Function git_compatible_diff_counts 

pub async fn git_compatible_diff_counts<A, O>(
    from: &Generation<A, O>,
    to: &Generation<A, O>,
    already_tracked: &BTreeSet<String>,
    maximum_changes: u32,
    cancellation: &CancellationToken,
) -> Result<GitDiffCounts, GitCaptureError>
where
    A: AsyncAuthorityStore,
    O: AsyncObjectStore,

Compares exact generations using the ignore policy belonging to each side.

Unlike commit capture, this read-only operation never forks or pins a workspace. Only ignore files on changed paths are read.