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