third_party/WebKit/Source/core/dom/ElementData.cpp

   1 /*
   2  * Copyright (C) 2013 Google 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 are
   6  * met:
   7  *
   8  *     * Redistributions of source code must retain the above copyright
   9  * notice, this list of conditions and the following disclaimer.
  10  *     * Redistributions in binary form must reproduce the above
  11  * copyright notice, this list of conditions and the following disclaimer
  12  * in the documentation and/or other materials provided with the
  13  * distribution.
  14  *     * Neither the name of Google Inc. nor the names of its
  15  * contributors may be used to endorse or promote products derived from
  16  * this software without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  22  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  23  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  24  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29  */
  30
  31 #include "config.h"
  32 #include "core/dom/ElementData.h"
  33
  34 #include "core/css/StylePropertySet.h"
  35 #include "core/dom/QualifiedName.h"
  36 #include "wtf/Vector.h"
  37
  38 namespace blink {
  39
  40 struct SameSizeAsElementData : public RefCountedWillBeGarbageCollectedFinalized<SameSizeAsElementData> {
  41     unsigned bitfield;
  42     void* pointers[3];
  43 };
  44
  45 static_assert(sizeof(ElementData) == sizeof(SameSizeAsElementData), "ElementData should stay small");
  46
  47 static size_t sizeForShareableElementDataWithAttributeCount(unsigned count)
  48 {
  49     return sizeof(ShareableElementData) + sizeof(Attribute) * count;
  50 }
  51
  52 ElementData::ElementData()
  53     : m_isUnique(true)
  54     , m_arraySize(0)
  55     , m_presentationAttributeStyleIsDirty(false)
  56     , m_styleAttributeIsDirty(false)
  57     , m_animatedSVGAttributesAreDirty(false)
  58 {
  59 }
  60
  61 ElementData::ElementData(unsigned arraySize)
  62     : m_isUnique(false)
  63     , m_arraySize(arraySize)
  64     , m_presentationAttributeStyleIsDirty(false)
  65     , m_styleAttributeIsDirty(false)
  66     , m_animatedSVGAttributesAreDirty(false)
  67 {
  68 }
  69
  70 ElementData::ElementData(const ElementData& other, bool isUnique)
  71     : m_isUnique(isUnique)
  72     , m_arraySize(isUnique ? 0 : other.attributes().size())
  73     , m_presentationAttributeStyleIsDirty(other.m_presentationAttributeStyleIsDirty)
  74     , m_styleAttributeIsDirty(other.m_styleAttributeIsDirty)
  75     , m_animatedSVGAttributesAreDirty(other.m_animatedSVGAttributesAreDirty)
  76     , m_classNames(other.m_classNames)
  77     , m_idForStyleResolution(other.m_idForStyleResolution)
  78 {
  79     // NOTE: The inline style is copied by the subclass copy constructor since we don't know what to do with it here.
  80 }
  81
  82 #if ENABLE(OILPAN)
  83 void ElementData::finalizeGarbageCollectedObject()
  84 {
  85     if (m_isUnique)
  86         toUniqueElementData(this)->~UniqueElementData();
  87     else
  88         toShareableElementData(this)->~ShareableElementData();
  89 }
  90 #else
  91 void ElementData::destroy()
  92 {
  93     if (m_isUnique)
  94         delete toUniqueElementData(this);
  95     else
  96         delete toShareableElementData(this);
  97 }
  98 #endif
  99
 100 PassRefPtrWillBeRawPtr<UniqueElementData> ElementData::makeUniqueCopy() const
 101 {
 102     if (isUnique())
 103         return adoptRefWillBeNoop(new UniqueElementData(toUniqueElementData(*this)));
 104     return adoptRefWillBeNoop(new UniqueElementData(toShareableElementData(*this)));
 105 }
 106
 107 bool ElementData::isEquivalent(const ElementData* other) const
 108 {
 109     AttributeCollection attributes = this->attributes();
 110     if (!other)
 111         return attributes.isEmpty();
 112
 113     AttributeCollection otherAttributes = other->attributes();
