use std::{path::Path, sync::atomic::AtomicBool}; use git_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)]    #[allow(missing_docs)]    pub enum Error {        #[error("Interrupted by user")]        Interrupted,        #[error("index checksum mismatch: expected {expected}, got {actual}")]        Mismatch {            expected: git_hash::ObjectId,            actual: git_hash::ObjectId,        },    }} /// 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(|| 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(desired_hash)` or `Err(Some(actual_hash))` is returned if the hash matches or mismatches./// If the `Err(None)` is returned, the operation was interrupted.pub fn checksum_on_disk_or_mmap(    data_path: &Path,    data: &[u8],    expected: git_hash::ObjectId,    object_hash: git_hash::Kind,    mut progress: impl Progress,    should_interrupt: &AtomicBool,) -> Result<git_hash::ObjectId, checksum::Error> {    let data_len_without_trailer = data.len() - object_hash.len_in_bytes();    let actual = match git_features::hash::bytes_of_file(        data_path,        data_len_without_trailer,        object_hash,        &mut progress,        should_interrupt,    ) {        Ok(id) => id,        Err(err) if err.kind() == std::io::ErrorKind::Interrupted => return Err(checksum::Error::Interrupted),        Err(_io_err) => {            let start = std::time::Instant::now();            let mut hasher = git_features::hash::hasher(object_hash);            hasher.update(&data[..data_len_without_trailer]);            progress.inc_by(data_len_without_trailer);            progress.show_throughput(start);            git_hash::ObjectId::from(hasher.digest())        }    };     if actual == expected {        Ok(actual)    } else {        Err(checksum::Error::Mismatch { actual, expected })    }}