ZODB: don't like self._p_changed

Thomas Guettler zopestoller at thomas-guettler.de
Thu Jan 9 13:58:49 CET 2003

Max M schrieb:
> Thomas Guettler wrote:
>> Max M schrieb:
>>> Probably not. How should an object know if a mutable subobject has 
>>> been changed?
>> The method "append" could set the flag.
> Then you would need to use specialized objects instead of the built in 
> objects. That would shurely be more cumbersome than setting the 
> persistence flag?

Yes, there a classes like PersistentList and PersistentMapping, but
this means I need to change my code.



my_list=some_other_list[1:] # now my_list is no more a persistent list

This means, I always need to keep in mind if a list is a peristent list
or not. That's like setting _p_changed=1.

1. Solution:

One solution could be to change the meaning of [] and {}.

import list_persistance
foo=[] # foo is now a persistent list.

I don't know if this is possible.

2. Solution:
Change the functions of list and mapping datatypes to set _p_changed if 
the content was changed. This might decrease performance for 
nonpersistent application. But since there changes need to be 
implemented in the python core, they would be in C.


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