//! Filesystem utilities//!//! These are will be parallel if the `parallel` feature is enabled, at the expense of compiling additional dependencies//! along with runtime costs for maintaining a global [`rayon`](https://docs.rs/rayon) thread pool.//!//! For information on how to use the [`WalkDir`] type, have a look at// TODO: Move all this to `gix-fs` in a breaking change. #[cfg(feature = "walkdir")]mod shared {    /// The desired level of parallelism.    pub enum Parallelism {        /// Do not parallelize at all by making a serial traversal on the current thread.        Serial,        /// Create a new thread pool for each traversal with up to 16 threads or the amount of logical cores of the machine.        ThreadPoolPerTraversal {            /// The base name of the threads we create as part of the thread-pool.            thread_name: &'static str,        },    }} #[cfg(any(feature = "walkdir", feature = "fs-read-dir"))]mod walkdir_precompose {    use std::{borrow::Cow, ffi::OsStr, path::Path};     #[derive(Debug)]    pub struct DirEntry<T: std::fmt::Debug> {        inner: T,        precompose_unicode: bool,    }     impl<T: std::fmt::Debug> DirEntry<T> {        /// Create a new instance.        pub fn new(inner: T, precompose_unicode: bool) -> Self {            Self {                inner,                precompose_unicode,            }        }    }     pub trait DirEntryApi {        fn path(&self) -> Cow<'_, Path>;        fn file_name(&self) -> Cow<'_, OsStr>;        fn file_type(&self) -> std::io::Result<std::fs::FileType>;    }     impl<T: DirEntryApi + std::fmt::Debug> DirEntry<T> {        /// Obtain the full path of this entry, possibly with precomposed unicode if enabled.        ///        /// Note that decomposing filesystem like those made by Apple accept both precomposed and        /// decomposed names, and consider them equal.        pub fn path(&self) -> Cow<'_, Path> {            let path = self.inner.path();            if self.precompose_unicode {                gix_utils::str::precompose_path(path)            } else {                path            }        }         /// Obtain filen name of this entry, possibly with precomposed unicode if enabled.        pub fn file_name(&self) -> Cow<'_, OsStr> {            let name = self.inner.file_name();            if self.precompose_unicode {                gix_utils::str::precompose_os_string(name)            } else {                name            }        }         /// Return the file type for the file that this entry points to.        ///        /// If `follow_links` was `true`, this is the file type of the item the link points to.        pub fn file_type(&self) -> std::io::Result<std::fs::FileType> {            self.inner.file_type()        }    }     /// A platform over entries in a directory, which may or may not precompose unicode after retrieving    /// paths from the file system.    #[cfg(feature = "walkdir")]    pub struct WalkDir<T> {        pub(crate) inner: Option<T>,        pub(crate) precompose_unicode: bool,    }     #[cfg(feature = "walkdir")]    pub struct WalkDirIter<T, I, E>    where        T: Iterator<Item = Result<I, E>>,        I: DirEntryApi,    {        pub(crate) inner: T,        pub(crate) precompose_unicode: bool,    }     #[cfg(feature = "walkdir")]    impl<T, I, E> Iterator for WalkDirIter<T, I, E>    where        T: Iterator<Item = Result<I, E>>,        I: DirEntryApi + std::fmt::Debug,    {        type Item = Result<DirEntry<I>, E>;         fn next(&mut self) -> Option<Self::Item> {            self.inner                .next()                .map(|res| res.map(|entry| DirEntry::new(entry, self.precompose_unicode)))        }    }} ///#[cfg(feature = "fs-read-dir")]pub mod read_dir {    use std::{borrow::Cow, ffi::OsStr, fs::FileType, path::Path};     /// A directory entry adding precompose-unicode support to [`std::fs::DirEntry`].    pub type DirEntry = super::walkdir_precompose::DirEntry<std::fs::DirEntry>;     impl super::walkdir_precompose::DirEntryApi for std::fs::DirEntry {        fn path(&self) -> Cow<'_, Path> {            self.path().into()        }         fn file_name(&self) -> Cow<'_, OsStr> {            self.file_name().into()        }         fn file_type(&self) -> std::io::Result<FileType> {            self.file_type()        }    }} ///#[cfg(feature = "walkdir")]pub mod walkdir {    use std::{borrow::Cow, ffi::OsStr, fs::FileType, path::Path};     pub use walkdir::Error;    use walkdir::{DirEntry as DirEntryImpl, WalkDir as WalkDirImpl};     /// A directory entry returned by [DirEntryIter].    