Add runtime statistics via engine.stats

src/sqlmem/engine.py

@@ -8,6 +8,7 @@ from .config import BACKUP_INTERVAL_SECONDS, CACHE_DB_PATH
 from .executor import QueryExecutor
 from .parser import parse
 from .registry import ColumnRegistry
+from .stats import Stats, StatsCollector
 
 
 class CachingEngine:
@@ -17,13 +18,18 @@ class CachingEngine:
         self._source_engine = source_engine
         self._cache = CacheManager(CACHE_DB_PATH, BACKUP_INTERVAL_SECONDS)
         self._registry = ColumnRegistry(self._cache.connection)
+        self._stats = StatsCollector()
         logger.info("CachingEngine initialized.")
 
+    @property
+    def stats(self) -> Stats:
+        return self._stats.snapshot(self._cache.connection)
+
     def execute(self, sql: str) -> list[dict]:
         parsed = parse(sql)
         with self._source_engine.connect() as sa_conn:
             raw_conn: sqlite3.Connection = sa_conn.connection.dbapi_connection
-            executor = QueryExecutor(self._cache, self._registry, raw_conn)
+            executor = QueryExecutor(self._cache, self._registry, raw_conn, self._stats)
             return executor.execute(parsed)
 
     def invalidate(self, table: str) -> None: