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

Source/core/dom/Node.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 1305 matching lines @@
 
     return true;
 }
 
 bool Node::isDefaultNamespace(const AtomicString& namespaceURIMaybeEmpty) const
 {
     const AtomicString& namespaceURI = namespaceURIMaybeEmpty.isEmpty() ? nullAtom : namespaceURIMaybeEmpty;
 
     switch (nodeType()) {
         case ELEMENT_NODE: {
-            const Element* elem = toElement(this);
+            const Element& element = toElement(*this);
 
-            if (elem->prefix().isNull())
-                return elem->namespaceURI() == namespaceURI;
+            if (element.prefix().isNull())
+                return element.namespaceURI() == namespaceURI;
 
-            if (elem->hasAttributes()) {
-                unsigned attributeCount = elem->attributeCount();
-                for (unsigned i = 0; i < attributeCount; ++i) {
-                    const Attribute& attr = elem->attributeItem(i);
-
-                    if (attr.localName() == xmlnsAtom)
-                        return attr.value() == namespaceURI;
+            if (element.hasAttributes()) {
+                AttributeIteratorAccessor attributes = element.attributesIterator();
+                AttributeConstIterator end = attributes.end();
+                for (AttributeConstIterator it = attributes.begin(); it != end; ++it) {
+                    if (it->localName() == xmlnsAtom)
+                        return it->value() == namespaceURI;
                 }
             }
 
             if (Element* parent = parentElement())
                 return parent->isDefaultNamespace(namespaceURI);
 
             return false;
         }
         case DOCUMENT_NODE:
             if (Element* de = toDocument(this)->documentElement())
@@ skipping 54 matching lines @@
 const AtomicString& Node::lookupNamespaceURI(const String& prefix) const
 {
     // Implemented according to
     // http://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/namespaces-algorithms.html#lookupNamespaceURIAlgo
 
     if (!prefix.isNull() && prefix.isEmpty())
         return nullAtom;
 
     switch (nodeType()) {
         case ELEMENT_NODE: {
-            const Element *elem = toElement(this);
+            const Element& element = toElement(*this);
 
-            if (!elem->namespaceURI().isNull() && elem->prefix() == prefix)
-                return elem->namespaceURI();
+            if (!element.namespaceURI().isNull() && element.prefix() == prefix)
+                return element.namespaceURI();
 
-            if (elem->hasAttributes()) {
-                unsigned attributeCount = elem->attributeCount();
-                for (unsigned i = 0; i < attributeCount; ++i) {
-                    const Attribute& attr = elem->attributeItem(i);
-
-                    if (attr.prefix() == xmlnsAtom && attr.localName() == prefix) {
-                        if (!attr.value().isEmpty())
-                            return attr.value();
-
+            if (element.hasAttributes()) {
+                AttributeIteratorAccessor attributes = element.attributesIterator();
+                AttributeConstIterator end = attributes.end();
+                for (AttributeConstIterator it = attributes.begin(); it != end; ++it) {
+                    if (it->prefix() == xmlnsAtom && it->localName() == prefix) {
+                        if (!it->value().isEmpty())
+                            return it->value();
                         return nullAtom;
                     }
-                    if (attr.localName() == xmlnsAtom && prefix.isNull()) {
-                        if (!attr.value().isEmpty())
-                            return attr.value();
-
+                    if (it->localName() == xmlnsAtom && prefix.isNull()) {
+                        if (!it->value().isEmpty())
+                            return it->value();
                         return nullAtom;
                     }
                 }
             }
             if (Element* parent = parentElement())
                 return parent->lookupNamespaceURI(prefix);
             return nullAtom;
         }
         case DOCUMENT_NODE:
             if (Element* de = toDocument(this)->documentElement())
@@ skipping 132 matching lines @@
     Vector<const Node*, 16> chain2;
     if (attr1)
         chain1.append(attr1);
     if (attr2)
         chain2.append(attr2);
 
     if (attr1 && attr2 && start1 == start2 && start1) {
         // We are comparing two attributes on the same node. Crawl our attribute map and see which one we hit first.
         const Element* owner1 = attr1->ownerElement();
         owner1->synchronizeAllAttributes();
-        unsigned length = owner1->attributeCount();
-        for (unsigned i = 0; i < length; ++i) {
+        AttributeIteratorAccessor attributes = owner1->attributesIterator();
+        AttributeConstIterator end = attributes.end();
+        for (AttributeConstIterator it = attributes.begin(); it != end; ++it) {
             // If neither of the two determining nodes is a child node and nodeType is the same for both determining nodes, then an
             // implementation-dependent order between the determining nodes is returned. This order is stable as long as no nodes of
             // the same nodeType are inserted into or removed from the direct container. This would be the case, for example,
             // when comparing two attributes of the same element, and inserting or removing additional attributes might change
             // the order between existing attributes.
-            const Attribute& attribute = owner1->attributeItem(i);
-            if (attr1->qualifiedName() == attribute.name())
+            if (attr1->qualifiedName() == it->name())
                 return DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC | DOCUMENT_POSITION_FOLLOWING;
-            if (attr2->qualifiedName() == attribute.name())
+            if (attr2->qualifiedName() == it->name())
                 return DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC | DOCUMENT_POSITION_PRECEDING;
         }
 
         ASSERT_NOT_REACHED();
         return DOCUMENT_POSITION_DISCONNECTED;
     }
 
     // If one node is in the document and the other is not, we must be disconnected.
     // If the nodes have different owning documents, they must be disconnected.  Note that we avoid
     // comparing Attr nodes here, since they return false from inDocument() all the time (which seems like a bug).
@@ skipping 973 matching lines @@
         node->showTreeForThis();
 }
 
 void showNodePath(const WebCore::Node* node)
 {
     if (node)
         node->showNodePathForThis();
 }
 
 #endif