kandev/docs/plans/storage-overview-cache/plan.md

spec, created, status

spec	created	status
docs/specs/system-page/requirements/storage-maintenance.md	2026-07-23	implemented

Implementation Plan: Storage Overview Cache and Settings Stability

Overview

Put a concurrency-safe 15-minute cache in front of the existing typed overview providers, then expose the snapshot timestamp through the existing Storage API. Manual Analyze uses the same cache owner but forces a refresh. The frontend displays snapshot age, hydrates the external Go-cache path from persisted settings, and separates policy-save blocking from unrelated analysis and cleanup activity.

Backend

Cached overview contract

• Add apps/backend/internal/system/storage/overview_cache.go with an OverviewSnapshot containing Summary and AnalyzedAt, plus cached and forced-refresh methods around the existing provider.
• Use a 15-minute default TTL, cache only successful scans, and serialize concurrent cache misses so page refreshes do not duplicate provider work.
• Keep the snapshot process-local. A backend restart starts with an empty cache.

API and composition

• Update apps/backend/internal/system/storage/handler.go so GET /storage returns cached summary and analyzed_at.
• Update apps/backend/internal/system/storage/operations.go so manual Analyze calls the forced refresh path and records that summary in the existing run.
• Wrap storageOverview once in apps/backend/internal/backendapp/storage_maintenance.go, then pass the same cache owner to the handler and operations so forced analysis immediately updates subsequent GET responses.
• Update handler/composition fakes that implement the overview interface.

Frontend

Contracts and analysis card

• Add analyzed_at to StorageOverviewResponse in apps/web/lib/types/system.ts.
• Update apps/web/components/settings/system/storage/storage-overview-card.tsx to render “Last analyzed …” using the shared formatRelativeTime helper and an absolute timestamp tooltip.
• Preserve the existing loading spinner while the first post-startup snapshot is measured.

Policy and external Go cache

• In storage-policy-card.tsx, initialize the external-cache input from savedSettings.go_cache.adopted_path and synchronize later persisted changes without overwriting an in-progress user edit.
• In storage-maintenance-settings.tsx, distinguish policy-mutating pending actions from analysis, cleanup, restore, and delete jobs. Those jobs must not disable policy editing.
• Do not mark the contributor invalid because its own save is in progress. If adoption is the conflicting mutation, show a specific adoption message rather than the generic current-action text.

Tests

• Cache freshness and forcing: apps/backend/internal/system/storage/overview_cache_test.go verifies one source call within 15 minutes, refresh after expiry, forced refresh inside the TTL, successful-snapshot timestamps, failed-refresh retention, and concurrent miss coalescing.
• Handler/operations wiring: focused tests in handler_test.go and operations_test.go verify analyzed_at output and that manual Analyze uses the forced path.
• External path hydration and save blocking: existing Storage component tests verify the adopted path survives rerender/reopen and analysis/cleanup do not disable policy controls or the shared Save action.
• Frontend contract: update Storage fixtures and API tests for analyzed_at.

E2E Tests

• Extend apps/web/e2e/tests/system/storage-maintenance.spec.ts to count overview measurements across page refresh/save and verify manual Analyze produces a newer displayed timestamp.
• Extend apps/web/e2e/tests/system/mobile-storage-maintenance.spec.ts to verify the relative analysis timestamp and persisted external-cache field remain usable without horizontal overflow.

Implementation Waves

Wave 1:

• Task 01: Backend cached overview

Wave 2:

• Task 02: Frontend settings stability

Wave 3:

• Task 03: Integrated desktop and mobile coverage

Risks

• Summary values can intentionally lag newly saved thresholds or an adopted path until manual Analyze or TTL expiry; analyzed_at makes that staleness visible.
• The cache must be shared by GET and manual Analyze. Separate wrappers would leave GET stale after a forced scan.
• Pending-state changes must retain mutual exclusion for adoption and saving without coupling policy controls to cleanup jobs that only consume a settings snapshot.