Start Core Hub FastAPI replacement foundation

src/core_hub/db.py

@@ -0,0 +1,36 @@
+from collections.abc import AsyncIterator
+from functools import lru_cache
+
+from sqlalchemy.ext.asyncio import (
+    AsyncEngine,
+    AsyncSession,
+    async_sessionmaker,
+    create_async_engine,
+)
+from sqlalchemy.orm import DeclarativeBase
+
+from .config import get_settings
+
+
+class Base(DeclarativeBase):
+    pass
+
+
+def make_engine(database_url: str) -> AsyncEngine:
+    return create_async_engine(database_url, pool_pre_ping=True)
+
+
+@lru_cache
+def get_engine() -> AsyncEngine:
+    return make_engine(get_settings().database_url)
+
+
+@lru_cache
+def get_sessionmaker() -> async_sessionmaker[AsyncSession]:
+    return async_sessionmaker(get_engine(), expire_on_commit=False)
+
+
+async def session_scope() -> AsyncIterator[AsyncSession]:
+    async_session = get_sessionmaker()
+    async with async_session() as session:
+        yield session