# Code Review Report

**Batch**: 37 (AZ-325 — C10 CacheProvisioner orchestrator)
**Date**: 2026-05-13
**Verdict**: PASS

## Scope

Single-task batch implementing the `CacheProvisioner` orchestrator per
`_docs/02_tasks/todo/AZ-325_c10_cache_provisioner.md` and the contract
`_docs/02_document/contracts/c10_provisioning/cache_provisioner.md`
(v1.1.0).

### Changed Files

- `pyproject.toml` — added `filelock>=3.13,<4.0`
- `src/gps_denied_onboard/components/c10_provisioning/errors.py` — added
  `BuildLockHeldError`, `ManifestCoverageError`
- `src/gps_denied_onboard/components/c10_provisioning/config.py` — added
  `C10ProvisionerConfig`, integrated into `C10ProvisioningConfig`
- `src/gps_denied_onboard/components/c10_provisioning/interface.py` —
  replaced placeholder `CacheProvisioner` Protocol with v1.1.0 surface;
  added `BuildOutcome`, `BuildRequest`, `BuildReport`,
  `SectorClassification`, `FileLockFactory`
- `src/gps_denied_onboard/components/c10_provisioning/provisioner.py` —
  new file: `CacheProvisionerImpl`, `_LockGuard`, `FilelockFileLockFactory`
- `src/gps_denied_onboard/components/c10_provisioning/__init__.py` —
  re-exports
- `src/gps_denied_onboard/runtime_root/c10_factory.py` — added
  `build_cache_provisioner` composition root
- `tests/unit/c10_provisioning/test_cache_provisioner.py` — new file
  covering AC-1..AC-16 + NFR-perf-coverage-walk

## Findings

| # | Severity | Category | File:Line | Title |
|---|----------|----------|-----------|-------|
| — | — | — | — | No new findings |

### Findings Carried Over (informational, not new)

- **F1 (Low / Maintainability)** — carried from batches 31–33 cumulative
  review. `provisioner.py` imports `_compute_manifest_hash` and
  `_aggregate_tile_hash` (leading-underscore private helpers) from
  `manifest_builder.py` to keep the build-identity hash byte-identical
  between AZ-323 emission and AZ-325 idempotence. Hygiene PBI to extract
  these into a shared `_build_identity` module is intentionally deferred
  and documented inline in `provisioner.py:43-50`. No new exposure
  introduced; the helpers are now used by exactly two sibling modules
  inside the same component.

## Phase Walkthrough

### Phase 2 — Spec Compliance

All 16 acceptance criteria are covered by tests in
`tests/unit/c10_provisioning/test_cache_provisioner.py`:

| AC   | Test |
|------|------|
| AC-1 | `test_ac1_cold_build_composes_phases_and_writes_manifest` |
| AC-2 | `test_ac2_warm_idempotent_re_run_skips_everything` |
| AC-3 | `test_ac3_different_bbox_triggers_full_rebuild_atomic_replace` |
| AC-4 | `test_ac4_empty_corpus_surfaces_failure_with_operator_hint` |
| AC-5 | `test_ac5_concurrent_invocation_raises_build_lock_held_error` |
| AC-6 | `test_ac6_manifest_coverage_error_rolls_back_to_prior` |
| AC-7 | `test_ac7_coverage_non_strict_mode_warns_but_continues` |
| AC-8 | `test_ac8_lock_released_on_every_exit_path` |
| AC-9 | `test_ac9_hard_errors_propagate_without_state_corruption` |
| AC-10 | `test_ac10_compile_engines_for_corpus_passthrough` (+ `test_diagnostic_engine_compile_does_not_acquire_lock`) |
| AC-11 | `test_ac11_protocol_conformance_isinstance` |
| AC-12 | `test_ac12_cold_build_benchmark_within_envelope` (skipped — GPU-only manual run) |
| AC-13 | `test_ac13_warm_idempotent_benchmark_within_envelope` |
| AC-14 | `test_ac14_takeoff_origin_mismatch_triggers_full_rebuild` |
| AC-15 | `test_ac15_takeoff_origin_none_propagates_with_no_flight_block` |
| AC-16 | `test_ac16_flight_id_participation_in_idempotence` |
| NFR-perf-coverage-walk | `test_nfr_perf_coverage_walk_under_one_second` |

**Contract verification**: `interface.py` matches contract v1.1.0 shape
(`BuildRequest` carries `takeoff_origin: LatLonAlt | None` and
`flight_id: UUID | None`, both defaulting to `None` for back-compat).
CP-INV-1..CP-INV-9 are enforced (CP-INV-8 + CP-INV-9 covered by
AC-14..AC-16 tests; CP-INV-4 by AC-5 + AC-8; CP-INV-3 by AC-6 + AC-7).

