index: make Index::load() return Arc<IndexFile> instead of Index

This removes one level of indirection, which is nice because it was
visible to the callers. The `Index` struct is now empty. The next step
is obviously to delete it (and perhaps rename `IndexFile` to `Index`
or `ReadonlyIndex`).

lib/src/index.rs

@@ -1103,9 +1103,7 @@ impl IndexFile {
     }
 }
 
-pub struct Index {
-    index_file: Arc<IndexFile>,
-}
+pub struct Index;
 
 impl Index {
     pub fn init(dir: PathBuf) {
@@ -1117,7 +1115,7 @@ impl Index {
         Index::init(dir);
     }
 
-    pub fn load(repo: &ReadonlyRepo, dir: PathBuf, op_id: OperationId) -> Index {
+    pub fn load(repo: &ReadonlyRepo, dir: PathBuf, op_id: OperationId) -> Arc<IndexFile> {
         let op_id_hex = op_id.hex();
         let op_id_file = dir.join("operations").join(&op_id_hex);
         let index_file = if op_id_file.exists() {
@@ -1128,15 +1126,7 @@ impl Index {
             IndexFile::index(repo.store(), &dir, &op).unwrap()
         };
 
-        Index {
-            index_file: Arc::new(index_file),
-        }
-    }
-
-    // TODO: Maybe just call this data() or something? We should also hide the
-    // IndexFile type from the API.
-    pub fn index_file(&self) -> Arc<IndexFile> {
-        self.index_file.clone()
+        Arc::new(index_file)
     }
 }
 

lib/src/repo.rs

@@ -24,7 +24,7 @@ use thiserror::Error;
 use crate::commit_builder::{new_change_id, signature};
 use crate::evolution::{Evolution, ReadonlyEvolution};
 use crate::git_store::GitStore;
-use crate::index::Index;
+use crate::index::{Index, IndexFile};
 use crate::local_store::LocalStore;
 use crate::operation::Operation;
 use crate::settings::{RepoSettings, UserSettings};
@@ -65,7 +65,7 @@ pub struct ReadonlyRepo {
     wc_path: PathBuf,
     store: Arc<StoreWrapper>,
     settings: RepoSettings,
-    index: Mutex<Option<Arc<Index>>>,
+    index: Mutex<Option<Arc<IndexFile>>>,
     working_copy: Arc<Mutex<WorkingCopy>>,
     view: ReadonlyView,
     evolution: Option<ReadonlyEvolution<'static>>,
@@ -217,20 +217,16 @@ impl ReadonlyRepo {
         &self.wc_path
     }
 
-    pub fn index(&self) -> Arc<Index> {
+    pub fn index(&self) -> Arc<IndexFile> {
         let mut locked_index = self.index.lock().unwrap();
         if locked_index.is_none() {
             let op_id = self.view.base_op_head_id().clone();
-            locked_index.replace(Arc::new(Index::load(
-                self,
-                self.repo_path.join("index"),
-                op_id,
-            )));
+            locked_index.replace(Index::load(self, self.repo_path.join("index"), op_id));
         }
         locked_index.as_ref().unwrap().clone()
     }
 
-    pub fn reindex(&mut self) -> Arc<Index> {
+    pub fn reindex(&mut self) -> Arc<IndexFile> {
         Index::reinit(self.repo_path.join("index"));
         {
             let mut locked_index = self.index.lock().unwrap();

lib/tests/test_index.rs

@@ -38,7 +38,7 @@ fn test_index_commits_empty_repo(use_git: bool) {
     let settings = testutils::user_settings();
     let (_temp_dir, repo) = testutils::init_repo(&settings, use_git);
 
-    let index = repo.index().index_file();
+    let index = repo.index();
     let index = index.as_composite();
     // There should be the root commit and the working copy commit
     assert_eq!(index.num_commits(), 2);
@@ -87,7 +87,7 @@ fn test_index_commits_standard_cases(use_git: bool) {
     tx.commit();
     Arc::get_mut(&mut repo).unwrap().reload();
 
-    let index = repo.index().index_file();
+    let index = repo.index();
     let index = index.as_composite();
     // There should be the root commit and the working copy commit, plus
     // 8 more
@@ -160,7 +160,7 @@ fn test_index_commits_criss_cross(use_git: bool) {
     tx.commit();
     Arc::get_mut(&mut repo).unwrap().reload();
 
