On Wed, May 19, 2010 at 10:40 AM, Vincent Pelletier <vinc...@nexedi.com> wrote: > Why not defining some kind of callbacks in Storage API, which would allow to > plug such mechanisms in a storage rather than wrapping around it ?
Mainly because that would be a major change to the storage API. The majority of storage methods would be affected by such a change. It would require reimplementing all existing storages. Also note that you often want to control where transfornations are applied. For example, when using ZEO, I want to normally compress and decompress on the client, so methods like load and store on the server shouldn't do any transformation, however, packing and conflict resolution on the server does need to deal with data transformations. To handle this use case would require passing 4 callbacks. If you want to combine transformation, for example compression and encryption, you'd need to layer the callbacks. Even with it's problems, a layered storage model seems cleaner to me. Jim -- Jim Fulton _______________________________________________ For more information about ZODB, see the ZODB Wiki: http://www.zope.org/Wikis/ZODB/ ZODB-Dev mailing list - ZODB-Dev@zope.org https://mail.zope.org/mailman/listinfo/zodb-dev
