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use std::fmt;
use std::io::{self, IoSlice, IoSliceMut, Read, Write};
use std::net::{self, Shutdown, SocketAddr};
#[cfg(unix)]
use std::os::unix::io::{AsRawFd, FromRawFd, IntoRawFd, RawFd};
#[cfg(windows)]
use std::os::windows::io::{AsRawSocket, FromRawSocket, IntoRawSocket, RawSocket};
use crate::io_source::IoSource;
use crate::sys::tcp::{connect, new_for_addr};
use crate::{event, Interest, Registry, Token};
/// A non-blocking TCP stream between a local socket and a remote socket.
///
/// The socket will be closed when the value is dropped.
///
/// # Examples
///
#[cfg_attr(feature = "os-poll", doc = "```")]
#[cfg_attr(not(feature = "os-poll"), doc = "```ignore")]
/// # use std::net::{TcpListener, SocketAddr};
/// # use std::error::Error;
/// #
/// # fn main() -> Result<(), Box<dyn Error>> {
/// let address: SocketAddr = "127.0.0.1:0".parse()?;
/// let listener = TcpListener::bind(address)?;
/// use mio::{Events, Interest, Poll, Token};
/// use mio::net::TcpStream;
/// use std::time::Duration;
///
/// let mut stream = TcpStream::connect(listener.local_addr()?)?;
///
/// let mut poll = Poll::new()?;
/// let mut events = Events::with_capacity(128);
///
/// // Register the socket with `Poll`
/// poll.registry().register(&mut stream, Token(0), Interest::WRITABLE)?;
///
/// poll.poll(&mut events, Some(Duration::from_millis(100)))?;
///
/// // The socket might be ready at this point
/// # Ok(())
/// # }
/// ```
pub struct TcpStream {
inner: IoSource<net::TcpStream>,
}
impl TcpStream {
/// Create a new TCP stream and issue a non-blocking connect to the
/// specified address.
///
/// # Notes
///
/// The returned `TcpStream` may not be connected (and thus usable), unlike
/// the API found in `std::net::TcpStream`. Because Mio issues a
/// *non-blocking* connect it will not block the thread and instead return
/// an unconnected `TcpStream`.
///
/// Ensuring the returned stream is connected is surprisingly complex when
/// considering cross-platform support. Doing this properly should follow
/// the steps below, an example implementation can be found
/// [here](https://github.com/Thomasdezeeuw/heph/blob/0c4f1ab3eaf08bea1d65776528bfd6114c9f8374/src/net/tcp/stream.rs#L560-L622).
///
/// 1. Call `TcpStream::connect`
/// 2. Register the returned stream with at least [read interest].
/// 3. Wait for a (readable) event.
/// 4. Check `TcpStream::peer_addr`. If it returns `libc::EINPROGRESS` or
/// `ErrorKind::NotConnected` it means the stream is not yet connected,
/// go back to step 3. If it returns an address it means the stream is
/// connected, go to step 5. If another error is returned something
/// whent wrong.
/// 5. Now the stream can be used.
///
/// [read interest]: Interest::READABLE
pub fn connect(addr: SocketAddr) -> io::Result<TcpStream> {
let socket = new_for_addr(addr)?;
#[cfg(unix)]
let stream = unsafe { TcpStream::from_raw_fd(socket) };
#[cfg(windows)]
let stream = unsafe { TcpStream::from_raw_socket(socket as _) };
connect(&stream.inner, addr)?;
Ok(stream)
}
/// Creates a new `TcpStream` from a standard `net::TcpStream`.
///
/// This function is intended to be used to wrap a TCP stream from the
/// standard library in the Mio equivalent. The conversion assumes nothing
/// about the underlying stream; it is left up to the user to set it in
/// non-blocking mode.
///
/// # Note
///
/// The TCP stream here will not have `connect` called on it, so it
/// should already be connected via some other means (be it manually, or
/// the standard library).
pub fn from_std(stream: net::TcpStream) -> TcpStream {
TcpStream {
inner: IoSource::new(stream),
}
}
/// Returns the socket address of the remote peer of this TCP connection.
pub fn peer_addr(&self) -> io::Result<SocketAddr> {
self.inner.peer_addr()
}
/// Returns the socket address of the local half of this TCP connection.
pub fn local_addr(&self) -> io::Result<SocketAddr> {
self.inner.local_addr()
}
/// Shuts down the read, write, or both halves of this connection.
///
/// This function will cause all pending and future I/O on the specified
/// portions to return immediately with an appropriate value (see the
/// documentation of `Shutdown`).
pub fn shutdown(&self, how: Shutdown) -> io::Result<()> {
self.inner.shutdown(how)
}
/// Sets the value of the `TCP_NODELAY` option on this socket.
///
/// If set, this option disables the Nagle algorithm. This means that
/// segments are always sent as soon as possible, even if there is only a
/// small amount of data. When not set, data is buffered until there is a
/// sufficient amount to send out, thereby avoiding the frequent sending of
/// small packets.
///
/// # Notes
///
/// On Windows make sure the stream is connected before calling this method,
/// by receiving an (writable) event. Trying to set `nodelay` on an
/// unconnected `TcpStream` is unspecified behavior.
pub fn set_nodelay(&self, nodelay: bool) -> io::Result<()> {
self.inner.set_nodelay(nodelay)
}
/// Gets the value of the `TCP_NODELAY` option on this socket.
