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Diffstat (limited to 'ACE/bin/PythonACE/fuzz/_singleton.py')
-rw-r--r-- | ACE/bin/PythonACE/fuzz/_singleton.py | 60 |
1 files changed, 0 insertions, 60 deletions
diff --git a/ACE/bin/PythonACE/fuzz/_singleton.py b/ACE/bin/PythonACE/fuzz/_singleton.py deleted file mode 100644 index f7a686d4988..00000000000 --- a/ACE/bin/PythonACE/fuzz/_singleton.py +++ /dev/null @@ -1,60 +0,0 @@ -""" Implements a singleton mixin class """ - -# The following code was written by Gary Robinson -# (grobinson@transpose.com) and placed in the public domain. His -# copyright notice is as follows: - -# By Gary Robinson, grobinson@transpose.com. No rights reserved -- -# placed in the public domain -- which is only reasonable considering -# how much it owes to other people's version which are in the -# public domain. The idea of using a metaclass came from -# a comment on Gary's blog (see -# http://www.garyrobinson.net/2004/03/python_singleto.html#comments). -# Other improvements came from comments and email from other -# people who saw it online. (See the blog post and comments -# for further credits.) - -# Not guaranteed to be fit for any particular purpose. Use at your -# own risk. - - -class SingletonException(Exception): - pass - -class MetaSingleton(type): - def __new__(metaclass, strName, tupBases, dict): - if dict.has_key('__new__'): - raise SingletonException, 'Can not override __new__ in a Singleton' - return super(MetaSingleton,metaclass).__new__(metaclass, strName, tupBases, dict) - - def __call__(cls, *lstArgs, **dictArgs): - raise SingletonException, 'Singletons may only be instantiated through getInstance()' - -class Singleton(object): - __metaclass__ = MetaSingleton - - def getInstance(cls, *lstArgs): - """ - Call this to instantiate an instance or retrieve the existing instance. - If the singleton requires args to be instantiated, include them the first - time you call getInstance. - """ - if cls._isInstantiated(): - if len(lstArgs) != 0: - raise SingletonException, 'If no supplied args, singleton must already be instantiated, or __init__ must require no args' - else: - if cls._getConstructionArgCountNotCountingSelf() > 0 and len(lstArgs) <= 0: - raise SingletonException, 'If the singleton requires __init__ args, supply them on first instantiation' - instance = cls.__new__(cls) - instance.__init__(*lstArgs) - cls.cInstance = instance - return cls.cInstance - getInstance = classmethod(getInstance) - - def _isInstantiated(cls): - return hasattr(cls, 'cInstance') - _isInstantiated = classmethod(_isInstantiated) - - def _getConstructionArgCountNotCountingSelf(cls): - return cls.__init__.im_func.func_code.co_argcount - 1 - _getConstructionArgCountNotCountingSelf = classmethod(_getConstructionArgCountNotCountingSelf) |