Title: [136615] trunk/Source/WebCore
- Revision
- 136615
- Author
- [email protected]
- Date
- 2012-12-04 20:05:33 -0800 (Tue, 04 Dec 2012)
Log Message
Style sharing: Allow sharing between elements with classes not referenced by any selectors.
<http://webkit.org/b/103925>
Reviewed by Antti Koivisto.
When looking for elements that can share style, instead of blindly rejecting candidates with
a different "class" attribute, check if it's actually referenced by any of the tracked style rules.
It's surprisingly common for web pages to have elements with classes to which no rules apply,
mediawiki content is especially good at this.
~2100 new sharing "hits" on <https://en.wikipedia.org/wiki/Steve_Jobs>.
* css/StyleResolver.cpp:
(WebCore::StyleResolver::canShareStyleWithElement):
Don't bail early if the two elements have different return values for hasClass().
(WebCore::StyleResolver::classNamesAffectedByRules):
Helper function that returns whether a SpaceSplitString contains a class name referenced
by any style rules.
(WebCore::StyleResolver::sharingCandidateHasIdenticalStyleAffectingAttributes):
Make this a member function since we need access to m_features.classesInRules.
* css/StyleResolver.h:
(StyleResolver):
* css/StyleResolver.cpp:
(WebCore::StyleResolver::locateSharedStyle):
Cache whether the element we're resolving style for has a "class" attribute referenced by style rules.
Modified Paths
Diff
Modified: trunk/Source/WebCore/ChangeLog (136614 => 136615)
--- trunk/Source/WebCore/ChangeLog 2012-12-05 04:01:17 UTC (rev 136614)
+++ trunk/Source/WebCore/ChangeLog 2012-12-05 04:05:33 UTC (rev 136615)
@@ -1,3 +1,38 @@
+2012-12-04 Andreas Kling <[email protected]>
+
+ Style sharing: Allow sharing between elements with classes not referenced by any selectors.
+ <http://webkit.org/b/103925>
+
+ Reviewed by Antti Koivisto.
+
+ When looking for elements that can share style, instead of blindly rejecting candidates with
+ a different "class" attribute, check if it's actually referenced by any of the tracked style rules.
+ It's surprisingly common for web pages to have elements with classes to which no rules apply,
+ mediawiki content is especially good at this.
+
+ ~2100 new sharing "hits" on <https://en.wikipedia.org/wiki/Steve_Jobs>.
+
+ * css/StyleResolver.cpp:
+ (WebCore::StyleResolver::canShareStyleWithElement):
+
+ Don't bail early if the two elements have different return values for hasClass().
+
+ (WebCore::StyleResolver::classNamesAffectedByRules):
+
+ Helper function that returns whether a SpaceSplitString contains a class name referenced
+ by any style rules.
+
+ (WebCore::StyleResolver::sharingCandidateHasIdenticalStyleAffectingAttributes):
+
+ Make this a member function since we need access to m_features.classesInRules.
+
+ * css/StyleResolver.h:
+ (StyleResolver):
+ * css/StyleResolver.cpp:
+ (WebCore::StyleResolver::locateSharedStyle):
+
+ Cache whether the element we're resolving style for has a "class" attribute referenced by style rules.
+
2012-12-04 Silvia Pfeiffer <[email protected]>
Refactor Media Control Elements to remove code duplication.
