {
loop {
let ev = ready!(self.io.poll_read_ready(cx))?;
// Safety: `UnixStream::read` will not peek at the maybe uinitialized bytes.
let b = unsafe {
&mut *(buf.unfilled_mut() as *mut [std::mem::MaybeUninit<u8>] as *mut [u8])
};
match self.io.get_ref().read(b) {
Err(ref e) if e.kind() == io::ErrorKind::WouldBlock => {
self.io.clear_readiness(ev);
}
Ok(n) => {
// Safety: We trust `UnixStream::read` to have filled up `n` bytes
// in the buffer.
unsafe {
buf.assume_init(n);
}
buf.advance(n);
return Poll::Ready(Ok(()));
}
Err(e) => return Poll::Ready(Err(e)),
}
}
}
pub(crate) fn poll_write_priv(
&self,
cx: &mut Context<'_>,
buf: &[u8],
) -> Poll<io::Result<usize>> {
loop {
let ev = ready!(self.io.poll_write_ready(cx))?;
match self.io.get_ref().write(buf) {
Err(ref e) if e.kind() == io::ErrorKind::WouldBlock => {
self.io.clear_readiness(ev);
}
x => return Poll::Ready(x),
}
}
}
}
impl fmt::Debug for UnixStream {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
self.io.get_ref().fmt(f)
}
}
impl AsRawFd for UnixStream {
fn as_raw_fd(&self) -> RawFd {
self.io.get_ref().as_raw_fd()
}
}