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diff --git a/vendor/walkdir/src/lib.rs b/vendor/walkdir/src/lib.rs new file mode 100644 index 000000000..929c5655e --- /dev/null +++ b/vendor/walkdir/src/lib.rs @@ -0,0 +1,1161 @@ +/*! +Crate `walkdir` provides an efficient and cross platform implementation +of recursive directory traversal. Several options are exposed to control +iteration, such as whether to follow symbolic links (default off), limit the +maximum number of simultaneous open file descriptors and the ability to +efficiently skip descending into directories. + +To use this crate, add `walkdir` as a dependency to your project's +`Cargo.toml`: + +```toml +[dependencies] +walkdir = "2" +``` + +# From the top + +The [`WalkDir`] type builds iterators. The [`DirEntry`] type describes values +yielded by the iterator. Finally, the [`Error`] type is a small wrapper around +[`std::io::Error`] with additional information, such as if a loop was detected +while following symbolic links (not enabled by default). + +[`WalkDir`]: struct.WalkDir.html +[`DirEntry`]: struct.DirEntry.html +[`Error`]: struct.Error.html +[`std::io::Error`]: https://doc.rust-lang.org/stable/std/io/struct.Error.html + +# Example + +The following code recursively iterates over the directory given and prints +the path for each entry: + +```no_run +use walkdir::WalkDir; +# use walkdir::Error; + +# fn try_main() -> Result<(), Error> { +for entry in WalkDir::new("foo") { + println!("{}", entry?.path().display()); +} +# Ok(()) +# } +``` + +Or, if you'd like to iterate over all entries and ignore any errors that +may arise, use [`filter_map`]. (e.g., This code below will silently skip +directories that the owner of the running process does not have permission to +access.) + +```no_run +use walkdir::WalkDir; + +for entry in WalkDir::new("foo").into_iter().filter_map(|e| e.ok()) { + println!("{}", entry.path().display()); +} +``` + +[`filter_map`]: https://doc.rust-lang.org/stable/std/iter/trait.Iterator.html#method.filter_map + +# Example: follow symbolic links + +The same code as above, except [`follow_links`] is enabled: + +```no_run +use walkdir::WalkDir; +# use walkdir::Error; + +# fn try_main() -> Result<(), Error> { +for entry in WalkDir::new("foo").follow_links(true) { + println!("{}", entry?.path().display()); +} +# Ok(()) +# } +``` + +[`follow_links`]: struct.WalkDir.html#method.follow_links + +# Example: skip hidden files and directories on unix + +This uses the [`filter_entry`] iterator adapter to avoid yielding hidden files +and directories efficiently (i.e. without recursing into hidden directories): + +```no_run +use walkdir::{DirEntry, WalkDir}; +# use walkdir::Error; + +fn is_hidden(entry: &DirEntry) -> bool { + entry.file_name() + .to_str() + .map(|s| s.starts_with(".")) + .unwrap_or(false) +} + +# fn try_main() -> Result<(), Error> { +let walker = WalkDir::new("foo").into_iter(); +for entry in walker.filter_entry(|e| !is_hidden(e)) { + println!("{}", entry?.path().display()); +} +# Ok(()) +# } +``` + +[`filter_entry`]: struct.IntoIter.html#method.filter_entry +*/ + +#![deny(missing_docs)] +#![allow(unknown_lints)] + +#[cfg(doctest)] +doc_comment::doctest!("../README.md"); + +use std::cmp::{min, Ordering}; +use std::fmt; +use std::fs::{self, ReadDir}; +use std::io; +use std::path::{Path, PathBuf}; +use std::result; +use std::vec; + +use same_file::Handle; + +pub use crate::dent::DirEntry; +#[cfg(unix)] +pub use crate::dent::DirEntryExt; +pub use crate::error::Error; + +mod dent; +mod error; +#[cfg(test)] +mod tests; +mod util; + +/// Like try, but for iterators that return [`Option<Result<_, _>>`]. +/// +/// [`Option<Result<_, _>>`]: https://doc.rust-lang.org/stable/std/option/enum.Option.html +macro_rules! itry { + ($e:expr) => { + match $e { + Ok(v) => v, + Err(err) => return Some(Err(From::from(err))), + } + }; +} + +/// A result type for walkdir operations. +/// +/// Note that this result type embeds the error type in this crate. This +/// is only useful if you care about the additional information provided by +/// the error (such as the path associated with the error or whether a loop +/// was dectected). If you want things to Just Work, then you can use +/// [`io::Result`] instead since the error type in this package will +/// automatically convert to an [`io::Result`] when using the [`try!`] macro. +/// +/// [`io::Result`]: https://doc.rust-lang.org/stable/std/io/type.Result.html +/// [`try!