-    let index = repo.index().index_file();
+    let index = repo.index();
     let index = index.as_composite();
     // There should the root commit and the working copy commit, plus 2 for each
     // generation
@@ -276,7 +276,7 @@ fn test_index_commits_previous_operations(use_git: bool) {
     std::fs::create_dir(&index_operations_dir).unwrap();
 
     let repo = ReadonlyRepo::load(&settings, repo.working_copy_path().clone());
-    let index = repo.index().index_file();
+    let index = repo.index();
     let index = index.as_composite();
     // There should be the root commit and the working copy commit, plus
     // 3 more
@@ -312,7 +312,7 @@ fn test_index_commits_incremental(use_git: bool) {
         child_commit(&settings, &repo, &root_commit).write_to_new_transaction(&repo, "test");
     Arc::get_mut(&mut repo).unwrap().reload();
 
-    let index = repo.index().index_file();
+    let index = repo.index();
     let index = index.as_composite();
     // There should be the root commit and the working copy commit, plus
     // 1 more
@@ -324,7 +324,7 @@ fn test_index_commits_incremental(use_git: bool) {
     tx.commit();
 
     let repo = ReadonlyRepo::load(&settings, repo.working_copy_path().clone());
-    let index = repo.index().index_file();
+    let index = repo.index();
     let index = index.as_composite();
     // There should be the root commit and the working copy commit, plus
     // 3 more
@@ -362,7 +362,7 @@ fn test_index_commits_incremental_empty_transaction(use_git: bool) {
         child_commit(&settings, &repo, &root_commit).write_to_new_transaction(&repo, "test");
     Arc::get_mut(&mut repo).unwrap().reload();
 
-    let index = repo.index().index_file();
+    let index = repo.index();
     let index = index.as_composite();
     // There should be the root commit and the working copy commit, plus
     // 1 more
@@ -371,7 +371,7 @@ fn test_index_commits_incremental_empty_transaction(use_git: bool) {
     repo.start_transaction("test").commit();
 
     let repo = ReadonlyRepo::load(&settings, repo.working_copy_path().clone());
-    let index = repo.index().index_file();
+    let index = repo.index();
     let index = index.as_composite();
     // There should be the root commit and the working copy commit, plus
     // 1 more

src/commands.rs

@@ -81,7 +81,7 @@ fn resolve_commit_id_prefix(
     repo: &ReadonlyRepo,
     prefix: &HexPrefix,
 ) -> Result<CommitId, CommandError> {
-    let index = repo.index().index_file();
+    let index = repo.index();
     match index.as_composite().resolve_prefix(prefix) {
         PrefixResolution::NoMatch => Err(CommandError::UserError(String::from("No such commit"))),
         PrefixResolution::AmbiguousMatch => {
@@ -1564,7 +1564,7 @@ fn cmd_debug(
         writeln!(ui, "{:?}", parse);
     } else if let Some(_reindex_matches) = sub_matches.subcommand_matches("index") {
         let repo = get_repo(ui, &matches)?;
-        let index = repo.index().index_file();
+        let index = repo.index();
         let stats = index.as_composite().stats();
         writeln!(ui, "Number of commits: {}", stats.num_commits);
         writeln!(ui, "Number of merges: {}", stats.num_merges);
@@ -1583,7 +1583,7 @@ fn cmd_debug(
         writeln!(
             ui,
             "Finished indexing {:?} commits.",
-            index.index_file().as_composite().num_commits()
+            index.as_composite().num_commits()
         );
     } else {
         panic!("unhandled command: {:#?}", matches);
@@ -1619,7 +1619,7 @@ fn cmd_bench(
             mut_repo,
             command_matches.value_of("descendant").unwrap(),
         )?;
-        let index = repo.index().index_file();
+        let index = repo.index();
         let index = index.as_composite();
         let routine = || index.is_ancestor(ancestor_commit.id(), descendant_commit.id());
         writeln!(ui, "Result: {:?}", routine());
@@ -1633,7 +1633,7 @@ fn cmd_bench(
             resolve_single_rev(ui, mut_repo, command_matches.value_of("unwanted").unwrap())?;
         let wanted_commit =
             resolve_single_rev(ui, mut_repo, command_matches.value_of("wanted").unwrap())?;
-        let index = repo.index().index_file();
+        let index = repo.index();
         let index = index.as_composite();
         let routine = || {
             index
@@ -1650,7 +1650,7 @@ fn cmd_bench(
     } else if let Some(command_matches) = sub_matches.subcommand_matches("resolveprefix") {
         let repo = get_repo(ui, &matches)?;
         let prefix = HexPrefix::new(command_matches.value_of("prefix").unwrap().to_string());
-        let index = repo.index().index_file();
+        let index = repo.index();
         let index = index.as_composite();
         let routine = || index.resolve_prefix(&prefix);
         writeln!(ui, "Result: {:?}", routine());