Coverage for manila/scheduler/base_handler.py: 100%

1# Copyright (c) 2011-2013 OpenStack Foundation. 

2# All Rights Reserved. 

3# 

4# Licensed under the Apache License, Version 2.0 (the "License"); you may 

5# not use this file except in compliance with the License. You may obtain 

6# a copy of the License at 

7# 

8# http://www.apache.org/licenses/LICENSE-2.0 

9# 

10# Unless required by applicable law or agreed to in writing, software 

11# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 

12# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the 

13# License for the specific language governing permissions and limitations 

14# under the License. 

15 

16""" 

17A common base for handling extension classes. 

18 

19Used by BaseFilterHandler and BaseWeightHandler 

20""" 

21 

22import inspect 

23 

24from stevedore import extension 

25 

26 

27class BaseHandler(object): 

28 """Base class to handle loading filter and weight classes.""" 

29 def __init__(self, modifier_class_type, modifier_namespace): 

30 self.namespace = modifier_namespace 

31 self.modifier_class_type = modifier_class_type 

32 self.extension_manager = extension.ExtensionManager(modifier_namespace) 

33 

34 def _is_correct_class(self, cls): 

35 """Check if an object is the correct type. 

36 

37 Return whether an object is a class of the correct type and 

38 is not prefixed with an underscore. 

39 """ 

40 return (inspect.isclass(cls) and 

41 not cls.__name__.startswith('_') and 

42 issubclass(cls, self.modifier_class_type)) 

43 

44 def get_all_classes(self): 

45 # We use a set, as some classes may have an entrypoint of their own, 

46 # and also be returned by a function such as 'all_filters' for example 

47 return [ext.plugin for ext in self.extension_manager if 

48 self._is_correct_class(ext.plugin)]