Struct DuplexStream

pub struct DuplexStream { /* private fields */ }

Available on crate feature io-util only.

A bidirectional pipe to read and write bytes in memory.

A pair of DuplexStreams are created together, and they act as a “channel” that can be used as in-memory IO types. Writing to one of the pairs will allow that data to be read from the other, and vice versa.

Closing a DuplexStream

If one end of the DuplexStream channel is dropped, any pending reads on the other side will continue to read data until the buffer is drained, then they will signal EOF by returning 0 bytes. Any writes to the other side, including pending ones (that are waiting for free space in the buffer) will return Err(BrokenPipe) immediately.

Example

let (mut client, mut server) = tokio::io::duplex(64);

client.write_all(b"ping").await?;

let mut buf = [0u8; 4];
server.read_exact(&mut buf).await?;
assert_eq!(&buf, b"ping");

server.write_all(b"pong").await?;

client.read_exact(&mut buf).await?;
assert_eq!(&buf, b"pong");

Trait Implementations

impl AsyncRead for DuplexStream

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

Attempts to read from the AsyncRead into buf.

impl AsyncWrite for DuplexStream

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

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

fn is_write_vectored(&self) -> bool

Determines if this writer has an efficient poll_write_vectored implementation.

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

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

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

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

impl Debug for DuplexStream

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

Formats the value using the given formatter.

impl Drop for DuplexStream

fn drop(&mut self)

Executes the destructor for this type.