baselines.md

Baselines

A baseline records what a scenario used to cost, so later runs can detect regressions. A baseline stores not only the CU figure but fingerprint metadata that decides whether a later comparison is still valid.

Commands

cu-profiler baseline save              # write current results to .cu/baseline.json
cu-profiler compare                    # compare current run vs baseline (exit 1 on regression)
cu-profiler baseline approve <name>    # mark a record as reviewed/approved

What a record contains

scenario name        program binary hash (when available)
actual units         scenario / fixture / config hashes (the fingerprint)
budget               solana crate versions (when available)
timestamp            profiler version
git commit           instrumentation mode
                     confidence score at record time

Staleness

A comparison is stale when any fingerprint component differs. The tool says exactly why, and lowers comparison confidence:

Baseline is stale because fixture hash changed.
Comparison confidence: Low.

A stale baseline never silently passes a regression check. Re-record with baseline save once you've confirmed the change is intended, then compare again. Use fail_on_stale_baseline = true in config to make staleness fail CI.

Fingerprinting

Fingerprints use FNV-1a (dependency-free, stable across Rust versions and platforms) so persisted baselines compare reliably over time.