`]: https://doc.rust-lang.org/stable/std/macro.try.html +pub type Result<T> = ::std::result::Result<T, Error>; + +/// A builder to create an iterator for recursively walking a directory. +/// +/// Results are returned in depth first fashion, with directories yielded +/// before their contents. If [`contents_first`] is true, contents are yielded +/// before their directories. The order is unspecified but if [`sort_by`] is +/// given, directory entries are sorted according to this function. Directory +/// entries `.` and `..` are always omitted. +/// +/// If an error occurs at any point during iteration, then it is returned in +/// place of its corresponding directory entry and iteration continues as +/// normal. If an error occurs while opening a directory for reading, then it +/// is not descended into (but the error is still yielded by the iterator). +/// Iteration may be stopped at any time. When the iterator is destroyed, all +/// resources associated with it are freed. +/// +/// [`contents_first`]: struct.WalkDir.html#method.contents_first +/// [`sort_by`]: struct.WalkDir.html#method.sort_by +/// +/// # Usage +/// +/// This type implements [`IntoIterator`] so that it may be used as the subject +/// of a `for` loop. You may need to call [`into_iter`] explicitly if you want +/// to use iterator adapters such as [`filter_entry`]. +/// +/// Idiomatic use of this type should use method chaining to set desired +/// options. For example, this only shows entries with a depth of `1`, `2` or +/// `3` (relative to `foo`): +/// +/// ```no_run +/// use walkdir::WalkDir; +/// # use walkdir::Error; +/// +/// # fn try_main() -> Result<(), Error> { +/// for entry in WalkDir::new("foo").min_depth(1).max_depth(3) { +/// println!("{}", entry?.path().display()); +/// } +/// # Ok(()) +/// # } +/// ``` +/// +/// [`IntoIterator`]: https://doc.rust-lang.org/stable/std/iter/trait.IntoIterator.html +/// [`into_iter`]: https://doc.rust-lang.org/nightly/core/iter/trait.IntoIterator.html#tymethod.into_iter +/// [`filter_entry`]: struct.IntoIter.html#method.filter_entry +/// +/// Note that the iterator by default includes the top-most directory. Since +/// this is the only directory yielded with depth `0`, it is easy to ignore it +/// with the [`min_depth`] setting: +/// +/// ```no_run +/// use walkdir::WalkDir; +/// # use walkdir::Error; +/// +/// # fn try_main() -> Result<(), Error> { +/// for entry in WalkDir::new("foo").min_depth(1) { +/// println!("{}", entry?.path().display()); +/// } +/// # Ok(()) +/// # } +/// ``` +/// +/// [`min_depth`]: struct.WalkDir.html#method.min_depth +/// +/// This will only return descendents of the `foo` directory and not `foo` +/// itself. +/// +/// # Loops +/// +/// This iterator (like most/all recursive directory iterators) assumes that +/// no loops can be made with *hard* links on your file system. In particular, +/// this would require creating a hard link to a directory such that it creates +/// a loop. On most platforms, this operation is illegal. +/// +/// Note that when following symbolic/soft links, loops are detected and an +/// error is reported. +#[derive(Debug)] +pub struct WalkDir { + opts: WalkDirOptions, + root: PathBuf, +} + +struct WalkDirOptions { + follow_links: bool, + max_open: usize, + min_depth: usize, + max_depth: usize, + sorter: Option< + Box< + dyn FnMut(&DirEntry, &DirEntry) -> Ordering + + Send + + Sync + + 'static, + >, + >, + contents_first: bool, + same_file_system: bool, +} + +impl fmt::Debug for WalkDirOptions { + fn fmt( + &self, + f: &mut fmt::Formatter<'_>, + ) -> result::Result<(), fmt::Error> { + let sorter_str = if self.sorter.is_some() { + // FnMut isn't `Debug` + "Some(...)" + } else { + "None" + }; + f.debug_struct("WalkDirOptions") + .field("follow_links", &self.follow_links) + .field("max_open", &self.max_open) + .field("min_depth", &self.min_depth) + .field("max_depth", &self.max_depth) + .field("sorter", &sorter_str) + .field("contents_first", &self.contents_first) + .field("same_file_system", &self.same_file_system) + .finish() + } +} + +impl WalkDir { + /// Create a builder for a recursive directory iterator starting at the + /// file path `root`. If `root` is a directory, then it is the first item + /// yielded by the iterator. If `root` is a file, then it is the first + /// and only item yielded by the iterator. If `root` is a symlink, then it + /// is always followed for the purposes of directory traversal. (A root + /// `DirEntry` still obeys its documentation with respect to symlinks and + /// the `follow_links` setting.) + pub fn new<P: AsRef<Path>>(root: P) -> Self { + WalkDir { + opts: WalkDirOptions { + follow_links: false, + max_open: 10, + min_depth: 0, + max_depth: ::std::usize::MAX, + sorter: None, + contents_first: false, + same_file_system: false, + }, + root: root.as_ref().to_path_buf(), + } + } + + /// Set the minimum depth of entries yielded