53 lines
1.4 KiB
Python

from __future__ import annotations
from sqlalchemy import URL
from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker, create_async_engine
from store.persistence import MappedBase
from store.persistence.shared import close_in_order
from store.persistence.types import AppPersistence
async def build_postgres_persistence(db_url: URL) -> AppPersistence:
from langgraph.checkpoint.postgres.aio import AsyncPostgresSaver
engine = create_async_engine(
db_url,
future=True,
)
session_factory = async_sessionmaker(
bind=engine,
class_=AsyncSession,
expire_on_commit=False,
autoflush=False,
)
saver_cm = AsyncPostgresSaver.from_conn_string(db_url)
checkpointer = await saver_cm.__aenter__()
async def setup() -> None:
# 1. LangGraph checkpoint tables / migrations
await checkpointer.setup()
# 2. ORM business tables
async with engine.begin() as conn:
await conn.run_sync(MappedBase.metadata.create_all)
async def _close_saver() -> None:
await saver_cm.__aexit__(None, None, None)
async def aclose() -> None:
await close_in_order(
engine.dispose,
_close_saver,
)
return AppPersistence(
checkpointer=checkpointer,
engine=engine,
session_factory=session_factory,
setup=setup,
aclose=aclose,
)