71 lines
1.7 KiB
Python
71 lines
1.7 KiB
Python
|
"""Async SQLAlchemy database session setup."""
|
||
|
|
|
||
|
|
from __future__ import annotations
|
||
|
|
|
||
|
|
from collections.abc import AsyncGenerator
|
||
|
|
|
||
|
|
from sqlalchemy.ext.asyncio import (
|
||
|
|
AsyncSession,
|
||
|
|
async_sessionmaker,
|
||
|
|
create_async_engine,
|
||
|
|
)
|
||
|
|
from sqlalchemy.orm import DeclarativeBase
|
||
|
|
|
||
|
|
from app.config import get_settings
|
||
|
|
|
||
|
|
|
||
|
|
class Base(DeclarativeBase):
|
||
|
|
"""Declarative base for all ORM models."""
|
||
|
|
|
||
|
|
|
||
|
|
_engine = None
|
||
|
|
_sessionmaker = None
|
||
|
|
|
||
|
|
|
||
|
|
def get_engine():
|
||
|
|
"""Lazy-create the global async engine."""
|
||
|
|
global _engine
|
||
|
|
if _engine is None:
|
||
|
|
cfg = get_settings()
|
||
|
|
_engine = create_async_engine(
|
||
|
|
cfg.database_url,
|
||
|
|
echo=cfg.db_echo,
|
||
|
|
pool_size=cfg.db_pool_size,
|
||
|
|
max_overflow=cfg.db_max_overflow,
|
||
|
|
future=True,
|
||
|
|
)
|
||
|
|
return _engine
|
||
|
|
|
||
|
|
|
||
|
|
def get_sessionmaker() -> async_sessionmaker[AsyncSession]:
|
||
|
|
"""Lazy-create the global session factory."""
|
||
|
|
global _sessionmaker
|
||
|
|
if _sessionmaker is None:
|
||
|
|
_sessionmaker = async_sessionmaker(
|
||
|
|
get_engine(),
|
||
|
|
class_=AsyncSession,
|
||
|
|
expire_on_commit=False,
|
||
|
|
autoflush=False,
|
||
|
|
)
|
||
|
|
return _sessionmaker
|
||
|
|
|
||
|
|
|
||
|
|
async def get_db() -> AsyncGenerator[AsyncSession, None]:
|
||
|
|
"""FastAPI dependency: yields an async session and rolls back on error."""
|
||
|
|
sm = get_sessionmaker()
|
||
|
|
async with sm() as session:
|
||
|
|
try:
|
||
|
|
yield session
|
||
|
|
except Exception:
|
||
|
|
await session.rollback()
|
||
|
|
raise
|
||
|
|
|
||
|
|
|
||
|
|
async def dispose_engine() -> None:
|
||
|
|
"""Dispose engine on application shutdown."""
|
||
|
|
global _engine, _sessionmaker
|
||
|
|
if _engine is not None:
|
||
|
|
await _engine.dispose()
|
||
|
|
_engine = None
|
||
|
|
_sessionmaker = None
|