Title: [134962] trunk/Source/WebCore
- Revision
- 134962
- Author
- [email protected]
- Date
- 2012-11-16 09:54:27 -0800 (Fri, 16 Nov 2012)
Log Message
StyleResolver: Optimize sharing candidate evaluation for elements with shared attribute data.
<http://webkit.org/b/102507>
Reviewed by Antti Koivisto.
When evaluating two elements as potential style sharing candidate, we have a whole bunch of code
comparing the various attributes that would prevent sharing.
If the two elements both share the same ElementAttributeData, we can skip all those checks
since they are guaranteed to have equal attributes.
Cuts the time spent in canShareStyleWithElement() by 25% on the HTML5 spec at <http://whatwg.org/c>.
* css/StyleResolver.cpp:
(WebCore::haveIdenticalStyleAffectingAttributes):
(WebCore::StyleResolver::canShareStyleWithElement):
Modified Paths
Diff
Modified: trunk/Source/WebCore/ChangeLog (134961 => 134962)
--- trunk/Source/WebCore/ChangeLog 2012-11-16 17:51:30 UTC (rev 134961)
+++ trunk/Source/WebCore/ChangeLog 2012-11-16 17:54:27 UTC (rev 134962)
@@ -1,3 +1,22 @@
+2012-11-16 Andreas Kling <[email protected]>
+
+ StyleResolver: Optimize sharing candidate evaluation for elements with shared attribute data.
+ <http://webkit.org/b/102507>
+
+ Reviewed by Antti Koivisto.
+
+ When evaluating two elements as potential style sharing candidate, we have a whole bunch of code
+ comparing the various attributes that would prevent sharing.
+
+ If the two elements both share the same ElementAttributeData, we can skip all those checks
+ since they are guaranteed to have equal attributes.
+
+ Cuts the time spent in canShareStyleWithElement() by 25% on the HTML5 spec at <http://whatwg.org/c>.
+
+ * css/StyleResolver.cpp:
+ (WebCore::haveIdenticalStyleAffectingAttributes):
+ (WebCore::StyleResolver::canShareStyleWithElement):
+
2012-11-16 Byungwoo Lee <[email protected]>
[EFL][GTK] Build fix after r134955
Modified: trunk/Source/WebCore/css/StyleResolver.cpp (134961 => 134962)
--- trunk/Source/WebCore/css/StyleResolver.cpp 2012-11-16 17:51:30 UTC (rev 134961)
+++ trunk/Source/WebCore/css/StyleResolver.cpp 2012-11-16 17:54:27 UTC (rev 134962)
@@ -1152,6 +1152,44 @@
return element->isHTMLElement() && toHTMLElement(element)->hasDirectionAuto();
}
+static inline bool haveIdenticalStyleAffectingAttributes(StyledElement* a, StyledElement* b)
+{
+ if (a->attributeData() == b->attributeData())
+ return true;
+ if (a->fastGetAttribute(XMLNames::langAttr) != b->fastGetAttribute(XMLNames::langAttr))
+ return false;
+ if (a->fastGetAttribute(langAttr) != b->fastGetAttribute(langAttr))
+ return false;
+ if (a->fastGetAttribute(readonlyAttr) != b->fastGetAttribute(readonlyAttr))
+ return false;
+ // FIXME: This is probably not necessary.
+ if (a->fastGetAttribute(cellpaddingAttr) != b->fastGetAttribute(cellpaddingAttr))
+ return false;
+ if (a->hasClass()) {
+#if ENABLE(SVG)
+ // SVG elements require a (slow!) getAttribute comparision because "class" is an animatable attribute for SVG.
+ if (a->isSVGElement()) {
+ if (a->getAttribute(classAttr) != b->getAttribute(classAttr))
+ return false;
+ } else
+#endif
+ if (a->fastGetAttribute(classAttr) != b->fastGetAttribute(classAttr))
+ return false;
+ }
+
+ if (a->presentationAttributeStyle() && !attributeStylesEqual(a->presentationAttributeStyle(), b->presentationAttributeStyle()))
+ return false;
+
+#if ENABLE(PROGRESS_ELEMENT)
+ if (a->hasTagName(progressTag)) {
+ if (static_cast<HTMLProgressElement*>(a)->isDeterminate() != static_cast<HTMLProgressElement*>(b)->isDeterminate())
+ return false;
+ }
+#endif
+
+ return true;
+}
+
bool StyleResolver::canShareStyleWithElement(StyledElement* element) const
{
RenderStyle* style = element->renderStyle();
@@ -1192,29 +1230,15 @@
return false;
if (element == element->document()->cssTarget())
return false;
- if (element->fastGetAttribute(XMLNames::langAttr) != m_element->fastGetAttribute(XMLNames::langAttr))
+
+ if (!haveIdenticalStyleAffectingAttributes(element, m_styledElement))
return false;
- if (element->fastGetAttribute(langAttr) != m_element->fastGetAttribute(langAttr))
- return false;
- if (element->fastGetAttribute(readonlyAttr) != m_element->fastGetAttribute(readonlyAttr))
- return false;
- if (element->fastGetAttribute(cellpaddingAttr) != m_element->fastGetAttribute(cellpaddingAttr))
- return false;
+
if (element->hasID() && m_features.idsInRules.contains(element->idForStyleResolution().impl()))
return false;
if (element->hasScopedHTMLStyleChild())
return false;
-#if ENABLE(PROGRESS_ELEMENT)
- if (element->hasTagName(progressTag)) {
- ASSERT(m_element->hasTagName(progressTag));
- HTMLProgressElement* thisProgressElement = static_cast<HTMLProgressElement*>(element);
- HTMLProgressElement* otherProgressElement = static_cast<HTMLProgressElement*>(m_element);
- if (thisProgressElement->isDeterminate() != otherProgressElement->isDeterminate())
- return false;
- }
-#endif
-
// FIXME: We should share style for option and optgroup whenever possible.
// Before doing so, we need to resolve issues in HTMLSelectElement::recalcListItems
// and RenderMenuList::setText. See also https://bugs.webkit.org/show_bug.cgi?id=88405
@@ -1247,21 +1271,6 @@
if (elementHasDirectionAuto(element))
return false;
- if (element->hasClass()) {
-#if ENABLE(SVG)
- // SVG elements require a (slow!) getAttribute comparision because "class" is an animatable attribute for SVG.
- if (element->isSVGElement()) {
- if (element->getAttribute(classAttr) != m_element->getAttribute(classAttr))
- return false;
- } else
-#endif
- if (element->fastGetAttribute(classAttr) != m_element->fastGetAttribute(classAttr))
- return false;
- }
-
- if (element->presentationAttributeStyle() && !attributeStylesEqual(element->presentationAttributeStyle(), m_styledElement->presentationAttributeStyle()))
- return false;
-
if (additionalPresentationAttributeStyleA && !attributeStylesEqual(additionalPresentationAttributeStyleA, additionalPresentationAttributeStyleB))
return false;
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