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/*
* Copyright (C) 2015-2019 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 "HTMLCollection.h"
#include "HTMLElement.h"
#include <wtf/IsoMalloc.h>
namespace WebCore {
template <typename HTMLCollectionClass, CollectionTraversalType traversalType>
class CachedHTMLCollection : public HTMLCollection {
WTF_MAKE_ISO_NONALLOCATABLE(CachedHTMLCollection);
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 AtomString& name) const override;
size_t memoryCost() const final
{
// memoryCost() may be invoked concurrently from a GC thread, and we need to be careful about what data we access here and how.
// Accessing m_indexCache.memoryCost() is safe because because it doesn't involve any pointer chasing.
// HTMLCollection::memoryCost() ensures its own thread safety.
return m_indexCache.memoryCost() + HTMLCollection::memoryCost();
}
// For CollectionIndexCache; do not use elsewhere.
using Traversal = CollectionTraversal<traversalType>;
using Iterator = typename Traversal::Iterator;
auto collectionBegin() const { return Traversal::begin(collection(), rootNode()); }
auto collectionLast() const { return Traversal::last(collection(), rootNode()); }
void collectionTraverseForward(Iterator& current, unsigned count, unsigned& traversedCount) const { Traversal::traverseForward(collection(), current, count, traversedCount); }
void collectionTraverseBackward(Iterator& current, unsigned count) const { Traversal::traverseBackward(collection(), current, count); }
bool collectionCanTraverseBackward() const { return traversalType != CollectionTraversalType::CustomForwardOnly; }
void willValidateIndexCache() const { document().registerCollection(const_cast<CachedHTMLCollection&>(*this)); }
void invalidateCacheForDocument(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, Iterator> m_indexCache;
};
template <typename HTMLCollectionClass, CollectionTraversalType traversalType>
CachedHTMLCollection<HTMLCollectionClass, traversalType>::CachedHTMLCollection(ContainerNode& base, CollectionType collectionType)
: HTMLCollection(base, collectionType)
{
}
template <typename HTMLCollectionClass, CollectionTraversalType traversalType>
CachedHTMLCollection<HTMLCollectionClass, traversalType>::~CachedHTMLCollection()
{
if (m_indexCache.hasValidCache())
document().unregisterCollection(*this);
}
template <typename HTMLCollectionClass, CollectionTraversalType traversalType>
void CachedHTMLCollection<HTMLCollectionClass, traversalType>::invalidateCacheForDocument(Document& document)
{
HTMLCollection::invalidateCacheForDocument(document);
if (m_indexCache.hasValidCache()) {
document.unregisterCollection(*this);
m_indexCache.invalidate();
}
}
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)
{
// https://html.spec.whatwg.org/multipage/infrastructure.html#all-named-elements
return element.hasTagName(HTMLNames::aTag)
|| element.hasTagName(HTMLNames::appletTag)
|| element.hasTagName(HTMLNames::buttonTag)
|| element.hasTagName(HTMLNames::embedTag)
|| element.hasTagName(HTMLNames::formTag)
|| element.hasTagName(HTMLNames::frameTag)
|| element.hasTagName(HTMLNames::framesetTag)
|| element.hasTagName(HTMLNames::iframeTag)
|| element.hasTagName(HTMLNames::imgTag)
|| element.hasTagName(HTMLNames::inputTag)
|| element.hasTagName(HTMLNames::mapTag)
|| element.hasTagName(HTMLNames::metaTag)
|| element.hasTagName(HTMLNames::objectTag)
|| element.hasTagName(HTMLNames::selectTag)
|| element.hasTagName(HTMLNames::textareaTag);
}
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 AtomString& 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