refactor: own subscription create transactions

app/startup/subscription.py

@@ -0,0 +1,70 @@
+"""订阅写入事务适配器的启动装配。"""
+
+from collections.abc import Callable
+from contextlib import AbstractAsyncContextManager
+
+from sqlalchemy.ext.asyncio import AsyncSession
+from sqlalchemy.orm import Session
+
+from app.application.subscription.write import (
+    AfterCommitEffect,
+    AsyncAfterCommitEffect,
+    AsyncCreateSubscriptionCommand,
+    CreateSubscriptionCommand,
+)
+from app.db.oper.subscribe import SubscribeOper
+from app.db.uow import SqlAlchemyAsyncUnitOfWork, SqlAlchemyUnitOfWork
+
+
+class TransactionalSubscribeWriter:
+    """为每次订阅新增创建独占会话，并把提交权交给 Application Command。"""
+
+    def __init__(
+        self,
+        sync_session: Callable[[], Session],
+        async_session: Callable[
+            [],
+            AbstractAsyncContextManager[AsyncSession],
+        ],
+    ) -> None:
+        """注入同步会话工厂和异步会话作用域。"""
+        self._sync_session = sync_session
+        self._async_session = async_session
+
+    def add(
+        self,
+        identity: dict,
+        payload: dict,
+        username: str | None = None,
+        after_commit: AfterCommitEffect | None = None,
+    ) -> tuple[int, str]:
+        """在独占同步会话内执行一次完整订阅新增事务。"""
+        session = self._sync_session()
+        try:
+            command = CreateSubscriptionCommand(
+                repository=SubscribeOper(session),
+                unit_of_work=SqlAlchemyUnitOfWork(session),
+            )
+            return command.execute(identity, payload, username, after_commit)
+        finally:
+            session.close()
+
+    async def async_add(
+        self,
+        identity: dict,
+        payload: dict,
+        username: str | None = None,
+        after_commit: AsyncAfterCommitEffect | None = None,
+    ) -> tuple[int, str]:
+        """在独占异步会话作用域内执行一次完整订阅新增事务。"""
+        async with self._async_session() as session:
+            command = AsyncCreateSubscriptionCommand(
+                repository=SubscribeOper(session),
+                unit_of_work=SqlAlchemyAsyncUnitOfWork(session),
+            )
+            return await command.execute(
+                identity,
+                payload,
+                username,
+                after_commit,
+            )