text: # Copyright (C) 2016, Red Hat, Inc.
  #
  #    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.
  
  from oslo_serialization import jsonutils
  from oslo_utils import versionutils
  
  from nova import db
  from nova.objects import base
  from nova.objects import fields
  
  
  @base.NovaObjectRegistry.register
  class DeviceBus(base.NovaObject):
      VERSION = '1.0'
  
  
  @base.NovaObjectRegistry.register
  class PCIDeviceBus(DeviceBus):
      VERSION = '1.0'
  
      fields = {
          'address': fields.PCIAddressField(),
      }
  
  
  @base.NovaObjectRegistry.register
  class USBDeviceBus(DeviceBus):
      VERSION = '1.0'
  
      fields = {
          'address': fields.USBAddressField(),
      }
  
  
  @base.NovaObjectRegistry.register
  class SCSIDeviceBus(DeviceBus):
      VERSION = '1.0'
  
      fields = {
          'address': fields.SCSIAddressField(),
      }
  
  
  @base.NovaObjectRegistry.register
  class IDEDeviceBus(DeviceBus):
      VERSION = '1.0'
  
      fields = {
          'address': fields.IDEAddressField(),
      }
  
  
  @base.NovaObjectRegistry.register
  class DeviceMetadata(base.NovaObject):
      VERSION = '1.0'
  
      fields = {
          'bus': fields.ObjectField("DeviceBus", subclasses=True),
          'tags': fields.ListOfStringsField(),
      }
  
  
  @base.NovaObjectRegistry.register
  class NetworkInterfaceMetadata(DeviceMetadata):
      # Version 1.0: Initial version
      # Version 1.1: Add vlans field
      VERSION = '1.1'
  
      fields = {
          'mac': fields.MACAddressField(),
          'vlan': fields.IntegerField(),
      }
  
      def obj_make_compatible(self, primitive, target_version):
          target_version = versionutils.convert_version_to_tuple(target_version)
          if target_version < (1, 1) and 'vlan' in primitive:
              del primitive['vlan']
  
  
  @base.NovaObjectRegistry.register
  class DiskMetadata(DeviceMetadata):
      VERSION = '1.0'
  
      fields = {
          'serial': fields.StringField(nullable=True),
          'path': fields.StringField(nullable=True),
      }
  
  
  @base.NovaObjectRegistry.register
  class InstanceDeviceMetadata(base.NovaObject):
      VERSION = '1.0'
      fields = {
          'devices': fields.ListOfObjectsField('DeviceMetadata',
                                               subclasses=True),
      }
  
      @classmethod
      def obj_from_db(cls, context, db_dev_meta):
          primitive = jsonutils.loads(db_dev_meta)
          device_metadata = cls.obj_from_primitive(primitive)
          return device_metadata
  
      @base.remotable_classmethod
      def get_by_instance_uuid(cls, context, instance_uuid):
          db_extra = db.instance_extra_get_by_instance_uuid(
                  context, instance_uuid, columns=['device_metadata'])
          if not db_extra or db_extra['device_metadata'] is None:
              return None
  
          primitive = jsonutils.loads(db_extra['device_metadata'])
          device_metadata = cls.obj_from_primitive(primitive)
          return device_metadata
  
      def _to_json(self):
          return jsonutils.dumps(self.obj_to_primitive())
  