Title: [148961] trunk/Source/WebCore
- Revision
- 148961
- Author
- [email protected]
- Date
- 2013-04-23 07:21:05 -0700 (Tue, 23 Apr 2013)
Log Message
Speed up ElementData::getAttributeItem(), which is hot.
<http://webkit.org/b/115031>
Reviewed by Antti Koivisto.
>From Blink r148622 by <[email protected]>.
The previous version had a couple of issues:
- Incurred new WTF::Vector::operator[] checks.
- Had a branch in _every_ loop iteration that checked whether the storage was Vector or array[] backed.
Both these issues are fixed, and CloneNodes.html seems reliably at +2%.
I also believe GetElement.html is maybe +1%.
For WebKit, also applied the same optimization to getAttributeItemIndex().
* dom/Element.h:
(WebCore::ElementData::attributeBase):
(WebCore::ElementData::getAttributeItemIndex):
(WebCore::ElementData::getAttributeItem):
(WebCore::ElementData::attributeItem):
Modified Paths
Diff
Modified: trunk/Source/WebCore/ChangeLog (148960 => 148961)
--- trunk/Source/WebCore/ChangeLog 2013-04-23 12:07:57 UTC (rev 148960)
+++ trunk/Source/WebCore/ChangeLog 2013-04-23 14:21:05 UTC (rev 148961)
@@ -1,3 +1,27 @@
+2013-04-23 Andreas Kling <[email protected]>
+
+ Speed up ElementData::getAttributeItem(), which is hot.
+ <http://webkit.org/b/115031>
+
+ Reviewed by Antti Koivisto.
+
+ From Blink r148622 by <[email protected]>.
+
+ The previous version had a couple of issues:
+ - Incurred new WTF::Vector::operator[] checks.
+ - Had a branch in _every_ loop iteration that checked whether the storage was Vector or array[] backed.
+
+ Both these issues are fixed, and CloneNodes.html seems reliably at +2%.
+ I also believe GetElement.html is maybe +1%.
+
+ For WebKit, also applied the same optimization to getAttributeItemIndex().
+
+ * dom/Element.h:
+ (WebCore::ElementData::attributeBase):
+ (WebCore::ElementData::getAttributeItemIndex):
+ (WebCore::ElementData::getAttributeItem):
+ (WebCore::ElementData::attributeItem):
+
2013-04-23 Antoine Quint <[email protected]>
Initial advance of text runs should be taken into account
Modified: trunk/Source/WebCore/dom/Element.h (148960 => 148961)
--- trunk/Source/WebCore/dom/Element.h 2013-04-23 12:07:57 UTC (rev 148960)
+++ trunk/Source/WebCore/dom/Element.h 2013-04-23 14:21:05 UTC (rev 148961)
@@ -110,6 +110,7 @@
friend class SVGElement;
#endif
+ const Attribute* attributeBase() const;
const Attribute* getAttributeItem(const AtomicString& name, bool shouldIgnoreAttributeCase) const;
size_t getAttributeItemIndexSlowCase(const AtomicString& name, bool shouldIgnoreAttributeCase) const;
@@ -940,6 +941,13 @@
return m_arraySize;
}
+inline const Attribute* ElementData::attributeBase() const
+{
+ if (m_isUnique)
+ return static_cast<const UniqueElementData*>(this)->m_attributeVector.data();
+ return static_cast<const ShareableElementData*>(this)->m_attributeArray;
+}
+
inline const StylePropertySet* ElementData::presentationAttributeStyle() const
{
if (!m_isUnique)
@@ -957,8 +965,9 @@
inline size_t ElementData::getAttributeItemIndex(const QualifiedName& name) const
{
- for (unsigned i = 0; i < length(); ++i) {
- if (attributeItem(i)->name().matches(name))
+ const Attribute* attributes = attributeBase();
+ for (unsigned i = 0, count = length(); i < count; ++i) {
+ if (attributes[i].name().matches(name))
return i;
}
return notFound;
@@ -968,15 +977,14 @@
// can tune the behavior (hasAttribute is case sensitive whereas getAttribute is not).
inline size_t ElementData::getAttributeItemIndex(const AtomicString& name, bool shouldIgnoreAttributeCase) const
{
- unsigned len = length();
+ const Attribute* attributes = attributeBase();
bool doSlowCheck = shouldIgnoreAttributeCase;
+ const AtomicString& caseAdjustedName = shouldIgnoreAttributeCase ? name.lower() : name;
- const AtomicString caseAdjustedName = shouldIgnoreAttributeCase ? name.lower() : name;
// Optimize for the case where the attribute exists and its name exactly matches.
- for (unsigned i = 0; i < len; ++i) {
- const Attribute* attribute = attributeItem(i);
- if (!attribute->name().hasPrefix()) {
- if (caseAdjustedName == attribute->localName())
+ for (unsigned i = 0, count = length(); i < count; ++i) {
+ if (!attributes[i].name().hasPrefix()) {
+ if (caseAdjustedName == attributes[i].localName())
return i;
} else
doSlowCheck = true;
@@ -989,9 +997,10 @@
inline const Attribute* ElementData::getAttributeItem(const QualifiedName& name) const
{
- for (unsigned i = 0; i < length(); ++i) {
- if (attributeItem(i)->name().matches(name))
- return attributeItem(i);
+ const Attribute* attributes = attributeBase();
+ for (unsigned i = 0, count = length(); i < count; ++i) {
+ if (attributes[i].name().matches(name))
+ return &attributes[i];
}
return 0;
}
@@ -999,9 +1008,7 @@
inline const Attribute* ElementData::attributeItem(unsigned index) const
{
ASSERT_WITH_SECURITY_IMPLICATION(index < length());
- if (m_isUnique)
- return &static_cast<const UniqueElementData*>(this)->m_attributeVector.at(index);
- return &static_cast<const ShareableElementData*>(this)->m_attributeArray[index];
+ return attributeBase() + index;
}
} // namespace
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