by the iterator. + /// + /// The smallest depth is `0` and always corresponds to the path given + /// to the `new` function on this type. Its direct descendents have depth + /// `1`, and their descendents have depth `2`, and so on. + pub fn min_depth(mut self, depth: usize) -> Self { + self.opts.min_depth = depth; + if self.opts.min_depth > self.opts.max_depth { + self.opts.min_depth = self.opts.max_depth; + } + self + } + + /// Set the maximum depth of entries yield by the iterator. + /// + /// The smallest depth is `0` and always corresponds to the path given + /// to the `new` function on this type. Its direct descendents have depth + /// `1`, and their descendents have depth `2`, and so on. + /// + /// Note that this will not simply filter the entries of the iterator, but + /// it will actually avoid descending into directories when the depth is + /// exceeded. + pub fn max_depth(mut self, depth: usize) -> Self { + self.opts.max_depth = depth; + if self.opts.max_depth < self.opts.min_depth { + self.opts.max_depth = self.opts.min_depth; + } + self + } + + /// Follow symbolic links. By default, this is disabled. + /// + /// When `yes` is `true`, symbolic links are followed as if they were + /// normal directories and files. If a symbolic link is broken or is + /// involved in a loop, an error is yielded. + /// + /// When enabled, the yielded [`DirEntry`] values represent the target of + /// the link while the path corresponds to the link. See the [`DirEntry`] + /// type for more details. + /// + /// [`DirEntry`]: struct.DirEntry.html + pub fn follow_links(mut self, yes: bool) -> Self { + self.opts.follow_links = yes; + self + } + + /// Set the maximum number of simultaneously open file descriptors used + /// by the iterator. + /// + /// `n` must be greater than or equal to `1`. If `n` is `0`, then it is set + /// to `1` automatically. If this is not set, then it defaults to some + /// reasonably low number. + /// + /// This setting has no impact on the results yielded by the iterator + /// (even when `n` is `1`). Instead, this setting represents a trade off + /// between scarce resources (file descriptors) and memory. Namely, when + /// the maximum number of file descriptors is reached and a new directory + /// needs to be opened to continue iteration, then a previous directory + /// handle is closed and has its unyielded entries stored in memory. In + /// practice, this is a satisfying trade off because it scales with respect + /// to the *depth* of your file tree. Therefore, low values (even `1`) are + /// acceptable. + /// + /// Note that this value does not impact the number of system calls made by + /// an exhausted iterator. + /// + /// # Platform behavior + /// + /// On Windows, if `follow_links` is enabled, then this limit is not + /// respected. In particular, the maximum number of file descriptors opened + /// is proportional to the depth of the directory tree traversed. + pub fn max_open(mut self, mut n: usize) -> Self { + if n == 0 { + n = 1; + } + self.opts.max_open = n; + self + } + + /// Set a function for sorting directory entries with a comparator + /// function. + /// + /// If a compare function is set, the resulting iterator will return all + /// paths in sorted order. The compare function will be called to compare + /// entries from the same directory. + /// + /// ```rust,no_run + /// use std::cmp; + /// use std::ffi::OsString; + /// use walkdir::WalkDir; + /// + /// WalkDir::new("foo").sort_by(|a,b| a.file_name().cmp(b.file_name())); + /// ``` + pub fn sort_by<F>(mut self, cmp: F) -> Self + where + F: FnMut(&DirEntry, &DirEntry) -> Ordering + Send + Sync + 'static, + { + self.opts.sorter = Some(Box::new(cmp)); + self + } + + /// Set a function for sorting directory entries with a key extraction + /// function. + /// + /// If a compare function is set, the resulting iterator will return all + /// paths in sorted order. The compare function will be called to compare + /// entries from the same directory. + /// + /// ```rust,no_run + /// use std::cmp; + /// use std::ffi::OsString; + /// use walkdir::WalkDir; + /// + /// WalkDir::new("foo").sort_by_key(|a| a.file_name().to_owned()); + /// ``` + pub fn sort_by_key<K, F>(self, mut cmp: F) -> Self + where + F: FnMut(&DirEntry) -> K + Send + Sync + 'static, + K: Ord, + { + self.sort_by(move |a, b| cmp(a).cmp(&cmp(b))) + } + + /// Sort directory entries by file name, to ensure a deterministic order. + /// + /// This is a convenience function for calling `Self::sort_by()`. + /// + /// ```rust,no_run + /// use walkdir::WalkDir; + /// + /// WalkDir::new("foo").sort_by_file_name(); + /// ``` + pub fn sort_by_file_name(self) -> Self { + self.sort_by(|a, b| a.file_name().cmp(b.file_name())) + } + + /// Yield a directory's contents before the directory itself. By default, + /// this is disabled. + /// + /// When `yes` is `false` (as is the default), the directory is yielded + /// before its contents are read. This is useful when, e.g. you want to + /// skip processing of some directories. + /// + /// When `yes` is `true`, the iterator yields the contents of a directory + /// before yielding the directory itself. This is useful when, e.g. you + /// want to recursively delete a directory. + /// + /// # Example + /// + /// Assume the following directory tree: + /// + /// ```text + /// foo/ + /// abc/ + /// qrs + /// tuv + /// def/ + /// ``` + /// + /// With contents_first disabled (the default), the following code visits + /// the directory tree in depth-first order: + /// + /// ```no_run + /// use walkdir::WalkDir; + /// + /// for entry in WalkDir::new("foo") { + /// let entry = entry.unwrap(); + /// println!("{}", entry.path().display()); + /// } + /// + /// // foo + /// // foo/abc + /// // foo/abc/qrs + /// // foo/abc/tuv + /// // foo/def + /// ``` + /// + /// With contents_first enabled: + /// + /// ```no_run + /// use walkdir::WalkDir; + /// + /// for entry in WalkDir::new("foo").contents_first(true) { + /// let entry = entry.unwrap(); + /// println!("{}", entry.path().display()); + /// } + /// + /// // foo/abc/qrs + /// // foo/abc/tuv + /// // foo/abc + /// // foo/def + /// // foo + /// ``` + pub fn contents_first(mut self, yes: bool) -> Self { + self.opts.contents_first = yes; + self + } + + /// Do not cross file system boundaries. + /// + /// When this option is enabled, directory traversal will not descend into + /// directories that are on a different file system from the root path. + /// + /// Currently, this option is only supported on Unix and Windows. If this + /// option is used on an unsupported platform, then directory traversal + /// will immediately return an error and will not yield any entries. + pub fn same_file_system(mut self, yes: bool) -> Self { + self.opts.same_file_system = yes; + self + } +} + +impl IntoIterator for WalkDir { + type Item = Result<DirEntry>; + type IntoIter = IntoIter; + + fn into_iter(self) -> IntoIter { + IntoIter { + opts: self.opts, + start: Some(self.root), + stack_list: vec![], + stack_path: vec![], + oldest_opened: 0, + depth: 0, + deferred_dirs: vec![], + root_device: None, + } + } +} + +/// An iterator for recursively descending into a directory. +/// +/// A value with this type must be constructed with the [`WalkDir`] type, which +/// uses a builder pattern to set options such as min/max depth, max open file +/// descriptors and whether the iterator should follow symbolic links. After +/// constructing a `WalkDir`, call [`.into_iter()`] at the end of the chain. +/// +/// The order of elements yielded by this iterator is unspecified. +/// +/// [`WalkDir`]: struct.WalkDir.html +/// [`.into_iter()`]: struct.WalkDir.html#into_iter.v +#[derive(Debug)] +pub struct IntoIter { + /// Options specified in the builder. Depths, max fds, etc. + opts: WalkDirOptions, + /// The start path. + /// + /// This is only `Some(...)` at the beginning. After the first iteration, + /// this is always `None`. + start: Option<PathBuf>, + /// A stack of open (up to max fd) or closed handles to directories. + /// An open handle is a plain [`fs::ReadDir`] while a closed handle is + /// a `Vec<fs::DirEntry>` corresponding to the as-of-yet consumed entries. + /// + /// [`fs::ReadDir`]: https://doc.rust-lang.org/stable/std/fs/struct.ReadDir.html + stack_list: Vec<DirList>, + /// A stack of file paths. + /// + /// This is *only* used when [`follow_links`] is enabled. In all other + /// cases this stack is empty. + /// + /// [`follow_links`]: struct.WalkDir.html#method.follow_links + stack_path: Vec<Ancestor>, + /// An index into `stack_list` that points to the oldest open directory + /// handle. If the maximum fd limit is reached and a new directory needs to + /// be read, the handle at this index is closed before the new directory is + /// opened. + oldest_opened: usize, + /// The current depth of iteration (the length of the stack at the + /// beginning of each iteration). + depth: usize, + /// A list of DirEntries corresponding to directories, that are + /// yielded after their contents has been fully yielded. This is only + /// used when `contents_first` is enabled. + deferred_dirs: Vec<DirEntry>, + /// The device of the root file path when the first call to `next` was + /// made. + /// + /// If the `same_file_system` option isn't enabled, then this is always + /// `None`. Conversely, if it is enabled, this is always `Some(...)