QtWebKit code camp 08-10.12.2009

More than 30 developers gathered together for QtWebKit code camp in Wiesbaden, Germany.

Intro & general presentations

In the beginning there were three presentations:

• Henri Haverinen: QtWebKit roadmapping & using ​Qt Jira
• Kenneth Christiansen: How Web and ​QML fit together
• Akos Kiss: WebKit related activities at the University of Szeged​

After that people were split into five work stream: Performance & Architecture, User Interface, JavaScriptCore, QA and Relasing & Roadmapping

Performance & Architecture

1st Day

• Anti talking about tile based rendering. Working prototype using QImage exists, need to get support from Qt to draw to QPixmap from a thread, Discussion if tiling should be supported for everyone or just mobile/QGraphicsView
• BenjaminP talking about plans for Qt4.7 to regularily run benchmarks, automate and store results during the development.
• Talking about OOM handling, checking each allocation vs. just getting killed by the OS vs. getting signals from the OS and then stop loading...
• Zoltan talks about a valgrind skin to instrument memory usage including showing how much and who was allocating the memory, common call frames can be removed from the trace.

2nd Day

• Holger talks about the QtWebKitPerformanceWork and QtWebKitPerformanceUtilities and how the can be used to measure Qt performance. Comments included limiting the bandwidth used for the fake http server.
• Shortly discussed the RGB16 approach to save some memory by using color converting RGB32 images to RGB16, specially on symbian a 16bit backingstore exists and painting can be done in 16 bit.
• Shortly discussed using WebCore/platform/image-decoders. The downsampling is a feature one would like to use, also the performance appears to be better. We should explore using them.

User Interface

Java Script Core

QA

Informal presentation with discussion:

• Andras Becsi (bbandix): Problems with the current Qt DRT, + a tool to monitor and query historic test results
• Gabor Rapcsanyi (rgabor): Current buildbot setup and the future upgrade possibilities
• Csaba Osztrogonac (ossy): Qt build infrastructure and problems with incremental builds
• Tor Arne Vestbø (torarne): Cross platform layout-test results using SVG-fonts and automation of interpreting results

The discussion spawned off a few action points:

• Use automated tools to parse test results and give us more information about where we are
• Split of Qt buildbot into build and tests stages (makes it easier to detect Qt build breaks)
• Fix the Qt incremental build to detect dependencies in generated sources correctly
• Try to use SVG fonts to get the same results on mac,win,linux (++)

Roadmap & Releasing