"""
Copyright 2008-2015 VMware, Inc.  All rights reserved. -- VMware Confidential

This module implements the cache decorator
"""
__author__ = "VMware, Inc"

def Cache(fn):
   """ Function cache decorator """
   def fnCache(*args, **kwargs):
      """ Cache function """
      key = (args and tuple(args) or None,
             kwargs and frozenset(list(kwargs.items())) or None)
      if key not in fn.__cached__:
         fn.__cached__[key] = cache = fn(*args, **kwargs)
      else:
         cache = fn.__cached__[key]
      return cache

   def ResetCache():
      """ Reset cache """
      fn.__cached__ = {}

   setattr(fn, "__cached__", {})
   setattr(fn, "__resetcache__", ResetCache)
   fnCache.__name__ = fn.__name__
   fnCache.__doc__ = fn.__doc__
   fnCache.__dict__.update(fn.__dict__)
   return fnCache
