Record validation performance baseline

docs/roadmap/implementation.md

@@ -1,6 +1,6 @@
 # Computational Efficiency Implementation Plan
 
-**Status:** Ready for implementation; all stages pending.
+**Status:** Stage 1 complete; Stages 2–11 pending.
 
 ## Purpose And Baseline
 
@@ -51,6 +51,50 @@ initialization mechanism.
 
 **Owners:** Benchmark files in `internal/validation` and root facade fixtures.
 
+**Completion:** Complete. Measurement-only benchmarks cover tree metadata,
+content reads and formatting for 1,000 unique or repeated-ID Go blobs in loose
+and packed repositories, repeated links to identical 1 MiB Markdown documents,
+retained content after processing, and a real offline facade `Check`. Fixtures
+verify committed bytes, unique/repeated object IDs, link counts, and Git pack
+state. The facade fixture selects Go formatting, local-replacement inspection,
+and Markdown while using test-owned module and build caches.
+
+### Baseline Measurement Record
+
+The baseline is commit `ca571aca4f2fd43798174a6d0d7c5a588b5347c9`, before adding
+measurement support. Results use Go `go1.26.8 linux/amd64`, Git `2.53.0`, and a
+Linux x86_64 Intel Core i5-7260U at 2.20 GHz. The command was
+`go test ./internal/validation . -run '^$' -bench '^BenchmarkPerformance' -benchmem -count=3`.
+Each candidate-content operation used a fresh empty content cache with tree
+metadata prepared outside its timer. The loose fixtures had loose objects and
+no pack; packed fixtures were checked after `git gc --aggressive --prune=now`.
+The unique Go fixture contains 1,000 distinct, formatted files totaling 49,000
+bytes. The repeated-ID fixture contains 1,000 paths sharing one 15-byte blob.
+The Markdown fixture contains two identical 1 MiB documents, a 47,780-byte
+index with 1,000 repeated links, and 2,144,932 bytes processed per check. The
+complete-check module contains 906 bytes of Go/module input. Its `GOMODCACHE`
+and `GOCACHE` are test-owned temporary directories, and module network access
+is disabled; the build cache is warmed before timing.
+
+| Measurement | Baseline observations | Final comparison |
+| --- | --- | --- |
+| Tree metadata, 1,000 entries | Loose: 27.5–28.2 ms; packed: 25.0–28.1 ms. About 1.28 MB allocated per operation. | Pending Stage 11. |
+| Unique-blob reads, 49,000 bytes | Loose: 1.86–1.96 s; packed: 2.57–3.08 s. About 34.57 MB allocated per operation. | Pending Stage 11. |
+| Repeated-ID reads, 15,000 bytes across 1,000 paths | Loose: 2.12–3.00 ms; packed: 3.42–7.75 ms. About 50.7 KB allocated per operation. | Pending Stage 11. |
+| Formatting, 1,000 unique files | Loose: 1.87–2.94 s; packed: 2.12–4.55 s. About 36.9 MB allocated per operation. | Pending Stage 11. |
+| Formatting, 1,000 paths sharing one object | Loose: 4.52–12.66 ms; packed: 6.11–8.62 ms. About 1.49 MB allocated per operation. | Pending Stage 11. |
+| Markdown links and parsing | 19.4–21.5 ms for two identical 1 MiB documents and 1,000 links; about 7.67 MB allocated per operation. | Pending Stage 11. |
+| Facade check, standard Go suite only | 385–690 ms; 906 module bytes; 336–340 KB allocated in the benchmark process. | Pending Stage 11. |
+| Facade check with selected file checks | 528–634 ms; 906 module bytes; 632–646 KB allocated in the benchmark process. | Pending Stage 11. |
+| Retained content after formatting and Markdown parsing | 1,385,040–1,385,616 bytes above the post-GC metadata baseline, with the candidate and Markdown cache kept alive. | Pending Stage 11. |
+
+Raw output is in temporary storage at `/tmp/releasekit-performance-baseline.txt`.
+The shared machine produced substantial timing variation, especially for packed
+content and the full check; allocations and retained-byte observations were
+more stable. `B/op` for facade checks measures allocations in the benchmark
+process and does not include allocations inside its Go subprocess. These are
+workload-specific component measurements, not runtime guarantees.
+
 1. Add benchmarks named with the `BenchmarkPerformance` prefix. Reuse local Git
    fixture patterns; adapt shared helper parameters to `testing.TB` only where
    a benchmark needs them.