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 put_bytes 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::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 MESSAGE: &[u8] = b"I \xf0\x9f\x96\xa4 \x00\xc0\xff\xee";

    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?;

    let buf_size = sender.send_buffer_size()?;
    let mut buf = ChunkedBytes::with_chunk_size_hint(buf_size);

    buf.put("I ".as_bytes());
    buf.put_bytes(Bytes::from("🖤 "));
    buf.put_u32(0xc0ffee);

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

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

Re-exports

pub use self::loosely::ChunkedBytes;

Modules

loosely	Buffer with a loose adherence to the preferred chunk size.
strictly	Buffer with a strict limit on the chunk sizes.

Structs

DrainChunks	The iterator produced by the drain_chunks method of ChunkedBytes.
IntoChunks	The iterator produced by the into_chunks method of ChunkedBytes.