⚡️ Speed up function get_patches_dir_for_project by 112% in PR #690 (worktree/persist-optimization-patches)

The optimization achieves a 112% speedup through two key changes:

1. **Replace `list(repo.iter_commits(...))` with `next(repo.iter_commits(...))`**: The original code materializes all root commits into a list just to access the first one. The optimized version uses `next()` to get only the first commit from the iterator, avoiding unnecessary memory allocation and iteration through all root commits. This is particularly beneficial for repositories with multiple root commits (though rare, they can occur in merged repositories).

2. **Remove redundant `Path()` wrapper**: The original code wraps `patches_dir / project_id` in `Path()`, but since `patches_dir` is already a `Path` object and the `/` operator returns a `Path`, the wrapper is unnecessary overhead.

The test results show consistent speedups across all scenarios (93-159% faster), with the optimization being especially effective for repositories with many commits (500 commits: 18.0μs → 9.09μs) and complex structures (unusual branches: 16.2μs → 8.28μs). The `next()` optimization provides the most significant performance gain since it eliminates the need to create intermediate list objects and stops iteration immediately after finding the first commit.

Author: codeflash-ai[bot]

codeflash/code_utils/git_worktree_utils.py

@@ -32,8 +32,7 @@
 def get_git_project_id() -> str:
     """Return the first commit sha of the repo."""
     repo: Repo = git.Repo(search_parent_directories=True)
-    root_commits = list(repo.iter_commits(rev="HEAD", max_parents=0))
-    return root_commits[0].hexsha
+    return next(repo.iter_commits(rev="HEAD", max_parents=0)).hexsha
 
 
 def create_worktree_snapshot_commit(worktree_dir: Path, commit_message: str) -> None:
@@ -97,7 +96,7 @@ def remove_worktree(worktree_dir: Path) -> None:
 @lru_cache(maxsize=1)
 def get_patches_dir_for_project() -> Path:
     project_id = get_git_project_id() or ""
-    return Path(patches_dir / project_id)
+    return patches_dir / project_id
 
 
 def get_patches_metadata() -> dict[str, Any]: