From: Thomas Vander Stichele email@example.com
Are there any active projects that use a database backend, twisted, persistent objects, and are freely available, that I can sneak a peek at for my further education ?
Take a look at my sAsync ("SQLAlchemy made Asynchronous") project at http://foss.eepatents.com/sAsync/. I think it does a lot of what you're looking for. I've got the lower-level foundation code unit tested and working fine, and am currently working on higher-level stuff like an asynchronously-accessible persistent "name:value" item store and a persistent dictionary that uses it.
The object you'll most want to get familiar with if you use sAsync is "AccessBroker" in the "database" module .
The synchronous-to-asynchronous interface problem, which must be dealt with by any Twisted-compatible DB-API that doesn't do the low-level network file or connections entirely on its own, is addressed in what I like to think is a pretty cool fashion via a priority queue that runs in a single, dedicated worker thread. See the "syncbridge" module for details .
By popular demand (well, one user to be exact), I've included a mildly informative "Usage" document at the site that may help explain how and why to use sAsync.
Best regards, Ed Suominen
--------------------------------------------  http://foss.eepatents.com/sAsync/browser/trunk/sasync/database.py  http://foss.eepatents.com/sAsync/browser/trunk/sasync/syncbridge.py