Bug 43933 – Improved Table Hit Testing and Painting Performance

• Status: RESOLVED
• Resolution: FIXED
• Component: Tables

[Fady Samuel]

Created attachment 64260 [details]
Table hit testing graph

Table hit testing performance in webkit is relatively poor especially when compared to Firefox. It is done currently by visiting every single cell in the table  until a cell is found that is interested in the hit. This can perform horribly as the table size gets larger. I have attached a log-log graph showing before and after performance of table hit testing as well as a comparison with firefox.

[Fady Samuel]

Created attachment 64261 [details]
Benchmark script

[Fady Samuel]

Created attachment 64263 [details]
Patch For Faster Table Hit Testing

[Fady Samuel]

As a real-world demo, this site's performance is SIGNIFICANTLY improved with this patch:

http://tekkub.net/

[Fady Samuel]

Created attachment 64277 [details]
128*128 table benchmark

[Dave Hyatt]

Comment on attachment 64263 [details]
Patch For Faster Table Hit Testing

Minusing.  Comments delivered on IRC.  The code can incorrectly paint a little too much.  Need some precise boundary detection and a simple repaint test etc.

[Fady Samuel]

Created attachment 64612 [details]
Revised Patch

Fixed as per dhyatt's comments.

[Fady Samuel]

Created attachment 64621 [details]
Revised Patch (Fixes merge conflict)

[Dave Hyatt]

Comment on attachment 64621 [details]
Revised Patch (Fixes merge conflict)

r=me

[WebKit Commit Bot]

Comment on attachment 64621 [details]
Revised Patch (Fixes merge conflict)

Rejecting patch 64621 from commit-queue.

Failed to run "[u'/Users/eseidel/Projects/CommitQueue/WebKitTools/Scripts/svn-apply', u'--reviewer', u'David Hyatt', u'--force']" exit_code: 255
Last 500 characters of output:
ng file LayoutTests/ChangeLog
Hunk #1 succeeded at 1 with fuzz 3.
patching file LayoutTests/fast/table/simple_paint.html
patching file LayoutTests/platform/chromium-linux/fast/table/simple_paint-expected.checksum
literal is only avaliable with the XS version at /Library/Perl/5.8.8/Compress/Zlib.pm line 9
BEGIN failed--compilation aborted at /Library/Perl/5.8.8/Compress/Zlib.pm line 9.
Compilation failed in require at /Users/eseidel/Projects/CommitQueue/WebKitTools/Scripts/VCSUtils.pm line 1662.

Full output: http://queues.webkit.org/results/3736294

[James Robinson]

Comment on attachment 64621 [details]
Revised Patch (Fixes merge conflict)

Clearing flags on attachment: 64621

Committed r65539: <http://trac.webkit.org/changeset/65539>

[James Robinson]

All reviewed patches have been landed.  Closing bug.

[James Robinson]

Landed by hand.  Eric, why did the commit queue barf on this?

[Eric Seidel (no email)]

We thought we had fixed this.  I just need to move the commit-queue to SnowLeopard to work around this and the CoreVideo media/compositing crash/timeouts.

[Eric Seidel (no email)]

This appears to be missing Mac results. :(

[Fady Samuel]

(In reply to comment #14)
> This appears to be missing Mac results. :(

Yup working on it.