linux-aio-tokio

This package provides an integration of Linux kernel-level asynchronous I/O to the Tokio platform.

Linux kernel-level asynchronous I/O is different from the Posix AIO library. Posix AIO is implemented using a pool of userland threads, which invoke regular, blocking system calls to perform file I/O. Linux kernel-level AIO, on the other hand, provides kernel-level asynchronous scheduling of I/O operations to the underlying block device.

Usage

Add this to your Cargo.toml:

[dependencies]
linux-aio-tokio = "0.1"

Examples

use tempfile::tempdir;

use linux_aio_tokio::{aio_context, LockedBuf, ReadFlags, WriteFlags, AioOpenOptionsExt};
use std::fs::OpenOptions;

#[tokio::main]
async fn main() {
    let (aio, aio_handle) = aio_context(8).unwrap();

    let dir = tempdir().unwrap();

    let mut open_options = OpenOptions::new();
    open_options
        .read(true)
        .create_new(true)
        .append(true)
        .write(true);

    let file = open_options
        .aio_open(dir.path().join("tmp"), false)
        .await
        .unwrap();

    let mut write_buf = LockedBuf::with_size(1024).unwrap();

    for i in 0..write_buf.size() {
        write_buf.as_mut()[i] = (i % 0xff) as u8;
    }

    file.write_at(&aio_handle, 0, &write_buf, WriteFlags::APPEND).await.unwrap();

    let mut read_buf = LockedBuf::with_size(1024).unwrap();

    file.read_at(&aio_handle, 0, &mut read_buf, ReadFlags::empty()).await.unwrap();

    assert_eq!(read_buf.as_ref(), write_buf.as_ref());

    aio.close().await;

    println!("all good!");
}

License

This code is licensed under the MIT license.

Credits

The current implementation is based on the code created by Hans-Martin Will, available at GitHub repository.