Struct TcpStream

pub struct TcpStream { /* private fields */ }

A TCP stream between a local and a remote socket.

A TcpStream can either be created by connecting to an endpoint, via the connect method, or by accepting a connection from a listener. It can be read or written to using the AsyncRead, AsyncWrite, and related extension traits in futures::io.

The connection will be closed when the value is dropped. The reading and writing portions of the connection can also be shut down individually with the [shutdown] method.

Implementations

impl TcpStream

pub fn connect(addr: &SocketAddr) -> ConnectFuture

Create a new TCP stream connected to the specified address.

This function will create a new TCP socket and attempt to connect it to the addr provided. The returned future will be resolved once the stream has successfully connected, or it will return an error if one occurs.

Examples

use futures_net::tcp::TcpStream;

let addr = "127.0.0.1".parse().unwrap();
TcpStream::connect(&addr).await

pub fn local_addr(&self) -> Result<SocketAddr>

Returns the local address that this stream is bound to.

Examples

use futures_net::tcp::TcpStream;
use std::net::{IpAddr, Ipv4Addr};

let addr = "127.0.0.1:8080".parse()?;
let stream = TcpStream::connect(&addr).await?;

let expected = IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1));
assert_eq!(stream.local_addr()?.ip(), expected);

pub fn peer_addr(&self) -> Result<SocketAddr>

Returns the remote address that this stream is connected to.

Examples

use futures_net::tcp::TcpStream;
use std::net::{Ipv4Addr, SocketAddr, SocketAddrV4};

let addr = "127.0.0.1:8080".parse()?;
let stream = TcpStream::connect(&addr).await?;

let expected = SocketAddrV4::new(Ipv4Addr::new(127, 0, 0, 1), 8080);
assert_eq!(stream.peer_addr()?, SocketAddr::V4(expected));

pub fn shutdown(&self, how: Shutdown) -> Result<()>

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).

Examples

use futures_net::tcp::TcpStream;
use std::net::Shutdown;

let addr = "127.0.0.1:8080".parse()?;
let stream = TcpStream::connect(&addr).await?;

stream.shutdown(Shutdown::Both)?;

pub fn nodelay(&self) -> Result<bool>

Gets the value of the TCP_NODELAY option on this socket.

For more information about this option, see set_nodelay.

Examples

use futures_net::tcp::TcpStream;

let addr = "127.0.0.1:8080".parse()?;
let stream = TcpStream::connect(&addr).await?;

stream.set_nodelay(true)?;
assert_eq!(stream.nodelay()?, true);

pub fn set_nodelay(&self, nodelay: bool) -> Result<()>

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.

Examples

use futures_net::tcp::TcpStream;

let addr = "127.0.0.1:8080".parse()?;
let stream = TcpStream::connect(&addr).await?;

stream.set_nodelay(true)?;

pub fn recv_buffer_size(&self) -> Result<usize>

Gets the value of the SO_RCVBUF option on this socket.

For more information about this option, see set_recv_buffer_size.

Examples

use futures_net::tcp::TcpStream;

let addr = "127.0.0.1:8080".parse()?;
let stream = TcpStream::connect(&addr).await?;

stream.set_recv_buffer_size(100);
assert_eq!(stream.recv_buffer_size()?, 100);

pub fn set_recv_buffer_size(&self, size: usize) -> Result<()>

Sets the value of the SO_RCVBUF option on this socket.

Changes the size of the operating system’s receive buffer associated with the socket.

Examples

use futures_net::tcp::TcpStream;

let addr = "127.0.0.1:8080".parse()?;
let stream = TcpStream::connect(&addr).await?;

stream.set_recv_buffer_size(100);

pub fn send_buffer_size(&self) -> Result<usize>

Gets the value of the SO_SNDBUF option on this socket.

For more information about this option, see set_send_buffer.

Examples

use futures_net::tcp::TcpStream;

let addr = "127.0.0.1:8080".parse()?;
let stream = TcpStream::connect(&addr).await?;

stream.set_send_buffer_size(100);
assert_eq!(stream.send_buffer_size()?, 100);

pub fn set_send_buffer_size(&self, size: usize) -> Result<()>

Sets the value of the SO_SNDBUF option on this socket.

Changes the size of the operating system’s send buffer associated with the socket.

Examples

use futures_net::tcp::TcpStream;

let addr = "127.0.0.1:8080".parse()?;
let stream = TcpStream::connect(&addr).await?;

stream.set_send_buffer_size(100);

pub fn keepalive(&self) -> Result<Option<Duration>>

Returns whether keepalive messages are enabled on this socket, and if so the duration of time between them.

For more information about this option, see set_keepalive.

Examples

use futures_net::tcp::TcpStream;
use std::time::Duration;

let addr = "127.0.0.1:8080".parse()?;
let stream = TcpStream::connect(&addr).await?;

stream.set_keepalive(Some(Duration::from_secs(60)))?;
assert_eq!(stream.keepalive()?, Some(Duration::from_secs(60)));

pub fn set_keepalive(&self, keepalive: Option<Duration>) -> Result<()>

Sets whether keepalive messages are enabled to be sent on this socket.

On Unix, this option will set the SO_KEEPALIVE as well as the TCP_KEEPALIVE or TCP_KEEPIDLE option (depending on your platform). On Windows, this will set the SIO_KEEPALIVE_VALS option.

If None is specified then keepalive messages are disabled, otherwise the duration specified will be the time to remain idle before sending a TCP keepalive probe.

Some platforms specify this value in seconds, so sub-second specifications may be omitted.

