Struct tokio::net::tcp::TcpStream

pub struct TcpStream { /* fields omitted */ }

An I/O object representing a TCP stream connected to a remote endpoint.

A TCP stream can either be created by connecting to an endpoint, via the connect method, or by accepting a connection from a listener.

Examples

#![feature(async_await)]

use tokio::net::TcpStream;
use tokio::prelude::*;
use std::error::Error;

#[tokio::main]
async fn main() -> Result<(), Box<dyn Error>> {
    let addr = "127.0.0.1:8080".parse()?;

    // Connect to a peer
    let mut stream = TcpStream::connect(&addr).await?;

    // Write some data.
    stream.write_all(b"hello world!").await?;

    Ok(())
}

Methods

impl TcpStream

pub fn connect(
    addr: &SocketAddr
) -> impl Future<Output = Result<TcpStream, Error>>

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

#![feature(async_await)]

use tokio::net::TcpStream;
use tokio::prelude::*;
use std::error::Error;

#[tokio::main]
async fn main() -> Result<(), Box<dyn Error>> {
    let addr = "127.0.0.1:8080".parse()?;

    // Connect to a peer
    let mut stream = TcpStream::connect(&addr).await?;

    // Write some data.
    stream.write_all(b"hello world!").await?;

    Ok(())
}

pub fn from_std(stream: TcpStream, handle: &Handle) -> Result<TcpStream, Error>

Create a new TcpStream from a net::TcpStream.

This function will convert a TCP stream created by the standard library to a TCP stream ready to be used with the provided event loop handle. Use Handle::default() to lazily bind to an event loop, just like connect does.

Examples

use tokio::net::TcpStream;
use tokio_reactor::Handle;

let std_stream = std::net::TcpStream::connect("127.0.0.1:34254")?;
let stream = TcpStream::from_std(std_stream, &Handle::default())?;

pub fn connect_std(
    stream: TcpStream,
    addr: &SocketAddr,
    handle: &Handle
) -> impl Future<Output = Result<TcpStream, Error>>

Creates a new TcpStream from the pending socket inside the given std::net::TcpStream, connecting it to the address specified.

This constructor allows configuring the socket before it's actually connected, and this function will transfer ownership to the returned TcpStream if successful. An unconnected TcpStream can be created with the net2::TcpBuilder type (and also configured via that route).

The platform specific behavior of this function looks like:

• On Unix, the socket is placed into nonblocking mode and then a connect call is issued.

• On Windows, the address is stored internally and the connect operation is issued when the returned TcpStream is registered with an event loop. Note that on Windows you must bind a socket before it can be connected, so if a custom TcpBuilder is used it should be bound (perhaps to INADDR_ANY) before this method is called.

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

Returns the local address that this stream is bound to.

Examples

#![feature(async_await)]

use tokio::net::TcpStream;
use std::net::SocketAddr;

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

println!("{:?}", stream.local_addr()?);

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

Returns the remote address that this stream is connected to.

Examples

#![feature(async_await)]

use tokio::net::TcpStream;
use std::net::SocketAddr;

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

println!("{:?}", stream.peer_addr()?);

pub fn peek(
    &'_ mut self,
    buf: &'_ mut [u8]
) -> impl Future<Output = Result<usize, 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.

Examples

#![feature(async_await)]

use tokio::net::TcpStream;
use tokio::prelude::*;
use std::error::Error;

#[tokio::main]
async fn main() -> Result<(), Box<dyn Error>> {
    let addr = "127.0.0.1:8080".parse()?;

    // Connect to a peer
    let mut stream = TcpStream::connect(&addr).await?;

    let mut b1 = [0; 10];
    let mut b2 = [0; 10];

    // Peek at the data
    let n = stream.peek(&mut b1).await?;

    // Read the data
    assert_eq!(n, stream.read(&mut b2[..n]).await?);
    assert_eq!(&b1[..n], &b2[..n]);

    Ok(())
}

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

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

#![feature(async_await)]

use tokio::net::TcpStream;
use tokio::prelude::*;
use std::error::Error;
use std::net::Shutdown;

#[tokio::main]
async fn main() -> Result<(), Box<dyn Error>> {
    let addr = "127.0.0.1:8080".parse()?;

    // Connect to a peer
    let mut stream = TcpStream::connect(&addr).await?;

    // Shutdown the stream
    stream.shutdown(Shutdown::Write)?;

    Ok(())
}

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

Gets the value of the TCP_NODELAY option on this socket.

For more information about this option, see set_nodelay.

