Struct TcpStream

pub struct TcpStream { /* private fields */ }

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

use futures::Future;
use tokio::io::AsyncWrite;
use tokio::net::TcpStream;
use std::net::SocketAddr;

let addr = "127.0.0.1:34254".parse::<SocketAddr>()?;
let stream = TcpStream::connect(&addr);
stream.map(|mut stream| {
    // Attempt to write bytes asynchronously to the stream
    stream.poll_write(&[1]);
});

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

let addr = "127.0.0.1:34254".parse::<SocketAddr>()?;
let stream = TcpStream::connect(&addr)
    .map(|stream|
        println!("successfully connected to {}", stream.local_addr().unwrap()));

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

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 std::net::TcpStream as StdTcpStream;
use tokio_reactor::Handle;

let std_stream = StdTcpStream::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, ) -> ConnectFuture

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 poll_read_ready(&self, mask: Ready) -> Poll<Ready, Error>

Check the TCP stream’s read readiness state.

The mask argument allows specifying what readiness to notify on. This can be any value, including platform specific readiness, except writable. HUP is always implicitly included on platforms that support it.

If the resource is not ready for a read then Async::NotReady is returned and the current task is notified once a new event is received.

The stream will remain in a read-ready state until calls to poll_read return NotReady.

Panics

This function panics if:

• ready includes writable.
• called from outside of a task context.

Examples

use mio::Ready;
use futures::Async;
use futures::Future;
use tokio::net::TcpStream;
use std::net::SocketAddr;

let addr = "127.0.0.1:34254".parse::<SocketAddr>()?;
let stream = TcpStream::connect(&addr);
stream.map(|stream| {
    match stream.poll_read_ready(Ready::readable()) {
        Ok(Async::Ready(_)) => println!("read ready"),
        Ok(Async::NotReady) => println!("not read ready"),
        Err(e) => eprintln!("got error: {}", e),
}
});

pub fn poll_write_ready(&self) -> Poll<Ready, Error>

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 Async::NotReady 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.

Examples

use futures::Async;
use futures::Future;
use tokio::net::TcpStream;
use std::net::SocketAddr;

let addr = "127.0.0.1:34254".parse::<SocketAddr>()?;
let stream = TcpStream::connect(&addr);
stream.map(|stream| {
    match stream.poll_write_ready() {
        Ok(Async::Ready(_)) => println!("write ready"),
        Ok(Async::NotReady) => println!("not write ready"),
        Err(e) => eprintln!("got error: {}", e),
}
});

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

Returns the local address that this stream is bound to.

Examples

use tokio::net::TcpStream;
use futures::Future;
use std::net::{Ipv4Addr, SocketAddr, SocketAddrV4};

let addr = "127.0.0.1:8080".parse::<SocketAddr>()?;
let stream = TcpStream::connect(&addr);
stream.map(|stream| {
    assert_eq!(stream.local_addr().unwrap(),
        SocketAddr::V4(SocketAddrV4::new(Ipv4Addr::new(127, 0, 0, 1), 8080)));
});

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

Returns the remote address that this stream is connected to.

Examples

use tokio::net::TcpStream;
use futures::Future;
use std::net::{Ipv4Addr, SocketAddr, SocketAddrV4};

let addr = "127.0.0.1:8080".parse::<SocketAddr>()?;
let stream = TcpStream::connect(&addr);
stream.map(|stream| {
    assert_eq!(stream.peer_addr().unwrap(),
        SocketAddr::V4(SocketAddrV4::new(Ipv4Addr::new(127, 0, 0, 1), 8080)));
});

pub fn poll_peek(&mut self, buf: &mut [u8]) -> Poll<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.

Return

On success, returns Ok(Async::Ready(num_bytes_read)).

If no data is available for reading, the method returns Ok(Async::NotReady) and arranges for the current task to receive a notification when the socket becomes readable or is closed.

Panics

This function will panic if called from outside of a task context.