///
/// For more information about this option, see [`set_nodelay`][link].
///
/// [link]: #method.set_nodelay
///
/// # Notes
///
/// On Windows make sure the stream is connected before calling this method,
/// by receiving an (writable) event. Trying to get `nodelay` on an
/// unconnected `TcpStream` is unspecified behavior.
pub fn nodelay(&self) -> io::Result<bool> {
self.inner.nodelay()
}
/// Sets the value for the `IP_TTL` option on this socket.
///
/// This value sets the time-to-live field that is used in every packet sent
/// from this socket.
///
/// # Notes
///
/// On Windows make sure the stream is connected before calling this method,
/// by receiving an (writable) event. Trying to set `ttl` on an
/// unconnected `TcpStream` is unspecified behavior.
pub fn set_ttl(&self, ttl: u32) -> io::Result<()> {
self.inner.set_ttl(ttl)
}
/// Gets the value of the `IP_TTL` option for this socket.
///
/// For more information about this option, see [`set_ttl`][link].
///
/// # Notes
///
/// On Windows make sure the stream is connected before calling this method,
/// by receiving an (writable) event. Trying to get `ttl` on an
/// unconnected `TcpStream` is unspecified behavior.
///
/// [link]: #method.set_ttl
pub fn ttl(&self) -> io::Result<u32> {
self.inner.ttl()
}
/// Get the value of the `SO_ERROR` option on this socket.
///
/// This will retrieve the stored error in the underlying socket, clearing
/// the field in the process. This can be useful for checking errors between
/// calls.
pub fn take_error(&self) -> io::Result<Option<io::Error>> {
self.inner.take_error()
}
/// Receives data on the socket from the remote address to which it is
/// connected, without removing that data from the queue. On success,
/// returns the number of bytes peeked.
///
/// Successive calls return the same data. This is accomplished by passing
/// `MSG_PEEK` as a flag to the underlying recv system call.
pub fn peek(&self, buf: &mut [u8]) -> io::Result<usize> {
self.inner.peek(buf)
}
}
impl Read for TcpStream {
fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
self.inner.do_io(|inner| (&*inner).read(buf))
}
fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
self.inner.do_io(|inner| (&*inner).read_vectored(bufs))
}
}
impl<'a> Read for &'a TcpStream {
fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
self.inner.do_io(|inner| (&*inner).read(buf))
}
fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
self.inner.do_io(|inner| (&*inner).read_vectored(bufs))
}
}
impl Write for TcpStream {
fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
self.inner.do_io(|inner| (&*inner).write(buf))
}
fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
self.inner.do_io(|inner| (&*inner).write_vectored(bufs))
}
fn flush(&mut self) -> io::Result<()> {
self.inner.do_io(|inner| (&*inner).flush())
}
}
impl<'a> Write for &'a TcpStream {
fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
self.inner.do_io(|inner| (&*inner).write(buf))
}
fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
self.inner.do_io(|inner| (&*inner).write_vectored(bufs))
}
fn flush(&mut self) -> io::Result<()> {
self.inner.do_io(|inner| (&*inner).flush())
}
}
impl event::Source for TcpStream {
fn register(
&mut self,
registry: &Registry,
token: Token,
interests: Interest,
) -> io::Result<()> {
self.inner.register(registry, token, interests)
}
fn reregister(
&mut self,
registry: &Registry,
token: Token,
interests: Interest,
) -> io::Result<()> {
self.inner.reregister(registry, token, interests)
}
fn deregister(&mut self, registry: &Registry) -> io::Result<()> {
self.inner.deregister(registry)
}
}
impl fmt::Debug for TcpStream {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
self.inner.fmt(f)
}
}
#[cfg(unix)]
impl IntoRawFd for TcpStream {
fn into_raw_fd(self) -> RawFd {
self.inner.into_inner().into_raw_fd()
}
}
#[cfg(unix)]
impl AsRawFd for TcpStream {
fn as_raw_fd(&self) -> RawFd {
self.inner.as_raw_fd()
}
}
#[cfg(unix)]
impl FromRawFd for TcpStream {
/// Converts a `RawFd` to a `TcpStream`.
///
/// # Notes
///
/// The caller is responsible for ensuring that the socket is in
/// non-blocking mode.
unsafe fn from_raw_fd(fd: RawFd) -> TcpStream {
TcpStream::from_std(FromRawFd::from_raw_fd(fd))
}
}
#[cfg(windows)]
impl IntoRawSocket for TcpStream {
fn into_raw_socket(self) -> RawSocket {
self.inner.into_inner().into_raw_socket()
}
}
#[cfg(windows)]
impl AsRawSocket for TcpStream {
fn as_raw_socket(&self) -> RawSocket {
self.inner.as_raw_socket()
}
}
#[cfg(windows)]
impl FromRawSocket for TcpStream {
/// Converts a `RawSocket` to a `TcpStream`.
///
/// # Notes
///
/// The caller is responsible for ensuring that the socket is in
/// non-blocking mode.
unsafe fn from_raw_socket(socket: RawSocket) -> TcpStream {
TcpStream::from_std(FromRawSocket::from_raw_socket(socket))
}
}