#[cfg(any(
    doc,
    target_os = "android",
    target_os = "dragonfly",
    target_os = "emscripten",
    target_os = "freebsd",
    target_os = "linux",
    target_os = "netbsd",
    target_os = "openbsd",
))]
use super::{recv_vectored_with_ancillary_from, send_vectored_with_ancillary_to, SocketAncillary};
use super::{sockaddr_un, SocketAddr};
use crate::fmt;
use crate::io::{self, Initializer, IoSlice, IoSliceMut};
use crate::net::Shutdown;
use crate::os::unix::io::{AsRawFd, FromRawFd, IntoRawFd, RawFd};
#[cfg(any(
    target_os = "android",
    target_os = "linux",
    target_os = "dragonfly",
    target_os = "freebsd",
    target_os = "ios",
    target_os = "macos",
    target_os = "openbsd"
))]
use crate::os::unix::ucred;
use crate::path::Path;
use crate::sys::cvt;
use crate::sys::net::Socket;
use crate::sys_common::{AsInner, FromInner, IntoInner};
use crate::time::Duration;

#[unstable(feature = "peer_credentials_unix_socket", issue = "42839", reason = "unstable")]
#[cfg(any(
    target_os = "android",
    target_os = "linux",
    target_os = "dragonfly",
    target_os = "freebsd",
    target_os = "ios",
    target_os = "macos",
    target_os = "openbsd"
))]
pub use ucred::UCred;

/// Unix 流套接字。
///
/// # Examples
///
/// ```no_run
/// use std::os::unix::net::UnixStream;
/// use std::io::prelude::*;
///
/// fn main() -> std::io::Result<()> {
///     let mut stream = UnixStream::connect("/path/to/my/socket")?;
///     stream.write_all(b"hello world")?;
///     let mut response = String::new();
///     stream.read_to_string(&mut response)?;
///     println!("{}", response);
///     Ok(())
/// }
/// ```
#[stable(feature = "unix_socket", since = "1.10.0")]
pub struct UnixStream(pub(super) Socket);

#[stable(feature = "unix_socket", since = "1.10.0")]
impl fmt::Debug for UnixStream {
    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
        let mut builder = fmt.debug_struct("UnixStream");
        builder.field("fd", self.0.as_inner());
        if let Ok(addr) = self.local_addr() {
            builder.field("local", &addr);
        }
        if let Ok(addr) = self.peer_addr() {
            builder.field("peer", &addr);
        }
        builder.finish()
    }
}

impl UnixStream {
    /// 连接到以 `path` 命名的套接字。
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::os::unix::net::UnixStream;
    ///
    /// let socket = match UnixStream::connect("/tmp/sock") {
    ///     Ok(sock) => sock,
    ///     Err(e) => {
    ///         println!("Couldn't connect: {:?}", e);
    ///         return
    ///     }
    /// };
    /// ```
    #[stable(feature = "unix_socket", since = "1.10.0")]
    pub fn connect<P: AsRef<Path>>(path: P) -> io::Result<UnixStream> {
        unsafe {
            let inner = Socket::new_raw(libc::AF_UNIX, libc::SOCK_STREAM)?;
            let (addr, len) = sockaddr_un(path.as_ref())?;

            cvt(libc::connect(*inner.as_inner(), &addr as *const _ as *const _, len))?;
            Ok(UnixStream(inner))
        }
    }

    /// 创建一对未命名的已连接套接字。
    ///
    /// 返回两个相互连接的 `UnixStream`。
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::os::unix::net::UnixStream;
    ///
    /// let (sock1, sock2) = match UnixStream::pair() {
    ///     Ok((sock1, sock2)) => (sock1, sock2),
    ///     Err(e) => {
    ///         println!("Couldn't create a pair of sockets: {:?}", e);
    ///         return
    ///     }
    /// };
    /// ```
    #[stable(feature = "unix_socket", since = "1.10.0")]
    pub fn pair() -> io::Result<(UnixStream, UnixStream)> {
        let (i1, i2) = Socket::new_pair(libc::AF_UNIX, libc::SOCK_STREAM)?;
        Ok((UnixStream(i1), UnixStream(i2)))
    }

