refactor (#16)

Author: Byron

src/index/diff.rs renamed to src/index/diff/mod.rs

@@ -29,6 +29,11 @@ impl Index {
         &self.repo
     }
 
+    /// Return the crates.io repository, mutably.
+    pub fn repository_mut(&mut self) -> &mut git::Repository {
+        &mut self.repo
+    }
+
     /// Return the reference pointing to the state we have seen after calling `fetch_changes()`.
     pub fn last_seen_reference(
         &self,

src/index/mod.rs

@@ -1,11 +1,10 @@
 use crate::index::index_ro;
 use crates_index_diff::{Change, CrateVersion, Index};
 use git_repository as git;
-use git_repository::prelude::ObjectIdExt;
 
 #[test]
 fn addition() -> crate::Result {
-    let changes = changes(&index_ro()?, ":/initial commit")?;
+    let changes = changes(index_ro()?, ":/initial commit")?;
     assert_eq!(changes.len(), 3228);
     assert!(matches!(
         changes
@@ -39,7 +38,7 @@ fn addition2() -> crate::Result {
 
 #[test]
 fn deletion() -> crate::Result {
-    let changes = changes(&index_ro()?, "@~326")?;
+    let changes = changes(index_ro()?, "@~326")?;
     assert_eq!(changes.len(), 1);
     assert_eq!(changes.first().and_then(|c| c.deleted()), Some("girl"));
     Ok(())
@@ -55,7 +54,7 @@ fn deletion2() -> crate::Result {
 
 #[test]
 fn new_version() -> crate::Result {
-    let changes = changes(&index_ro()?, ":/Updating crate `git-repository#0.22.1`")?;
+    let changes = changes(index_ro()?, ":/Updating crate `git-repository#0.22.1`")?;
     assert_eq!(changes.len(), 1);
     assert_eq!(
         changes
@@ -81,7 +80,7 @@ fn new_version2() -> crate::Result {
 
 #[test]
 fn yanked() -> crate::Result {
-    let changes = changes(&index_ro()?, ":/Yanking crate `github_release_rs#0.1.0`")?;
+    let changes = changes(index_ro()?, ":/Yanking crate `github_release_rs#0.1.0`")?;
     assert_eq!(changes.len(), 1);
     assert_eq!(
         changes
@@ -107,7 +106,7 @@ fn yanked2() -> crate::Result {
 
 #[test]
 fn unyanked_crates_recognized_as_added() -> crate::Result {
-    let changes = changes(&index_ro()?, ":/Unyanking crate `git2mail#0.3.2`")?;
+    let changes = changes(index_ro()?, ":/Unyanking crate `git2mail#0.3.2`")?;
     assert_eq!(changes.len(), 1);
     assert_eq!(
         changes
@@ -133,7 +132,7 @@ fn unyanked_crates_recognized_as_added2() -> crate::Result {
 
 #[test]
 fn normalization() -> crate::Result {
-    let changes = changes(&index_ro()?, ":/normalize")?;
+    let changes = changes(index_ro()?, ":/normalize")?;
     assert_eq!(
         changes.len(),
         2356, // should be 0
@@ -153,27 +152,52 @@ fn normalization2() -> crate::Result {
     Ok(())
 }
 
-fn changes(index: &Index, revspec: &str) -> crate::Result<Vec<Change>> {
-    let repo = git::open(index.repository().path())?;
-    let commit = repo.rev_parse(revspec)?.single().unwrap();
-    let ancestor_tree = commit
-        .object()?
-        .into_commit()
-        .parent_ids()
-        .next()
-        .and_then(|parent| parent.object().ok()?.into_commit().tree_id().ok())
-        .unwrap_or_else(|| git::hash::ObjectId::empty_tree(repo.object_hash()).attach(&repo));
-    Ok(index.changes_between_commits(ancestor_tree, commit)?)
+fn changes(mut index: Index, revspec: &str) -> crate::Result<Vec<Change>> {
+    let (prev, current) = {
+        let repo = index.repository_mut();
+        repo.object_cache_size_if_unset(4 * 1024 * 1024);
+        let commit = repo.rev_parse(revspec)?.single().unwrap();
+        let ancestor_tree = commit
+            .object()?
+            .into_commit()
+            .parent_ids()
+            .next()
+            .and_then(|parent| {
+                parent
+                    .object()
+                    .ok()?
+                    .into_commit()
+                    .tree_id()
+                    .ok()
+                    .map(|id| id.detach())
+            })
+            .unwrap_or_else(|| git::hash::ObjectId::empty_tree(repo.object_hash()));
+        (ancestor_tree, commit.detach())
+    };
+    Ok(index.changes_between_commits(prev, current)?)
 }
+
 fn changes2(mut index: Index, revspec: &str) -> crate::Result<Vec<Change>> {
-    let repo = git::open(index.repository().path())?;
-    let commit = repo.rev_parse(revspec)?.single().unwrap();
-    let ancestor_tree = commit
-        .object()?
-        .into_commit()
-        .parent_ids()
-        .next()
-        .and_then(|parent| parent.object().ok()?.into_commit().tree_id().ok())
-        .unwrap_or_else(|| git::hash::ObjectId::empty_tree(repo.object_hash()).attach(&repo));
-    Ok(index.changes_between_commits2(ancestor_tree, commit)?)
+    let (prev, current) = {
+        let repo = index.repository_mut();
+        repo.object_cache_size_if_unset(4 * 1024 * 1024);
+        let commit = repo.rev_parse(revspec)?.single().unwrap();
+        let ancestor_tree = commit
+            .object()?
+            .into_commit()
+            .parent_ids()
+            .next()
+            .and_then(|parent| {
+                parent
+                    .object()
+                    .ok()?
+                    .into_commit()
+                    .tree_id()
+                    .ok()
+                    .map(|id| id.detach())
+            })
+            .unwrap_or_else(|| git::hash::ObjectId::empty_tree(repo.object_hash()));
+        (ancestor_tree, commit.detach())
+    };
+    Ok(index.changes_between_commits2(prev, current)?)
 }