rust-utils: use new find_dirs iterator

In cad3dde7a573, the `find_dirs` util was introduced, but the second changeset
that made use of it didn't apply. This change fixes the issue.

Differential Revision: https://phab.mercurial-scm.org/D6639

rust/hg-core/src/dirstate/dirs_multiset.rs

@@ -1,360 +1,329 b''
 // dirs_multiset.rs
 //
 // Copyright 2019 Raphaël Gomès <[e-mail]>
 //
 // This software may be used and distributed according to the terms of the
 // GNU General Public License version 2 or any later version.
 
 //! A multiset of directory names.
 //!
 //! Used to counts the references to directories in a manifest or dirstate.
 use std::collections::hash_map::{Entry, Iter};
 use std::collections::HashMap;
 use {DirsIterable, DirstateEntry, DirstateMapError};
+use utils::files;
 
 #[derive(PartialEq, Debug)]
 pub struct DirsMultiset {
     inner: HashMap<Vec<u8>, u32>,
 }
 
 impl DirsMultiset {
     /// Initializes the multiset from a dirstate or a manifest.
     ///
     /// If `skip_state` is provided, skips dirstate entries with equal state.
     pub fn new(iterable: DirsIterable, skip_state: Option<i8>) -> Self {
         let mut multiset = DirsMultiset {
             inner: HashMap::new(),
         };
 
         match iterable {
             DirsIterable::Dirstate(vec) => {
                 for (ref filename, DirstateEntry { state, .. }) in vec {
                     // This `if` is optimized out of the loop
                     if let Some(skip) = skip_state {
                         if skip != state {
                             multiset.add_path(filename);
                         }
                     } else {
                         multiset.add_path(filename);
                     }
                 }
             }
             DirsIterable::Manifest(vec) => {
                 for ref filename in vec {
                     multiset.add_path(filename);
                 }
             }
         }
 
         multiset
     }
 
-    /// Returns the slice up to the next directory name from right to left,
-    /// without trailing slash
-    fn find_dir(path: &[u8]) -> &[u8] {
-        let mut path = path;
-        loop {
-            if let Some(new_pos) = path.len().checked_sub(1) {
-                if path[new_pos] == b'/' {
-                    break &path[..new_pos];
-                }
-                path = &path[..new_pos];
-            } else {
-                break &[];
-            }
-        }
-    }
-
     /// Increases the count of deepest directory contained in the path.
     ///
     /// If the directory is not yet in the map, adds its parents.
     pub fn add_path(&mut self, path: &[u8]) {
-        let mut pos = path.len();
-
-        loop {
-            let subpath = Self::find_dir(&path[..pos]);
+        for subpath in files::find_dirs(path) {
             if let Some(val) = self.inner.get_mut(subpath) {
                 *val += 1;
                 break;
             }
             self.inner.insert(subpath.to_owned(), 1);
-
-            pos = subpath.len();
-            if pos == 0 {
-                break;
-            }
         }
     }
 
     /// Decreases the count of deepest directory contained in the path.
     ///
     /// If it is the only reference, decreases all parents until one is
     /// removed.
     /// If the directory is not in the map, something horrible has happened.
     pub fn delete_path(
         &mut self,
         path: &[u8],
     ) -> Result<(), DirstateMapError> {
-        let mut pos = path.len();
-
-        loop {
-            let subpath = Self::find_dir(&path[..pos]);
+        for subpath in files::find_dirs(path) {
             match self.inner.entry(subpath.to_owned()) {
                 Entry::Occupied(mut entry) => {
                     let val = entry.get().clone();
                     if val > 1 {
                         entry.insert(val - 1);
                         break;
                     }
                     entry.remove();
                 }
                 Entry::Vacant(_) => {
                     return Err(DirstateMapError::PathNotFound(
                         path.to_owned(),
                     ))
                 }
             };
-
-            pos = subpath.len();
-            if pos == 0 {
-                break;
-            }
         }
 