### Phase 3 — Code Quality

- **SRP**: `CacheProvisionerImpl` has a clear public surface
  (`build_cache_artifacts`, `compile_engines_for_corpus`); each helper
  has a single purpose (idempotence check, active build, coverage walk,
  rollback, snapshot, etc.).
- **Error handling**: every failure path emits a structured ERROR/WARN
  log with `kind` + `kv`; every exception path is in a `try/except` that
  restores prior state (no bare `except`).
- **Naming**: `_run_active_build`, `_check_idempotence`, `_verify_coverage`,
  `_snapshot_prior_manifest`, `_restore_prior_manifest` — all
  caller-clear.
- **Complexity**: `build_cache_artifacts` is 50 lines and delegates to
  helpers; `_run_active_build` is ~110 lines but linearly walks the four
  phases (engine compile, descriptor populate, manifest build, coverage
  verify) with a single rollback point per phase.
- **DRY**: `_restore_prior_manifest` is the single rollback site; called
  from every error/abort path inside `_run_active_build`.
- **Test quality**: every test uses Arrange/Act/Assert markers;
  assertions cover both observable outcome (`outcome`, `manifest_hash`,
  on-disk files) AND collaborator behavior (call counts on fakes).
- **Dead code**: none introduced.

### Phase 4 — Security Quick-Scan

- No SQL, no shell-out, no subprocess, no eval.
- No hardcoded secrets. Operator key is a `Path` injected via the
  `BuildRequest` and forwarded to AZ-323 (CP-INV-7 — key is read once,
  zeroized by AZ-323's signer).
- No sensitive data in logs (calibration / engine bytes / key bytes are
  never logged; only paths and SHA-256 prefixes).
- Lockfile path is bound to `cache_root` (operator-controlled); no path
  traversal vector.

### Phase 5 — Performance Scan

- Coverage walk: single `Path.rglob("*")` pass, O(N files), benchmarked
  by `test_nfr_perf_coverage_walk_under_one_second` (well under 1 s for
  2k files).
- Tile query: single `query_by_bbox` call per invocation; sorted once.
- Idempotence path: zero compute outside SHA-256 of calibration bytes
  and tile hash aggregate; warm path measured at < 1 ms in the unit
  test.
- No N+1, no unbounded fetch, no blocking I/O in async context.

### Phase 6 — Cross-Task Consistency

- Composes AZ-321 (`EngineCompiler`), AZ-322 (`DescriptorBatcher`),
  AZ-323 (`ManifestBuilder`) per the contract.
- Build-identity hash uses AZ-323's existing
  `_compute_manifest_hash` + `_aggregate_tile_hash` — guaranteeing
  byte-for-byte agreement with the emitted `build.manifest_hash`. The
  shared-helper hygiene PBI is documented in-file.
- DTOs follow the project's existing pattern: frozen `@dataclass`,
  `Protocol`s with `@runtime_checkable`.

### Phase 7 — Architecture Compliance

- Layer direction: `provisioner.py` imports only from sibling C10
  modules, `_types/`, `helpers/`, `clock`, `errors`, `interface`,
  `config`. No upward dependency.
- Public API respect: `c10_factory.py` imports from
  `c10_provisioning`'s top-level `__init__.py` re-exports only — no
  internal-file imports across components.
- No new cyclic dependencies (verified by import graph: `provisioner →
  manifest_builder` is a peer-within-component dependency, no back
  edge).
- Cross-cutting concerns: logger / clock / atomic-write helpers come
  from the shared layers (`gps_denied_onboard.clock`,
  `gps_denied_onboard.helpers.sha256_sidecar`); none re-implemented
  locally.

## Test Run

```
tests/unit/c10_provisioning/test_cache_provisioner.py  17 passed, 1 skipped
tests/unit/c10_provisioning/                            85 passed, 3 skipped, 1 pre-existing failure
```

Pre-existing failure: `test_descriptor_batcher.py::test_ac6_descriptor_id_mapping_matches_az306_scheme` —
fails identically on `HEAD` without this batch's changes
(`ModuleNotFoundError: No module named 'faiss'`). Not introduced by
AZ-325.

## Verdict Logic

- 0 Critical, 0 High, 0 Medium, 0 Low (new) findings → **PASS**.
- F1 carried over from prior cumulative review is informational only
  (Low / Maintainability) and remains tracked as a deferred hygiene
  PBI.