    /// 为基础套接字创建一个新的独立拥有的句柄。
    ///
    /// 返回的 `UnixStream` 是与此 object 引用相同的流的引用。
    /// 两个句柄将读取和写入相同的数据流，并且在一个流上设置的选项将传播到另一流。
    ///
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::os::unix::net::UnixStream;
    ///
    /// fn main() -> std::io::Result<()> {
    ///     let socket = UnixStream::connect("/tmp/sock")?;
    ///     let sock_copy = socket.try_clone().expect("Couldn't clone socket");
    ///     Ok(())
    /// }
    /// ```
    ///
    #[stable(feature = "unix_socket", since = "1.10.0")]
    pub fn try_clone(&self) -> io::Result<UnixStream> {
        self.0.duplicate().map(UnixStream)
    }

    /// 返回此连接本地一半的套接字地址。
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::os::unix::net::UnixStream;
    ///
    /// fn main() -> std::io::Result<()> {
    ///     let socket = UnixStream::connect("/tmp/sock")?;
    ///     let addr = socket.local_addr().expect("Couldn't get local address");
    ///     Ok(())
    /// }
    /// ```
    #[stable(feature = "unix_socket", since = "1.10.0")]
    pub fn local_addr(&self) -> io::Result<SocketAddr> {
        SocketAddr::new(|addr, len| unsafe { libc::getsockname(*self.0.as_inner(), addr, len) })
    }

    /// 返回此连接的另一半的套接字地址。
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::os::unix::net::UnixStream;
    ///
    /// fn main() -> std::io::Result<()> {
    ///     let socket = UnixStream::connect("/tmp/sock")?;
    ///     let addr = socket.peer_addr().expect("Couldn't get peer address");
    ///     Ok(())
    /// }
    /// ```
    #[stable(feature = "unix_socket", since = "1.10.0")]
    pub fn peer_addr(&self) -> io::Result<SocketAddr> {
        SocketAddr::new(|addr, len| unsafe { libc::getpeername(*self.0.as_inner(), addr, len) })
    }

    /// 获取此 Unix 域套接字的对等凭据。
    ///
    /// # Examples
    ///
    /// ```no_run
    /// #![feature(peer_credentials_unix_socket)]
    /// use std::os::unix::net::UnixStream;
    ///
    /// fn main() -> std::io::Result<()> {
    ///     let socket = UnixStream::connect("/tmp/sock")?;
    ///     let peer_cred = socket.peer_cred().expect("Couldn't get peer credentials");
    ///     Ok(())
    /// }
    /// ```
    #[unstable(feature = "peer_credentials_unix_socket", issue = "42839", reason = "unstable")]
    #[cfg(any(
        target_os = "android",
        target_os = "linux",
        target_os = "dragonfly",
        target_os = "freebsd",
        target_os = "ios",
        target_os = "macos",
        target_os = "openbsd"
    ))]
    pub fn peer_cred(&self) -> io::Result<UCred> {
        ucred::peer_cred(self)
    }

    /// 设置套接字的读取超时。
    ///
    /// 如果提供的值为 [`None`]，则 [`read`] 调用将无限期阻塞。
    /// 如果将零 [`Duration`] 传递给此方法，则返回 [`Err`]。
    ///
    /// [`read`]: io::Read::read
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::os::unix::net::UnixStream;
    /// use std::time::Duration;
    ///
    /// fn main() -> std::io::Result<()> {
    ///     let socket = UnixStream::connect("/tmp/sock")?;
    ///     socket.set_read_timeout(Some(Duration::new(1, 0))).expect("Couldn't set read timeout");
    ///     Ok(())
    /// }
    /// ```
    ///
    /// 如果将零 [`Duration`] 传递给此方法，则返回 [`Err`]:
    ///
    /// ```no_run
    /// use std::io;
    /// use std::os::unix::net::UnixStream;
    /// use std::time::Duration;
    ///
    /// fn main() -> std::io::Result<()> {
    ///     let socket = UnixStream::connect("/tmp/sock")?;
    ///     let result = socket.set_read_timeout(Some(Duration::new(0, 0)));
    ///     let err = result.unwrap_err();
    ///     assert_eq!(err.kind(), io::ErrorKind::InvalidInput);
    ///     Ok(())
    /// }
    /// ```
    ///
    ///
    #[stable(feature = "unix_socket", since = "1.10.0")]
    pub fn set_read_timeout(&self, timeout: Option<Duration>) -> io::Result<()> {
        self.0.set_timeout(timeout, libc::SO_RCVTIMEO)
    }

