PackageKit backend for Software Center: week 1 report

This week was a good week for coding, and the best part about it: most of my changes are now in s-c’s upstream trunk.

I started out trying to populate s-c database with only a few applications; this meant updating the update-software-center tool, and also changing some bits on the database update module. I was glad to discover that some functionality I have planned to develop in week 6 (parsing AppStream app-data xmls) was already there, thus making my job easier :-)

After that, work continued by abstracting backend parts, such as InstallBackend and TransactionsWatcher, and also isolating as much as posible apt and apt_pkg usage. I have then expanded the PackageInfo abstraction to implement a dictionary like interface, containing _Package objects (before that, apt.Package were returned). It took some small steps, and sometimes mistakes from my side, but in the end, I guess I have got it done right. Work still needs to be done regarding usage of candidate and installed properties (which currently are apt.Version objects), and also on AptCache try_install_and_*depends methods (this should be either abstracted, either made apt-backend specific.

At the end of the week, preparing the next point of focus, I have managed to get a developing environment with PackageKit with Python gobject introspection data. Here comes the bad news: the py GI for packagekit is not ready for prime time. Reasons for that: GI is relatively new, there are no other users of PK from Python (only C and Vala). With help from ximion, hughsie, dantti and tomeu (and many other kind souls on #PackageKit, #introspection or #python), we isolated the problem inside pygobject, apparently an incomplete implementation of GPtrArray. I hope to get it fixed next week :-) , so that I can continue work with PK.

Although I am a bit worried seeing segfaults in Python, it’s a sunny day out here (so I can finish my report on a non-technical note) so I’m sure that with help from these awesome people on IRC,  problem will be solved, and my project will continue according to the plan.

Next week: gi ninja and more PK!


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