dojox.gfx: Performance degradation in version 1.6 in IE ‎(VML)

[yehuda]

Performance in IE7 and IE8 (VML) has deteriorated dramatically in version 1.6 of dojox.gfx compared to 1.5

To reproduce the issue, I used the 100 circles demo ​http://download.dojotoolkit.org/release-1.6.0/dojo-release-1.6.0/dojox/gfx/demos/circles.html and added some timers inside the code. I ran each test with 50, 100, 150, and 200 circles using version 1.5 and 1.6 and found that performance gets exponentially bad as the number of circles get large. See the numbers below and the attached graph showing the response time as a function of the number of circles and dojo's version.

Dojo 1.5: 50 circles in 0.13 seconds; 100 circles in 0.25 seconds; 150 circles in 0.41 seconds; 200 circles in 0.56 seconds Dojo 1.6: 50 circles in 0.69 seconds; 100 circles in 2.69 seconds; 150 circles in 6.14 seconds; 200 circles in 11.75 seconds

This looks like a side-effect of the fix to #9624

[yehuda]

Performance degradation in dojox.gfx 1.6

[Kenneth G. Franqueiro]

I don't suppose there's any chance of this getting looked at for 1.7 considering how late in the cycle we are? I've seen a number of threads on the mailing list by people running into this, it's quite unfortunate if it remains an issue for another whole cycle.

[Chris Mitchell]

Discussed with Eugene and Patrick at Dojo conf. This is an important defect to fix before 1.7 ga. Rather than backing out #9624, we will default behavior to the fully functional #9624 behavior, but add a config setting to disable 9624 for VML.

[Patrick Ruzand]

Fix as discussed at dojoconf. Behavior can be chosen via the config.fixVmlAdd flag. Default is to enable the patched behavior. false revert to 1.5 impl (solve perf. issue, but might be buggy)

[Eugene Lazutkin]

The patch is totally fine --- exactly in line with what we discussed. Please commit it.

[Patrick Ruzand]

After some discussions, seems more natural to have the performance-friendly behavior by default. Reworked patch accordingly (set fixVmlAdd to true to enable #9624 fix)

[Patrick Ruzand]

In [26722]:

fix performance regression. #9624 patch should now be explicitly enabled via a djConfig flag (fixVmlAdd:true), disabled by default., fixes #12456, refs #9624

[Patrick Ruzand]

In [28142]:

backport vml perf regression patch, refs #12456.