Replace tree-traversal with State

helix-vcs/src/git.rs

@@ -5,9 +5,10 @@ use std::{
 };
 
 use anyhow::Result;
+use git::index::{entry::Mode, State};
 use git::objs::tree::EntryMode;
-use git::sec::trust::DefaultForLevel;
-use git::{Commit, ObjectId, Repository, ThreadSafeRepository, Tree};
+use git::{prelude::FindExt, sec::trust::DefaultForLevel};
+use git::{Commit, ObjectId, Repository, ThreadSafeRepository};
 use git_repository as git;
 use ignore::WalkBuilder;
 use sha1::Digest;
@@ -19,12 +20,6 @@ mod test;
 
 pub struct Git;
 
-struct GitFileMeta {
-    entry_mode: FileEntryMode,
-    oid: ObjectId,
-    path: PathBuf,
-}
-
 /// A subset of `git_repository::objs::tree::EntryMode` that actually makes sense for tree nodes.
 #[derive(Hash, PartialEq, Eq)]
 enum FileEntryMode {
@@ -118,65 +113,65 @@ impl Git {
 
         // TODO: allow diffing against another ref
         let head_tree = repo.head_commit()?.tree()?;
-
-        let mut head_tree_files = vec![];
-        let mut submodule_paths = vec![PathBuf::from(".git")];
-        traverse_tree(
-            &head_tree,
-            repo,
-            PathBuf::new(),
-            &mut head_tree_files,
-            &mut submodule_paths,
-        )?;
-
-        submodule_paths
-            .iter_mut()
-            .for_each(|path| *path = work_dir.join(&path));
+        let head_state = State::from_tree(&head_tree.id, |oid, buf| {
+            repo.objects.find_tree_iter(oid, buf).ok()
+        })?;
 
         let mut head_tree_set = HashSet::new();
+        let mut submodule_paths = vec![];
 
         let mut raw_changes = RawChanges::default();
 
-        // Looks for modified & deleted files by walking the head tree and probing the fs
-        for item in head_tree_files.into_iter() {
-            let full_path = work_dir.join(&item.path);
+        for item in head_state.entries() {
+            let full_path = work_dir.join(&PathBuf::from(item.path(&head_state).to_string()));
 
-            match git_meta_from_path(&full_path, autocrlf)? {
-                Some((new_entry_mode, new_oid)) => {
-                    // On Windows, physical files are _always_ inferred as `Blob`. We simply don't
-                    // compare the entry mode as it's pointless.
-                    let entry_mode_changed = {
-                        #[cfg(unix)]
-                        {
-                            new_entry_mode != item.entry_mode
-                        }
+            if item.mode == Mode::COMMIT {
+                submodule_paths.push(full_path);
+            } else {
+                let old_entry_mode = match item.mode {
+                    Mode::FILE => FileEntryMode::Blob,
+                    Mode::FILE_EXECUTABLE => FileEntryMode::BlobExecutable,
+                    Mode::SYMLINK => FileEntryMode::Link,
+                    _ => anyhow::bail!("unexpected entry mode"),
+                };
 
-                        #[cfg(not(unix))]
-                        {
-                            false
+                match git_meta_from_path(&full_path, autocrlf)? {
+                    Some((new_entry_mode, new_oid)) => {
+                        // On Windows, physical files are _always_ inferred as `Blob`. We simply don't
+                        // compare the entry mode as it's pointless.
+                        let entry_mode_changed = {
+                            #[cfg(unix)]
+                            {
+                                new_entry_mode != old_entry_mode
+                            }
+
+                            #[cfg(not(unix))]
+                            {
+                                false
+                            }
+                        };
+
+                        if entry_mode_changed || new_oid != item.id {
+                            raw_changes.add_modification(RawModification {
+                                previous_entry_mode: old_entry_mode,
+                                previous_oid: item.id,
+                                entry_mode: new_entry_mode,
+                                oid: new_oid,
+                                path: full_path.clone(),
+                            });
                         }
-                    };
-
-                    if entry_mode_changed || new_oid != item.oid {
-                        raw_changes.add_modification(RawModification {
-                            previous_entry_mode: item.entry_mode,
-                            previous_oid: item.oid,
-                            entry_mode: new_entry_mode,
-                            oid: new_oid,
+                    }
+                    None => {
+                        raw_changes.add_deletion(RawDeletion {
+                            entry_mode: old_entry_mode,
+                            oid: item.id,
                             path: full_path.clone(),
                         });
                     }
                 }
-                None => {
-                    raw_changes.add_deletion(RawDeletion {
-                        entry_mode: item.entry_mode,
-                        oid: item.oid,
-                        path: full_path.clone(),
-                    });
-                }
-            }
 
-            head_tree_set.insert(full_path);
+                head_tree_set.insert(full_path);
+            }
         }
 
         // Looks for untracked files by walking the fs and probing the (cached) head tree
@@ -346,58 +341,6 @@ fn find_file_in_commit(repo: &Repository, commit: &Commit, file: &Path) -> Optio
     }
 }
 
-/// Traverses a tree with recursion.
-fn traverse_tree(
-    tree: &Tree,
-    repo: &Repository,
-    base: PathBuf,
-    all_files: &mut Vec<GitFileMeta>,
-    submodules: &mut Vec<PathBuf>,
-) -> Result<()> {
-    for entry in tree.iter() {
-        let entry = entry?;
-        let mut new_base = base.clone();
-        new_base.push(entry.filename().to_string());
-
-        match entry.mode() {
-            EntryMode::Tree => {
-                let obj = repo.find_object(entry.id())?;
-                let new_tree = obj.try_into_tree()?;
-                traverse_tree(&new_tree, repo, new_base, all_files, submodules)?;
-            }
-            EntryMode::Commit => {
-                // Submodules not supported yet. We return the path so that the fs walk can ignore
-                // them.
-                // TODO: support option for recursively looking into submodules
-                submodules.push(new_base);
-            }
-            EntryMode::Link => {
-                all_files.push(GitFileMeta {
-                    entry_mode: FileEntryMode::Link,
-                    oid: entry.oid(),
-                    path: new_base,
-                });
-            }
-            EntryMode::Blob => {
-                all_files.push(GitFileMeta {
-                    entry_mode: FileEntryMode::Blob,
-                    oid: entry.oid(),
-                    path: new_base,
-                });
-            }
-            EntryMode::BlobExecutable => {
-                all_files.push(GitFileMeta {
-                    entry_mode: FileEntryMode::BlobExecutable,
-                    oid: entry.oid(),
-                    path: new_base,
-                });
-            }
-        }
-    }
-
-    Ok(())
-}
-
 fn git_meta_from_path(
     path: &Path,
     autocrlf: bool,