51 lines
1.5 KiB
Python
51 lines
1.5 KiB
Python
"""MySQL 会话(懒):首次访问才创建 AsyncEngine + 连接池,不随应用启动初始化。
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引擎/会话工厂都是函数式访问,第一次调用时建出单例;dispose 清理已建对象。
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"""
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from sqlalchemy import text
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from sqlalchemy.ext.asyncio import async_sessionmaker, create_async_engine
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from config.settings import settings
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_engine = None
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_sessionmaker = None
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def get_engine():
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global _engine
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if _engine is None:
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_engine = create_async_engine(
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settings.mysql.url,
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pool_size=settings.mysql.pool_size,
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max_overflow=settings.mysql.max_overflow,
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pool_recycle=settings.mysql.pool_recycle,
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pool_pre_ping=True, # 取/还连接时探测,自动剔除死连接
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pool_timeout=settings.mysql.pool_timeout,
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connect_args={"connect_timeout": settings.mysql.connect_timeout},
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)
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return _engine
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def get_session_factory():
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global _sessionmaker
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if _sessionmaker is None:
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_sessionmaker = async_sessionmaker(bind=get_engine(), expire_on_commit=False)
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return _sessionmaker
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async def init_db() -> None:
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"""手动预热入口(registry.init_db 逐库调用;不随应用启动自动执行)。"""
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get_engine()
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async def dispose() -> None:
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global _engine, _sessionmaker
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if _engine is not None:
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await _engine.dispose()
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_engine = None
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_sessionmaker = None
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async def check_health() -> None:
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async with get_engine().connect() as conn:
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await conn.execute(text("SELECT 1")) |