[Zope] Posible memory leak?

[Dieter Maurer]

Dylan Reinhardt wrote at 2003-11-30 20:01 -0800:
 > ...
 > > You mean: when you do store *NON*-persistent objects within persistent
 > > objects, then ...
 > 
 > I meant what I said, but it's quite possible I was wrong.  :-)
 > 
 > > 
 > > Otherwise, any change in your Zope hierarchy would write the complete
 > > hierarchy (which, of course, is not the case) as "ObjectManager"
 > > (a persistent object) does store its content items (again
 > > persistent objects) as attributes.
 > 
 > But isn't that *exactly* the problem you face if you do this in a
 > non-ObjectManager object?  Any change to any part of the object
 > necessitates saving a copy of the *whole* object.  

You do *NOT* face this problem when you use persistent subobjects
whether they are in an ObjectManager or some other persistent object.

You *DO* face this problem when the subobjects are not persistent.

 > I'm under the distinct impression that ObjectManager is special in this
 > regard

This impression is not supported by the "ObjectManager" code ;-)

"ObjectManager" is not special with respect to persistence...

 > and that's why it's the recommended solution for storing any
 > non-trivial number of persistent objects.  I'd greatly appreciate a
 > correction if I've misunderstood something about that.

I think, I stated it already 3 times. Not sure, I can convince you.
But, you may look at the "ObjectManager" code (--> "OFS/ObjectManager.py").
You will find no magic with respect to persistence. It is not even
mentioned.


What "ObjectManager" does:

  *  provide creation/deletion/cloning hooks ("manage_afterAdd",
     "manage_beforeDelete", "manage_afterClone")

  *  handle "ownership" and "Owner" role

  *  "object*" methods to work with your content items

You loose these services when you do not derive from "ObjectManager".
But you do not loose elementary persistency behaviour.

-- 
Dieter