Add iterator object to iterate efficiently over an Element's attributes

Source/core/dom/DatasetDOMStringMap.cpp

 /*
  * Copyright (C) 2010 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 139 matching lines @@
 {
     m_element->deref();
 }
 #endif
 
 void DatasetDOMStringMap::getNames(Vector<String>& names)
 {
     if (!m_element->hasAttributes())
         return;
 
-    unsigned length = m_element->attributeCount();
-    for (unsigned i = 0; i < length; i++) {
-        const Attribute& attribute = m_element->attributeItem(i);
-        if (isValidAttributeName(attribute.localName()))
-            names.append(convertAttributeNameToPropertyName(attribute.localName()));
+    AttributeIteratorAccessor attributes = m_element->attributesIterator();
+    AttributeConstIterator end = attributes.end();
+    for (AttributeConstIterator it = attributes.begin(); it != end; ++it) {
+        if (isValidAttributeName(it->localName()))
+            names.append(convertAttributeNameToPropertyName(it->localName()));
     }
 }
 
 String DatasetDOMStringMap::item(const String& name)
 {
     if (!m_element->hasAttributes())
         return String();
 
-    unsigned length = m_element->attributeCount();
-    for (unsigned i = 0; i < length; i++) {
-        const Attribute& attribute = m_element->attributeItem(i);
-        if (propertyNameMatchesAttributeName(name, attribute.localName()))
-            return attribute.value();
+    AttributeIteratorAccessor attributes = m_element->attributesIterator();
+    AttributeConstIterator end = attributes.end();
+    for (AttributeConstIterator it = attributes.begin(); it != end; ++it) {
+        if (propertyNameMatchesAttributeName(name, it->localName()))
+            return it->value();
     }
 
     return String();
 }
 
 bool DatasetDOMStringMap::contains(const String& name)
 {
     if (!m_element->hasAttributes())
         return false;
 
-    unsigned length = m_element->attributeCount();
-    for (unsigned i = 0; i < length; i++) {
-        const Attribute& attribute = m_element->attributeItem(i);
-        if (propertyNameMatchesAttributeName(name, attribute.localName()))
+    AttributeIteratorAccessor attributes = m_element->attributesIterator();
+    AttributeConstIterator end = attributes.end();
+    for (AttributeConstIterator it = attributes.begin(); it != end; ++it) {
+        if (propertyNameMatchesAttributeName(name, it->localName()))
             return true;
     }
-
     return false;
 }
 
 void DatasetDOMStringMap::setItem(const String& name, const String& value, ExceptionState& exceptionState)
 {
     if (!isValidPropertyName(name)) {
         exceptionState.throwDOMException(SyntaxError, "'" + name + "' is not a valid property name.");
         return;
     }
 
@@ skipping 12 matching lines @@
     return false;
 }
 
 void DatasetDOMStringMap::trace(Visitor* visitor)
 {
     visitor->trace(m_element);
     DOMStringMap::trace(visitor);
 }
 
 } // namespace WebCore