pub type DirEntry = super::walkdir_precompose::DirEntry<DirEntryImpl>;    /// A platform to create a [DirEntryIter] from.    pub type WalkDir = super::walkdir_precompose::WalkDir<WalkDirImpl>;     pub use super::shared::Parallelism;     impl super::walkdir_precompose::DirEntryApi for DirEntryImpl {        fn path(&self) -> Cow<'_, Path> {            self.path().into()        }         fn file_name(&self) -> Cow<'_, OsStr> {            self.file_name().into()        }         fn file_type(&self) -> std::io::Result<FileType> {            Ok(self.file_type())        }    }     impl IntoIterator for WalkDir {        type Item = Result<DirEntry, walkdir::Error>;        type IntoIter = DirEntryIter;         fn into_iter(self) -> Self::IntoIter {            DirEntryIter {                inner: self.inner.expect("always set (builder fix)").into_iter(),                precompose_unicode: self.precompose_unicode,            }        }    }     impl WalkDir {        /// Set the minimum component depth of paths of entries.        pub fn min_depth(mut self, min: usize) -> Self {            self.inner = Some(self.inner.take().expect("always set").min_depth(min));            self        }        /// Set the maximum component depth of paths of entries.        pub fn max_depth(mut self, max: usize) -> Self {            self.inner = Some(self.inner.take().expect("always set").max_depth(max));            self        }        /// Follow symbolic links.        pub fn follow_links(mut self, toggle: bool) -> Self {            self.inner = Some(self.inner.take().expect("always set").follow_links(toggle));            self        }    }     /// Instantiate a new directory iterator which will not skip hidden files, with the given level of `parallelism`.    ///    /// Use `precompose_unicode` to represent the `core.precomposeUnicode` configuration option.    pub fn walkdir_new(root: &Path, _: Parallelism, precompose_unicode: bool) -> WalkDir {        WalkDir {            inner: WalkDirImpl::new(root).into(),            precompose_unicode,        }    }     /// Instantiate a new directory iterator which will not skip hidden files and is sorted, with the given level of `parallelism`.    ///    /// Use `precompose_unicode` to represent the `core.precomposeUnicode` configuration option.    /// Use `max_depth` to limit the depth of the recursive walk.    ///   * `0`    ///       - Returns only the root path with no children    ///   * `1`    ///       - Root directory and children.    ///   * `1..n`    ///       - Root directory, children and {n}-grandchildren    pub fn walkdir_sorted_new(root: &Path, _: Parallelism, max_depth: usize, precompose_unicode: bool) -> WalkDir {        WalkDir {            inner: WalkDirImpl::new(root)                .max_depth(max_depth)                .sort_by(|a, b| {                    let storage_a;                    let storage_b;                    let a_name = match gix_path::os_str_into_bstr(a.file_name()) {                        Ok(f) => f,                        Err(_) => {                            storage_a = a.file_name().to_string_lossy();                            storage_a.as_ref().into()                        }                    };                    let b_name = match gix_path::os_str_into_bstr(b.file_name()) {                        Ok(f) => f,                        Err(_) => {                            storage_b = b.file_name().to_string_lossy();                            storage_b.as_ref().into()                        }                    };                    // "common." < "common/" < "common0"                    let common = a_name.len().min(b_name.len());                    a_name[..common].cmp(&b_name[..common]).then_with(|| {                        let a = a_name.get(common).or_else(|| a.file_type().is_dir().then_some(&b'/'));                        let b = b_name.get(common).or_else(|| b.file_type().is_dir().then_some(&b'/'));                        a.cmp(&b)                    })                })                .into(),            precompose_unicode,        }    }     /// The Iterator yielding directory items    pub type DirEntryIter = super::walkdir_precompose::WalkDirIter<walkdir::IntoIter, DirEntryImpl, walkdir::Error>;} #[cfg(feature = "walkdir")]pub use self::walkdir::{WalkDir, walkdir_new, walkdir_sorted_new}; /// Prepare open options which won't follow symlinks when the file is opened.////// Note: only effective on unix currently.pub fn open_options_no_follow() -> std::fs::OpenOptions {    #[cfg_attr(not(unix), allow(unused_mut))]    let mut options = std::fs::OpenOptions::new();    #[cfg(unix)]    {        /// Make sure that it's impossible to follow through to the target of symlinks.        /// Note that this will still follow symlinks in the path, which is what we assume        /// has been checked separately.        use std::os::unix::fs::OpenOptionsExt;        options.custom_flags(libc::O_NOFOLLOW);    }    options}