third_party/WebKit/Source/wtf/ArrayBuffer.h

   1 /*
   2  * Copyright (C) 2009 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 #ifndef ArrayBuffer_h
  27 #define ArrayBuffer_h
  28
  29 #include "wtf/ArrayBufferContents.h"
  30 #include "wtf/HashSet.h"
  31 #include "wtf/PassRefPtr.h"
  32 #include "wtf/RefCounted.h"
  33 #include "wtf/WTFExport.h"
  34
  35 namespace WTF {
  36
  37 class ArrayBuffer;
  38 class ArrayBufferView;
  39
  40 class WTF_EXPORT ArrayBuffer : public RefCounted<ArrayBuffer> {
  41 public:
  42     static inline PassRefPtr<ArrayBuffer> create(unsigned numElements, unsigned elementByteSize);
  43     static inline PassRefPtr<ArrayBuffer> create(ArrayBuffer*);
  44     static inline PassRefPtr<ArrayBuffer> create(const void* source, unsigned byteLength);
  45     static inline PassRefPtr<ArrayBuffer> create(ArrayBufferContents&);
  46
  47     static inline PassRefPtr<ArrayBuffer> createOrNull(unsigned numElements, unsigned elementByteSize);
  48
  49     // Only for use by XMLHttpRequest::responseArrayBuffer and Internals::serializeObject
  50     // (through DOMArrayBuffer::createUninitialized).
  51     static inline PassRefPtr<ArrayBuffer> createUninitialized(unsigned numElements, unsigned elementByteSize);
  52
  53     static inline PassRefPtr<ArrayBuffer> createShared(unsigned numElements, unsigned elementByteSize);
  54     static inline PassRefPtr<ArrayBuffer> createShared(const void* source, unsigned byteLength);
  55
  56     inline void* data();
  57     inline const void* data() const;
  58     inline unsigned byteLength() const;
  59
  60     // Creates a new ArrayBuffer object with copy of bytes in this object
  61     // ranging from |begin| upto but not including |end|.
  62     inline PassRefPtr<ArrayBuffer> slice(int begin, int end) const;
  63     inline PassRefPtr<ArrayBuffer> slice(int begin) const;
  64
  65     void addView(ArrayBufferView*);
  66     void removeView(ArrayBufferView*);
  67
  68     bool transfer(ArrayBufferContents&);
  69     bool shareContentsWith(ArrayBufferContents&);
  70     bool isNeutered() const { return m_isNeutered; }
  71     bool isShared() const { return m_contents.isShared(); }
  72
  73     ~ArrayBuffer() { }
  74
  75 protected:
  76     inline explicit ArrayBuffer(ArrayBufferContents&);
  77
  78 private:
  79     static inline PassRefPtr<ArrayBuffer> create(unsigned numElements, unsigned elementByteSize, ArrayBufferContents::InitializationPolicy);
  80     static inline PassRefPtr<ArrayBuffer> createOrNull(unsigned numElements, unsigned elementByteSize, ArrayBufferContents::InitializationPolicy);
  81     static inline PassRefPtr<ArrayBuffer> createShared(unsigned numElements, unsigned elementByteSize, ArrayBufferContents::InitializationPolicy);
  82
  83     inline PassRefPtr<ArrayBuffer> sliceImpl(unsigned begin, unsigned end) const;
  84     inline unsigned clampIndex(int index) const;
  85     static inline int clampValue(int x, int left, int right);
  86
  87     ArrayBufferContents m_contents;
  88     ArrayBufferView* m_firstView;
  89     bool m_isNeutered;
  90 };
  91
  92 int ArrayBuffer::clampValue(int x, int left, int right)
  93 {
  94     ASSERT(left <= right);
  95     if (x < left)
  96         x = left;
  97     if (right < x)
  98         x = right;
  99     return x;
 100 }
 101
 102 PassRefPtr<ArrayBuffer> ArrayBuffer::create(unsigned numElements, unsigned elementByteSize)
 103 {
 104     return create(numElements, elementByteSize, ArrayBufferContents::ZeroInitialize);
 105 }
 106
 107 PassRefPtr<ArrayBuffer> ArrayBuffer::create(ArrayBuffer* other)
 108 {
 109     // TODO(binji): support creating a SharedArrayBuffer by copying another ArrayBuffer?
