fixed-buffer

This is a Rust library with fixed-size buffers, useful for network protocol parsers.

Features

Limitations

Examples

Read and handle requests from a remote client: ```rust use fixed_buffer::FixedBuf; use std::io::Error; use tokio::io::AsyncWriteExt; use tokio::net::TcpStream;

async fn handleconn(mut tcpstream: TcpStream) -> Result<(), Error> { let (mut input, mut output) = tcpstream.split(); let mut buf: FixedBuf<[u8; 4096]> = FixedBuf::new([0; 4096]); loop { // Read a line and leave leftover bytes in buf. let linebytes = match buf.readdelimited(&mut input, b"\n").await? { Some(linebytes) => linebytes, None => return Ok(()), }; let request = Request::parse(linebytes)?; // Read any request payload from buf + TcpStream. let payloadreader = tokio::io::AsyncReadExt::chain(&mut buf, &mut input); handlerequest(&mut output, payload_reader, request).await?; } } ``` For a runnable example, see examples/server.rs.

Read and process records: ```rust fn tryprocessrecord(b: &[u8]) -> Result { if b.len() < 2 { return Ok(0) } if b.startswith("ab".asbytes()) { println!("found record"); Ok(2) } else { Err(Error::new(ErrorKind::InvalidData, "bad record")) } }

async fn readandprocess(mut input: R) -> Result<(), Error> { let mut buf: FixedBuf<[u8; 1024]> = FixedBuf::new([0; 1024]); loop { // Read a chunk into the buffer. let mut writable = buf.writable() .okor(Error::new(ErrorKind::InvalidData, "record too long, buffer full"))?; let byteswritten = AsyncReadExt::read(&mut input, &mut writable).await?; if byteswritten == 0 { return if buf.len() == 0 { Ok(()) // EOF at record boundary } else { // EOF in the middle of a record Err(Error::from(ErrorKind::UnexpectedEof)) }; } buf.wrote(byteswritten);

    // Process records in the buffer.
    loop {
        let bytes_read = try_process_record(buf.readable())?;
        if bytes_read == 0 {
            break;
        }
        buf.read_bytes(bytes_read);
    }
    // Shift data in the buffer to free up space at the end for writing.
    buf.shift();
}

} ```

Documentation

https://docs.rs/fixed-buffer

The filled constructor is useful in tests.

Alternatives

Release Process

  1. Edit Cargo.toml and bump version number.
  2. Run ./release.sh

Changelog

TODO