WIP: rename

Author: wfraser

src/inode_table.rs

@@ -4,10 +4,11 @@
 //
 
 use std::borrow::Borrow;
-use std::cmp::{Eq, PartialEq};
-use std::collections::{HashMap, VecDeque};
-use std::collections::hash_map::Entry::*;
+use std::cmp::{Eq, Ordering, PartialEq};
+use std::collections::{BTreeMap, VecDeque};
+use std::collections::btree_map::Entry::*;
 use std::hash::{Hash, Hasher};
+use std::ops::Bound::{Excluded, Included, Unbounded};
 use std::path::{Path, PathBuf};
 use std::sync::Arc;
 
@@ -27,7 +28,7 @@ struct InodeTableEntry {
 pub struct InodeTable {
     table: Vec<InodeTableEntry>,
     free_list: VecDeque<usize>,
-    by_path: HashMap<Arc<PathBuf>, usize>,
+    by_path: BTreeMap<Arc<PathBuf>, usize>,
 }
 
 impl InodeTable {
@@ -42,7 +43,7 @@ impl InodeTable {
         let mut inode_table = InodeTable {
             table: Vec::new(),
             free_list: VecDeque::new(),
-            by_path: HashMap::new()
+            by_path: BTreeMap::new()
         };
         let root = Arc::new(PathBuf::from("/"));
         inode_table.table.push(InodeTableEntry {
@@ -180,9 +181,38 @@ impl InodeTable {
     /// Change an inode's path to a different one, without changing the inode number.
     /// Lookup counts remain unchanged, even if this is replacing another file.
     pub fn rename(&mut self, oldpath: &Path, newpath: Arc<PathBuf>) {
-        let idx = self.by_path.remove(Pathish::new(oldpath)).unwrap();
-        self.table[idx].path = Some(newpath.clone());
-        self.by_path.insert(newpath, idx); // this can replace a path with a new inode
+        // none means it's a single path
+        let mut range = None;
+        for (candidate, _) in self.by_path.range::<Pathish, _>((Excluded(Pathish::new(oldpath)),  Unbounded)) {
+            if candidate.starts_with(oldpath) {
+                if let Some((start, _end)) = range {
+                    range = Some((start, Included(candidate.clone())));
+                } else {
+                    range = Some((Included(Arc::new(oldpath.to_owned())), Included(Arc::clone(candidate))));
+                }
+            } else {
+                break;
+            }
+        }
+
+        if let Some(range) = range {
+            let mut new_entries = vec![];
+            for (path, idx) in self.by_path.extract_if(range, |_, _| true) {
+                let suffix = path.strip_prefix(oldpath).unwrap();
+                let new_entry_path = if suffix.as_os_str().is_empty() {
+                    Arc::clone(&newpath)
+                } else {
+                    Arc::new(newpath.as_path().join(suffix))
+                };
+                self.table[idx].path = Some(Arc::clone(&new_entry_path));
+                new_entries.push((new_entry_path, idx));
+            }
+            self.by_path.extend(new_entries);
+        } else {
+            let idx = self.by_path.remove(Pathish::new(oldpath)).unwrap();
+            self.table[idx].path = Some(newpath.clone());
+            self.by_path.insert(newpath, idx); // this can replace a path with a new inode
+        }
     }
 
     /// Remove the path->inode mapping for a given path, but keep the inode around.
@@ -245,6 +275,18 @@ impl Hash for Pathish {
 impl Eq for Pathish {
 }
 
+impl PartialOrd<Self> for Pathish {
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        Some(self.cmp(other))
+    }
+}
+
+impl Ord for Pathish {
+    fn cmp(&self, other: &Self) -> Ordering {
+        self.inner.cmp(&other.inner)
+    }
+}
+
 impl PartialEq for Pathish {
     fn eq(&self, other: &Pathish) -> bool {
         self.inner.eq(&other.inner)
@@ -341,3 +383,31 @@ fn test_unlink() {
     assert_eq!(0, table.forget(inode, 1));
     assert!(table.get_path(inode).is_none());
 }
+
+#[test]
+fn test_rename_directory() {
+    let mut table = InodeTable::new();
+    let a = table.add(Arc::new(PathBuf::from("/a_file")));
+    let d = table.add(Arc::new(PathBuf::from("/directory")));
+    let d_f1 = table.add(Arc::new(PathBuf::from("/directory/file1")));
+    let d_f2 = table.add(Arc::new(PathBuf::from("/directory/file2")));
+    let z = table.add(Arc::new(PathBuf::from("/z_file")));
+
+    table.rename(Path::new("/a_file"), Arc::new(PathBuf::from("/a_file_renamed")));
+    assert_eq!(table.get_inode(Path::new("/a_file")), None);
+    assert_eq!(table.get_inode(Path::new("/a_file_renamed")), Some(a.0));
+
+    table.rename(Path::new("/directory"), Arc::new(PathBuf::from("/new_directory")));
+
+    assert_eq!(table.get_inode(Path::new("/a_file_renamed")), Some(a.0));
+    assert_eq!(table.get_inode(Path::new("/z_file")), Some(z.0));
+
+    assert_eq!(table.get_inode(Path::new("/new_directory")), Some(d.0));
+    assert_eq!(table.get_inode(Path::new("/new_directory/file1")), Some(d_f1.0));
+    assert_eq!(table.get_inode(Path::new("/new_directory/file2")), Some(d_f2.0));
+
+    assert_eq!(table.get_inode(Path::new("/directory")), None);
+    assert_eq!(table.get_inode(Path::new("/directory/file1")), None);
+    assert_eq!(table.get_inode(Path::new("/directory/file2")), None);
+
+}