Examples

#![feature(async_await)]

use tokio::net::TcpStream;
use std::net::SocketAddr;

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

println!("{:?}", stream.nodelay()?);

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

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

#![feature(async_await)]

use tokio::net::TcpStream;
use std::net::SocketAddr;

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, Error>

Gets the value of the SO_RCVBUF option on this socket.

For more information about this option, see set_recv_buffer_size.

Examples

#![feature(async_await)]

use tokio::net::TcpStream;
use std::net::SocketAddr;

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

println!("{:?}", stream.recv_buffer_size()?);

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

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

#![feature(async_await)]

use tokio::net::TcpStream;
use std::net::SocketAddr;

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, Error>

Gets the value of the SO_SNDBUF option on this socket.

For more information about this option, see set_send_buffer.

Examples

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

#![feature(async_await)]

use tokio::net::TcpStream;
use std::net::SocketAddr;

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

println!("{:?}", stream.send_buffer_size()?);

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

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

#![feature(async_await)]

use tokio::net::TcpStream;
use std::net::SocketAddr;

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>, Error>

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

#![feature(async_await)]

use tokio::net::TcpStream;
use std::net::SocketAddr;

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

println!("{:?}", stream.keepalive()?);

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

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

#![feature(async_await)]

use tokio::net::TcpStream;
use std::net::SocketAddr;

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

stream.set_keepalive(None)?;

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

Gets the value of the IP_TTL option for this socket.

For more information about this option, see set_ttl.

Examples

#![feature(async_await)]

use tokio::net::TcpStream;
use std::net::SocketAddr;

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

println!("{:?}", stream.ttl()?);

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

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

#![feature(async_await)]

use tokio::net::TcpStream;
use std::net::SocketAddr;

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

stream.set_ttl(123)?;

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

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

For more information about this option, see set_linger.

Examples

#![feature(async_await)]

use tokio::net::TcpStream;
use std::net::SocketAddr;

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

println!("{:?}", stream.linger()?);

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

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

#![feature(async_await)]

use tokio::net::TcpStream;
use std::net::SocketAddr;

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

stream.set_linger(None)?;

pub fn split(self) -> (TcpStreamReadHalf, TcpStreamWriteHalf)

Split a TcpStream into a read half and a write half, which can be used to read and write the stream concurrently.

See the module level documenation of split for more details.

pub fn split_mut(&mut self) -> (TcpStreamReadHalfMut, TcpStreamWriteHalfMut)

Split a TcpStream into a read half and a write half, which can be used to read and write the stream concurrently.

See the module level documenation of split for more details.

Trait Implementations

impl Debug for TcpStream

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

Formats the value using the given formatter.

impl AsyncRead for TcpStream

unsafe fn prepare_uninitialized_buffer(&self, &mut [u8]) -> bool

Prepares an uninitialized buffer to be safe to pass to read. Returns true if the supplied buffer was zeroed out.

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

Attempt to read from the AsyncRead into buf.

fn poll_read_buf<B>(
    self: Pin<&mut TcpStream>,
    cx: &mut Context,
    buf: &mut B
) -> Poll<Result<usize, Error>> where
    B: BufMut, 

Pull some bytes from this source into the specified BufMut, returning how many bytes were read.

impl AsyncWrite for TcpStream

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

Attempt to write bytes from buf into the object.

fn poll_flush(
    self: Pin<&mut TcpStream>,
    &mut Context
) -> Poll<Result<(), Error>>

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

fn poll_shutdown(
    self: Pin<&mut TcpStream>,
    &mut Context
) -> Poll<Result<(), Error>>

Initiates or attempts to shut down this writer, returning success when the I/O connection has completely shut down.

fn poll_write_buf<B>(
    self: Pin<&mut TcpStream>,
    cx: &mut Context,
    buf: &mut B
) -> Poll<Result<usize, Error>> where
    B: Buf, 

Write a Buf into this value, returning how many bytes were written.

impl AsRawFd for TcpStream

fn as_raw_fd(&self) -> i32

Extracts the raw file descriptor.

impl AsRef<TcpStream> for TcpStreamWriteHalf

fn as_ref(&self) -> &TcpStream

Performs the conversion.

impl<'_> AsRef<TcpStream> for TcpStreamReadHalfMut<'_>

fn as_ref(&self) -> &TcpStream

Performs the conversion.

impl AsRef<TcpStream> for TcpStreamReadHalf

fn as_ref(&self) -> &TcpStream

Performs the conversion.

impl<'_> AsRef<TcpStream> for TcpStreamWriteHalfMut<'_>

fn as_ref(&self) -> &TcpStream

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<TcpStream, <TcpStream as TryFrom<TcpStream>>::Error>

Consumes stream, returning the tokio I/O object.

This is equivalent to TcpStream::from_std(stream, &Handle::default()).