January 2010 - webkit-dev - lists.webkit.org

Is it OK to remove Frame::setIsDisconnected() and isDisconnected() ?
by Sverrir Á. Berg 09 Apr '12

09 Apr '12

Working on a change in FrameTree and noticed that the checks in top() and parent() for 'checkForDisconnectedFrame' rely on a flag in Frame that as far as I can tell is never set.So my naive question is: Can I remove the corresponding code from Frame and FrameTree? If not I would like if somebody could explain how they are used so I don't break anything with my change. More detail: * My search for calls to Frame::setIsDisconnected reveals no callers in WebKit, Chromium or Google code search. * This functionality is disjoint from Frame::disconnectOwnerElement(). Thanks, Sverrir

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ImageLoader class
by Sergiy Byelozyorov 09 Jul '11

09 Jul '11

Hello, I am writing my own class using ImageLoader. Can somebody, please, help me with these questions: 1. How do I know that the image was loaded already? Can I set up callback somehow? 2. What should functions sourceURI() and dispatchLoadEvent() do? 3. What is pixel format for m_imageLoader.image()->image()->data()->data()? Is this the right way to access loaded image raw pixel data? 4. How can I handle animations (e.g. GIF files)? How do I know when the next image in the animation suquence is ready? Another callback? 5. Which image formats are supported? Can I add my own, like HDR? Thank you. Sergiy

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New requirement for building on Windows coming
by Chris Marrin 19 Oct '10

19 Oct '10

I've submitted a patch for accelerated compositing support on Windows. I hope to land it today. When I do it will require d3d9.lib to link. The feature will be turned off at first, but the build still needs to find the library. So the build-bots will need to be updated with DirectX 9.0 SDK Update (December 2004): http://www.microsoft.com/downloads/details.aspx?FamilyId=4E825A37-0C94-4421… You'll also need to add a path to this SDK in your MSDev Include and Library paths. The WebKit build-bots have already been updated, but external ones should make the changes in preparation. I'll br adding this info to webkit.org today. ----- ~Chris cmarrin(a)apple.com

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Running pixel tests on build.webkit.org
by Dimitri Glazkov 18 Mar '10

18 Mar '10

Are we planning to run pixel tests on the build bots? What's the general opinion here? We're running them over at Chromium and it seems like a really good idea. Case in point: Change http://trac.webkit.org/changeset/52900 broke a bunch of layout tests, all pixel results, and as such didn't register on the waterfall. I rolled out the change for now. :DG<

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global new/delete operator in WebKit
by Darin Adler 18 Feb '10

18 Feb '10

In the discussion in bug 32831, Yong Li asked me why we are planning, in the future, to remove the global new/delete operator in the Mac OS X WebKit. I decided it was worth answering here. Why does WebKit override operator new/delete? Historically on Mac OS X we got faster performance by using a custom malloc in the WebKit framework. At some future date we may discover that we no longer get a performance boost from this, and change this on Mac OS X. Ports to other platforms should not assume they need to use a custom allocator. It’s not a given that the FastMalloc code will be faster than using the platform malloc/free directly. But it was true in the first WebKit platform, Mac OS X, at the time. On Mac OS X, WebKit overrides the global operator new and delete to accomplish this. That was a big time saver — it made all new and delete use the faster allocator without code changes to all the classes. This particular technique works well for frameworks on Mac OS X. The inlined new and delete operator functions are marked “private extern”, which means they are visible inside the WebKit umbrella framework, but not seen by programs loading the framework. As long as we don’t have any new/delete allocations that cross the boundary between WebKit and the host application or other frameworks, this works fine. The new/delete invocations inside WebKit use the global new/delete defined inside the framework and the new/delete invocations outside WebKit are not affected. On some other platforms, though, this creates problems. An operator new and delete defined inside the WebKit library may not even work, depending on how C++ binds the symbols. The “private extern” extension may not work at all. Or the API for that platform might involve objects where the new is done inside the framework and the delete is done outside the framework. A simple solution would be to not override the global new/delete operator on those platforms. But some contributors want to use a custom allocator even though the global new/delete operator technique does not work on the platform they care about. So they began the massive task of adding code so that all allocations in WebKit were done through the custom allocator without relying on global new/delete. This project, see <https://bugs.webkit.org/show_bug.cgi?id=20422> began in 2008. The check-ins to put it into practice began las April <http://trac.webkit.org/changeset/42344>. We’ve still got a ways to go to get it deployed throughout the WebKit code. To keep this code maintained properly, I propose that no platform rely on overriding the global new/delete operator inside WebKit once the work is complete. Instead I think we can use global new/delete operator as a debugging technique to make sure people remember to use FastAllocBase and fastNew/Delete rather than invoking the built-in C++ new/delete by accident. This has no direct benefit for the Mac OS X version of WebKit, but I believe it’s helpful for the community to use that platform to support the others that wish to do this. Yong Li also asked about standard library functions calling new and delete, specifically STL. I believe we have been avoiding calling these functions in WebKit, but I may be mistaken. I haven’t discussed this tradeoff in detail with others at Apple, so I’m not absolutely certain what we’ll do in the Mac OS X version. If you have any questions or concerns, please bring them up here. -- Darin

