Bug 190105
| Summary: | Setting a style height value to the existing value still triggers a clone of StyleBoxData and thus slows down RenderStyle::diff | ||
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| Product: | WebKit | Reporter: | Simon Fraser (smfr) <simon.fraser> |
| Component: | CSS | Assignee: | Nobody <webkit-unassigned> |
| Status: | RESOLVED INVALID | ||
| Severity: | Normal | CC: | koivisto, mitz, simon.fraser, zalan |
| Priority: | P2 | ||
| Version: | WebKit Nightly Build | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
Simon Fraser (smfr)
If script keeps setting style.height to the same value, RenderStyle::setHeight still triggers access() which clones StyleBoxData, thus making future calls to RenderStyle::diff slower, since the pointer comparison fails.
Probably true of most of the DataRef<> types.
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| Add attachment proposed patch, testcase, etc. |
Simon Fraser (smfr)
Seen in MotionMark leaves test.
Simon Fraser (smfr)
Actually SET_VAR() already does a compareEqual(), so we're good.