    /// 设置套接字的写超时。
    ///
    /// 如果提供的值为 [`None`]，则 [`write`] 调用将无限期阻塞。
    /// 如果将零 [`Duration`] 传递给此方法，则返回 [`Err`]。
    ///
    /// [`read`]: io::Read::read
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::os::unix::net::UnixStream;
    /// use std::time::Duration;
    ///
    /// fn main() -> std::io::Result<()> {
    ///     let socket = UnixStream::connect("/tmp/sock")?;
    ///     socket.set_write_timeout(Some(Duration::new(1, 0)))
    ///         .expect("Couldn't set write timeout");
    ///     Ok(())
    /// }
    /// ```
    ///
    /// 如果将零 [`Duration`] 传递给此方法，则返回 [`Err`]:
    ///
    /// ```no_run
    /// use std::io;
    /// use std::net::UdpSocket;
    /// use std::time::Duration;
    ///
    /// fn main() -> std::io::Result<()> {
    ///     let socket = UdpSocket::bind("127.0.0.1:34254")?;
    ///     let result = socket.set_write_timeout(Some(Duration::new(0, 0)));
    ///     let err = result.unwrap_err();
    ///     assert_eq!(err.kind(), io::ErrorKind::InvalidInput);
    ///     Ok(())
    /// }
    /// ```
    ///
    ///
    #[stable(feature = "unix_socket", since = "1.10.0")]
    pub fn set_write_timeout(&self, timeout: Option<Duration>) -> io::Result<()> {
        self.0.set_timeout(timeout, libc::SO_SNDTIMEO)
    }

    /// 返回此套接字的读取超时。
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::os::unix::net::UnixStream;
    /// use std::time::Duration;
    ///
    /// fn main() -> std::io::Result<()> {
    ///     let socket = UnixStream::connect("/tmp/sock")?;
    ///     socket.set_read_timeout(Some(Duration::new(1, 0))).expect("Couldn't set read timeout");
    ///     assert_eq!(socket.read_timeout()?, Some(Duration::new(1, 0)));
    ///     Ok(())
    /// }
    /// ```
    #[stable(feature = "unix_socket", since = "1.10.0")]
    pub fn read_timeout(&self) -> io::Result<Option<Duration>> {
        self.0.timeout(libc::SO_RCVTIMEO)
    }

    /// 返回此套接字的写入超时。
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::os::unix::net::UnixStream;
    /// use std::time::Duration;
    ///
    /// fn main() -> std::io::Result<()> {
    ///     let socket = UnixStream::connect("/tmp/sock")?;
    ///     socket.set_write_timeout(Some(Duration::new(1, 0)))
    ///         .expect("Couldn't set write timeout");
    ///     assert_eq!(socket.write_timeout()?, Some(Duration::new(1, 0)));
    ///     Ok(())
    /// }
    /// ```
    #[stable(feature = "unix_socket", since = "1.10.0")]
    pub fn write_timeout(&self) -> io::Result<Option<Duration>> {
        self.0.timeout(libc::SO_SNDTIMEO)
    }

    /// 将套接字移入或移出非阻塞模式。
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::os::unix::net::UnixStream;
    ///
    /// fn main() -> std::io::Result<()> {
    ///     let socket = UnixStream::connect("/tmp/sock")?;
    ///     socket.set_nonblocking(true).expect("Couldn't set nonblocking");
    ///     Ok(())
    /// }
    /// ```
    #[stable(feature = "unix_socket", since = "1.10.0")]
    pub fn set_nonblocking(&self, nonblocking: bool) -> io::Result<()> {
        self.0.set_nonblocking(nonblocking)
    }

    /// 移动套接字以将 unix 凭据作为 [`SocketAncillary`] 中的控制消息传递。
    ///
    /// 设置套接字选项 `SO_PASSCRED`。
    ///
    /// # Examples
    ///
    #[cfg_attr(any(target_os = "android", target_os = "linux"), doc = "```no_run")]
    #[cfg_attr(not(any(target_os = "android", target_os = "linux")), doc = "```ignore")]
    /// #![feature(unix_socket_ancillary_data)]
    /// use std::os::unix::net::UnixStream;
    ///
    /// fn main() -> std::io::Result<()> {
    ///     let socket = UnixStream::connect("/tmp/sock")?;
    ///     socket.set_passcred(true).expect("Couldn't set passcred");
    ///     Ok(())
    /// }
    /// ```
    #[cfg(any(doc, target_os = "android", target_os = "linux",))]
    #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
    pub fn set_passcred(&self, passcred: bool) -> io::Result<()> {
        self.0.set_passcred(passcred)
    }