Examples

use futures_net::tcp::TcpStream;
use std::time::Duration;

let addr = "127.0.0.1:8080".parse()?;
let stream = TcpStream::connect(&addr).await?;

stream.set_keepalive(Some(Duration::from_secs(60)))?;

pub fn ttl(&self) -> Result<u32>

Gets the value of the IP_TTL option for this socket.

For more information about this option, see set_ttl.

Examples

use futures_net::tcp::TcpStream;

let addr = "127.0.0.1:8080".parse()?;
let stream = TcpStream::connect(&addr).await?;

stream.set_ttl(100)?;
assert_eq!(stream.ttl()?, 100);

pub fn set_ttl(&self, ttl: u32) -> Result<()>

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.

Examples

use futures_net::tcp::TcpStream;

let addr = "127.0.0.1:8080".parse()?;
let stream = TcpStream::connect(&addr).await?;

stream.set_ttl(100)?;

pub fn linger(&self) -> Result<Option<Duration>>

Reads the linger duration for this socket by getting the SO_LINGER option.

For more information about this option, see set_linger.

Examples

use futures_net::tcp::TcpStream;
use std::time::Duration;

let addr = "127.0.0.1:8080".parse()?;
let stream = TcpStream::connect(&addr).await?;

stream.set_linger(Some(Duration::from_millis(100)))?;
assert_eq!(stream.linger()?, Some(Duration::from_millis(100)));

pub fn set_linger(&self, dur: Option<Duration>) -> Result<()>

Sets the linger duration of this socket by setting the SO_LINGER option.

This option controls the action taken when a stream has unsent messages and the stream is closed. If SO_LINGER is set, the system shall block the process until it can transmit the data or until the time expires.

If SO_LINGER is not specified, and the stream is closed, the system handles the call in a way that allows the process to continue as quickly as possible.

Examples

use futures_net::tcp::TcpStream;
use std::time::Duration;

let addr = "127.0.0.1:8080".parse()?;
let stream = TcpStream::connect(&addr).await?;

stream.set_linger(Some(Duration::from_millis(100)))?;

Trait Implementations

impl AsRawFd for TcpStream

fn as_raw_fd(&self) -> RawFd

Extracts the raw file descriptor.

impl AsyncRead for TcpStream

fn poll_read( self: Pin<&mut Self>, cx: &mut Context<'_>, buf: &mut [u8], ) -> Poll<Result<usize>>

Attempt to read from the AsyncRead into buf.

fn poll_read_vectored( self: Pin<&mut Self>, cx: &mut Context<'_>, bufs: &mut [IoSliceMut<'_>], ) -> Poll<Result<usize, Error>>

Attempt to read from the AsyncRead into bufs using vectored IO operations.

impl AsyncReadReady for TcpStream

fn poll_read_ready( self: Pin<&mut Self>, cx: &mut Context<'_>, ) -> Poll<Result<Self::Ok, Self::Err>>

Poll the TCP stream’s readiness for reading.

If the stream is not ready for a read then the method will return Poll::Pending and schedule the current task for wakeup upon read-readiness.

Once the stream is ready for reading, it will remain so until all available bytes have been extracted (via futures::io::AsyncRead and related traits).

type Ok = Ready

The type of successful values yielded by this trait.

type Err = Error

The type of failures yielded by this trait.

fn poll_read_ready_unpin( &mut self, cx: &mut Context<'_>, ) -> Poll<Result<Self::Ok, Self::Err>>

where Self: Sized + Unpin,

A convenience for calling AsyncReadReady::poll_read_ready on Unpin types.

impl AsyncWrite for TcpStream

fn poll_write( self: Pin<&mut Self>, cx: &mut Context<'_>, buf: &[u8], ) -> Poll<Result<usize>>

Attempt to write bytes from buf into the object.

fn poll_flush(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<()>>

Attempt to flush the object, ensuring that any buffered data reach their destination.

fn poll_close(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<()>>

Attempt to close the object.

fn poll_write_vectored( self: Pin<&mut Self>, cx: &mut Context<'_>, bufs: &[IoSlice<'_>], ) -> Poll<Result<usize, Error>>

Attempt to write bytes from bufs into the object using vectored IO operations.

impl AsyncWriteReady for TcpStream

fn poll_write_ready( self: Pin<&mut Self>, cx: &mut Context<'_>, ) -> Poll<Result<Self::Ok, Self::Err>>

Check the TCP stream’s write readiness state.

This always checks for writable readiness and also checks for HUP readiness on platforms that support it.

If the resource is not ready for a write then Poll::Pending is returned and the current task is notified once a new event is received.

The I/O resource will remain in a write-ready state until calls to poll_write return NotReady.

Panics

This function panics if called from outside of a task context.

type Ok = Ready

The type of successful values yielded by this trait.

type Err = Error

The type of failures yielded by this trait.

fn poll_write_ready_unpin( &mut self, cx: &mut Context<'_>, ) -> Poll<Result<Self::Ok, Self::Err>>

where Self: Sized + Unpin,

A convenience for calling AsyncWriteReady::poll_write_ready on Unpin types.

impl Debug for TcpStream

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl TryFrom<&SocketAddr> for TcpStream

type Error = Error

The type returned in the event of a conversion error.

fn try_from(addr: &SocketAddr) -> Result<Self, Self::Error>

Performs the conversion.

impl TryFrom<TcpStream> for TcpStream

type Error = Error

The type returned in the event of a conversion error.

fn try_from(stream: TcpStream) -> Result<Self, Self::Error>

Performs the conversion.

impl Unpin for TcpStream