Hello all, Available at http://live.gnome.org/GAP/AtSpiDbusInvestigation is the results of an investigation into a move of the AT-SPI interface to a D-Bus transport. The investigation mainly looks at the relative performance of ORBit and D-Bus, but also details some architectural issues and a preliminary task list.
In brief: Performance: GOK and Orca were profiled to get a good idea of the type of traffic on the AT-SPI interface. Using this information the performance of some of the most common method calls were tested in D-Bus and ORBit. D-Bus is undoubtedly slower at most of the common method calls, 5-6x slower when making a call that passes one int as an argument. When passing more data per call this speed difference decreases. ORBit takes a long time to pass an Object reference, making D-Bus up to 1.5x faster at these method calls. Although D-Bus is the slower transport, looking at the calls made by Orca and GOK, we feel it will be possible to provide sensible caching that should mitigate this effect. Tasks: For a switchover to D-Bus a number of core libraries will need to have the transport mechanism changed: cspi, pyatspi, GAIL. There will also need to be a new Java accessibility back end. Some core D-Bus work is also needed, in the areas of interface specification, bindings and possibly optimisation. If you are interested please go and take a look at the wiki page. We'd really like to get every ones opinion on what the way forward for AT-SPI is in terms of its transport mechanism. Thanks Mark -- Mark Doffman, Codethink Ltd. - http://codethink.co.uk _______________________________________________ Gnome-accessibility-devel mailing list Gnome-accessibility-devel@gnome.org http://mail.gnome.org/mailman/listinfo/gnome-accessibility-devel
