[Zope-dev] Re: ThreadSafeCounter

[Steve Alexander]

Andy McKay wrote:

>> A simpler solution is to use a mounted storage that doesn't do undo, and 
>> stores changes in place.
> 
> You are the second person to answer with that. Would anyone care to give a
> quick how-to on how to mount a non-undoing storage, such as FileStorage

FileStorage is what the standard Data.fs is, and it supports undo.

> since this doesnt seem immediately obvious to me.

Take a look at ExternalMount, and at what's used in the CoreSessionTracking product.

I can't find a URL for ExternalMount at the moment. I'm using it though, so it *definitely* exists!


Also, see lib/python/ZODB/dbmStorage.py

"""Very Simple dbm-based ZODB storage
 
This storage provides for use of dbm files as storages that
don't support versions or Undo.  This may be useful when implementing
objects like hit counters that don't need or want to participate
in undo or versions.
"""                          

--
Steve Alexander
Software Engineer
Cat-Box limited
http://www.cat-box.net