Git Bench

Benchmarks git client implementations against a clone of torvalds/linux:

Runner	Implementation description
git-cli	Subprocess to system git
libgit2-ffi	bun:ffi bindings to system libgit2
gitoxide	gix CLI (Rust)
isomorphic-git	Pure JS over node:fs
ziggit	Pure Zig implementation (Coming Soon)

Operations measured:

1. Current branch: Resolve HEAD to a short branch name.
2. Status: Worktree and index status (porcelain).
3. Log (100): Walk the 100 most recent commits from HEAD.
4. Tracked files: Enumerate all paths tracked in the index.
5. Changed files: Name-only diff between HEAD~1 and HEAD.
6. Read 25 blobs: Read 25 fixed file blobs at HEAD by path.

Prerequisites

• git on PATH (used by the git-cli runner and the clone script).
• gix on PATH for the gitoxide runner (install via cargo install gitoxide).
• libgit2 shared library installed system-wide for the libgit2-ffi runner (e.g., apt install libgit2-dev or brew install libgit2). Set GIT_BENCH_LIBGIT2=/path/to/libgit2.so if auto-detection fails.

If a runner is missing dependencies, its results are reported as err to make the missing requirement obvious.

Note

The isomorphic-git runner is limited to operations current-branch and status due to the Linux kernel pack files exceeding the maximum size it can read into a single Buffer (>2 GB). This limitation of the pure-JS implementation is itself a benchmark result.

Running

bun install
bun run bench:clone   # Clone torvalds/linux (~5 GB)
bun run bench         # Run benchmarks and write to lib/bench/results.json
bun run dev           # Start the dashboard at http://localhost:3000

Environment overrides:

• REPO_DIR: Path to the cloned repository (defaults to .git-bench-repos/linux).
• SAMPLES: Samples per operation (defaults to 5).
• GIX_BIN: gix executable path (defaults to gix on PATH).
• GIT_BENCH_LIBGIT2: Explicit path to libgit2.so for the FFI runner.

Methodology

Each runner runs one warmup iteration, followed by SAMPLES timed iterations of each operation. Setup tasks (like opening the repository or loading JS modules) run outside the timed region to avoid skewing the results. The dashboard displays the median time per operation; the underlying JSON also records the mean, min, max, and sample count.

The libgit2-ffi runner includes minimal bindings (initialization, opening the repository, and resolving HEAD). The remaining operations are stubbed; you can add bindings in scripts/runners/libgit2-ffi.ts to implement them.