use std::{path::Path, sync::atomic::AtomicBool}; use gix_features::progress::Progress; ///pub mod checksum {    /// Returned by various methods to verify the checksum of a memory mapped file that might also exist on disk.    #[derive(thiserror::Error, Debug)]    #[expect(missing_docs)]    pub enum Error {        #[error("Interrupted by user")]        Interrupted,        #[error("Failed to hash data")]        Hasher(#[from] gix_hash::hasher::Error),        #[error(transparent)]        Verify(#[from] gix_hash::verify::Error),    }} /// Returns the `index` at which the following `index + 1` value is not an increment over the value at `index`.pub fn fan(data: &[u32]) -> Option<usize> {    data.windows(2)        .enumerate()        .find_map(|(win_index, v)| (v[0] > v[1]).then_some(win_index))} /// Calculate the hash of the given kind by trying to read the file from disk at `data_path` or falling back on the mapped content in `data`./// `Ok(expected)` or [`checksum::Error::Verify`] is returned if the hash matches or mismatches./// If the [`checksum::Error::Interrupted`] is returned, the operation was interrupted.pub fn checksum_on_disk_or_mmap(    data_path: &Path,    data: &[u8],    expected: gix_hash::ObjectId,    object_hash: gix_hash::Kind,    progress: &mut dyn Progress,    should_interrupt: &AtomicBool,) -> Result<gix_hash::ObjectId, checksum::Error> {    let data_len_without_trailer = data.len() - object_hash.len_in_bytes();    let actual = match gix_hash::bytes_of_file(        data_path,        data_len_without_trailer as u64,        object_hash,        progress,        should_interrupt,    ) {        Ok(id) => id,        Err(gix_hash::io::Error::Io(err)) if err.kind() == std::io::ErrorKind::Interrupted => {            return Err(checksum::Error::Interrupted);        }        Err(gix_hash::io::Error::Io(_io_err)) => {            let start = std::time::Instant::now();            let mut hasher = gix_hash::hasher(object_hash);            hasher.update(&data[..data_len_without_trailer]);            progress.inc_by(data_len_without_trailer);            progress.show_throughput(start);            hasher.try_finalize()?        }        Err(gix_hash::io::Error::Hasher(err)) => return Err(checksum::Error::Hasher(err)),    };     actual.verify(&expected)?;    Ok(actual)}