    /// 获取用于在 [`SocketAncillary`] 中传递 unix 凭据的套接字的当前值。
    /// 可以通过 [`set_passcred`] 更改此值。
    ///
    /// 获取套接字选项 `SO_PASSCRED`。
    ///
    /// [`set_passcred`]: UnixStream::set_passcred
    #[cfg(any(doc, target_os = "android", target_os = "linux",))]
    #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
    pub fn passcred(&self) -> io::Result<bool> {
        self.0.passcred()
    }

    /// 返回 `SO_ERROR` 选项的值。
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::os::unix::net::UnixStream;
    ///
    /// fn main() -> std::io::Result<()> {
    ///     let socket = UnixStream::connect("/tmp/sock")?;
    ///     if let Ok(Some(err)) = socket.take_error() {
    ///         println!("Got error: {:?}", err);
    ///     }
    ///     Ok(())
    /// }
    /// ```
    ///
    /// # 特定于平台
    /// 在 Redox 上，它总是返回 `None`。
    #[stable(feature = "unix_socket", since = "1.10.0")]
    pub fn take_error(&self) -> io::Result<Option<io::Error>> {
        self.0.take_error()
    }

    /// 关闭此连接的读取，写入或两半。
    ///
    /// 此函数将导致对指定部分的所有未决和 future I/O 调用立即返回适当的值 (请参见 [`Shutdown`] 的文档)。
    ///
    ///
    /// # Examples
    ///
    /// ```no_run
    /// use std::os::unix::net::UnixStream;
    /// use std::net::Shutdown;
    ///
    /// fn main() -> std::io::Result<()> {
    ///     let socket = UnixStream::connect("/tmp/sock")?;
    ///     socket.shutdown(Shutdown::Both).expect("shutdown function failed");
    ///     Ok(())
    /// }
    /// ```
    ///
    #[stable(feature = "unix_socket", since = "1.10.0")]
    pub fn shutdown(&self, how: Shutdown) -> io::Result<()> {
        self.0.shutdown(how)
    }

    /// 从套接字所连接的远程地址接收套接字上的数据，而无需从队列中删除该数据。
    ///
    /// 成功时，返回偷看的字节数。
    ///
    /// 连续调用返回相同的数据。
    /// 这是通过将 `MSG_PEEK` 作为标志传递到基础 `recv` 系统调用来完成的。
    ///
    /// # Examples
    ///
    /// ```no_run
    /// #![feature(unix_socket_peek)]
    ///
    /// use std::os::unix::net::UnixStream;
    ///
    /// fn main() -> std::io::Result<()> {
    ///     let socket = UnixStream::connect("/tmp/sock")?;
    ///     let mut buf = [0; 10];
    ///     let len = socket.peek(&mut buf).expect("peek failed");
    ///     Ok(())
    /// }
    /// ```
    #[unstable(feature = "unix_socket_peek", issue = "76923")]
    pub fn peek(&self, buf: &mut [u8]) -> io::Result<usize> {
        self.0.peek(buf)
    }

    /// 从套接字接收数据和辅助数据。
    ///
    /// 成功时，返回读取的字节数。
    ///
    /// # Examples
    ///
    /// ```no_run
    /// #![feature(unix_socket_ancillary_data)]
    /// use std::os::unix::net::{UnixStream, SocketAncillary, AncillaryData};
    /// use std::io::IoSliceMut;
    ///
    /// fn main() -> std::io::Result<()> {
    ///     let socket = UnixStream::connect("/tmp/sock")?;
    ///     let mut buf1 = [1; 8];
    ///     let mut buf2 = [2; 16];
    ///     let mut buf3 = [3; 8];
    ///     let mut bufs = &mut [
    ///         IoSliceMut::new(&mut buf1),
    ///         IoSliceMut::new(&mut buf2),
    ///         IoSliceMut::new(&mut buf3),
    ///     ][..];
    ///     let mut fds = [0; 8];
    ///     let mut ancillary_buffer = [0; 128];
    ///     let mut ancillary = SocketAncillary::new(&mut ancillary_buffer[..]);
    ///     let size = socket.recv_vectored_with_ancillary(bufs, &mut ancillary)?;
    ///     println!("received {}", size);
    ///     for ancillary_result in ancillary.messages() {
    ///         if let AncillaryData::ScmRights(scm_rights) = ancillary_result.unwrap() {
    ///             for fd in scm_rights {
    ///                 println!("receive file descriptor: {}", fd);
    ///             }
    ///         }
    ///     }
    ///     Ok(())
    /// }
    /// ```
    #[cfg(any(
        target_os = "android",
        target_os = "dragonfly",
        target_os = "emscripten",
        target_os = "freebsd",
        target_os = "linux",
        target_os = "netbsd",
        target_os = "openbsd",
    ))]
    #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
    pub fn recv_vectored_with_ancillary(
        &self,
        bufs: &mut [IoSliceMut<'_>],
        ancillary: &mut SocketAncillary<'_>,
    ) -> io::Result<usize> {
        let (count, _, _) = recv_vectored_with_ancillary_from(&self.0, bufs, ancillary)?;

