Struct tokio::net::tcp::ReadHalf [−][src]
pub struct ReadHalf<'a>(_);Expand description
Borrowed read half of a TcpStream, created by split.
Reading from a ReadHalf is usually done using the convenience methods found on the
AsyncReadExt trait.
Implementations
Attempt to receive data on the socket, without removing that data from the queue, registering the current task for wakeup if data is not yet available.
Note that on multiple calls to poll_peek or poll_read, only the
Waker from the Context passed to the most recent call is scheduled
to receive a wakeup.
See the TcpStream::poll_peek level documentation for more details.
Examples
use tokio::io::{self, ReadBuf};
use tokio::net::TcpStream;
use futures::future::poll_fn;
#[tokio::main]
async fn main() -> io::Result<()> {
let mut stream = TcpStream::connect("127.0.0.1:8000").await?;
let (mut read_half, _) = stream.split();
let mut buf = [0; 10];
let mut buf = ReadBuf::new(&mut buf);
poll_fn(|cx| {
read_half.poll_peek(cx, &mut buf)
}).await?;
Ok(())
}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.
See the TcpStream::peek level documentation for more details.
Examples
use tokio::net::TcpStream;
use tokio::io::AsyncReadExt;
use std::error::Error;
#[tokio::main]
async fn main() -> Result<(), Box<dyn Error>> {
// Connect to a peer
let mut stream = TcpStream::connect("127.0.0.1:8080").await?;
let (mut read_half, _) = stream.split();
let mut b1 = [0; 10];
let mut b2 = [0; 10];
// Peek at the data
let n = read_half.peek(&mut b1).await?;
// Read the data
assert_eq!(n, read_half.read(&mut b2[..n]).await?);
assert_eq!(&b1[..n], &b2[..n]);
Ok(())
}The read method is defined on the AsyncReadExt trait.