1 /* 2 * Copyright (C) 2012, 2013 Apple Inc. All Rights Reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY 14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR 17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY 21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 * 25 */ 26 27 #include "config.h" 28 #include "core/dom/DocumentSharedObjectPool.h" 29 30 #include "core/dom/Element.h" 31 32 namespace WebCore { 33 34 class ShareableElementDataCacheKey { 35 public: 36 ShareableElementDataCacheKey(const Attribute* attributes, unsigned attributeCount) 37 : m_attributes(attributes) 38 , m_attributeCount(attributeCount) 39 { } 40 41 bool operator!=(const ShareableElementDataCacheKey& other) const 42 { 43 if (m_attributeCount != other.m_attributeCount) 44 return true; 45 return memcmp(m_attributes, other.m_attributes, sizeof(Attribute) * m_attributeCount); 46 } 47 48 unsigned hash() const 49 { 50 return StringHasher::hashMemory(m_attributes, m_attributeCount * sizeof(Attribute)); 51 } 52 53 private: 54 const Attribute* m_attributes; 55 unsigned m_attributeCount; 56 }; 57 58 class ShareableElementDataCacheEntry { 59 public: 60 ShareableElementDataCacheEntry(const ShareableElementDataCacheKey& k, PassRefPtr<ShareableElementData> v) 61 : key(k) 62 , value(v) 63 { } 64 65 ShareableElementDataCacheKey key; 66 RefPtr<ShareableElementData> value; 67 }; 68 69 PassRefPtr<ShareableElementData> DocumentSharedObjectPool::cachedShareableElementDataWithAttributes(const Vector<Attribute>& attributes) 70 { 71 ASSERT(!attributes.isEmpty()); 72 73 ShareableElementDataCacheKey cacheKey(attributes.data(), attributes.size()); 74 unsigned cacheHash = cacheKey.hash(); 75 76 ShareableElementDataCache::iterator cacheIterator = m_shareableElementDataCache.add(cacheHash, nullptr).iterator; 77 if (cacheIterator->value && cacheIterator->value->key != cacheKey) 78 cacheHash = 0; 79 80 RefPtr<ShareableElementData> elementData; 81 if (cacheHash && cacheIterator->value) 82 elementData = cacheIterator->value->value; 83 else 84 elementData = ShareableElementData::createWithAttributes(attributes); 85 86 if (!cacheHash || cacheIterator->value) 87 return elementData.release(); 88 89 cacheIterator->value = adoptPtr(new ShareableElementDataCacheEntry(ShareableElementDataCacheKey(elementData->m_attributeArray, elementData->length()), elementData)); 90 91 return elementData.release(); 92 } 93 94 DocumentSharedObjectPool::DocumentSharedObjectPool() 95 { 96 } 97 98 DocumentSharedObjectPool::~DocumentSharedObjectPool() 99 { 100 } 101 102 } 103