webkitgtk-2.16.5HEADwebkitgtk-2.16.5master

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diff --git a/Source/WebCore/html/CachedHTMLCollection.h b/Source/WebCore/html/CachedHTMLCollection.h
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+/*
+ * Copyright (C) 2015 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
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+ * THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include "CollectionTraversal.h"
+#include "HTMLCollection.h"
+#include "HTMLElement.h"
+
+namespace WebCore {
+
+template <typename HTMLCollectionClass, CollectionTraversalType traversalType>
+class CachedHTMLCollection : public HTMLCollection {
+public:
+    CachedHTMLCollection(ContainerNode& base, CollectionType);
+
+    virtual ~CachedHTMLCollection();
+
+    unsigned length() const final { return m_indexCache.nodeCount(collection()); }
+    Element* item(unsigned offset) const override { return m_indexCache.nodeAt(collection(), offset); }
+    Element* namedItem(const AtomicString& name) const override;
+    size_t memoryCost() const final { return m_indexCache.memoryCost() + HTMLCollection::memoryCost(); }
+
+    // For CollectionIndexCache; do not use elsewhere.
+    using CollectionTraversalIterator = typename CollectionTraversal<traversalType>::Iterator;
+    CollectionTraversalIterator collectionBegin() const { return CollectionTraversal<traversalType>::begin(collection(), rootNode()); }
+    CollectionTraversalIterator collectionLast() const { return CollectionTraversal<traversalType>::last(collection(), rootNode()); }
+    CollectionTraversalIterator collectionEnd() const { return CollectionTraversal<traversalType>::end(rootNode()); }
+    void collectionTraverseForward(CollectionTraversalIterator& current, unsigned count, unsigned& traversedCount) const { CollectionTraversal<traversalType>::traverseForward(collection(), current, count, traversedCount); }
+    void collectionTraverseBackward(CollectionTraversalIterator& current, unsigned count) const { CollectionTraversal<traversalType>::traverseBackward(collection(), current, count); }
+    bool collectionCanTraverseBackward() const { return traversalType != CollectionTraversalType::CustomForwardOnly; }
+    void willValidateIndexCache() const { document().registerCollection(const_cast<CachedHTMLCollection<HTMLCollectionClass, traversalType>&>(*this)); }
+
+    void invalidateCache(Document&) override;
+
+    bool elementMatches(Element&) const;
+
+private:
+    HTMLCollectionClass& collection() { return static_cast<HTMLCollectionClass&>(*this); }
+    const HTMLCollectionClass& collection() const { return static_cast<const HTMLCollectionClass&>(*this); }
+
+    mutable CollectionIndexCache<HTMLCollectionClass, CollectionTraversalIterator> m_indexCache;
+};
+
+template <typename HTMLCollectionClass, CollectionTraversalType traversalType>
+CachedHTMLCollection<HTMLCollectionClass, traversalType>::CachedHTMLCollection(ContainerNode& base, CollectionType collectionType)
+    : HTMLCollection(base, collectionType)
+    , m_indexCache(collection())
+{ }
+
+template <typename HTMLCollectionClass, CollectionTraversalType traversalType>
+CachedHTMLCollection<HTMLCollectionClass, traversalType>::~CachedHTMLCollection()
+{
+    if (m_indexCache.hasValidCache(collection()))
+        document().unregisterCollection(*this);
+}
+
+template <typename HTMLCollectionClass, CollectionTraversalType traversalType>
+void CachedHTMLCollection<HTMLCollectionClass, traversalType>::invalidateCache(Document& document)
+{
+    HTMLCollection::invalidateCache(document);
+    if (m_indexCache.hasValidCache(collection())) {
+        document.unregisterCollection(*this);
+        m_indexCache.invalidate(collection());
+    }
+}
+
+template <typename HTMLCollectionClass, CollectionTraversalType traversalType>
+bool CachedHTMLCollection<HTMLCollectionClass, traversalType>::elementMatches(Element&) const
+{
+    // We call the elementMatches() method directly on the subclass instead for performance.
+    ASSERT_NOT_REACHED();
+    return false;
+}
+
+static inline bool nameShouldBeVisibleInDocumentAll(HTMLElement& element)
+{
+    // The document.all collection returns only certain types of elements by name,
+    // although it returns any type of element by id.
+    return element.hasTagName(HTMLNames::appletTag)
+        || element.hasTagName(HTMLNames::embedTag)
+        || element.hasTagName(HTMLNames::formTag)
+        || element.hasTagName(HTMLNames::imgTag)
+        || element.hasTagName(HTMLNames::inputTag)
+        || element.hasTagName(HTMLNames::objectTag)
+        || element.hasTagName(HTMLNames::selectTag);
+}
+
+static inline bool nameShouldBeVisibleInDocumentAll(Element& element)
+{
+    return is<HTMLElement>(element) && nameShouldBeVisibleInDocumentAll(downcast<HTMLElement>(element));
+}
+
+template <typename HTMLCollectionClass, CollectionTraversalType traversalType>
+Element* CachedHTMLCollection<HTMLCollectionClass, traversalType>::namedItem(const AtomicString& name) const
+{
+    // http://msdn.microsoft.com/workshop/author/dhtml/reference/methods/nameditem.asp
+    // This method first searches for an object with a matching id
+    // attribute. If a match is not found, the method then searches for an
+    // object with a matching name attribute, but only on those elements
+    // that are allowed a name attribute.
+
+    if (name.isEmpty())
+        return nullptr;
+
+    ContainerNode& root = rootNode();
+    if (traversalType != CollectionTraversalType::CustomForwardOnly && root.isInTreeScope()) {
+        Element* candidate = nullptr;
+
+        TreeScope& treeScope = root.treeScope();
+        if (treeScope.hasElementWithId(*name.impl())) {
+            if (!treeScope.containsMultipleElementsWithId(name))
+                candidate = treeScope.getElementById(name);
+        } else if (treeScope.hasElementWithName(*name.impl())) {
+            if (!treeScope.containsMultipleElementsWithName(name)) {
+                if ((candidate = treeScope.getElementByName(name))) {
+                    if (!is<HTMLElement>(*candidate))
+                        candidate = nullptr;
+                    else if (type() == DocAll && !nameShouldBeVisibleInDocumentAll(*candidate))
+                        candidate = nullptr;
+                }
+            }
+        } else
+            return nullptr;
+
+        if (candidate && collection().elementMatches(*candidate)) {
+            if (traversalType == CollectionTraversalType::ChildrenOnly ? candidate->parentNode() == &root : candidate->isDescendantOf(root))
+                return candidate;
+        }
+    }
+
+    return namedItemSlow(name);
+}
+
+} // namespace WebCore