Improve performance of project panel with many git statuses (#25465)

Closes #ISSUE

Release Notes:

- Improved performance of project panel in large git repositories

crates/project_panel/src/project_panel.rs

@@ -18,7 +18,7 @@ use file_icons::FileIcons;
 use git::status::GitSummary;
 use gpui::{
     actions, anchored, deferred, div, impl_actions, point, px, size, uniform_list, Action,
-    AnyElement, App, AsyncWindowContext, Bounds, ClipboardItem, Context, DismissEvent, Div,
+    AnyElement, App, ArcCow, AsyncWindowContext, Bounds, ClipboardItem, Context, DismissEvent, Div,
     DragMoveEvent, Entity, EventEmitter, ExternalPaths, FocusHandle, Focusable, Hsla,
     InteractiveElement, KeyContext, ListHorizontalSizingBehavior, ListSizingBehavior, MouseButton,
     MouseDownEvent, ParentElement, Pixels, Point, PromptLevel, Render, ScrollStrategy, Stateful,
@@ -2700,7 +2700,7 @@ impl ProjectPanel {
                     else {
                         continue;
                     };
-                    let path = Arc::from(Path::new(path_name));
+                    let path = ArcCow::Borrowed(Path::new(path_name));
                     let depth = 0;
                     (depth, path)
                 } else if entry.is_file() {
@@ -2712,7 +2712,7 @@ impl ProjectPanel {
                     else {
                         continue;
                     };
-                    let path = Arc::from(Path::new(path_name));
+                    let path = ArcCow::Borrowed(Path::new(path_name));
                     let depth = entry.path.ancestors().count() - 1;
                     (depth, path)
                 } else {
@@ -2732,11 +2732,11 @@ impl ProjectPanel {
                                 .ok()
                                 .and_then(|suffix| {
                                     let full_path = Path::new(root_folded_entry.file_name()?);
-                                    Some(Arc::<Path>::from(full_path.join(suffix)))
+                                    Some(ArcCow::Owned(Arc::<Path>::from(full_path.join(suffix))))
                                 })
                         })
-                        .or_else(|| entry.path.file_name().map(Path::new).map(Arc::from))
-                        .unwrap_or_else(|| entry.path.clone());
+                        .or_else(|| entry.path.file_name().map(Path::new).map(ArcCow::Borrowed))
+                        .unwrap_or_else(|| ArcCow::Owned(entry.path.clone()));
                     let depth = path.components().count();
                     (depth, path)
                 };

crates/worktree/src/worktree.rs

@@ -206,15 +206,19 @@ pub struct RepositoryEntry {
     pub current_merge_conflicts: TreeSet<RepoPath>,
 }
 
-impl Deref for RepositoryEntry {
-    type Target = WorkDirectory;
-
-    fn deref(&self) -> &Self::Target {
-        &self.work_directory
-    }
-}
-
 impl RepositoryEntry {
+    pub fn relativize(&self, path: &Path) -> Result<RepoPath> {
+        self.work_directory.relativize(path)
+    }
+
+    pub fn unrelativize(&self, path: &RepoPath) -> Option<Arc<Path>> {
+        self.work_directory.unrelativize(path)
+    }
+
+    pub fn directory_contains(&self, path: impl AsRef<Path>) -> bool {
+        self.work_directory.directory_contains(path)
+    }
+
     pub fn branch(&self) -> Option<&Branch> {
         self.current_branch.as_ref()
     }
@@ -2834,7 +2838,7 @@ impl Snapshot {
     pub fn repository_for_path(&self, path: &Path) -> Option<&RepositoryEntry> {
         self.repositories
             .iter()
-            .filter(|repo| repo.work_directory.directory_contains(path))
+            .filter(|repo| repo.directory_contains(path))
             .last()
     }
 
@@ -6023,7 +6027,13 @@ impl<'a> GitTraversal<'a> {
         };
 
         // Update our state if we changed repositories.
-        if reset || self.repo_location.as_ref().map(|(prev_repo, _)| prev_repo) != Some(&repo) {
+        if reset
+            || self
+                .repo_location
+                .as_ref()
+                .map(|(prev_repo, _)| &prev_repo.work_directory)
+                != Some(&repo.work_directory)
+        {
             self.repo_location = Some((repo, repo.statuses_by_path.cursor::<PathProgress>(&())));
         }