Examples

use tokio::net::TcpStream;
use futures::Async;
use futures::Future;
use std::net::SocketAddr;

let addr = "127.0.0.1:8080".parse::<SocketAddr>()?;
let stream = TcpStream::connect(&addr);
stream.map(|mut stream| {
    let mut buf = [0; 10];
    match stream.poll_peek(&mut buf) {
       Ok(Async::Ready(len)) => println!("read {} bytes", len),
       Ok(Async::NotReady) => println!("no data available"),
       Err(e) => eprintln!("got error: {}", e),
    }
});

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 tokio::net::TcpStream;
use futures::Future;
use std::net::{Shutdown, SocketAddr};

let addr = "127.0.0.1:8080".parse::<SocketAddr>()?;
let stream = TcpStream::connect(&addr);
stream.map(|stream| {
    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 tokio::net::TcpStream;
use futures::Future;
use std::net::SocketAddr;

let addr = "127.0.0.1:8080".parse::<SocketAddr>()?;
let stream = TcpStream::connect(&addr);
stream.map(|stream| {
    stream.set_nodelay(true).expect("set_nodelay call failed");;
    assert_eq!(stream.nodelay().unwrap_or(false), 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 tokio::net::TcpStream;
use futures::Future;
use std::net::SocketAddr;

let addr = "127.0.0.1:8080".parse::<SocketAddr>()?;
let stream = TcpStream::connect(&addr);
stream.map(|stream| {
    stream.set_nodelay(true).expect("set_nodelay call failed");
});

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

let addr = "127.0.0.1:8080".parse::<SocketAddr>()?;
let stream = TcpStream::connect(&addr);
stream.map(|stream| {
    stream.set_recv_buffer_size(100).expect("set_recv_buffer_size failed");
    assert_eq!(stream.recv_buffer_size().unwrap_or(0), 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 tokio::net::TcpStream;
use futures::Future;
use std::net::SocketAddr;

let addr = "127.0.0.1:8080".parse::<SocketAddr>()?;
let stream = TcpStream::connect(&addr);
stream.map(|stream| {
    stream.set_recv_buffer_size(100).expect("set_recv_buffer_size failed");
});

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

let addr = "127.0.0.1:8080".parse::<SocketAddr>()?;
let stream = TcpStream::connect(&addr);
stream.map(|stream| {
    stream.set_send_buffer_size(100).expect("set_send_buffer_size failed");
    assert_eq!(stream.send_buffer_size().unwrap_or(0), 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 tokio::net::TcpStream;
use futures::Future;
use std::net::SocketAddr;

let addr = "127.0.0.1:8080".parse::<SocketAddr>()?;
let stream = TcpStream::connect(&addr);
stream.map(|stream| {
    stream.set_send_buffer_size(100).expect("set_send_buffer_size failed");
});

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

let addr = "127.0.0.1:8080".parse::<SocketAddr>()?;
let stream = TcpStream::connect(&addr);
stream.map(|stream| {
    stream.set_keepalive(None).expect("set_keepalive failed");
    assert_eq!(stream.keepalive().unwrap(), None);
});

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

let addr = "127.0.0.1:8080".parse::<SocketAddr>()?;
let stream = TcpStream::connect(&addr);
stream.map(|stream| {
    stream.set_keepalive(None).expect("set_keepalive failed");
});

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

let addr = "127.0.0.1:8080".parse::<SocketAddr>()?;
let stream = TcpStream::connect(&addr);
stream.map(|stream| {
    stream.set_ttl(100).expect("set_ttl failed");
    assert_eq!(stream.ttl().unwrap_or(0), 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 tokio::net::TcpStream;
use futures::Future;
use std::net::SocketAddr;

let addr = "127.0.0.1:8080".parse::<SocketAddr>()?;
let stream = TcpStream::connect(&addr);
stream.map(|stream| {
    stream.set_ttl(100).expect("set_ttl failed");
});

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

let addr = "127.0.0.1:8080".parse::<SocketAddr>()?;
let stream = TcpStream::connect(&addr);
stream.map(|stream| {
    stream.set_linger(None).expect("set_linger failed");
    assert_eq!(stream.linger().unwrap(), None);
});

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

let addr = "127.0.0.1:8080".parse::<SocketAddr>()?;
let stream = TcpStream::connect(&addr);
stream.map(|stream| {
    stream.set_linger(None).expect("set_linger failed");
});

