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:
ShareableElementDataCacheKey(const Attribute * attributes,unsigned attributeCount)36 ShareableElementDataCacheKey(const Attribute* attributes, unsigned attributeCount)
37 : m_attributes(attributes)
38 , m_attributeCount(attributeCount)
39 { }
40
operator !=(const ShareableElementDataCacheKey & other) const41 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
hash() const48 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:
ShareableElementDataCacheEntry(const ShareableElementDataCacheKey & k,PassRefPtr<ShareableElementData> v)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
cachedShareableElementDataWithAttributes(const Vector<Attribute> & attributes)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
DocumentSharedObjectPool()94 DocumentSharedObjectPool::DocumentSharedObjectPool()
95 {
96 }
97
~DocumentSharedObjectPool()98 DocumentSharedObjectPool::~DocumentSharedObjectPool()
99 {
100 }
101
102 }
103