Implement the caching layer that enables fast subsequent runs by
persisting parsed session data in SQLite:
- store/schema.go: DDL for three tables — sessions (primary metrics
with file_mtime_ns/file_size for change detection), session_models
(per-model breakdown, FK cascade on delete), and file_tracker
(path -> mtime+size mapping for cache invalidation). Indexes on
start_time and project for efficient time-range and filter queries.
- store/cache.go: Cache struct wrapping database/sql with WAL mode
and synchronous=normal for concurrent read safety and write
performance. Key operations:
* Open: creates the cache directory, opens/creates the database,
and ensures the schema is applied (idempotent via IF NOT EXISTS).
* GetTrackedFiles: returns the mtime/size map used by the pipeline
to determine which files need reparsing.
* SaveSession: transactional upsert of session stats + model
breakdown + file tracker entry. Uses INSERT OR REPLACE to handle
both new files and files that changed since last parse.
* LoadAllSessions: batch-loads all cached sessions with a two-pass
strategy — first loads session rows, then batch-loads model data
with an index map for O(1) join, avoiding N+1 queries.
Uses modernc.org/sqlite (pure-Go, no CGO) for zero-dependency
cross-platform builds.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
