stgit/lib/objcache.py

   1 class ObjectCache:
   2     """Cache to ensure only one Python object is created per Git object.
   3
   4     This reduces memory consumption and makes object comparison very cheap.
   5
   6     """
   7
   8     def __init__(self, create):
   9         self.__objects = {}
  10         self.__create = create
  11
  12     def __getitem__(self, name):
  13         if name not in self.__objects:
  14             self.__objects[name] = self.__create(name)
  15         return self.__objects[name]
  16
  17     def __contains__(self, name):
  18         return name in self.__objects
  19
  20     def __setitem__(self, name, val):
  21         assert name not in self.__objects
  22         self.__objects[name] = val