1 /*
2 * Copyright (C) 2011 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 INC. AND ITS CONTRIBUTORS ``AS IS''
14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
23 * THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26 #include "config.h"
27 #include "CSSPrimitiveValueCache.h"
28
29 namespace WebCore {
30
CSSPrimitiveValueCache()31 CSSPrimitiveValueCache::CSSPrimitiveValueCache()
32 : m_colorTransparent(CSSPrimitiveValue::createColor(Color::transparent))
33 , m_colorWhite(CSSPrimitiveValue::createColor(Color::white))
34 , m_colorBlack(CSSPrimitiveValue::createColor(Color::black))
35 , m_pixelZero(CSSPrimitiveValue::create(0, CSSPrimitiveValue::CSS_PX))
36 , m_percentZero(CSSPrimitiveValue::create(0, CSSPrimitiveValue::CSS_PERCENTAGE))
37 , m_numberZero(CSSPrimitiveValue::create(0, CSSPrimitiveValue::CSS_NUMBER))
38 {
39 }
40
~CSSPrimitiveValueCache()41 CSSPrimitiveValueCache::~CSSPrimitiveValueCache()
42 {
43 }
44
createIdentifierValue(int ident)45 PassRefPtr<CSSPrimitiveValue> CSSPrimitiveValueCache::createIdentifierValue(int ident)
46 {
47 if (ident <= 0 || ident >= numCSSValueKeywords)
48 return CSSPrimitiveValue::createIdentifier(ident);
49
50 RefPtr<CSSPrimitiveValue> dummyValue;
51 pair<IdentifierValueCache::iterator, bool> entry = m_identifierValueCache.add(ident, dummyValue);
52 if (entry.second)
53 entry.first->second = CSSPrimitiveValue::createIdentifier(ident);
54 return entry.first->second;
55 }
56
createColorValue(unsigned rgbValue)57 PassRefPtr<CSSPrimitiveValue> CSSPrimitiveValueCache::createColorValue(unsigned rgbValue)
58 {
59 // These are the empty and deleted values of the hash table.
60 if (rgbValue == Color::transparent)
61 return m_colorTransparent;
62 if (rgbValue == Color::white)
63 return m_colorWhite;
64 // Just because it is common.
65 if (rgbValue == Color::black)
66 return m_colorBlack;
67
68 // Just wipe out the cache and start rebuilding if it gets too big.
69 const int maximumColorCacheSize = 512;
70 if (m_colorValueCache.size() > maximumColorCacheSize)
71 m_colorValueCache.clear();
72
73 RefPtr<CSSPrimitiveValue> dummyValue;
74 pair<ColorValueCache::iterator, bool> entry = m_colorValueCache.add(rgbValue, dummyValue);
75 if (entry.second)
76 entry.first->second = CSSPrimitiveValue::createColor(rgbValue);
77 return entry.first->second;
78 }
79
createValue(double value,CSSPrimitiveValue::UnitTypes type)80 PassRefPtr<CSSPrimitiveValue> CSSPrimitiveValueCache::createValue(double value, CSSPrimitiveValue::UnitTypes type)
81 {
82 // Small positive integers repeat often.
83 static const int maximumCacheableValue = 256;
84 if (value < 0 || value > maximumCacheableValue)
85 return CSSPrimitiveValue::create(value, type);
86
87 int intValue = static_cast<int>(value);
88 if (value != intValue)
89 return CSSPrimitiveValue::create(value, type);
90
91 IntegerValueCache* cache;
92 switch (type) {
93 case CSSPrimitiveValue::CSS_PX:
94 if (intValue == 0)
95 return m_pixelZero;
96 cache = &m_pixelValueCache;
97 break;
98 case CSSPrimitiveValue::CSS_PERCENTAGE:
99 if (intValue == 0)
100 return m_percentZero;
101 cache = &m_percentValueCache;
102 break;
103 case CSSPrimitiveValue::CSS_NUMBER:
104 if (intValue == 0)
105 return m_numberZero;
106 cache = &m_numberValueCache;
107 break;
108 default:
109 return CSSPrimitiveValue::create(value, type);
110 }
111
112 RefPtr<CSSPrimitiveValue> dummyValue;
113 pair<IntegerValueCache::iterator, bool> entry = cache->add(intValue, dummyValue);
114 if (entry.second)
115 entry.first->second = CSSPrimitiveValue::create(value, type);
116 return entry.first->second;
117 }
118
119 }
120