Crate chunked_bytes

A non-contiguous buffer for efficient serialization of data structures and vectored output.

This crate provides ChunkedBytes, a rope-like byte container based on Bytes and BytesMut from the bytes crate. Its primary purpose is to serve as an intermediate buffer for serializing fields of data structures into byte sequences of varying length, without whole-buffer reallocations like those performed to grow a Vec, and then consuming the bytes in bulk, split into regularly sized chunks suitable for vectored output.

ChunkedBytes implements the traits Buf and BufMut for read and write access to the buffered data. It also provides the push_chunk method for appending a Bytes slice to its queue of non-contiguous chunks without copying the data.

Examples

use bytes::{BufMut, Bytes};
use chunked_bytes::ChunkedBytes;
use std::error::Error;
use std::net::SocketAddr;
use tokio::io::AsyncWriteExt;
use tokio::net::{TcpListener, TcpStream};
use tokio::task::JoinHandle;
use tokio::prelude::*;

#[tokio::main]
async fn main() -> io::Result<()> {
    const SEND_BUFFER_SIZE: usize = 1024;
    const MESSAGE: &[u8] = b"I \xf0\x9f\x96\xa4 \x00\xc0\xff\xee";

    let mut buf = ChunkedBytes::with_preferred_chunk_size(SEND_BUFFER_SIZE);
    buf.put("I ".as_bytes());
    buf.push_chunk(Bytes::from("🖤 "));
    buf.put_u32(0xc0ffee);

    let listen_addr = "127.0.0.1:0".parse::<SocketAddr>().unwrap();
    let mut server = TcpListener::bind(listen_addr).await?;
    let server_addr = server.local_addr()?;

    let server_handle: JoinHandle<io::Result<()>> = tokio::spawn(async move {
        let (mut receiver, _) = server.accept().await?;
        let mut buf = Vec::with_capacity(64);
        receiver.read_to_end(&mut buf).await?;
        assert_eq!(buf.as_slice(), MESSAGE);
        Ok(())
    });

    let mut sender = TcpStream::connect(server_addr).await?;
    sender.set_send_buffer_size(SEND_BUFFER_SIZE)?;

    let bytes_written = sender.write_buf(&mut buf).await?;
    assert_eq!(bytes_written, MESSAGE.len());
    AsyncWriteExt::shutdown(&mut sender).await?;

    server_handle.await??;
    Ok(())
}

Structs

ChunkedBytes	A non-contiguous buffer for efficient serialization of data structures.
DrainChunks	The iterator produced by the drain_chunks method of ChunkedBytes.
IntoChunks	The iterator produced by the into_chunks method of ChunkedBytes.