Trait Implementations

impl AsRawFd for TcpStream

fn as_raw_fd(&self) -> RawFd

Extracts the raw file descriptor.

impl<'a> AsyncRead for &'a 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 read_buf<B: BufMut>(&mut self, buf: &mut B) -> Poll<usize, Error>

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

fn poll_read(&mut self, buf: &mut [u8]) -> Result<Async<usize>, Error>

Attempt to read from the AsyncRead into buf.

fn framed<T>(self, codec: T) -> Framed<Self, T>

where T: Encoder + Decoder, Self: Sized + AsyncWrite,

👎Deprecated since 0.1.7: Use tokio_codec::Decoder::framed instead

Provides a Stream and Sink interface for reading and writing to this I/O object, using Decode and Encode to read and write the raw data.

fn split(self) -> (ReadHalf<Self>, WriteHalf<Self>)

where Self: Sized + AsyncWrite,

Helper method for splitting this read/write object into two halves.

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 read_buf<B: BufMut>(&mut self, buf: &mut B) -> Poll<usize, Error>

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

fn poll_read(&mut self, buf: &mut [u8]) -> Result<Async<usize>, Error>

Attempt to read from the AsyncRead into buf.

fn framed<T>(self, codec: T) -> Framed<Self, T>

where T: Encoder + Decoder, Self: Sized + AsyncWrite,

👎Deprecated since 0.1.7: Use tokio_codec::Decoder::framed instead

Provides a Stream and Sink interface for reading and writing to this I/O object, using Decode and Encode to read and write the raw data.

fn split(self) -> (ReadHalf<Self>, WriteHalf<Self>)

where Self: Sized + AsyncWrite,

Helper method for splitting this read/write object into two halves.

impl<'a> AsyncWrite for &'a TcpStream

fn shutdown(&mut self) -> Poll<(), Error>

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

fn write_buf<B: Buf>(&mut self, buf: &mut B) -> Poll<usize, Error>

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

fn poll_write(&mut self, buf: &[u8]) -> Result<Async<usize>, Error>

Attempt to write bytes from buf into the object.

fn poll_flush(&mut self) -> Result<Async<()>, Error>

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

impl AsyncWrite for TcpStream

fn shutdown(&mut self) -> Poll<(), Error>

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

fn write_buf<B: Buf>(&mut self, buf: &mut B) -> Poll<usize, Error>

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

fn poll_write(&mut self, buf: &[u8]) -> Result<Async<usize>, Error>

Attempt to write bytes from buf into the object.

fn poll_flush(&mut self) -> Result<Async<()>, Error>

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

impl Debug for TcpStream

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

Formats the value using the given formatter.

impl<'a> Read for &'a TcpStream

fn read(&mut self, buf: &mut [u8]) -> Result<usize>

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

fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> Result<usize, Error>

Like read, except that it reads into a slice of buffers.

fn is_read_vectored(&self) -> bool

🔬This is a nightly-only experimental API. (can_vector)

Determines if this Reader has an efficient read_vectored implementation.

fn read_to_end(&mut self, buf: &mut Vec<u8>) -> Result<usize, Error>

Reads all bytes until EOF in this source, placing them into buf.

fn read_to_string(&mut self, buf: &mut String) -> Result<usize, Error>

Reads all bytes until EOF in this source, appending them to buf.

fn read_exact(&mut self, buf: &mut [u8]) -> Result<(), Error>

Reads the exact number of bytes required to fill buf.

fn read_buf(&mut self, buf: BorrowedCursor<'_>) -> Result<(), Error>

🔬This is a nightly-only experimental API. (read_buf)

Pull some bytes from this source into the specified buffer.

fn read_buf_exact(&mut self, cursor: BorrowedCursor<'_>) -> Result<(), Error>

🔬This is a nightly-only experimental API. (read_buf)

Reads the exact number of bytes required to fill cursor.

fn by_ref(&mut self) -> &mut Self

where Self: Sized,

Creates a “by reference” adaptor for this instance of Read.

fn bytes(self) -> Bytes<Self>

where Self: Sized,

Transforms this Read instance to an Iterator over its bytes.

fn chain<R>(self, next: R) -> Chain<Self, R>

where R: Read, Self: Sized,

Creates an adapter which will chain this stream with another.

