EDS DBus vs CORBA
Ah, Novell have released an initial report comparing the DBus and CORBA ports of EDS. As the author of the DBus port, I should make some observations.
The incorrect reporting of large numbers of contacts in a book view is very odd, and I've not seen that before. I'll try and replicate that locally, I did change some message limits so maybe they are being hit.
Occassional dbus_g_proxy_cancel_call assertions are known to happen. I've a potential fix locally, but it requires a patch to DBus, which hasn't been committed yet.
Now to the benchmarks. The primary optimisation target for my work has been in the book views, as these are the primary bottleneck in a real-world application. This is visible in Test 1, where the DBus port takes 17 seconds compared to 72 seconds for CORBA. A number of the optimisations I've made can be applied directly to the CORBA code too, and are currently sitting in Bugzilla.
Test 2, calling e_book_get_contacts() is interesting. It may be that verbose mode is enabled in DBus, which has a serious performance impact on large messages (and this is a very large message). Alternatively this difference may simply be due the message bus, which adds a layer of IPC (and thus string copies) which CORBA doesn't have. As very few real-world applications (I'd say none) use this function (it blocks the interface unlike book views which are asynchronous), this isn't a very meaningful benchmark in the scheme of things.
For the calendar, there has been no performance turning done at all. It's known that the calendar port to DBus isn't quite complete, and needs cleaning up and performance work.
Contacts
We've just open-sourced Contacts, our light addressbook that uses Evolution Data Server as a backend. Although it was designed for handheld devices, its very usable on desktops too. Chris Lord, who wrote it in the summer whilst interning at Opened Hand, has more details and screenshots.
