git-async

An async-first Rust library for reading git repositories

Usage

The main entry point is the Repo object, which represents a git repository. Refs and objects are looked up via methods on Repo.

The library is agnostic as to the async runtime in use, so consumers must implement a couple of traits that provide filesystem operations. See the file_system module for further details.

For example, these could use Tokio, or the web filesystem API using wasm-bindgen's support for transforming JS promises to Rust futures. A dummy implementation could use the Rust standard library's synchronous filesystem operations.

A future goal is to provide some standard implementations for commonly-used async runtimes.

Example

async fn example() -> GResult<()> {
    let repo = Repo::<MyFS>::open(MyDirectory::new("a-repository")).await?;
    let head = repo.head().await?;
    let commit = head.peel_to_commit(&repo).await?.unwrap();
    let message = commit.message();
    println!("{}", str::from_utf8(message).unwrap());
    Ok(())
}

Caveats

There are a few things this crate cannot (yet) do. They are in scope, so future versions may support them, but for now they are not implemented.

• It only supports read operations on git repositories
• It ignores the working tree. Only operations involving the actual repository structure are supported
• The diff algorithm is naive and quite slow. I have not looked into how git diff manages to be so fast, but I imagine it uses the packfile delta encoding somehow to optimize diffing.