cache_bench_summary.md

Cache Benchmark Summary

Date: 2026-03-01

Scope

Benchmarked Bosatsu CLI cache behavior for:

• lib check
• lib build

Cache modes:

• no_cache (explicit --no_cache)
• cold_cache (empty cache dir each run)
• warm_cache (cache pre-warmed before timed runs)

Method

• Runner: ./bosatsuj
• Runs per mode: 3
• Warm mode includes 1 unmeasured warmup run
• Reported numbers below are median wall-clock seconds

Commands:

• lib check
  • ./bosatsuj lib check --repo_root . --quiet --color none --no_cache
  • add --cache_dir /tmp/bosatsu_bench_cache_check for cache modes
• lib build
  • ./bosatsuj lib build --repo_root . --main_pack Bosatsu/IO/CreateModeMain --outdir /tmp/bosatsu_bench_build_out --color none --no_cache
  • add --cache_dir /tmp/bosatsu_bench_cache_build for cache modes

Results (Median of 3)

lib check

• no_cache: 8.245s
• cold_cache: 8.716s
• warm_cache: 5.584s
• warm vs no_cache: 1.48x faster (32.3% lower)
• warm vs cold_cache: 1.56x faster (35.9% lower)

lib build

• no_cache: 11.360s
• cold_cache: 11.515s
• warm_cache: 7.477s
• warm vs no_cache: 1.52x faster (34.2% lower)
• warm vs cold_cache: 1.54x faster (35.1% lower)

Raw Artifacts

• /tmp/bosatsu_bench_results.tsv
• /tmp/bosatsu_bench_results_norm.tsv