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Refactoring the Clipboard class
by Daniel Cheng 07 Feb '10

07 Feb '10

Currently, the Clipboard class is used for both drag-and-drop data and for copy-and-paste operations. There are several limitations to the Clipboard class; you cannot use arbitrary types, and the system pasteboard is always cleared prior to dispatching cut/copy events to the page ( http://www.quirksmode.org/dom/events/cutcopypaste.html) I propose refactoring Clipboard and pulling more code into the base implementation. At a high-level, I'd like to change it so: - Clipboard has an internal HashMap cache mapping formats to data. Calling getData() and clearData() will only result in changes to the internal cache. - Clipboard can take an optional ClipboardDataSource in its constructor, which wraps access to the system pasteboard or native drag and drop data. This data source is read-only; data is never written back through the data source. If this data source is supplied, calls to getData() will only refer to the supplied data source. - Clipboard has one method to write back data in its cache back to the system pasteboard. > If setData() and clearData() were never called, this will be a no-op. This allows pages to prevent the default action from occurring on cut/copy without clearing the clipboard. > If setData() or clearData() were called, the system pasteboard will be cleared before the contents of the cache are written in. Not all types in the cache will necessarily be serialized to the system pasteboard; on Windows, application/x-my-crazy-mime-type won't be visible to other native apps. - Clipboard has one method to write back data in its cache to a native drag and drop object. Similar restrictions apply on types, depending on the platform. - All the types set by Javascript using setData() will magically work within WebKit. For drag and drop, this is simple. For copy and paste, it's a little more involved; WebKit will need to keep the Clipboard cache around globally, and install a clipboard listener to invalidate the cache if the clipboard changes outside of WebKit. With this change, the example snippets in the HTML5 draft for drag-and-drop should work out of the box. Doing this will greatly simplify platform implementations of Clipboard, and move access checks into a central location. It can be done in several patches alongside the existing code; the Clipboard functions affected by this change are virtual so base implementations can be added, and the original platform implementations removed as each platform implementation is updated.. Thoughts or comments? Daniel

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debug the webkit with visual studio 2005
by 赵经纬 05 Feb '10

05 Feb '10

HI: I am an neebie, i want to debug the webkit with visual studio 2005.now i have finished the steps: 1、 *Installing the Developer Tools* <http://webkit.org/building/tools.html> 2、*Getting WebKit* <http://webkit.org/building/checkout.html> 3、*Building WebKit* <http://webkit.org/building/build.html> now i want to run webkit, i open a Cygwin Shell and type this command in the shell WebKit/WebKitTools/Scripts/run-safari --debug but the result is: ERROR:couldn't determine installed safari path setting enviroments for using microsoft visual studio 2005 x86 tools How can i debug the webkit step by step? thank you!

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DOM Serialization?
by Christopher White 03 Feb '10

03 Feb '10

Is it possible to save the DOM resulting from the parsing of HTML / CSS into a file and then read it back instead of re-parsing the HTML (similar to Java object serialization). Does it save any time or is it a wash? I know there is a dump render tree function but does it save everything you need so that you can re-render the HTML page w/o the original HTML / CSS files?

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Reviewers Needed!
by Eric Seidel 02 Feb '10

02 Feb '10

https://bugs.webkit.org/buglist.cgi?field0-0-0=flagtypes.name&type0-0-0=equ… There are 30 bugs fewer than when I started an epic review-them-all two hours ago, but we still need more help! 71 patches up for review. Please knock a few off the list. An r- with comments is better than a rotten patch. -eric

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commit-queue is behind
by Eric Seidel 02 Feb '10

02 Feb '10

Sorry, the commit-queue got behind today (currently 19 patches in the queue) due to the bots being red much of the day and whole bunch of reviewing. :) http://build.webkit.org/console It should catch up over night. Thanks for your patience. -eric

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