         Ok(())
     }
 
     pub fn contains_key(&self, key: &[u8]) -> bool {
         self.inner.contains_key(key)
     }
 
     pub fn iter(&self) -> Iter<Vec<u8>, u32> {
         self.inner.iter()
     }
 
     pub fn len(&self) -> usize {
         self.inner.len()
     }
 }
 
 #[cfg(test)]
 mod tests {
     use super::*;
 
     #[test]
     fn test_delete_path_path_not_found() {
         let mut map = DirsMultiset::new(DirsIterable::Manifest(vec![]), None);
         let path = b"doesnotexist/";
         assert_eq!(
             Err(DirstateMapError::PathNotFound(path.to_vec())),
             map.delete_path(path)
         );
     }
 
     #[test]
     fn test_delete_path_empty_path() {
         let mut map =
             DirsMultiset::new(DirsIterable::Manifest(vec![vec![]]), None);
         let path = b"";
         assert_eq!(Ok(()), map.delete_path(path));
         assert_eq!(
             Err(DirstateMapError::PathNotFound(path.to_vec())),
             map.delete_path(path)
         );
     }
 
     #[test]
     fn test_delete_path_successful() {
         let mut map = DirsMultiset {
             inner: [("", 5), ("a", 3), ("a/b", 2), ("a/c", 1)]
                 .iter()
                 .map(|(k, v)| (k.as_bytes().to_vec(), *v))
                 .collect(),
         };
 
         assert_eq!(Ok(()), map.delete_path(b"a/b/"));
         assert_eq!(Ok(()), map.delete_path(b"a/b/"));
         assert_eq!(
             Err(DirstateMapError::PathNotFound(b"a/b/".to_vec())),
             map.delete_path(b"a/b/")
         );
 
         assert_eq!(2, *map.inner.get(&b"a".to_vec()).unwrap());
         assert_eq!(1, *map.inner.get(&b"a/c".to_vec()).unwrap());
         eprintln!("{:?}", map);
         assert_eq!(Ok(()), map.delete_path(b"a/"));
         eprintln!("{:?}", map);
 
         assert_eq!(Ok(()), map.delete_path(b"a/c/"));
         assert_eq!(
             Err(DirstateMapError::PathNotFound(b"a/c/".to_vec())),
             map.delete_path(b"a/c/")
         );
     }
 
     #[test]
     fn test_add_path_empty_path() {
         let mut map = DirsMultiset::new(DirsIterable::Manifest(vec![]), None);
         let path = b"";
         map.add_path(path);
 
         assert_eq!(1, map.len());
     }
 
     #[test]
     fn test_add_path_successful() {
         let mut map = DirsMultiset::new(DirsIterable::Manifest(vec![]), None);
 
         map.add_path(b"a/");
         assert_eq!(1, *map.inner.get(&b"a".to_vec()).unwrap());
         assert_eq!(1, *map.inner.get(&Vec::new()).unwrap());
         assert_eq!(2, map.len());
 
         // Non directory should be ignored
         map.add_path(b"a");
         assert_eq!(1, *map.inner.get(&b"a".to_vec()).unwrap());
         assert_eq!(2, map.len());
 
         // Non directory will still add its base
         map.add_path(b"a/b");
         assert_eq!(2, *map.inner.get(&b"a".to_vec()).unwrap());
         assert_eq!(2, map.len());
 
         // Duplicate path works
         map.add_path(b"a/");
         assert_eq!(3, *map.inner.get(&b"a".to_vec()).unwrap());
 
         // Nested dir adds to its base
         map.add_path(b"a/b/");
         assert_eq!(4, *map.inner.get(&b"a".to_vec()).unwrap());
         assert_eq!(1, *map.inner.get(&b"a/b".to_vec()).unwrap());
 