fn take(self, limit: u64) -> Take<Self>

where Self: Sized,

Creates an adapter which will read at most limit bytes from it.

impl Read for TcpStream

fn read(&mut self, buf: &mut [u8]) -> Result<usize>

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

fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> Result<usize, Error>

Like read, except that it reads into a slice of buffers.

fn is_read_vectored(&self) -> bool

🔬This is a nightly-only experimental API. (can_vector)

Determines if this Reader has an efficient read_vectored implementation.

fn read_to_end(&mut self, buf: &mut Vec<u8>) -> Result<usize, Error>

Reads all bytes until EOF in this source, placing them into buf.

fn read_to_string(&mut self, buf: &mut String) -> Result<usize, Error>

Reads all bytes until EOF in this source, appending them to buf.

fn read_exact(&mut self, buf: &mut [u8]) -> Result<(), Error>

Reads the exact number of bytes required to fill buf.

fn read_buf(&mut self, buf: BorrowedCursor<'_>) -> Result<(), Error>

🔬This is a nightly-only experimental API. (read_buf)

Pull some bytes from this source into the specified buffer.

fn read_buf_exact(&mut self, cursor: BorrowedCursor<'_>) -> Result<(), Error>

🔬This is a nightly-only experimental API. (read_buf)

Reads the exact number of bytes required to fill cursor.

fn by_ref(&mut self) -> &mut Self

where Self: Sized,

Creates a “by reference” adaptor for this instance of Read.

fn bytes(self) -> Bytes<Self>

where Self: Sized,

Transforms this Read instance to an Iterator over its bytes.

fn chain<R>(self, next: R) -> Chain<Self, R>

where R: Read, Self: Sized,

Creates an adapter which will chain this stream with another.

fn take(self, limit: u64) -> Take<Self>

where Self: Sized,

Creates an adapter which will read at most limit bytes from it.

impl<'a> Write for &'a TcpStream

fn write(&mut self, buf: &[u8]) -> Result<usize>

Writes a buffer into this writer, returning how many bytes were written.

fn flush(&mut self) -> Result<()>

Flushes this output stream, ensuring that all intermediately buffered contents reach their destination.

fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> Result<usize, Error>

Like write, except that it writes from a slice of buffers.

fn is_write_vectored(&self) -> bool

🔬This is a nightly-only experimental API. (can_vector)

Determines if this Writer has an efficient write_vectored implementation.

fn write_all(&mut self, buf: &[u8]) -> Result<(), Error>

Attempts to write an entire buffer into this writer.

fn write_all_vectored(&mut self, bufs: &mut [IoSlice<'_>]) -> Result<(), Error>

🔬This is a nightly-only experimental API. (write_all_vectored)

Attempts to write multiple buffers into this writer.

fn write_fmt(&mut self, fmt: Arguments<'_>) -> Result<(), Error>

Writes a formatted string into this writer, returning any error encountered.

fn by_ref(&mut self) -> &mut Self

where Self: Sized,

Creates a “by reference” adapter for this instance of Write.

impl Write for TcpStream

fn write(&mut self, buf: &[u8]) -> Result<usize>

Writes a buffer into this writer, returning how many bytes were written.

fn flush(&mut self) -> Result<()>

Flushes this output stream, ensuring that all intermediately buffered contents reach their destination.

fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> Result<usize, Error>

Like write, except that it writes from a slice of buffers.

fn is_write_vectored(&self) -> bool

🔬This is a nightly-only experimental API. (can_vector)

Determines if this Writer has an efficient write_vectored implementation.

fn write_all(&mut self, buf: &[u8]) -> Result<(), Error>

Attempts to write an entire buffer into this writer.

fn write_all_vectored(&mut self, bufs: &mut [IoSlice<'_>]) -> Result<(), Error>

🔬This is a nightly-only experimental API. (write_all_vectored)

Attempts to write multiple buffers into this writer.

fn write_fmt(&mut self, fmt: Arguments<'_>) -> Result<(), Error>

Writes a formatted string into this writer, returning any error encountered.

fn by_ref(&mut self) -> &mut Self

where Self: Sized,

Creates a “by reference” adapter for this instance of Write.