Struct tokio_util::io::ReaderStream

pub struct ReaderStream<R> {
    reader: Option<R>,
    buf: BytesMut,
    capacity: usize,
}

Convert an AsyncRead into a Stream of byte chunks.

This stream is fused. It performs the inverse operation of StreamReader.

Example

use tokio_stream::StreamExt;
use tokio_util::io::ReaderStream;

// Create a stream of data.
let data = b"hello, world!";
let mut stream = ReaderStream::new(&data[..]);

// Read all of the chunks into a vector.
let mut stream_contents = Vec::new();
while let Some(chunk) = stream.next().await {
   stream_contents.extend_from_slice(&chunk?);
}

// Once the chunks are concatenated, we should have the
// original data.
assert_eq!(stream_contents, data);

Fields

reader: Option<R>

buf: BytesMut

capacity: usize

Implementations

impl<R: AsyncRead> ReaderStream<R>

pub fn new(reader: R) -> Self

Convert an AsyncRead into a Stream with item type Result<Bytes, std::io::Error>.

pub fn with_capacity(reader: R, capacity: usize) -> Self

Convert an AsyncRead into a Stream with item type Result<Bytes, std::io::Error>, with a specific read buffer initial capacity.

Trait Implementations

impl<R: Debug> Debug for ReaderStream<R>

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

Formats the value using the given formatter.

impl<R: AsyncRead> Stream for ReaderStream<R>

type Item = Result<Bytes, Error>

Values yielded by the stream.

fn poll_next( self: Pin<&mut Self>, cx: &mut Context<'_>, ) -> Poll<Option<Self::Item>>

Attempt to pull out the next value of this stream, registering the current task for wakeup if the value is not yet available, and returning None if the stream is exhausted.

fn size_hint(&self) -> (usize, Option<usize>)

Returns the bounds on the remaining length of the stream.

impl<'__pin, R> Unpin for ReaderStream<R>

where PinnedFieldsOf<__Origin<'__pin, R>>: Unpin,