sandfs

Lazy, copy-on-write workspaces over host folders and git repositories, saved on disk and mounted as real directories: FUSE on Linux, and on macOS an NFS server on localhost that macOS's own client mounts, so nothing needs installing there. This is the library behind the sandfs command, for a program that wants its workspaces without running it.

fn main() -> anyhow::Result<()> {
    // First thing in `main`: sandfs runs this program again to serve mounts.
    sandfs::handle_relaunch(&["sandfs"]);
    let home = sandfs::Home::locate()?;
    let repo = home.mount("https://github.com/lydakis/sandfs", "/tmp/sandfs".as_ref(), &Default::default())?;
    let task = home.fork(&repo.name, Some("/tmp/task".as_ref()), &Default::default())?;
    std::fs::write("/tmp/task/NOTES.md", "a task's notes\n")?;
    for change in home.changes(&task.name, &Default::default())?.changes {
        println!("{:?} {}", change.kind, change.path);
    }
    home.update(&task.name, None)?; // onto the newest commit, in place
    home.remove(&task.name, true)?;
    Ok(())
}

Each command of sandfs is a method of Home: mount, fork, changes (with copy_to), update, workspaces, unmount, remove, clean, serve_mcp and shell. They return what they found instead of printing it. The sandfs-cli README says what each does in detail.

The mount process

A mount is served by one background process per home, which outlives the program that asked for it. sandfs starts that process by running the current program again, with the words given to handle_relaunch followed by its own (daemon --serve); git's file monitor in a git mount and shell on macOS run it the same way. So handle_relaunch must come first in main: in those runs it does what they were started for and exits. A program with commands of its own gives a prefix none of them uses, such as &["sandfs"]; the sandfs command gives none.

The home is $SANDFS_HOME, else $XDG_DATA_HOME/sandfs, else ~/.local/share/sandfs, shared with the sandfs command. Without the default mount feature (and on Windows) everything but mounting works.

sandfs-core is the in-memory engine underneath: sources, O(1) forks and changes, with nothing on disk.

License

MIT, except src/nfsserve, which is from the nfsserve crate under BSD-3-Clause (see its LICENSE).