        Ok(count)
    }

    /// 在套接字上发送数据和辅助数据。
    ///
    /// 成功时，返回写入的字节数。
    ///
    /// # Examples
    ///
    /// ```no_run
    /// #![feature(unix_socket_ancillary_data)]
    /// use std::os::unix::net::{UnixStream, SocketAncillary};
    /// use std::io::IoSlice;
    ///
    /// fn main() -> std::io::Result<()> {
    ///     let socket = UnixStream::connect("/tmp/sock")?;
    ///     let buf1 = [1; 8];
    ///     let buf2 = [2; 16];
    ///     let buf3 = [3; 8];
    ///     let bufs = &[
    ///         IoSlice::new(&buf1),
    ///         IoSlice::new(&buf2),
    ///         IoSlice::new(&buf3),
    ///     ][..];
    ///     let fds = [0, 1, 2];
    ///     let mut ancillary_buffer = [0; 128];
    ///     let mut ancillary = SocketAncillary::new(&mut ancillary_buffer[..]);
    ///     ancillary.add_fds(&fds[..]);
    ///     socket.send_vectored_with_ancillary(bufs, &mut ancillary)
    ///         .expect("send_vectored_with_ancillary function failed");
    ///     Ok(())
    /// }
    /// ```
    #[cfg(any(
        target_os = "android",
        target_os = "dragonfly",
        target_os = "emscripten",
        target_os = "freebsd",
        target_os = "linux",
        target_os = "netbsd",
        target_os = "openbsd",
    ))]
    #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
    pub fn send_vectored_with_ancillary(
        &self,
        bufs: &[IoSlice<'_>],
        ancillary: &mut SocketAncillary<'_>,
    ) -> io::Result<usize> {
        send_vectored_with_ancillary_to(&self.0, None, bufs, ancillary)
    }
}

#[stable(feature = "unix_socket", since = "1.10.0")]
impl io::Read for UnixStream {
    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
        io::Read::read(&mut &*self, buf)
    }

    fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
        io::Read::read_vectored(&mut &*self, bufs)
    }

    #[inline]
    fn is_read_vectored(&self) -> bool {
        io::Read::is_read_vectored(&&*self)
    }

    #[inline]
    unsafe fn initializer(&self) -> Initializer {
        Initializer::nop()
    }
}

#[stable(feature = "unix_socket", since = "1.10.0")]
impl<'a> io::Read for &'a UnixStream {
    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)
    }

    #[inline]
    fn is_read_vectored(&self) -> bool {
        self.0.is_read_vectored()
    }

    #[inline]
    unsafe fn initializer(&self) -> Initializer {
        Initializer::nop()
    }
}

#[stable(feature = "unix_socket", since = "1.10.0")]
impl io::Write for UnixStream {
    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
        io::Write::write(&mut &*self, buf)
    }

    fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
        io::Write::write_vectored(&mut &*self, bufs)
    }

    #[inline]
    fn is_write_vectored(&self) -> bool {
        io::Write::is_write_vectored(&&*self)
    }

    fn flush(&mut self) -> io::Result<()> {
        io::Write::flush(&mut &*self)
    }
}

#[stable(feature = "unix_socket", since = "1.10.0")]
impl<'a> io::Write for &'a UnixStream {
    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)
    }

    #[inline]
    fn is_write_vectored(&self) -> bool {
        self.0.is_write_vectored()
    }

    fn flush(&mut self) -> io::Result<()> {
        Ok(())
    }
}

#[stable(feature = "unix_socket", since = "1.10.0")]
impl AsRawFd for UnixStream {
    #[inline]
    fn as_raw_fd(&self) -> RawFd {
        *self.0.as_inner()
    }
}

#[stable(feature = "unix_socket", since = "1.10.0")]
impl FromRawFd for UnixStream {
    #[inline]
    unsafe fn from_raw_fd(fd: RawFd) -> UnixStream {
        UnixStream(Socket::from_inner(fd))
    }
}

#[stable(feature = "unix_socket", since = "1.10.0")]
impl IntoRawFd for UnixStream {
    #[inline]
    fn into_raw_fd(self) -> RawFd {
        self.0.into_inner()
    }
}