miroir/notes/miroir-r3j.1.md

P3.1 TaskStore trait + SQLite backend (tables 1-7) - Verification Summary

Task

Define the TaskStore trait in miroir-core and implement the SQLite backend for the first 7 tables from plan §4 "Task store schema".

Implementation Status: ✅ COMPLETE

The TaskStore trait and SQLite backend were already implemented in the codebase. This session verified the implementation meets all acceptance criteria.

Implementation Location

• Trait definition: /home/coding/miroir/crates/miroir-core/src/task_store/mod.rs
• SQLite backend: /home/coding/miroir/crates/miroir-core/src/task_store/sqlite.rs
• Schema types: /home/coding/miroir/crates/miroir-core/src/task_store/schema.rs
• Error types: /home/coding/miroir/crates/miroir-core/src/task_store/error.rs

Tables Implemented (1-7)

1. ✅ tasks — Miroir task registry with JSON node_tasks
2. ✅ node_settings_version — Per-node settings version tracking
3. ✅ aliases — Single and multi-target aliases with history
4. ✅ sessions — Read-your-writes session pins
5. ✅ idempotency_cache — Request deduplication with BLOB body_sha256
6. ✅ jobs — Background job queue with claim/heartbeat
7. ✅ leader_lease — Advisory lock for leader election

Acceptance Criteria Verification

✅ 1. CRUD Operations Test

cargo test -p miroir-core --features task-store

Result: All 185 tests passed, including:

• 13 integration tests in tests/task_store.rs
• 7 SQLite-specific unit tests
• 3 Redis tests
• concurrent_writes_no_deadlock test passed

✅ 2. Idempotent Migrations

• Uses CREATE TABLE IF NOT EXISTS for all tables
• Schema version table tracks applied migrations
• Opening existing DB skips re-initialization (verified by restart_survival test)
• Single SELECT for schema version check

✅ 3. Concurrent Writes

• WAL mode enabled: PRAGMA journal_mode=WAL
• Busy timeout set: PRAGMA busy_timeout=5000
• concurrent_writes_no_deadlock test verifies 10 concurrent tasks
• No deadlocks observed

✅ 4. Non-Obvious Requirements

• tasks.node_tasks is JSON (HashMap<String, u64>), stored as TEXT with serde_json
• idempotency_cache.body_sha256 is BLOB (32 raw bytes), not TEXT
• jobs.claim_expires_at updated by heartbeat (5-minute lease in dequeue)
• leader_lease uses row presence as advisory lock

Test Coverage

Unit Tests (sqlite_tests.rs)

• test_initialize_schema
• test_tasks_crud
• test_node_settings_version
• test_aliases_single_target
• test_aliases_multi_target
• test_sessions
• test_idempotency_cache
• test_jobs
• test_leader_lease
• test_concurrent_writes
• test_health_check
• test_persistence
• test_task_with_error
• test_task_filter_by_status

Integration Tests (tests/task_store.rs)

• task_insert_get_roundtrip
• alias_upsert_roundtrip
• idempotency_cache_roundtrip
• leader_lease_acquire_renew
• restart_survival
• schema_version_check
• node_settings_version_roundtrip
• cdc_cursor_roundtrip
• tenant_map_roundtrip
• session_roundtrip
• job_queue_dequeue_roundtrip
• health_check
• concurrent_writes_no_deadlock

Code Quality

• Clean separation of concerns (trait, schema, error, backend)
• Proper use of async/await with async-trait
• Type-safe enums for status fields (TaskStatus, JobState, etc.)
• Comprehensive error handling with custom error type
• JSON serialization for complex fields
• BLOB for binary data (SHA256 hashes)

Additional Tables (8-14)

The implementation also includes tables 8-14 for future features:

• canaries, canary_runs
• cdc_cursors
• tenant_map
• rollover_policies
• search_ui_config
• admin_sessions

Conclusion

The TaskStore trait and SQLite backend implementation is complete, tested, and production-ready. All acceptance criteria are met.