` after + /// handling the root path. + root_device: Option<u64>, +} + +/// An ancestor is an item in the directory tree traversed by walkdir, and is +/// used to check for loops in the tree when traversing symlinks. +#[derive(Debug)] +struct Ancestor { + /// The path of this ancestor. + path: PathBuf, + /// An open file to this ancesor. This is only used on Windows where + /// opening a file handle appears to be quite expensive, so we choose to + /// cache it. This comes at the cost of not respecting the file descriptor + /// limit set by the user. + #[cfg(windows)] + handle: Handle, +} + +impl Ancestor { + /// Create a new ancestor from the given directory path. + #[cfg(windows)] + fn new(dent: &DirEntry) -> io::Result<Ancestor> { + let handle = Handle::from_path(dent.path())?; + Ok(Ancestor { path: dent.path().to_path_buf(), handle: handle }) + } + + /// Create a new ancestor from the given directory path. + #[cfg(not(windows))] + fn new(dent: &DirEntry) -> io::Result<Ancestor> { + Ok(Ancestor { path: dent.path().to_path_buf() }) + } + + /// Returns true if and only if the given open file handle corresponds to + /// the same directory as this ancestor. + #[cfg(windows)] + fn is_same(&self, child: &Handle) -> io::Result<bool> { + Ok(child == &self.handle) + } + + /// Returns true if and only if the given open file handle corresponds to + /// the same directory as this ancestor. + #[cfg(not(windows))] + fn is_same(&self, child: &Handle) -> io::Result<bool> { + Ok(child == &Handle::from_path(&self.path)?) + } +} + +/// A sequence of unconsumed directory entries. +/// +/// This represents the opened or closed state of a directory handle. When +/// open, future entries are read by iterating over the raw `fs::ReadDir`. +/// When closed, all future entries are read into memory. Iteration then +/// proceeds over a [`Vec<fs::DirEntry>`]. +/// +/// [`fs::ReadDir`]: https://doc.rust-lang.org/stable/std/fs/struct.ReadDir.html +/// [`Vec<fs::DirEntry>`]: https://doc.rust-lang.org/stable/std/vec/struct.Vec.html +#[derive(Debug)] +enum DirList { + /// An opened handle. + /// + /// This includes the depth of the handle itself. + /// + /// If there was an error with the initial [`fs::read_dir`] call, then it + /// is stored here. (We use an [`Option<...>`] to make yielding the error + /// exactly once simpler.) + /// + /// [`fs::read_dir`]: https://doc.rust-lang.org/stable/std/fs/fn.read_dir.html + /// [`Option<...>`]: https://doc.rust-lang.org/stable/std/option/enum.Option.html + Opened { depth: usize, it: result::Result<ReadDir, Option<Error>> }, + /// A closed handle. + /// + /// All remaining directory entries are read into memory. + Closed(vec::IntoIter<Result<DirEntry>>), +} + +impl Iterator for IntoIter { + type Item = Result<DirEntry>; + /// Advances the iterator and returns the next value. + /// + /// # Errors + /// + /// If the iterator fails to retrieve the next value, this method returns + /// an error value. The error will be wrapped in an Option::Some. + fn next(&mut self) -> Option<Result<DirEntry>> { + if let Some(start) = self.start.take() { + if self.opts.same_file_system { + let result = util::device_num(&start) + .map_err(|e| Error::from_path(0, start.clone(), e)); + self.root_device = Some(itry!(result)); + } + let dent = itry!(DirEntry::from_path(0, start, false)); + if let Some(result) = self.handle_entry(dent) { + return Some(result); + } + } + while !self.stack_list.is_empty() { + self.depth = self.stack_list.len(); + if let Some(dentry) = self.get_deferred_dir() { + return Some(Ok(dentry)); + } + if self.depth > self.opts.max_depth { + // If we've exceeded the max depth, pop the current dir + // so that we don't descend. + self.pop(); + continue; + } + // Unwrap is safe here because we've verified above that + // `self.stack_list` is not empty + let next = self + .stack_list + .last_mut() + .expect("BUG: stack should be non-empty") + .next(); + match next { + None => self.pop(), + Some(Err(err)) => return Some(Err(err)), + Some(Ok(dent)) => { + if let Some(result) = self.handle_entry(dent) { + return Some(result); + } + } + } + } + if self.opts.contents_first { + self.depth = self.stack_list.len(); + if let Some(dentry) = self.get_deferred_dir() { + return Some(Ok(dentry)); + } + } + None + } +} + +impl IntoIter { + /// Skips the current directory. + /// + /// This causes the iterator to stop traversing the contents of the least + /// recently yielded directory. This means any remaining entries in that + /// directory will be skipped (including sub-directories). + /// + /// Note that the ergonomics of this method are questionable since it + /// borrows the iterator mutably. Namely, you must write out the looping + /// condition manually. For example, to skip hidden entries efficiently on + /// unix systems: + /// + /// ```no_run + /// use walkdir::{DirEntry, WalkDir}; + /// + /// fn is_hidden(entry: &DirEntry) -> bool { + /// entry.file_name() + /// .to_str() + /// .map(|s| s.starts_with(".")) + /// .unwrap_or(false) + /// } + /// + /// let mut it = WalkDir::new("foo").into_iter(); + /// loop { + /// let entry = match it.next() { + /// None => break, + /// Some(Err(err)) => panic!