Optimize a parity-proven ome-zarr native C++ surface for measurable speedups by improving data layout, copies, cache behavior, and boundary design without changing behavior.

2026-04-171

benchmark-first

strmt7/ome-zarr-C

Benchmark converted code against the frozen upstream implementation before making performance claims.

2026-04-171

cpp-parity-porting

strmt7/ome-zarr-C

Port one upstream ome-zarr-py surface to standalone native C++ without touching the frozen snapshot.

2026-04-161

name	immutable-parity-proof
description	Produce content-addressed parity evidence and protect the frozen upstream snapshot while porting or verifying native surfaces.
origin	repo-local, grounded in official GitHub Actions artifact and benchmark guidance

Immutable Parity Proof

Use this skill whenever a parity claim, frozen-snapshot claim, or native-C++ claim is about to be made.

Required checks

Verify the frozen snapshot manifest with: .venv/bin/python scripts/frozen_source_manifest.py --verify
Run differential tests against the frozen snapshot on identical inputs.
Prefer content-addressed comparisons:
- serialized output trees for store-backed paths
- patched outbound call payloads for external side effects
- stable JSON-like outcome snapshots for deterministic object behavior
If the change touches cpp/, scan the native tree with: .venv/bin/python scripts/check_native_cpp.py --all
Treat any embedded-Python execution in cpp/ as native-debt, not as fully converted C++ coverage.

Reporting rule

State the manifest verification result.
State the exact parity suites that ran.
If a surface is still wrapper-heavy or depends on embedded Python in cpp/, do not count it as native-converted coverage.