Bug 71555

The goal of this bug is to measure the performance and memory consumption differences between WebCore imagedecoders and QImageDecoder, furthermore - based on the results and the discussions - we should decide either to keep the current QImageDecoder implementation or change to WebCore's imagedecoders as we changed for WebCore's one for the N9 browser. Setup: Slackware 13.1 - 32 bit, Intel(R) Core(TM)2 Duo CPU E6550 @ 2.33GHz, this is a dedicated pc for benchmarking purposes # Memory consumption (Maximum Resident Set Size (RSS), based on kernels smaps information): Methanol suite with 18 custom sites for benchmark imagedecoding. http://zoltan.sed.hu/WebKit/methanol_imgdecoder/fire.html?iter=1 WebCoreImageDecoders: avg 295 624 kbytes +/- 1.6% (min: 290 804 kbytes, max: 303 334 kbytes) QtImageDecoders: avg 293 556 kbytes +/- 2.1% (min: 286 052 kbytes, max: 303 804 kbytes) Methanol suite with the first individual 23 sites from alexa top100. (mirrored) http://zoltan.sed.hu/WebKit/methanolx/fire.html?iter=1 WebCoreImageDecoders: avg 70 856 kbytes +/- 2.5% (min: 68 772 kbytes, max: 73 736 kbytes) QtImageDecoders: avg 70 639 kbytes +/- 1.1% (min: 70 056 kbytes, max: 72 016 kbytes) As we see there are no big differences in the numbers, the memory consumption is almost the same with both type of implementation. # Performance (Methanol provided the results) http://zoltan.sed.hu/WebKit/methanol_imgdecoder/fire.html?iter=1 QtImageDecoders: avg 15 632 ms +/- 5.1% (min: 14 344ms, max: 16 406ms) WebCoreImageDecoders: avg 20 895 ms +/- 5.6% (min: 19 116ms, max: 22314ms) WebCoreImageDecoder is 33.6% slower. Methanol suite with the first individual 23 sites from alexa top100. (mirrored) http://zoltan.sed.hu/WebKit/methanolx/fire.html?iter=1 QtImageDecoders: avg 7 492ms +/- 6.5% (min: 7 124ms, max: 8 216ms) WebCoreImageDecoders: avg 7 798ms +/- 9.06% (min: 7 332ms, max: 9 153ms) WebCoreImageDecoder is 4.08% slower. Based on this results I think we will keep QImageDecoders, but I'm interested in your thoughts!