| # Copyright 2013 the Melange authors. |
| # |
| # Licensed under the Apache License, Version 2.0 (the "License"); |
| # you may not use this file except in compliance with the License. |
| # You may obtain a copy of the License at |
| # |
| # http://www.apache.org/licenses/LICENSE-2.0 |
| # |
| # Unless required by applicable law or agreed to in writing, software |
| # distributed under the License is distributed on an "AS IS" BASIS, |
| # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| # See the License for the specific language governing permissions and |
| # limitations under the License. |
| |
| """MapReduce that removes all entities of the model which is specified |
| as its parameter. |
| |
| Be aware that these scripts delete all the data belonging to a model. It |
| may be impossible to restore that data, so please use this module with |
| extreme caution after you have consulted the development mailing list. |
| """ |
| |
| from google.appengine.ext import ndb |
| |
| from mapreduce import operation |
| |
| |
| def process(entity): |
| """Processes the entity by deleting it. |
| |
| Args: |
| entity: the specified entity |
| """ |
| yield operation.db.Delete(entity) |
| yield operation.counters.Increment('entity_deleted') |
| |
| |
| @ndb.transactional |
| def _deleteEntityTxn(entity_key): |
| """Deletes the specified entity in a transaction. |
| |
| Args: |
| entity: Entity's key. |
| """ |
| ndb.Key.from_old_key(entity_key).delete() |
| |
| |
| def processNDB(entity_key): |
| """Processes the entity by deleting it. |
| |
| Args: |
| entity: the specified entity |
| """ |
| _deleteEntityTxn(entity_key) |
| yield operation.counters.Increment('entity_deleted') |