text: # Copyright 2015 Intel Corp.
  #
  # 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.
  
  
  """
  Snapshot object
  """
  
  from oslo_versionedobjects import base
  from oslo_versionedobjects import fields
  
  from heat.db import api as db_api
  from heat.objects import fields as heat_fields
  
  
  class Snapshot(base.VersionedObject,
                 base.VersionedObjectDictCompat,
                 base.ComparableVersionedObject):
  
      fields = {
          'id': fields.StringField(),
          'name': fields.StringField(nullable=True),
          'stack_id': fields.StringField(),
          'data': heat_fields.JsonField(nullable=True),
          'tenant': fields.StringField(),
          'status': fields.StringField(nullable=True),
          'status_reason': fields.StringField(nullable=True),
          'created_at': fields.DateTimeField(read_only=True),
          'updated_at': fields.DateTimeField(nullable=True),
      }
  
      @staticmethod
      def _from_db_object(context, snapshot, db_snapshot):
          for field in snapshot.fields:
              snapshot[field] = db_snapshot[field]
          snapshot._context = context
          snapshot.obj_reset_changes()
          return snapshot
  
      @classmethod
      def create(cls, context, values):
          return cls._from_db_object(
              context, cls(), db_api.snapshot_create(context, values))
  
      @classmethod
      def get_snapshot_by_stack(cls, context, snapshot_id, stack):
          return cls._from_db_object(
              context, cls(), db_api.snapshot_get_by_stack(
                  context, snapshot_id, stack))
  
      @classmethod
      def update(cls, context, snapshot_id, values):
          db_snapshot = db_api.snapshot_update(context, snapshot_id, values)
          return cls._from_db_object(context, cls(), db_snapshot)
  
      @classmethod
      def delete(cls, context, snapshot_id):
          db_api.snapshot_delete(context, snapshot_id)
  
      @classmethod
      def get_all(cls, context, stack_id):
          return [cls._from_db_object(context, cls(), db_snapshot)
                  for db_snapshot in db_api.snapshot_get_all(context, stack_id)]
  