| Dennis Dmitriev | 6f59add | 2016-10-18 13:45:27 +0300 | [diff] [blame] | 1 | # Copyright 2016 Mirantis, Inc. |
| 2 | # |
| 3 | # Licensed under the Apache License, Version 2.0 (the "License"); you may |
| 4 | # not use this file except in compliance with the License. You may obtain |
| 5 | # a copy of the License at |
| 6 | # |
| 7 | # http://www.apache.org/licenses/LICENSE-2.0 |
| 8 | # |
| 9 | # Unless required by applicable law or agreed to in writing, software |
| 10 | # distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| 11 | # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the |
| 12 | # License for the specific language governing permissions and limitations |
| 13 | # under the License. |
| 14 | |
| 15 | |
| 16 | class SingletonMeta(type): |
| 17 | """Metaclass for Singleton |
| 18 | |
| 19 | Main goals: not need to implement __new__ in singleton classes |
| 20 | """ |
| 21 | _instances = {} |
| 22 | |
| 23 | def __call__(cls, *args, **kwargs): |
| 24 | if cls not in cls._instances: |
| 25 | cls._instances[cls] = super( |
| 26 | SingletonMeta, cls).__call__(*args, **kwargs) |
| 27 | return cls._instances[cls] |