         // but not its base's base, because it already existed
         map.add_path(b"a/b/c/");
         assert_eq!(4, *map.inner.get(&b"a".to_vec()).unwrap());
         assert_eq!(2, *map.inner.get(&b"a/b".to_vec()).unwrap());
 
         map.add_path(b"a/c/");
         assert_eq!(1, *map.inner.get(&b"a/c".to_vec()).unwrap());
 
         let expected = DirsMultiset {
             inner: [("", 2), ("a", 5), ("a/b", 2), ("a/b/c", 1), ("a/c", 1)]
                 .iter()
                 .map(|(k, v)| (k.as_bytes().to_vec(), *v))
                 .collect(),
         };
         assert_eq!(map, expected);
     }
 
     #[test]
     fn test_dirsmultiset_new_empty() {
         use DirsIterable::{Dirstate, Manifest};
 
         let new = DirsMultiset::new(Manifest(vec![]), None);
         let expected = DirsMultiset {
             inner: HashMap::new(),
         };
         assert_eq!(expected, new);
 
         let new = DirsMultiset::new(Dirstate(vec![]), None);
         let expected = DirsMultiset {
             inner: HashMap::new(),
         };
         assert_eq!(expected, new);
     }
 
     #[test]
     fn test_dirsmultiset_new_no_skip() {
         use DirsIterable::{Dirstate, Manifest};
 
         let input_vec = ["a/", "b/", "a/c", "a/d/"]
             .iter()
             .map(|e| e.as_bytes().to_vec())
             .collect();
         let expected_inner = [("", 2), ("a", 3), ("b", 1), ("a/d", 1)]
             .iter()
             .map(|(k, v)| (k.as_bytes().to_vec(), *v))
             .collect();
 
         let new = DirsMultiset::new(Manifest(input_vec), None);
         let expected = DirsMultiset {
             inner: expected_inner,
         };
         assert_eq!(expected, new);
 
         let input_map = ["a/", "b/", "a/c", "a/d/"]
             .iter()
             .map(|f| {
                 (
                     f.as_bytes().to_vec(),
                     DirstateEntry {
                         state: 0,
                         mode: 0,
                         mtime: 0,
                         size: 0,
                     },
                 )
             })
             .collect();
         let expected_inner = [("", 2), ("a", 3), ("b", 1), ("a/d", 1)]
             .iter()
             .map(|(k, v)| (k.as_bytes().to_vec(), *v))
             .collect();
 
         let new = DirsMultiset::new(Dirstate(input_map), None);
         let expected = DirsMultiset {
             inner: expected_inner,
         };
         assert_eq!(expected, new);
     }
 
     #[test]
     fn test_dirsmultiset_new_skip() {
         use DirsIterable::{Dirstate, Manifest};
 
         let input_vec = ["a/", "b/", "a/c", "a/d/"]
             .iter()
             .map(|e| e.as_bytes().to_vec())
             .collect();
         let expected_inner = [("", 2), ("a", 3), ("b", 1), ("a/d", 1)]
             .iter()
             .map(|(k, v)| (k.as_bytes().to_vec(), *v))
             .collect();
 
         let new = DirsMultiset::new(Manifest(input_vec), Some('n' as i8));
         let expected = DirsMultiset {
             inner: expected_inner,
         };
         // Skip does not affect a manifest
         assert_eq!(expected, new);
 
         let input_map =
             [("a/", 'n'), ("a/b/", 'n'), ("a/c", 'r'), ("a/d/", 'm')]
                 .iter()
                 .map(|(f, state)| {
                     (
                         f.as_bytes().to_vec(),
                         DirstateEntry {
                             state: *state as i8,
                             mode: 0,
                             mtime: 0,
                             size: 0,
                         },
                     )
                 })
                 .collect();
 
         // "a" incremented with "a/c" and "a/d/"
         let expected_inner = [("", 1), ("a", 2), ("a/d", 1)]
             .iter()
             .map(|(k, v)| (k.as_bytes().to_vec(), *v))
             .collect();
 
         let new = DirsMultiset::new(Dirstate(input_map), Some('n' as i8));
         let expected = DirsMultiset {
             inner: expected_inner,
         };
         assert_eq!(expected, new);
     }
 
 }