reflection_test.py 文件源码

def testDescriptorProtoSupport(self):
    # Hand written descriptors/reflection are only supported by the pure-Python
    # implementation of the API.
    if api_implementation.Type() != 'python':
      return

    def AddDescriptorField(proto, field_name, field_type):
      AddDescriptorField.field_index += 1
      new_field = proto.field.add()
      new_field.name = field_name
      new_field.type = field_type
      new_field.number = AddDescriptorField.field_index
      new_field.label = descriptor_pb2.FieldDescriptorProto.LABEL_OPTIONAL

    AddDescriptorField.field_index = 0

    desc_proto = descriptor_pb2.DescriptorProto()
    desc_proto.name = 'Car'
    fdp = descriptor_pb2.FieldDescriptorProto
    AddDescriptorField(desc_proto, 'name', fdp.TYPE_STRING)
    AddDescriptorField(desc_proto, 'year', fdp.TYPE_INT64)
    AddDescriptorField(desc_proto, 'automatic', fdp.TYPE_BOOL)
    AddDescriptorField(desc_proto, 'price', fdp.TYPE_DOUBLE)
    # Add a repeated field
    AddDescriptorField.field_index += 1
    new_field = desc_proto.field.add()
    new_field.name = 'owners'
    new_field.type = fdp.TYPE_STRING
    new_field.number = AddDescriptorField.field_index
    new_field.label = descriptor_pb2.FieldDescriptorProto.LABEL_REPEATED

    desc = descriptor.MakeDescriptor(desc_proto)
    self.assertTrue('name' in desc.fields_by_name)
    self.assertTrue('year' in desc.fields_by_name)
    self.assertTrue('automatic' in desc.fields_by_name)
    self.assertTrue('price' in desc.fields_by_name)
    self.assertTrue('owners' in desc.fields_by_name)

    class CarMessage(six.with_metaclass(reflection.GeneratedProtocolMessageType, message.Message)):
      DESCRIPTOR = desc

    prius = CarMessage()
    prius.name = 'prius'
    prius.year = 2010
    prius.automatic = True
    prius.price = 25134.75
    prius.owners.extend(['bob', 'susan'])

    serialized_prius = prius.SerializeToString()
    new_prius = reflection.ParseMessage(desc, serialized_prius)
    self.assertTrue(new_prius is not prius)
    self.assertEqual(prius, new_prius)

    # these are unnecessary assuming message equality works as advertised but
    # explicitly check to be safe since we're mucking about in metaclass foo
    self.assertEqual(prius.name, new_prius.name)
    self.assertEqual(prius.year, new_prius.year)
    self.assertEqual(prius.automatic, new_prius.automatic)
    self.assertEqual(prius.price, new_prius.price)
    self.assertEqual(prius.owners, new_prius.owners)