[Configobj-develop] [Fwd: ConfigObj and pickle bug]

[Michael F. <fuz...@vo...>]

Looks like we need to support pickle after all. *sigh*

-------- Original Message --------
Subject: 	ConfigObj and pickle bug
Date: 	Mon, 08 Sep 2008 10:30:26 +0200
From: 	Christian Heimes <c.h...@se...>
To: 	Michael Foord <fuz...@vo...>
CC: 	Dirk Rothe <d....@se...>



Dear Michael!

I run into some trouble when I used a ConfigObj object as an argument to 
parallel python. After some debugging I spotted a design issue in your code.

configobj.Section is a subclass of dict but it doesn't overwrite the 
pickle hook __reduce__. Pickling a section or configobj keeps the data 
in self (aka the dict) but not the data in self.__dict__. I came up with 
a quick hotfix for the problem.

# ---
import configobj
import copy_reg

def configobj_factory(cls):
    return cls.__new__(cls)

copy_reg.constructor(configobj_factory)

class SectionPatch(object):

    def __setstate__(self, state):
        dict.update(self, state[0])
        self.__dict__.update(state[1])

    def __reduce__(self):
        state = (dict(self), dict(self.__dict__))
        return (configobj_factory, (self.__class__, ), state)

def patch(cls, patchcls):
    bases = cls.__bases__
    if not patchcls in bases:
        cls.__bases__ = (patchcls,) + bases

patch(configobj.Section, SectionPatch)
# ---

Greeting
Christian


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