shinken/singleton.py

   1 #!/usr/bin/env python
   2 #Copyright (C) 2009-2010 :
   3 #    Gabes Jean, naparuba@gmail.com
   4 #    Gerhard Lausser, Gerhard.Lausser@consol.de
   5 #
   6 #This file is part of Shinken.
   7 #
   8 #Shinken is free software: you can redistribute it and/or modify
   9 #it under the terms of the GNU Affero General Public License as published by
  10 #the Free Software Foundation, either version 3 of the License, or
  11 #(at your option) any later version.
  12 #
  13 #Shinken is distributed in the hope that it will be useful,
  14 #but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 #MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 #GNU Affero General Public License for more details.
  17 #
  18 #You should have received a copy of the GNU Affero General Public License
  19 #along with Shinken.  If not, see <http://www.gnu.org/licenses/>.
  20
  21
  22 #The classic Singleton class. So all instance of this class will be the same
  23 #instance in fact.
  24
  25 class Singleton(type):
  26     def __init__(cls, name, bases, dict):
  27         print "Init de singleton"
  28         super(Singleton, cls).__init__(name, bases, dict)
  29         cls.instance = None
  30
  31     def __call__(cls, *args, **kw):
  32         if cls.instance is None:
  33             cls.instance = super(Singleton, cls).__call__(*args, **kw)
  34             return cls.instance