Consistently cache ElementData::length() before loops

Source/core/dom/ElementData.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 82 matching lines @@
     if (isUnique())
         return adoptRef(new UniqueElementData(static_cast<const UniqueElementData&>(*this)));
     return adoptRef(new UniqueElementData(static_cast<const ShareableElementData&>(*this)));
 }
 
 bool ElementData::isEquivalent(const ElementData* other) const
 {
     if (!other)
         return isEmpty();
 
-    unsigned len = length();
-    if (len != other->length())
+    unsigned length = this->length();
+    if (length != other->length())
         return false;
 
-    for (unsigned i = 0; i < len; i++) {
+    for (unsigned i = 0; i < length; ++i) {
         const Attribute* attribute = attributeItem(i);
         const Attribute* otherAttr = other->getAttributeItem(attribute->name());
         if (!otherAttr || attribute->value() != otherAttr->value())
             return false;
     }
 
     return true;
 }
 
 size_t ElementData::getAttrIndex(Attr* attr) const
 {
     // This relies on the fact that Attr's QualifiedName == the Attribute's name.
-    for (unsigned i = 0; i < length(); ++i) {
+    unsigned length = this->length();
+    for (unsigned i = 0; i < length; ++i) {
         if (attributeItem(i)->name() == attr->qualifiedName())
             return i;
     }
     return kNotFound;
 }
 
 size_t ElementData::getAttributeItemIndexSlowCase(const AtomicString& name, bool shouldIgnoreAttributeCase) const
 {
     // Continue to checking case-insensitively and/or full namespaced names if necessary:
-    for (unsigned i = 0; i < length(); ++i) {
+    unsigned length = this->length();
+    for (unsigned i = 0; i < length; ++i) {
         const Attribute* attribute = attributeItem(i);
         // FIXME: Why check the prefix? Namespace is all that should matter
         // and all HTML/SVG attributes have a null namespace!
         if (!attribute->name().hasPrefix()) {
             if (shouldIgnoreAttributeCase && equalIgnoringCase(name, attribute->localName()))
                 return i;
         } else {
             // FIXME: Would be faster to do this comparison without calling toString, which
             // generates a temporary string by concatenation. But this branch is only reached
             // if the attribute name has a prefix, which is rare in HTML.
@@ skipping 48 matching lines @@
     m_inlineStyle = other.m_inlineStyle ? other.m_inlineStyle->mutableCopy() : nullptr;
 }
 
 UniqueElementData::UniqueElementData(const ShareableElementData& other)
     : ElementData(other, true)
 {
     // An ShareableElementData should never have a mutable inline StylePropertySet attached.
     ASSERT(!other.m_inlineStyle || !other.m_inlineStyle->isMutable());
     m_inlineStyle = other.m_inlineStyle;
 
-    m_attributeVector.reserveCapacity(other.length());
-    for (unsigned i = 0; i < other.length(); ++i)
+    unsigned length = other.length();
+    m_attributeVector.reserveCapacity(length);
+    for (unsigned i = 0; i < length; ++i)
         m_attributeVector.uncheckedAppend(other.m_attributeArray[i]);
 }
 
 PassRefPtr<UniqueElementData> UniqueElementData::create()
 {
     return adoptRef(new UniqueElementData);
 }
 
 PassRefPtr<ShareableElementData> UniqueElementData::makeShareableCopy() const
 {
     void* slot = WTF::fastMalloc(sizeForShareableElementDataWithAttributeCount(m_attributeVector.size()));
     return adoptRef(new (slot) ShareableElementData(*this));
 }
 
 Attribute* UniqueElementData::getAttributeItem(const QualifiedName& name)
 {
-    for (unsigned i = 0; i < length(); ++i) {
+    unsigned length = this->length();
+    for (unsigned i = 0; i < length; ++i) {
         if (m_attributeVector.at(i).name().matches(name))
             return &m_attributeVector.at(i);
     }
     return 0;
 }
 
 } // namespace WebCore