 110     ASSERT(!other->isShared());
 111     return ArrayBuffer::create(other->data(), other->byteLength());
 112 }
 113
 114 PassRefPtr<ArrayBuffer> ArrayBuffer::create(const void* source, unsigned byteLength)
 115 {
 116     ArrayBufferContents contents(byteLength, 1, ArrayBufferContents::NotShared, ArrayBufferContents::ZeroInitialize);
 117     RELEASE_ASSERT(contents.data());
 118     RefPtr<ArrayBuffer> buffer = adoptRef(new ArrayBuffer(contents));
 119     memcpy(buffer->data(), source, byteLength);
 120     return buffer.release();
 121 }
 122
 123 PassRefPtr<ArrayBuffer> ArrayBuffer::create(ArrayBufferContents& contents)
 124 {
 125     RELEASE_ASSERT(contents.data());
 126     return adoptRef(new ArrayBuffer(contents));
 127 }
 128
 129 PassRefPtr<ArrayBuffer> ArrayBuffer::createOrNull(unsigned numElements, unsigned elementByteSize)
 130 {
 131     return createOrNull(numElements, elementByteSize, ArrayBufferContents::ZeroInitialize);
 132 }
 133
 134 PassRefPtr<ArrayBuffer> ArrayBuffer::createUninitialized(unsigned numElements, unsigned elementByteSize)
 135 {
 136     return create(numElements, elementByteSize, ArrayBufferContents::DontInitialize);
 137 }
 138
 139 PassRefPtr<ArrayBuffer> ArrayBuffer::create(unsigned numElements, unsigned elementByteSize, ArrayBufferContents::InitializationPolicy policy)
 140 {
 141     ArrayBufferContents contents(numElements, elementByteSize, ArrayBufferContents::NotShared, policy);
 142     RELEASE_ASSERT(contents.data());
 143     return adoptRef(new ArrayBuffer(contents));
 144 }
 145
 146 PassRefPtr<ArrayBuffer> ArrayBuffer::createOrNull(unsigned numElements, unsigned elementByteSize, ArrayBufferContents::InitializationPolicy policy)
 147 {
 148     ArrayBufferContents contents(numElements, elementByteSize, ArrayBufferContents::NotShared, policy);
 149     if (!contents.data())
 150         return nullptr;
 151     return adoptRef(new ArrayBuffer(contents));
 152 }
 153
 154 PassRefPtr<ArrayBuffer> ArrayBuffer::createShared(unsigned numElements, unsigned elementByteSize)
 155 {
 156     return createShared(numElements, elementByteSize, ArrayBufferContents::ZeroInitialize);
 157 }
 158
 159 PassRefPtr<ArrayBuffer> ArrayBuffer::createShared(const void* source, unsigned byteLength)
 160 {
 161     ArrayBufferContents contents(byteLength, 1, ArrayBufferContents::Shared, ArrayBufferContents::ZeroInitialize);
 162     RELEASE_ASSERT(contents.data());
 163     RefPtr<ArrayBuffer> buffer = adoptRef(new ArrayBuffer(contents));
 164     memcpy(buffer->data(), source, byteLength);
 165     return buffer.release();
 166 }
 167
 168 PassRefPtr<ArrayBuffer> ArrayBuffer::createShared(unsigned numElements, unsigned elementByteSize, ArrayBufferContents::InitializationPolicy policy)
 169 {
 170     ArrayBufferContents contents(numElements, elementByteSize, ArrayBufferContents::Shared, policy);
 171     RELEASE_ASSERT(contents.data());
 172     return adoptRef(new ArrayBuffer(contents));
 173 }
 174
 175 ArrayBuffer::ArrayBuffer(ArrayBufferContents& contents)
 176     : m_firstView(0), m_isNeutered(false)
 177 {
 178     if (contents.isShared())
 179         contents.shareWith(m_contents);
 180     else
 181         contents.transfer(m_contents);
 182 }
 183
 184 void* ArrayBuffer::data()
 185 {
 186     return m_contents.data();
 187 }
 188
 189 const void* ArrayBuffer::data() const
 190 {
 191     return m_contents.data();
 192 }
 193
 194 unsigned ArrayBuffer::byteLength() const
 195 {
 196     return m_contents.sizeInBytes();
 197 }
 198
 199 PassRefPtr<ArrayBuffer> ArrayBuffer::slice(int begin, int end) const
 200 {
 201     return sliceImpl(clampIndex(begin), clampIndex(end));
 202 }
 203
 204 PassRefPtr<ArrayBuffer> ArrayBuffer::slice(int begin) const
 205 {
 206     return sliceImpl(clampIndex(begin), byteLength());
 207 }
 208
 209 PassRefPtr<ArrayBuffer> ArrayBuffer::sliceImpl(unsigned begin, unsigned end) const
 210 {
 211     unsigned size = begin <= end ? end - begin : 0;
 212     return ArrayBuffer::create(static_cast<const char*>(data()) + begin, size);
 213 }
 214
 215 unsigned ArrayBuffer::clampIndex(int index) const
 216 {
 217     unsigned currentLength = byteLength();
 218     if (index < 0)
 219         index = currentLength + index;
 220     return clampValue(index, 0, currentLength);
 221 }
 222
 223 } // namespace WTF
 224
 225 using WTF::ArrayBuffer;
 226
 227 #endif // ArrayBuffer_h