//! A crate with utility types for use by other crates that implement specifics.//!//! Unless specified differently, all operations need an index file (e.g. `.git/index`) as driver.//!//! ## Feature Flags#![cfg_attr(    all(doc, feature = "document-features"),    doc = ::document_features::document_features!())]#![cfg_attr(all(doc, feature = "document-features"), feature(doc_cfg))]#![deny(missing_docs, unsafe_code)]use bstr::BString;/// Provides types needed for using [`stack::Platform::matching_attributes()`].#[cfg(feature = "attributes")]pub use gix_attributes as attributes;/// A way to access the [`Case`](glob::pattern::Case) enum which used throughout this API.pub use gix_glob as glob;/// Provides types needed for using [`stack::Platform::excluded_kind()`].pub use gix_ignore as ignore;/// Provides types needed for using [`Stack::at_path()`] and [`Stack::at_entry()`].pub use gix_index as index;/// Provides types needed for using [`Stack::at_path()`] and [`Stack::at_entry()`].pub use gix_object as object;/// Provides types needed for using [`stack::State::for_checkout()`].#[cfg(feature = "attributes")]pub use gix_validate as validate; /// A cache for efficiently executing operations on directories and files which are encountered in sorted order./// That way, these operations can be re-used for subsequent invocations in the same directory.////// This cache can be configured to create directories efficiently, read git-ignore files and git-attribute files,/// in any combination.////// A cache for directory creation to reduce the amount of stat calls when creating/// directories safely, that is without following symlinks that might be on the way.////// As a special case, it offers a 'prefix' which (by itself) is assumed to exist and may contain symlinks./// Everything past that prefix boundary must not contain a symlink. We do this by allowing any input path.////// Another added benefit is its ability to store the path of full path of the entry to which leading directories/// are to be created to avoid allocating memory.////// For this to work, it remembers the last 'good' path to a directory and assumes that all components of it/// are still valid, too./// As directories are created, the cache will be adjusted to reflect the latest seen directory.////// The caching is only useful if consecutive calls to create a directory are using a sorted list of entries.#[derive(Clone)]pub struct Stack {    stack: gix_fs::Stack,    /// tells us what to do as we change paths.    state: stack::State,    /// A buffer used when reading attribute or ignore files or their respective objects from the object database.    buf: Vec<u8>,    /// If case folding should happen when looking up attributes or exclusions.    case: gix_glob::pattern::Case,    /// A lookup table for object ids to read from in some situations when looking up attributes or exclusions.    id_mappings: Vec<PathIdMapping>,    statistics: stack::Statistics,} pub(crate) type PathIdMapping = (BString, gix_hash::ObjectId); ///pub mod stack;