feat(T2.4): implement fast lessons file indexing
- Add internal/indexing package for lessons index
- Implement LessonIndex with multi-field index structure
- Index by task type, activity type, failure type, and pattern
- Fast lookups: O(1) map access for all query types
- Build from JSONL file with streaming parse
- Support incremental lesson addition
- Query operations with optional AND logic
- Time range queries for temporal analysis
- Similarity search by failure message substring
- Most frequent failures ranking
- 20 indexing tests, all passing
Features:
- FindByTaskType() - query by task type
- FindByActivityType() - query by activity type
- FindByFailureType() - query by failure type
- FindByPattern() - query by pattern
- FindSimilar() - substring search in failure messages
- QueryMultiple() - AND logic for multi-field queries
- GetByTimeRange() - temporal range queries
- GetMostFrequentFailures() - ranked by frequency
- BuildFromFile() - load from JSONL
- AddLesson() - incremental updates
Performance Verified:
- Lookup < 10ms for 1000s entries ✓
- <10ms for 10,000 entries ✓
- Concurrent queries supported ✓
- O(1) average lookup complexity
- Index rebuilding efficient
Test Coverage:
- 20 indexing tests (build, query, range, stats)
- Latency verification (< 10ms)
- Concurrency testing
- Time range queries
- Multi-field queries
- Large dataset support (10k entries)
Index Structures:
- lessons: ID -> Lesson (full lookup)
- byTaskType: TaskType -> []*Lesson
- byActivityType: ActivityType -> []*Lesson
- byFailureType: FailureType -> []*Lesson
- byPattern: Pattern -> []*Lesson
- All RWMutex-protected for thread safety
Next: T2.5 (Git operation batching)
Test
87ceea3d30