("ERROR: {}", err), + /// Some(Ok(entry)) => entry, + /// }; + /// if is_hidden(&entry) { + /// if entry.file_type().is_dir() { + /// it.skip_current_dir(); + /// } + /// continue; + /// } + /// println!("{}", entry.path().display()); + /// } + /// ``` + /// + /// You may find it more convenient to use the [`filter_entry`] iterator + /// adapter. (See its documentation for the same example functionality as + /// above.) + /// + /// [`filter_entry`]: #method.filter_entry + pub fn skip_current_dir(&mut self) { + if !self.stack_list.is_empty() { + self.pop(); + } + } + + /// Yields only entries which satisfy the given predicate and skips + /// descending into directories that do not satisfy the given predicate. + /// + /// The predicate is applied to all entries. If the predicate is + /// true, iteration carries on as normal. If the predicate is false, the + /// entry is ignored and if it is a directory, it is not descended into. + /// + /// This is often more convenient to use than [`skip_current_dir`]. For + /// example, to skip hidden files and directories efficiently on unix + /// systems: + /// + /// ```no_run + /// use walkdir::{DirEntry, WalkDir}; + /// # use walkdir::Error; + /// + /// fn is_hidden(entry: &DirEntry) -> bool { + /// entry.file_name() + /// .to_str() + /// .map(|s| s.starts_with(".")) + /// .unwrap_or(false) + /// } + /// + /// # fn try_main() -> Result<(), Error> { + /// for entry in WalkDir::new("foo") + /// .into_iter() + /// .filter_entry(|e| !is_hidden(e)) { + /// println!("{}", entry?.path().display()); + /// } + /// # Ok(()) + /// # } + /// ``` + /// + /// Note that the iterator will still yield errors for reading entries that + /// may not satisfy the predicate. + /// + /// Note that entries skipped with [`min_depth`] and [`max_depth`] are not + /// passed to this predicate. + /// + /// Note that if the iterator has `contents_first` enabled, then this + /// method is no different than calling the standard `Iterator::filter` + /// method (because directory entries are yielded after they've been + /// descended into). + /// + /// [`skip_current_dir`]: #method.skip_current_dir + /// [`min_depth`]: struct.WalkDir.html#method.min_depth + /// [`max_depth`]: struct.WalkDir.html#method.max_depth + pub fn filter_entry<P>(self, predicate: P) -> FilterEntry<Self, P> + where + P: FnMut(&DirEntry) -> bool, + { + FilterEntry { it: self, predicate: predicate } + } + + fn handle_entry( + &mut self, + mut dent: DirEntry, + ) -> Option<Result<DirEntry>> { + if self.opts.follow_links && dent.file_type().is_symlink() { + dent = itry!(self.follow(dent)); + } + let is_normal_dir = !dent.file_type().is_symlink() && dent.is_dir(); + if is_normal_dir { + if self.opts.same_file_system && dent.depth() > 0 { + if itry!(self.is_same_file_system(&dent)) { + itry!(self.push(&dent)); + } + } else { + itry!(self.push(&dent)); + } + } else if dent.depth() == 0 && dent.file_type().is_symlink() { + // As a special case, if we are processing a root entry, then we + // always follow it even if it's a symlink and follow_links is + // false. We are careful to not let this change the semantics of + // the DirEntry however. Namely, the DirEntry should still respect + // the follow_links setting. When it's disabled, it should report + // itself as a symlink. When it's enabled, it should always report + // itself as the target. + let md = itry!(fs::metadata(dent.path()).map_err(|err| { + Error::from_path(dent.depth(), dent.path().to_path_buf(), err) + })); + if md.file_type().is_dir() { + itry!