修复：消除托盘与用户分配查询竞态

shierfeng-fastapi-backend/module_business/service/pallet_service.py

@@ -1,7 +1,7 @@
 import secrets
 from datetime import datetime
 from io import BytesIO
-from typing import Any, Literal
+from typing import Literal
 
 import qrcode
 from sqlalchemy.exc import IntegrityError
@@ -11,7 +11,6 @@ from common.vo import CrudResponseModel, PageModel
 from exceptions.exception import ServiceException
 from module_business.dao.access_dao import AccessDao
 from module_business.dao.master_dao import MasterDao
-from module_business.domain.enums import PalletFlowState
 from module_business.entity.do.master_do import BizPallet
 from module_business.entity.do.operation_do import BizPalletInventory
 from module_business.entity.vo.master_vo import (
@@ -58,18 +57,6 @@ class PalletService:
             raise ServiceException(message='托盘ID不能重复')
         return sorted(pallet_ids)
 
-    @classmethod
-    async def _can_remove(cls, db: AsyncSession, pallet_id: int) -> bool:
-        inventory = await MasterDao.get_pallet_inventory(db, pallet_id)
-        if inventory is None or inventory.flow_state != PalletFlowState.UNSTOCKED.value:
-            return False
-        return await MasterDao.count_pallet_events(db, pallet_id) == 0
-
-    @classmethod
-    async def _to_pallet_model(cls, db: AsyncSession, record: Any) -> PalletModel:
-        model = PalletModel.model_validate(record)
-        return model.model_copy(update={'can_remove': await cls._can_remove(db, model.pallet_id)})
-
     @classmethod
     async def _lock_pallet_inventory(cls, db: AsyncSession, pallet_id: int) -> tuple[BizPallet, BizPalletInventory]:
         """按库存、托盘顺序加锁，避免与流转事务形成反序死锁。"""
@@ -91,17 +78,25 @@ class PalletService:
         is_page: bool = True,
     ) -> PageModel | list[PalletModel]:
         result = await MasterDao.list_pallet(db, query_object, is_page)
+        records = result.rows if isinstance(result, PageModel) else result
+        models = [PalletModel.model_validate(record) for record in records]
+        removability = await MasterDao.get_pallet_removability(
+            db,
+            [model.pallet_id for model in models],
+        )
+        rows = [model.model_copy(update={'can_remove': removability.get(model.pallet_id, False)}) for model in models]
         if isinstance(result, PageModel):
-            rows = [await cls._to_pallet_model(db, row) for row in result.rows]
             return result.model_copy(update={'rows': rows})
-        return [await cls._to_pallet_model(db, row) for row in result]
+        return rows
 
     @classmethod
     async def detail_pallet(cls, db: AsyncSession, pallet_id: int) -> PalletModel:
         pallet = await MasterDao.get_pallet(db, pallet_id)
         if pallet is None:
             raise ServiceException(message='托盘不存在')
-        return await cls._to_pallet_model(db, pallet)
+        model = PalletModel.model_validate(pallet)
+        removability = await MasterDao.get_pallet_removability(db, [pallet_id])
+        return model.model_copy(update={'can_remove': removability.get(pallet_id, False)})
 
     @classmethod
     async def add_pallet(
@@ -179,11 +174,11 @@ class PalletService:
         try:
             pallet_ids = cls._extract_pallet_ids(value)
             for pallet_id in pallet_ids:
-                _, inventory = await cls._lock_pallet_inventory(db, pallet_id)
-                if inventory.flow_state != PalletFlowState.UNSTOCKED.value:
-                    raise ServiceException(message='托盘未处于未入库状态，不能删除')
-                if await MasterDao.count_pallet_events(db, pallet_id) > 0:
-                    raise ServiceException(message='托盘已有流转事件，不能删除')
+                await cls._lock_pallet_inventory(db, pallet_id)
+
+            removability = await MasterDao.get_pallet_removability(db, pallet_ids)
+            if not all(removability.get(pallet_id, False) for pallet_id in pallet_ids):
+                raise ServiceException(message='托盘状态或关联数据不允许删除')
 
             for pallet_id in pallet_ids:
                 await MasterDao.delete_pallet_inventory(db, pallet_id)
@@ -208,19 +203,16 @@ class PalletService:
             raise ServiceException(message=f'{_ASSIGNMENT_LABELS[resource]}不存在')
 
         users = await MasterDao.list_assignable_users(db)
-        result = []
-        association_method = getattr(AccessDao, f'list_user_{resource}_ids')
-        for user in users:
-            assigned_ids = await association_method(db, user.user_id)
-            result.append(
-                BusinessUserOptionModel(
-                    user_id=user.user_id,
-                    user_name=user.user_name,
-                    nick_name=user.nick_name,
-                    assigned=resource_id in assigned_ids,
-                )
+        assigned_user_ids = set(await getattr(MasterDao, f'list_{resource}_assigned_user_ids')(db, resource_id))
+        return [
+            BusinessUserOptionModel(
+                user_id=user.user_id,
+                user_name=user.user_name,
+                nick_name=user.nick_name,
+                assigned=user.user_id in assigned_user_ids,
             )
-        return result
+            for user in users
+        ]
 
     @classmethod
     async def list_warehouse_users(
@@ -248,7 +240,14 @@ class PalletService:
     ) -> CrudResponseModel:
         label = _ASSIGNMENT_LABELS[resource]
         try:
-            if await getattr(MasterDao, f'get_{resource}')(db, resource_id) is None:
+            if (
+                await getattr(MasterDao, f'get_{resource}')(
+                    db,
+                    resource_id,
+                    for_update=True,
+                )
+                is None
+            ):
                 raise ServiceException(message=f'{label}不存在')
             users = await MasterDao.list_assignable_users_by_ids(db, assignment.user_ids)
             if {user.user_id for user in users} != set(assignment.user_ids):