sccache 0.15.0

Sccache is a ccache-like tool. It is used as a compiler wrapper and avoids compilation when possible. Sccache has the capability to utilize caching in remote storage environments, including various cloud storage options, or alternatively, in local storage.
Documentation
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use fs_err as fs;

use std::path::Path;

use crate::errors::*;

/// Normalize key `abcdef` into `a/b/c/abcdef`
pub(in crate::cache) fn normalize_key(key: &str) -> String {
    format!("{}/{}/{}/{}", &key[0..1], &key[1..2], &key[2..3], &key)
}

#[cfg(unix)]
pub(in crate::cache) fn get_file_mode(file: &fs::File) -> Result<Option<u32>> {
    use std::os::unix::fs::MetadataExt;
    Ok(Some(file.metadata()?.mode()))
}

#[cfg(windows)]
#[allow(clippy::unnecessary_wraps)]
pub(in crate::cache) fn get_file_mode(_file: &fs::File) -> Result<Option<u32>> {
    Ok(None)
}

#[cfg(unix)]
pub(in crate::cache) fn set_file_mode(path: &Path, mode: u32) -> Result<()> {
    use std::fs::Permissions;
    use std::os::unix::fs::PermissionsExt;
    let p = Permissions::from_mode(mode);
    fs::set_permissions(path, p)?;
    Ok(())
}

#[cfg(windows)]
#[allow(clippy::unnecessary_wraps)]
pub(in crate::cache) fn set_file_mode(_path: &Path, _mode: u32) -> Result<()> {
    Ok(())
}

#[cfg(test)]
mod test {
    use super::*;

    #[test]
    fn test_normalize_key() {
        assert_eq!(
            normalize_key("0123456789abcdef0123456789abcdef"),
            "0/1/2/0123456789abcdef0123456789abcdef"
        );
    }
}