Add autosplit committed-window reader

[bootjp]

Summary

• add committed window boundaries to keyviz matrix columns
• add an autosplit snapshot reader that converts committed keyviz columns into detector windows without calling SplitRange
• document the M3-PR2b-a slice and leave Top-K, leadership watermarks, and scheduler wiring as remaining M3 work

Evidence

• go test ./keyviz ./distribution/autosplit
• go test ./adapter ./internal/admin -run 'KeyViz|Subrange|TestCommittedWindows|TestObserveSnapshot|TestFlushStampsWindowStart'\n- git diff --check\n\nAuthor: bootjp

Summary by CodeRabbit

• 新機能
  • スナップショットから確定済みウィンドウを読み取り、観測専用の自動分割判定を実行できるようになりました。
  • ウィンドウ開始時刻を優先して処理し、不正なデータをスキップできるようになりました。
• 改善
  • サンプラーがウィンドウの開始・終了時刻を正確に保持するようになりました。
  • スナップショットのコピー時にもウィンドウ境界情報が維持されます。
• ドキュメント
  • 自動化マイルストーンの進捗と関連作業の整理を更新しました。
• テスト
  • ウィンドウ境界、読み取り範囲、データ欠落時のリセット動作を検証するテストを追加しました。

[gemini-code-assist]

Caution

The consumer version of Gemini Code Assist on GitHub has been sunset. All code review activity has officially ceased.

[github-actions]

TLA+ spec divergence review (auto-triggered)

This PR touches files that the TLA+ safety spec has an anchor on (per
docs/design/2026_05_28_implemented_tla_safety_spec.md §3),
so an AI review is requested below to verify the implementation has not drifted
from the model.

Anchored files changed in this PR head (63ea6a7):

• distribution/autosplit/detector.go
• distribution/autosplit/sampler_reader.go
• distribution/autosplit/sampler_reader_test.go

What to check, by subsystem:

• kv/hlc*.go — Next() must respect the HLC-4 preconditions (i)/(ii)/(iii) from the design doc: bounded skew, logical-counter handoff on leader change (strategy (c) Observe(MaxAppliedHLC)), and the commit-time ceiling fence (fail-closed when wall_now >= physicalCeiling). Any change to the bit layout (48/16), the CAS loop, or the ceiling getter/setter is in scope.
• kv/coordinator.go, kv/sharded_coordinator.go — RunHLCLeaseRenewal, hlcRenewalInterval, hlcPhysicalWindowMs constants, and the new-term detection that calls Observe(fsm.MaxAppliedHLC()) (strategy (c)). Any change to renewal cadence, group selection, or fail-closed behaviour is in scope.
• kv/transaction.go, kv/lock_resolver.go — OCC commit-ts assignment, lock-map encoding (key, lock_ts) -> start_ts, and the LockResolver action OCC-3 depends on. (M2 spec will land OCC-1..OCC-5; until then the spec doc §5.2 is the contract.)
• kv/fsm.go — FSM apply of HLC lease entries (SetPhysicalCeiling), and any future MaxAppliedHLC() accessor that strategy (c) needs.
• store/mvcc_store.go — version visibility, snapshot install, and the MVCC-1..MVCC-4 invariants (M3 scope).
• distribution/** — route catalog versioning, SplitRange atomicity, and CatalogWatcher async fan-out (M4 scope).

If the change is correct but requires a spec update, edit tla/hlc/HLC.tla (or the corresponding M2..M5 module once landed) and the design doc in the same PR. The tla-check workflow runs the TLC model check on the same paths.

---

@claude review please verify TLA+ spec divergence per the checklist above.

@codex review please verify TLA+ spec divergence per the checklist above.

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Review details

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: 47269cc2-1e3b-4c41-b370-9c3a30bc8232

📥 Commits

Reviewing files that changed from the base of the PR and between 63ea6a7 and c1eb6bb.

📒 Files selected for processing (4)

• distribution/autosplit/sampler_reader.go
• distribution/autosplit/sampler_reader_test.go
• docs/design/2026_06_11_partial_hotspot_split_milestone3_automation.md
• keyviz/sampler.go

📝 Walkthrough

Walkthrough

MatrixColumn にコミット区間の開始時刻を追加し、deep copy で保持するよう変更しました。スナップショットを ColumnWindow に変換して autosplit detector で評価する observe-only 読み取り経路と、その境界処理・リセット処理のテストを追加しました。

Changes

コミット済みウィンドウと observe-only 統合

Layer / File(s)	Summary
MatrixColumn の境界保持と deep copy keyviz/sampler.go, keyviz/ring_buffer.go, keyviz/sampler_test.go	MemSampler.Flush が WindowStart を設定し、Snapshot の deep copy が境界情報を保持するよう変更しました。
スナップショットから detector への変換 distribution/autosplit/detector.go, distribution/autosplit/sampler_reader.go	スナップショット読み取り設定と結果型を追加し、WindowStart を優先した ColumnWindow 変換結果を Evaluate へ渡す経路を追加しました。
読み取り経路の検証と設計記録 distribution/autosplit/sampler_reader_test.go, docs/design/...	境界フォールバック、取得範囲、無効列のスキップ、サイレントギャップのリセット処理をテストし、Milestone 3 の PR 分割記録を更新しました。