 114     if (attributes.size() != otherAttributes.size())
 115         return false;
 116
 117     for (const Attribute& attribute : attributes) {
 118         const Attribute* otherAttr = otherAttributes.find(attribute.name());
 119         if (!otherAttr || attribute.value() != otherAttr->value())
 120             return false;
 121     }
 122     return true;
 123 }
 124
 125 DEFINE_TRACE(ElementData)
 126 {
 127     if (m_isUnique)
 128         toUniqueElementData(this)->traceAfterDispatch(visitor);
 129     else
 130         toShareableElementData(this)->traceAfterDispatch(visitor);
 131 }
 132
 133 DEFINE_TRACE_AFTER_DISPATCH(ElementData)
 134 {
 135     visitor->trace(m_inlineStyle);
 136 }
 137
 138 ShareableElementData::ShareableElementData(const Vector<Attribute>& attributes)
 139     : ElementData(attributes.size())
 140 {
 141     for (unsigned i = 0; i < m_arraySize; ++i)
 142         new (&m_attributeArray[i]) Attribute(attributes[i]);
 143 }
 144
 145 ShareableElementData::~ShareableElementData()
 146 {
 147     for (unsigned i = 0; i < m_arraySize; ++i)
 148         m_attributeArray[i].~Attribute();
 149 }
 150
 151 ShareableElementData::ShareableElementData(const UniqueElementData& other)
 152     : ElementData(other, false)
 153 {
 154     ASSERT(!other.m_presentationAttributeStyle);
 155
 156     if (other.m_inlineStyle) {
 157         m_inlineStyle = other.m_inlineStyle->immutableCopyIfNeeded();
 158     }
 159
 160     for (unsigned i = 0; i < m_arraySize; ++i)
 161         new (&m_attributeArray[i]) Attribute(other.m_attributeVector.at(i));
 162 }
 163
 164 PassRefPtrWillBeRawPtr<ShareableElementData> ShareableElementData::createWithAttributes(const Vector<Attribute>& attributes)
 165 {
 166 #if ENABLE(OILPAN)
 167     void* slot = Heap::allocate<ElementData>(sizeForShareableElementDataWithAttributeCount(attributes.size()));
 168 #else
 169     void* slot = WTF::fastMalloc(sizeForShareableElementDataWithAttributeCount(attributes.size()));
 170 #endif
 171     return adoptRefWillBeNoop(new (slot) ShareableElementData(attributes));
 172 }
 173
 174 UniqueElementData::UniqueElementData()
 175 {
 176 }
 177
 178 UniqueElementData::UniqueElementData(const UniqueElementData& other)
 179     : ElementData(other, true)
 180     , m_presentationAttributeStyle(other.m_presentationAttributeStyle)
 181     , m_attributeVector(other.m_attributeVector)
 182 {
 183     m_inlineStyle = other.m_inlineStyle ? other.m_inlineStyle->mutableCopy() : nullptr;
 184 }
 185
 186 UniqueElementData::UniqueElementData(const ShareableElementData& other)
 187     : ElementData(other, true)
 188 {
 189     // An ShareableElementData should never have a mutable inline StylePropertySet attached.
 190     ASSERT(!other.m_inlineStyle || !other.m_inlineStyle->isMutable());
 191     m_inlineStyle = other.m_inlineStyle;
 192
 193     unsigned length = other.attributes().size();
 194     m_attributeVector.reserveCapacity(length);
 195     for (unsigned i = 0; i < length; ++i)
 196         m_attributeVector.uncheckedAppend(other.m_attributeArray[i]);
 197 }
 198
 199 PassRefPtrWillBeRawPtr<UniqueElementData> UniqueElementData::create()
 200 {
 201     return adoptRefWillBeNoop(new UniqueElementData);
 202 }
 203
 204 PassRefPtrWillBeRawPtr<ShareableElementData> UniqueElementData::makeShareableCopy() const
 205 {
 206 #if ENABLE(OILPAN)
 207     void* slot = Heap::allocate<ElementData>(sizeForShareableElementDataWithAttributeCount(m_attributeVector.size()));
 208 #else
 209     void* slot = WTF::fastMalloc(sizeForShareableElementDataWithAttributeCount(m_attributeVector.size()));
 210 #endif
 211     return adoptRefWillBeNoop(new (slot) ShareableElementData(*this));
 212 }
 213
 214 DEFINE_TRACE_AFTER_DISPATCH(UniqueElementData)
 215 {
 216     visitor->trace(m_presentationAttributeStyle);
 217     ElementData::traceAfterDispatch(visitor);
 218 }
 219
 220 } // namespace blink