Mercurial > hg
diff rust/hg-core/src/utils/files.rs @ 42586:cad3dde7a573
rust-dirstate: add helper to iterate ancestor paths
This is modeled after std::path::Path::ancestors().
find_dirs(b"") yields b"" because Mercurial's util.finddirs() works in that
way, and the test case for DirsMultiset expects such behavior.
author | Yuya Nishihara <yuya@tcha.org> |
---|---|
date | Sun, 30 Jun 2019 18:32:43 +0900 |
parents | f305f1d7d559 |
children | 4b3b27d567d5 |
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--- a/rust/hg-core/src/utils/files.rs Tue Jul 09 20:51:48 2019 -0400 +++ b/rust/hg-core/src/utils/files.rs Sun Jun 30 18:32:43 2019 +0900 @@ -1,3 +1,4 @@ +use std::iter::FusedIterator; use std::path::Path; pub fn get_path_from_bytes(bytes: &[u8]) -> &Path { @@ -17,3 +18,66 @@ Path::new(os_str) } + +/// An iterator over repository path yielding itself and its ancestors. +#[derive(Copy, Clone, Debug)] +pub struct Ancestors<'a> { + next: Option<&'a [u8]>, +} + +impl<'a> Iterator for Ancestors<'a> { + // if we had an HgPath type, this would yield &'a HgPath + type Item = &'a [u8]; + + fn next(&mut self) -> Option<Self::Item> { + let next = self.next; + self.next = match self.next { + Some(s) if s.is_empty() => None, + Some(s) => { + let p = s.iter().rposition(|&c| c == b'/').unwrap_or(0); + Some(&s[..p]) + } + None => None, + }; + next + } +} + +impl<'a> FusedIterator for Ancestors<'a> {} + +/// Returns an iterator yielding ancestor directories of the given repository +/// path. +/// +/// The path is separated by '/', and must not start with '/'. +/// +/// The path itself isn't included unless it is b"" (meaning the root +/// directory.) +pub fn find_dirs<'a>(path: &'a [u8]) -> Ancestors<'a> { + let mut dirs = Ancestors { next: Some(path) }; + if !path.is_empty() { + dirs.next(); // skip itself + } + dirs +} + +#[cfg(test)] +mod tests { + #[test] + fn find_dirs_some() { + let mut dirs = super::find_dirs(b"foo/bar/baz"); + assert_eq!(dirs.next(), Some(b"foo/bar".as_ref())); + assert_eq!(dirs.next(), Some(b"foo".as_ref())); + assert_eq!(dirs.next(), Some(b"".as_ref())); + assert_eq!(dirs.next(), None); + assert_eq!(dirs.next(), None); + } + + #[test] + fn find_dirs_empty() { + // looks weird, but mercurial.util.finddirs(b"") yields b"" + let mut dirs = super::find_dirs(b""); + assert_eq!(dirs.next(), Some(b"".as_ref())); + assert_eq!(dirs.next(), None); + assert_eq!(dirs.next(), None); + } +}