Estimated code review effort: 3 (Moderate) | ~20 minutes

Sequence Diagram(s)

sequenceDiagram
participant ObserveSnapshot
participant ReadCommittedWindows
participant SnapshotSource
participant CommittedWindowsFromColumns
participant Evaluate
ObserveSnapshot->>ReadCommittedWindows: SnapshotReadConfig を渡す
ReadCommittedWindows->>SnapshotSource: Snapshot(from, now)
SnapshotSource-->>ReadCommittedWindows: MatrixColumn スナップショット
ReadCommittedWindows->>CommittedWindowsFromColumns: 列を ColumnWindow へ変換
CommittedWindowsFromColumns-->>ReadCommittedWindows: Windows と newest を返す
ObserveSnapshot->>Evaluate: Windows と Now を渡す
Evaluate-->>ObserveSnapshot: Result を返す

Loading

Possibly related PRs

• bootjp/elastickv#639: cloneColumn が MatrixColumn.WindowStart を保持する変更に関連します。
• bootjp/elastickv#1097: committed MatrixColumn を ColumnWindow に変換して detector の Evaluate へ渡す経路に関連します。

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 33.33% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	タイトルは主要変更であるautosplitのcommitted-window reader追加を簡潔に表しています。
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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[coderabbitai]

Actionable comments posted: 2

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.
Inline comments:
In `@docs/design/2026_06_11_partial_hotspot_split_milestone3_automation.md`:
- Line 12: Update the “Updated” date in the milestone 3 automation design
document to the actual modification date, replacing the future/review-following
date while preserving the document’s date format.
In `@keyviz/sampler.go`:
- Around line 1239-1243: Flush 全体を専用 mutex で直列化し、At の取得から history への push、および
lastFlushAt の更新までを同じロックで保護してください。対象は Flush の処理フローと、WindowStart を補正して col
を追加する箇所であり、並行実行時も列順序と実際の window 境界が一致する状態を維持してください。

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: fe18b72f-4498-4d5e-ace9-832fcc18f14d

📥 Commits

Reviewing files that changed from the base of the PR and between 5d4c5ca and 63ea6a7.

📒 Files selected for processing (7)

• distribution/autosplit/detector.go
• distribution/autosplit/sampler_reader.go
• distribution/autosplit/sampler_reader_test.go
• docs/design/2026_06_11_partial_hotspot_split_milestone3_automation.md
• keyviz/ring_buffer.go
• keyviz/sampler.go
• keyviz/sampler_test.go

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit:63ea6a7f62

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[bootjp]

@codex review

[github-actions]

TLA+ spec divergence review (auto-triggered)

This PR touches files that the TLA+ safety spec has an anchor on (per
docs/design/2026_05_28_implemented_tla_safety_spec.md §3),
so an AI review is requested below to verify the implementation has not drifted
from the model.

Anchored files changed in this PR head (c1eb6bb):

• distribution/autosplit/detector.go
• distribution/autosplit/sampler_reader.go
• distribution/autosplit/sampler_reader_test.go

What to check, by subsystem:

• kv/hlc*.go — Next() must respect the HLC-4 preconditions (i)/(ii)/(iii) from the design doc: bounded skew, logical-counter handoff on leader change (strategy (c) Observe(MaxAppliedHLC)), and the commit-time ceiling fence (fail-closed when wall_now >= physicalCeiling). Any change to the bit layout (48/16), the CAS loop, or the ceiling getter/setter is in scope.
• kv/coordinator.go, kv/sharded_coordinator.go — RunHLCLeaseRenewal, hlcRenewalInterval, hlcPhysicalWindowMs constants, and the new-term detection that calls Observe(fsm.MaxAppliedHLC()) (strategy (c)). Any change to renewal cadence, group selection, or fail-closed behaviour is in scope.
• kv/transaction.go, kv/lock_resolver.go — OCC commit-ts assignment, lock-map encoding (key, lock_ts) -> start_ts, and the LockResolver action OCC-3 depends on. (M2 spec will land OCC-1..OCC-5; until then the spec doc §5.2 is the contract.)
• kv/fsm.go — FSM apply of HLC lease entries (SetPhysicalCeiling), and any future MaxAppliedHLC() accessor that strategy (c) needs.
• store/mvcc_store.go — version visibility, snapshot install, and the MVCC-1..MVCC-4 invariants (M3 scope).
• distribution/** — route catalog versioning, SplitRange atomicity, and CatalogWatcher async fan-out (M4 scope).

If the change is correct but requires a spec update, edit tla/hlc/HLC.tla (or the corresponding M2..M5 module once landed) and the design doc in the same PR. The tla-check workflow runs the TLC model check on the same paths.

---

@claude review please verify TLA+ spec divergence per the checklist above.

@codex review please verify TLA+ spec divergence per the checklist above.

[chatgpt-codex-connector]

To use Codex here, create a Codex account and connect to github.

[chatgpt-codex-connector]

Codex Review: Didn't find any major issues. Swish!

Reviewed commit:c1eb6bb506

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

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