wren
40 lines
1.2 KiB
Python
40 lines
1.2 KiB
Python
"""SQLAlchemy 异步引擎和 session 工厂。"""
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from __future__ import annotations
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from contextlib import asynccontextmanager
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from sqlalchemy.ext.asyncio import AsyncEngine, AsyncSession, async_sessionmaker, create_async_engine
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from sqlalchemy.pool import NullPool
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from fastapi_admin.config import ASYNCPG_DATABASE_URL
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_engine: AsyncEngine | None = None
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_AsyncSessionFactory: async_sessionmaker[AsyncSession] | None = None
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def _get_session_factory() -> async_sessionmaker[AsyncSession]:
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"""按需创建 session factory，避免 reload/多事件循环复用旧连接池。"""
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global _engine, _AsyncSessionFactory
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if _AsyncSessionFactory is None:
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_engine = create_async_engine(
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ASYNCPG_DATABASE_URL,
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echo=False,
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poolclass=NullPool,
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)
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_AsyncSessionFactory = async_sessionmaker(
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_engine,
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class_=AsyncSession,
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expire_on_commit=False,
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)
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return _AsyncSessionFactory
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@asynccontextmanager
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async def GetAsyncSession():
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"""获取异步数据库 session（上下文管理器）。"""
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SessionFactory = _get_session_factory()
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async with SessionFactory() as session:
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yield session
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await session.commit()
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