jam-cloud/.planning/STATE.md

112 lines
5.0 KiB
Markdown

# Project State
## Project Reference
See: .planning/PROJECT.md (updated 2026-03-03)
**Core value:** Modernize session features from legacy jQuery/Rails to React patterns
**Current focus:** v1.7 Performance Optimization - Eliminate page freezes from excessive re-renders
## Current Position
Phase: 32 of 32 (State Update Optimization)
Plan: 2 of 2 (Mixer Categorization Optimization)
Status: In progress
Last activity: 2026-03-05 — Completed 32-02-PLAN.md
Progress: [█████████░] 82%
## Performance Metrics
**v1.0 - v1.6 Summary:**
- Total milestones shipped: 7
- Total phases completed: 27
- Total plans completed: 49
**v1.7 Performance Optimization (In Progress):**
- Phases: 5 (phases 28-32)
- Phases completed: 4 (Phases 28, 29, 30, 31)
- Requirements: 19 (15 complete)
- Plans completed: 7
## Accumulated Context
### Decisions
See PROJECT.md Key Decisions table for full history.
Recent decisions (v1.7):
- External VU store over Redux (50-70 updates/sec would overwhelm Redux) - 28-01
- useSyncExternalStore shim for React 16 compatibility - 28-01
- Dual hook API (useAllVuLevels and useVuLevel) for flexibility - 28-01
- RAF batching centralized in store vs per-component - 28-01
- Context splitting (separates high-frequency from low-frequency updates)
- React.memo over PureComponent (functional components standard in codebase)
- requestAnimationFrame batching (limits to 60fps, matches display refresh)
- Route VU data directly to vuStore in bridge callback, bypassing React state - 28-02
- Per-component RAF loops over centralized subscription system (simpler for multiple mixer IDs) - 28-02
- React.memo on SessionTrackVU to prevent parent re-render propagation - 28-02
- className assignment over classList.add/remove for DOM efficiency - 28-02
- getMixer stabilization via useCallback prevents cascade of function recreations - 29-01
- Context value memoization only effective when hook functions are stable - 29-01
- React.memo on consumers completes the optimization chain - 29-01
- Container component memoization completes memoization chain from Phase 29 - 30-01
- Default shallow comparison sufficient when props are stable from upstream - 30-01
- Group selectors by usage pattern (core, track, lookup, metadata) - 31-01
- shallowEqual with composed selectors for object return comparisons - 31-01
- Single debounced track sync call prevents triple API calls on session join - 32-01
- useCallback with stable dependency array for debounce instance prevents recreation - 32-01
- Ref-based tracking for previous category values avoids circular updates - 32-02
- ID-based array comparison faster than deep equality for mixer arrays - 32-02
### Investigation Findings (v1.7)
**Root causes of page freezes:**
1. VU meter updates at 50-70/sec through Redux - FIXED (Phase 28)
2. MixersContext creates new reference every render - FIXED (Phase 29)
3. 18+ individual selectors in useMixerHelper - FIXED (Phase 31)
4. Triple track sync calls on session join - FIXED (Phase 32-01)
5. Debounce instance recreation on dependency change - FIXED (Phase 32-01)
6. Missing React.memo on child components - FIXED (Phase 30)
7. Redundant mixer categorization dispatches - FIXED (Phase 32-02)
**Hotspot files:**
- `useMixerStore.js:178-185` - VU update dispatch - FIXED
- `useVuHelpers.js:99-104` - setVuStates object creation - FIXED
- `mixersSlice.js:145-165` - updateMixer creates new objects
- `JKSessionScreen.js:463-475` - Triple track sync calls - FIXED
- `useSessionModel.js:605-614` - Debounced trackChanges - FIXED
- `MixersContext.js:10` - Unmemoized context value - FIXED
- `useMixerHelper.js:291-295` - Unconditional category dispatches - FIXED
### Deferred Issues
1. **End-of-track restart requires double-click** (Minor) - From v1.0
2. **Loop functionality not working** (Medium) - From v1.0
3. **Volume control not working in popup mode** (Medium) - From v1.0
4. **WebSocket chat messages only broadcast to musicians** (Medium) - From v1.2
5. **mp3 backend support** (Medium) - Frontend allows, backend whitelist doesn't support
6. **Pre-existing test failures in JKChatMessageList.test.js** (Low) - Missing activeSession state
7. **Duplicate recording start paths** (Low) - From v1.5
### Roadmap Evolution
- **v1.0 Media Players** (Phases 1-5): Shipped 2026-01-14
- **v1.1 Music Session Chat** (Phases 6-11): Shipped 2026-01-31
- **v1.2 Session Attachments** (Phases 12-16): Shipped 2026-02-07
- **v1.3 Session Settings Tests** (Phases 17-18): Shipped 2026-02-08
- **v1.4 Memory Leak Prevention** (Phases 19-23): Shipped 2026-02-10
- **v1.5 Fix Session Recording** (Phases 24-25): Shipped 2026-02-25
- **v1.6 Media Features Polish** (Phases 26-27): Shipped 2026-03-03
- **v1.7 Performance Optimization** (Phases 28-32): In Progress
## Session Continuity
Last session: 2026-03-05
Stopped at: Completed 32-02-PLAN.md (Mixer Categorization Optimization)
Resume file: None
**Next steps:**
1. Continue Phase 32 execution or verify all performance optimizations complete
2. Plan verification/performance testing if needed