CI and git notes

tak stores measurements under refs/notes/tak as one JSON object per line. The notes merge with git's cat_sort_uniq strategy, allowing concurrent writers to deduplicate byte-identical records without a custom service.

Record a run

Build the subject first, then record the declared benchmarks:

tak run --record

Nothing leaves the machine until you push the notes:

tak push

Fetch measurements

tak history and tak compare fetch remote measurements into the scratch ref refs/notes/tak-remote, then merge them into the local notes without discarding records that have not been pushed. Normally no manual fetch is needed.

For a read-only checkout that will never record measurements locally, teach its origin remote to fetch the notes ref with plain git fetch:

tak init
git fetch

The notes tree uses commit SHAs as path names rather than object references. A shallow fetch of the notes ref can therefore retrieve the full measurement history without fetching the annotated project commits.

Do not use that direct-fetch configuration in a checkout where you run tak run --record: plain git fetch has no way to merge unpushed local notes. Let tak history, tak compare, and tak push use the scratch ref instead.

Compare revisions

Compare the current revision with the recorded baseline:

tak compare origin/main

An instruction-count increase beyond the configured gate fails the command. Wall-clock changes are displayed but never gate the result.

Always keep measurements partitioned by runner class. Comparing numbers across runner classes turns an infrastructure change into an apparent code regression.