[Twisted-Python] DirDBM possible bug

[Jean-Paul Calderone]

On Fri, 9 Nov 2007 12:23:31 -0500, Christopher Zorn <christopher.zorn at gmail.com> wrote:
>On Nov 9, 2007 12:04 PM, Jean-Paul Calderone <exarkun at divmod.com> wrote:
>
>> On Fri, 09 Nov 2007 11:54:10 -0500, Itamar Shtull-Trauring <
>> itamar at itamarst.org> wrote:
>> >On Fri, 2007-11-09 at 11:20 -0500, Christopher Zorn wrote:
>> >> There is a bug, I have attached a patch. It would be cool if we could
>> >> get this fixed upstream. :) I guess I should file a ticket.
>> >
>> >Yes, please do.
>> >
>>
>> Certainly do, and we'll apply a patch (unit tests are required) as soon as
>> possible.
>>
>> However, I would strongly recommend against using DirDBM.  It's not very
>> good at all.
>>
>
>Well, this is a bug for pickling domish elements. It is not  exactly a
>dirdbm bug.
>

Still, I suggest not using DirDBM - or, more generally, anything based on
pickle for long-term persistence of objects.  Pickling is very complex and
there is no guarantee that an object from Twisted (eg, domish.Element) which
is pickled in Twisted X will be unpickleable in Twisted X+1.  If that is not
a problematic constraint, then perhaps using DirDBM is not a catastrophic
decision.

Jean-Paul