optimize

crates/signed_git/src/lib.rs

@@ -240,17 +240,24 @@ fn open_with_cache(workdir: &Path) -> Result<gix::Repository> {
     Ok(repo)
 }
 
-/// A [`FileCommit`] from a walk commit: author, message title and shortened id.
-fn file_commit(commit: &gix::Commit<'_>) -> Result<FileCommit> {
+/// A [`FileCommit`] from a walk commit: author, message title and shortened
+/// id. `include_description` controls whether the message body is copied;
+/// history lists never display it, so skipping it saves a string allocation
+/// per listed commit (the diff panel fetches the full commit on demand).
+fn file_commit(commit: &gix::Commit<'_>, include_description: bool) -> Result<FileCommit> {
     let author = commit.author()?;
     let message = commit.message()?;
     Ok(FileCommit {
         id: commit.id().shorten_or_id().to_string(),
         summary: String::from_utf8_lossy(message.title).trim().to_string(),
-        description: message
-            .body
-            .map(|body| String::from_utf8_lossy(body).trim().to_string())
-            .filter(|body| !body.is_empty()),
+        description: if include_description {
+            message
+                .body
+                .map(|body| String::from_utf8_lossy(body).trim().to_string())
+                .filter(|body| !body.is_empty())
+        } else {
+            None
+        },
         author: String::from_utf8_lossy(author.name).trim().to_string(),
         time: author.time()?.seconds,
     })
@@ -332,7 +339,7 @@ fn last_commits(repo: &gix::Repository, rels: &[PathBuf]) -> Result<Vec<(PathBuf
 
             if blob.map(|entry| entry.id().detach()) != parent_blob.map(|entry| entry.id().detach())
             {
-                found.push((rel.clone(), file_commit(&commit)?));
+                found.push((rel.clone(), file_commit(&commit, true)?));
                 pending.swap_remove(ix);
             } else {
                 ix += 1;
@@ -381,7 +388,7 @@ pub fn all_commits(repo: &gix::Repository) -> Result<CommitList> {
         let info = info?;
         total += 1;
         if commits.len() < MAX_LISTED_COMMITS {
-            commits.push(file_commit(&info.object()?)?);
+            commits.push(file_commit(&info.object()?, false)?);
         }
     }
     Ok(CommitList { total, commits })
@@ -681,23 +688,29 @@ pub fn head_commit(repo: &gix::Repository) -> Result<Option<FileCommit>> {
         return Ok(None);
     };
     let commit = head.object()?.into_commit();
-    let author = commit.author()?;
-    let message = commit.message()?;
-    Ok(Some(FileCommit {
-        id: commit.id().shorten_or_id().to_string(),
-        summary: String::from_utf8_lossy(message.title).trim().to_string(),
-        description: message
-            .body
-            .map(|body| String::from_utf8_lossy(body).trim().to_string())
-            .filter(|body| !body.is_empty()),
-        author: String::from_utf8_lossy(author.name).trim().to_string(),
-        time: author.time()?.seconds,
-    }))
+    Ok(Some(file_commit(&commit, true)?))
 }
 
-/// Short names of local branches (`refs/heads/*`), sorted alphabetically.
-pub fn worktree_branches(workdir: &Path) -> Result<Vec<String>> {
+/// Full metadata of the commit `id` (short or full) in the repository at
+/// `workdir`, like [`head_commit`] for an arbitrary commit. Returns
+/// `Ok(None)` when the id cannot be resolved.
+///
+/// The commit list ([`all_commits`]) omits message bodies to keep the walk
+/// cheap; the diff panel uses this to fetch the full commit on demand.
+pub fn worktree_commit(workdir: &Path, id: &str) -> Result<Option<FileCommit>> {
     let repo = open_with_cache(workdir)?;
+    match repo.rev_parse_single(id.as_bytes()) {
+        Ok(commit_id) => {
+            let commit = commit_id.object()?.into_commit();
+            Ok(Some(file_commit(&commit, true)?))
+        }
+        Err(_) => Ok(None),
+    }
+}
+
+/// Short names of local branches (`refs/heads/*`) of `repo`, sorted
+/// alphabetically.
+pub fn repo_branches(repo: &gix::Repository) -> Result<Vec<String>> {
     let mut names = Vec::new();
     for reference in repo.references()?.local_branches()? {
         let reference = reference.map_err(|error| anyhow::anyhow!("{error}"))?;
@@ -707,9 +720,8 @@ pub fn worktree_branches(workdir: &Path) -> Result<Vec<String>> {
     Ok(names)
 }
 
-/// Short names of tags (`refs/tags/*`), sorted alphabetically.
-pub fn worktree_tags(workdir: &Path) -> Result<Vec<String>> {
-    let repo = open_with_cache(workdir)?;
+/// Short names of tags (`refs/tags/*`) of `repo`, sorted alphabetically.
+pub fn repo_tags(repo: &gix::Repository) -> Result<Vec<String>> {
     let mut names = Vec::new();
     for reference in repo.references()?.tags()? {
         let reference = reference.map_err(|error| anyhow::anyhow!("{error}"))?;
@@ -719,6 +731,16 @@ pub fn worktree_tags(workdir: &Path) -> Result<Vec<String>> {
     Ok(names)
 }
 
+/// Short names of local branches (`refs/heads/*`), sorted alphabetically.
+pub fn worktree_branches(workdir: &Path) -> Result<Vec<String>> {
+    repo_branches(&open_with_cache(workdir)?)
+}
+
+/// Short names of tags (`refs/tags/*`), sorted alphabetically.
+pub fn worktree_tags(workdir: &Path) -> Result<Vec<String>> {
+    repo_tags(&open_with_cache(workdir)?)
+}
+
 /// Short name of the branch HEAD points to, or `None` when detached (e.g.
 /// after checking out a tag or a commit directly).
 pub fn current_branch(repo: &gix::Repository) -> Result<Option<String>> {