blob: b5f721cae86b87a7de45d2d56e0f4ae1de57706c [file] [log] [blame]
/*
* Copyright (C) 2012, 2013 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. ``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
* 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.
*
*/
#include "config.h"
#include "DocumentSharedObjectPool.h"
#include "Element.h"
namespace WebCore {
inline unsigned attributeHash(const Vector<Attribute>& attributes)
{
return StringHasher::hashMemory(attributes.data(), attributes.size() * sizeof(Attribute));
}
inline bool hasSameAttributes(const Vector<Attribute>& attributes, ShareableElementData& elementData)
{
if (attributes.size() != elementData.length())
return false;
return !memcmp(attributes.data(), elementData.m_attributeArray, attributes.size() * sizeof(Attribute));
}
Ref<ShareableElementData> DocumentSharedObjectPool::cachedShareableElementDataWithAttributes(const Vector<Attribute>& attributes)
{
ASSERT(!attributes.isEmpty());
auto& cachedData = m_shareableElementDataCache.add(attributeHash(attributes), nullptr).iterator->value;
// FIXME: This prevents sharing when there's a hash collision.
if (cachedData && !hasSameAttributes(attributes, *cachedData))
return ShareableElementData::createWithAttributes(attributes);
if (!cachedData)
cachedData = ShareableElementData::createWithAttributes(attributes);
return *cachedData;
}
}