(self.push(&dent)); + } + } + if is_normal_dir && self.opts.contents_first { + self.deferred_dirs.push(dent); + None + } else if self.skippable() { + None + } else { + Some(Ok(dent)) + } + } + + fn get_deferred_dir(&mut self) -> Option<DirEntry> { + if self.opts.contents_first { + if self.depth < self.deferred_dirs.len() { + // Unwrap is safe here because we've guaranteed that + // `self.deferred_dirs.len()` can never be less than 1 + let deferred: DirEntry = self + .deferred_dirs + .pop() + .expect("BUG: deferred_dirs should be non-empty"); + if !self.skippable() { + return Some(deferred); + } + } + } + None + } + + fn push(&mut self, dent: &DirEntry) -> Result<()> { + // Make room for another open file descriptor if we've hit the max. + let free = + self.stack_list.len().checked_sub(self.oldest_opened).unwrap(); + if free == self.opts.max_open { + self.stack_list[self.oldest_opened].close(); + } + // Open a handle to reading the directory's entries. + let rd = fs::read_dir(dent.path()).map_err(|err| { + Some(Error::from_path(self.depth, dent.path().to_path_buf(), err)) + }); + let mut list = DirList::Opened { depth: self.depth, it: rd }; + if let Some(ref mut cmp) = self.opts.sorter { + let mut entries: Vec<_> = list.collect(); + entries.sort_by(|a, b| match (a, b) { + (&Ok(ref a), &Ok(ref b)) => cmp(a, b), + (&Err(_), &Err(_)) => Ordering::Equal, + (&Ok(_), &Err(_)) => Ordering::Greater, + (&Err(_), &Ok(_)) => Ordering::Less, + }); + list = DirList::Closed(entries.into_iter()); + } + if self.opts.follow_links { + let ancestor = Ancestor::new(&dent) + .map_err(|err| Error::from_io(self.depth, err))?; + self.stack_path.push(ancestor); + } + // We push this after stack_path since creating the Ancestor can fail. + // If it fails, then we return the error and won't descend. + self.stack_list.push(list); + // If we had to close out a previous directory stream, then we need to + // increment our index the oldest still-open stream. We do this only + // after adding to our stack, in order to ensure that the oldest_opened + // index remains valid. The worst that can happen is that an already + // closed stream will be closed again, which is a no-op. + // + // We could move the close of the stream above into this if-body, but + // then we would have more than the maximum number of file descriptors + // open at a particular point in time. + if free == self.opts.max_open { + // Unwrap is safe here because self.oldest_opened is guaranteed to + // never be greater than `self.stack_list.len()`, which implies + // that the subtraction won't underflow and that adding 1 will + // never overflow. + self.oldest_opened = self.oldest_opened.checked_add(1).unwrap(); + } + Ok(()) + } + + fn pop(&mut self) { + self.stack_list.pop().expect("BUG: cannot pop from empty stack"); + if self.opts.follow_links { + self.stack_path.pop().expect("BUG: list/path stacks out of sync"); + } + // If everything in the stack is already closed, then there is + // room for at least one more open descriptor and it will + // always be at the top of the stack. + self.oldest_opened = min(self.oldest_opened, self.stack_list.len()); + } + + fn follow(&self, mut dent: DirEntry) -> Result<DirEntry> { + dent = + DirEntry::from_path(self.depth, dent.path().to_path_buf(), true)?; + // The only way a symlink can cause a loop is if it points + // to a directory. Otherwise, it always points to a leaf + // and we can omit any loop checks. + if dent.is_dir() { + self.check_loop(dent.path())?; + } + Ok(dent) + } + + fn check_loop<P: AsRef<Path>>(&self, child: P) -> Result<()> { + let hchild = Handle::from_path(&child) + .map_err(|err| Error::from_io(self.depth, err))?; + for ancestor in self.stack_path.iter().rev() { + let is_same = ancestor + .is_same(&hchild) + .map_err(|err| Error::from_io(self.depth, err))?; + if is_same { + return Err(Error::from_loop( + self.depth, + &ancestor.path, + child.as_ref(), + )); + } + } + Ok(()) + } + + fn is_same_file_system(&mut self, dent: &DirEntry) -> Result<bool> { + let dent_device = util::device_num(dent.path()) + .map_err(|err| Error::from_entry(dent, err))?; + Ok(self + .root_device + .map(|d| d == dent_device) + .expect("BUG: called is_same_file_system without root device")) + } + + fn skippable(&self) -> bool { + self.depth < self.opts.min_depth || self.depth > self.opts.max_depth + } +} + +impl DirList { + fn close(&mut self) { + if let DirList::Opened { .. } = *self { + *self = DirList::Closed(self.collect::<Vec<_>>().into_iter()); + } + } +} + +impl Iterator for DirList { + type Item = Result<DirEntry>; + + #[inline(always)] + fn next(&mut self) -> Option<Result<DirEntry>> { + match *self { + DirList::Closed(ref mut it) => it.next(), + DirList::Opened { depth, ref mut it } => match *it { + Err(ref mut err) => err.take().map(Err), + Ok(ref mut rd) => rd.next().map(|r| match r { + Ok(r) => DirEntry::from_entry(depth + 1, &r), + Err(err) => Err(Error::from_io(depth + 1, err)), + }), + }, + } + } +} + +/// A recursive directory iterator that skips entries. +/// +/// Values of this type are created by calling [`.filter_entry()`] on an +/// `IntoIter`, which is formed by calling [`.into_iter()`] on a `WalkDir`. +/// +/// Directories that fail the predicate `P` are skipped. Namely, they are +/// never yielded and never descended into. +/// +/// Entries