- Add internal/pause package for pause/resume orchestration
- Implement WorkflowSnapshot for complete state serialization
- Implement SnapshotManager for snapshot storage and recovery
- Implement PauseHandler for pause/resume signal handling
- Implement PauseSignal and ResumeSignal types
- Implement PauseState for tracking pause status
Snapshot Features:
- Capture complete workflow state (tasks, metrics, config)
- Persist to JSON files for recovery after pod restart
- Track paused_at and resumed_at timestamps
- Support snapshot cleanup and batch removal
- Load/save from disk with persistence layer
Pause Handling:
- Accept pause signals with reason and grace period
- Save current state before pausing
- Block workflow execution during pause
- Support multiple concurrent paused workflows
- Channel-based signal reception (Temporal-compatible)
Resume Handling:
- Accept resume signals with reason
- Restore workflow state from snapshots
- Continue execution from exact pause point
- Update timestamps on resumption
- Enable recovery after pod restarts
Signal Management:
- Non-blocking signal reception with timeout
- WaitForPauseOrResume() for blocking operations
- ConfigurableWait duration
- Error handling for invalid transitions
Analytics:
- GetPauseStats() for pause/resume metrics
- GetSnapshotStats() for snapshot inventory
- Timestamp tracking (paused, resumed)
- Multi-workflow state aggregation
Test Coverage:
- 16 snapshot tests (creation, persistence, cleanup)
- 18 handler tests (signals, state, snapshots)
- 34 total pause/resume tests, all passing
- Edge cases: concurrent workflows, nil signals, timeouts
- State transition verification
Key Design:
- Separate Snapshot Manager (storage) and Pause Handler (orchestration)
- JSON persistence for debuggability
- Thread-safe with RWMutex
- Compatible with Temporal signal patterns
- Non-destructive pause (snapshot before blocking)
Closes T1.5
Test
37d7aea5a7