62 lines
1.6 KiB
Python
62 lines
1.6 KiB
Python
"""Async engine + session factory, created lazily from settings.
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The engine is process-global and cached. The API binds a session per request
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(see ``app.api.deps``); workers and scripts use :func:`session_scope`.
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"""
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from collections.abc import AsyncIterator
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from contextlib import asynccontextmanager
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from functools import lru_cache
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from sqlalchemy.ext.asyncio import (
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AsyncEngine,
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AsyncSession,
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async_sessionmaker,
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create_async_engine,
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)
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from app.core.config import get_settings
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@lru_cache
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def get_engine() -> AsyncEngine:
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settings = get_settings()
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return create_async_engine(
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settings.database_url,
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echo=settings.db_echo,
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pool_size=settings.db_pool_size,
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max_overflow=settings.db_max_overflow,
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pool_pre_ping=True, # survive Postgres restarts / idle drops
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)
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@lru_cache
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def get_sessionmaker() -> async_sessionmaker[AsyncSession]:
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return async_sessionmaker(
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bind=get_engine(),
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expire_on_commit=False,
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autoflush=False,
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)
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@asynccontextmanager
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async def session_scope() -> AsyncIterator[AsyncSession]:
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"""Transactional session for workers/scripts: commit on success, rollback on error."""
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session = get_sessionmaker()()
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try:
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yield session
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await session.commit()
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except Exception:
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await session.rollback()
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raise
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finally:
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await session.close()
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async def dispose_engine() -> None:
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"""Dispose the pooled engine on shutdown. Safe to call if never initialized."""
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if get_engine.cache_info().currsize:
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await get_engine().dispose()
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get_engine.cache_clear()
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get_sessionmaker.cache_clear()
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