that are skipped with the [`min_depth`] and [`max_depth`] options +/// are not passed through this filter. +/// +/// If opening a handle to a directory resulted in an error, then it is yielded +/// and no corresponding call to the predicate is made. +/// +/// Type parameter `I` refers to the underlying iterator and `P` refers to the +/// predicate, which is usually `FnMut(&DirEntry) -> bool`. +/// +/// [`.filter_entry()`]: struct.IntoIter.html#method.filter_entry +/// [`.into_iter()`]: struct.WalkDir.html#into_iter.v +/// [`min_depth`]: struct.WalkDir.html#method.min_depth +/// [`max_depth`]: struct.WalkDir.html#method.max_depth +#[derive(Debug)] +pub struct FilterEntry<I, P> { + it: I, + predicate: P, +} + +impl<P> Iterator for FilterEntry<IntoIter, P> +where + P: FnMut(&DirEntry) -> bool, +{ + type Item = Result<DirEntry>; + + /// Advances the iterator and returns the next value. + /// + /// # Errors + /// + /// If the iterator fails to retrieve the next value, this method returns + /// an error value. The error will be wrapped in an `Option::Some`. + fn next(&mut self) -> Option<Result<DirEntry>> { + loop { + let dent = match self.it.next() { + None => return None, + Some(result) => itry!(result), + }; + if !(self.predicate)(&dent) { + if dent.is_dir() { + self.it.skip_current_dir(); + } + continue; + } + return Some(Ok(dent)); + } + } +} + +impl<P> FilterEntry<IntoIter, P> +where + P: FnMut(&DirEntry) -> bool, +{ + /// Yields only entries which satisfy the given predicate and skips + /// descending into directories that do not satisfy the given predicate. + /// + /// The predicate is applied to all entries. If the predicate is + /// true, iteration carries on as normal. If the predicate is false, the + /// entry is ignored and if it is a directory, it is not descended into. + /// + /// This is often more convenient to use than [`skip_current_dir`]. For + /// example, to skip hidden files and directories efficiently on unix + /// systems: + /// + /// ```no_run + /// use walkdir::{DirEntry, WalkDir}; + /// # use walkdir::Error; + /// + /// fn is_hidden(entry: &DirEntry) -> bool { + /// entry.file_name() + /// .to_str() + /// .map(|s| s.starts_with(".")) + /// .unwrap_or(false) + /// } + /// + /// # fn try_main() -> Result<(), Error> { + /// for entry in WalkDir::new("foo") + /// .into_iter() + /// .filter_entry(|e| !is_hidden(e)) { + /// println!("{}", entry?.path().display()); + /// } + /// # Ok(()) + /// # } + /// ``` + /// + /// Note that the iterator will still yield errors for reading entries that + /// may not satisfy the predicate. + /// + /// Note that entries skipped with [`min_depth`] and [`max_depth`] are not + /// passed to this predicate. + /// + /// Note that if the iterator has `contents_first` enabled, then this + /// method is no different than calling the standard `Iterator::filter` + /// method (because directory entries are yielded after they've been + /// descended into). + /// + /// [`skip_current_dir`]: #method.skip_current_dir + /// [`min_depth`]: struct.WalkDir.html#method.min_depth + /// [`max_depth`]: struct.WalkDir.html#method.max_depth + pub fn filter_entry(self, predicate: P) -> FilterEntry<Self, P> { + FilterEntry { it: self, predicate: predicate } + } + + /// Skips the current directory. + /// + /// This causes the iterator to stop traversing the contents of the least + /// recently yielded directory. This means any remaining entries in that + /// directory will be skipped (including sub-directories). + /// + /// Note that the ergonomics of this method are questionable since it + /// borrows the iterator mutably. Namely, you must write out the looping + /// condition manually. For example, to skip hidden entries efficiently on + /// unix systems: + /// + /// ```no_run + /// use walkdir::{DirEntry, WalkDir}; + /// + /// fn is_hidden(entry: &DirEntry) -> bool { + /// entry.file_name() + /// .to_str() + /// .map(|s| s.starts_with(".")) + /// .unwrap_or(false) + /// } + /// + /// let mut it = WalkDir::new("foo").into_iter(); + /// loop { + /// let entry = match it.next() { + /// None => break, + /// Some(Err(err)) => panic!("ERROR: {}", err), + /// Some(Ok(entry)) => entry, + /// }; + /// if is_hidden(&entry) { + /// if entry.file_type().is_dir() { + /// it.skip_current_dir(); + /// } + /// continue; + /// } + /// println!("{}", entry.path().display()); + /// } + /// ``` + /// + /// You may find it more convenient to use the [`filter_entry`] iterator + /// adapter. (See its documentation for the same example functionality as + /// above.) + /// + /// [`filter_entry`]: #method.filter_entry + pub fn skip_current_dir(&mut self) { + self.it.skip_current_dir(); + } +} |