Modified: trunk/Source/WebCore/css/StyleResolver.cpp (136614 => 136615)
--- trunk/Source/WebCore/css/StyleResolver.cpp 2012-12-05 04:01:17 UTC (rev 136614)
+++ trunk/Source/WebCore/css/StyleResolver.cpp 2012-12-05 04:05:33 UTC (rev 136615)
@@ -961,6 +961,15 @@
#endif
}
+bool StyleResolver::classNamesAffectedByRules(const SpaceSplitString& classNames) const
+{
+ for (unsigned i = 0; i < classNames.size(); ++i) {
+ if (m_features.classesInRules.contains(classNames[i].impl()))
+ return true;
+ }
+ return false;
+}
+
inline void StyleResolver::initElement(Element* e)
{
if (m_element != e) {
@@ -1134,32 +1143,38 @@
return element->isHTMLElement() && toHTMLElement(element)->hasDirectionAuto();
}
-static inline bool haveIdenticalStyleAffectingAttributes(StyledElement* a, StyledElement* b)
+bool StyleResolver::sharingCandidateHasIdenticalStyleAffectingAttributes(StyledElement* sharingCandidate) const
{
- if (a->attributeData() == b->attributeData())
+ if (m_element->attributeData() == sharingCandidate->attributeData())
return true;
- if (a->fastGetAttribute(XMLNames::langAttr) != b->fastGetAttribute(XMLNames::langAttr))
+ if (m_element->fastGetAttribute(XMLNames::langAttr) != sharingCandidate->fastGetAttribute(XMLNames::langAttr))
return false;
- if (a->fastGetAttribute(langAttr) != b->fastGetAttribute(langAttr))
+ if (m_element->fastGetAttribute(langAttr) != sharingCandidate->fastGetAttribute(langAttr))
return false;
- if (a->hasClass()) {
+
+ if (!m_elementAffectedByClassRules) {
+ if (sharingCandidate->hasClass() && classNamesAffectedByRules(sharingCandidate->classNames()))
+ return false;
+ } else if (sharingCandidate->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))
+ if (m_element->isSVGElement()) {
+ if (m_element->getAttribute(classAttr) != sharingCandidate->getAttribute(classAttr))
return false;
- } else
+ } else {
#endif
- if (a->attributeData()->classNames() != b->attributeData()->classNames())
- return false;
- }
+ if (m_element->classNames() != sharingCandidate->classNames())
+ return false;
+ }
+ } else
+ return false;
- if (a->presentationAttributeStyle() != b->presentationAttributeStyle())
+ if (m_styledElement->presentationAttributeStyle() != sharingCandidate->presentationAttributeStyle())
return false;
#if ENABLE(PROGRESS_ELEMENT)
- if (a->hasTagName(progressTag)) {
- if (static_cast<HTMLProgressElement*>(a)->isDeterminate() != static_cast<HTMLProgressElement*>(b)->isDeterminate())
+ if (m_element->hasTagName(progressTag)) {
+ if (static_cast<HTMLProgressElement*>(m_element)->isDeterminate() != static_cast<HTMLProgressElement*>(sharingCandidate)->isDeterminate())
return false;
}
#endif
@@ -1177,8 +1192,6 @@
return false;
if (element->tagQName() != m_element->tagQName())
return false;
- if (element->hasClass() != m_element->hasClass())
- return false;
if (element->inlineStyle())
return false;
if (element->needsStyleRecalc())
@@ -1199,7 +1212,7 @@
return false;
if (element == element->document()->cssTarget())
return false;
- if (!haveIdenticalStyleAffectingAttributes(element, m_styledElement))
+ if (!sharingCandidateHasIdenticalStyleAffectingAttributes(element))
return false;
if (element->additionalPresentationAttributeStyle() != m_styledElement->additionalPresentationAttributeStyle())
return false;
@@ -1293,6 +1306,10 @@
if (elementHasDirectionAuto(m_element))
return 0;
+ // Cache whether m_element is affected by any known class selectors.
+ // FIXME: This shouldn't be a member variable. The style sharing code could be factored out of StyleResolver.
+ m_elementAffectedByClassRules = m_element && m_element->hasClass() && classNamesAffectedByRules(m_element->classNames());
+
// Check previous siblings and their cousins.
unsigned count = 0;
unsigned visitedNodeCount = 0;
Modified: trunk/Source/WebCore/css/StyleResolver.h (136614 => 136615)
--- trunk/Source/WebCore/css/StyleResolver.h 2012-12-05 04:01:17 UTC (rev 136614)
+++ trunk/Source/WebCore/css/StyleResolver.h 2012-12-05 04:05:33 UTC (rev 136615)
@@ -457,6 +457,9 @@
// the last reference to a style declaration are garbage collected.
void sweepMatchedPropertiesCache(Timer<StyleResolver>*);
+ bool classNamesAffectedByRules(const SpaceSplitString&) const;
+ bool sharingCandidateHasIdenticalStyleAffectingAttributes(StyledElement*) const;
+
unsigned m_matchedPropertiesCacheAdditionsSinceLastSweep;
typedef HashMap<unsigned, MatchedPropertiesCacheItem> MatchedPropertiesCache;
@@ -488,6 +491,7 @@
StyledElement* m_styledElement;
RenderRegion* m_regionForStyling;
EInsideLink m_elementLinkState;
+ bool m_elementAffectedByClassRules;
ContainerNode* m_parentNode;
CSSValue* m_lineHeightValue;
bool m_fontDirty;
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