1/* 2 * Copyright (C) 2009, 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 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 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 ArrayBufferView_h 27#define ArrayBufferView_h 28 29#include "ArrayBuffer.h" 30#include "TypedArrayType.h" 31#include <algorithm> 32#include <limits.h> 33#include <wtf/PassRefPtr.h> 34#include <wtf/RefCounted.h> 35#include <wtf/RefPtr.h> 36 37namespace JSC { 38 39class JSArrayBufferView; 40class JSGlobalObject; 41class ExecState; 42 43class ArrayBufferView : public RefCounted<ArrayBufferView> { 44public: 45 virtual TypedArrayType getType() const = 0; 46 47 bool isNeutered() const 48 { 49 return !m_buffer || m_buffer->isNeutered(); 50 } 51 52 PassRefPtr<ArrayBuffer> buffer() const 53 { 54 if (isNeutered()) 55 return 0; 56 return m_buffer; 57 } 58 59 void* baseAddress() const 60 { 61 if (isNeutered()) 62 return 0; 63 return m_baseAddress; 64 } 65 66 unsigned byteOffset() const 67 { 68 if (isNeutered()) 69 return 0; 70 return m_byteOffset; 71 } 72 73 virtual unsigned byteLength() const = 0; 74 75 JS_EXPORT_PRIVATE void setNeuterable(bool flag); 76 bool isNeuterable() const { return m_isNeuterable; } 77 78 JS_EXPORT_PRIVATE virtual ~ArrayBufferView(); 79 80 // Helper to verify that a given sub-range of an ArrayBuffer is 81 // within range. 82 // FIXME: This should distinguish between alignment errors and bounds errors. 83 // https://bugs.webkit.org/show_bug.cgi?id=125391 84 template <typename T> 85 static bool verifySubRange( 86 PassRefPtr<ArrayBuffer> buffer, 87 unsigned byteOffset, 88 unsigned numElements) 89 { 90 unsigned byteLength = buffer->byteLength(); 91 if (sizeof(T) > 1 && byteOffset % sizeof(T)) 92 return false; 93 if (byteOffset > byteLength) 94 return false; 95 unsigned remainingElements = (byteLength - byteOffset) / sizeof(T); 96 if (numElements > remainingElements) 97 return false; 98 return true; 99 } 100 101 virtual JSArrayBufferView* wrap(ExecState*, JSGlobalObject*) = 0; 102 103protected: 104 JS_EXPORT_PRIVATE ArrayBufferView(PassRefPtr<ArrayBuffer>, unsigned byteOffset); 105 106 inline bool setImpl(ArrayBufferView*, unsigned byteOffset); 107 108 inline bool setRangeImpl(const char* data, size_t dataByteLength, unsigned byteOffset); 109 110 inline bool zeroRangeImpl(unsigned byteOffset, size_t rangeByteLength); 111 112 static inline void calculateOffsetAndLength( 113 int start, int end, unsigned arraySize, 114 unsigned* offset, unsigned* length); 115 116 // Input offset is in number of elements from this array's view; 117 // output offset is in number of bytes from the underlying buffer's view. 118 template <typename T> 119 static void clampOffsetAndNumElements( 120 PassRefPtr<ArrayBuffer> buffer, 121 unsigned arrayByteOffset, 122 unsigned *offset, 123 unsigned *numElements) 124 { 125 unsigned maxOffset = (UINT_MAX - arrayByteOffset) / sizeof(T); 126 if (*offset > maxOffset) { 127 *offset = buffer->byteLength(); 128 *numElements = 0; 129 return; 130 } 131 *offset = arrayByteOffset + *offset * sizeof(T); 132 *offset = std::min(buffer->byteLength(), *offset); 133 unsigned remainingElements = (buffer->byteLength() - *offset) / sizeof(T); 134 *numElements = std::min(remainingElements, *numElements); 135 } 136 137 // This is the address of the ArrayBuffer's storage, plus the byte offset. 138 void* m_baseAddress; 139 140 unsigned m_byteOffset : 31; 141 bool m_isNeuterable : 1; 142 143private: 144 friend class ArrayBuffer; 145 RefPtr<ArrayBuffer> m_buffer; 146}; 147 148bool ArrayBufferView::setImpl(ArrayBufferView* array, unsigned byteOffset) 149{ 150 if (byteOffset > byteLength() 151 || byteOffset + array->byteLength() > byteLength() 152 || byteOffset + array->byteLength() < byteOffset) { 153 // Out of range offset or overflow 154 return false; 155 } 156 157 char* base = static_cast<char*>(baseAddress()); 158 memmove(base + byteOffset, array->baseAddress(), array->byteLength()); 159 return true; 160} 161 162bool ArrayBufferView::setRangeImpl(const char* data, size_t dataByteLength, unsigned byteOffset) 163{ 164 if (byteOffset > byteLength() 165 || byteOffset + dataByteLength > byteLength() 166 || byteOffset + dataByteLength < byteOffset) { 167 // Out of range offset or overflow 168 return false; 169 } 170 171 char* base = static_cast<char*>(baseAddress()); 172 memmove(base + byteOffset, data, dataByteLength); 173 return true; 174} 175 176bool ArrayBufferView::zeroRangeImpl(unsigned byteOffset, size_t rangeByteLength) 177{ 178 if (byteOffset > byteLength() 179 || byteOffset + rangeByteLength > byteLength() 180 || byteOffset + rangeByteLength < byteOffset) { 181 // Out of range offset or overflow 182 return false; 183 } 184 185 char* base = static_cast<char*>(baseAddress()); 186 memset(base + byteOffset, 0, rangeByteLength); 187 return true; 188} 189 190void ArrayBufferView::calculateOffsetAndLength( 191 int start, int end, unsigned arraySize, unsigned* offset, unsigned* length) 192{ 193 if (start < 0) 194 start += arraySize; 195 if (start < 0) 196 start = 0; 197 if (end < 0) 198 end += arraySize; 199 if (end < 0) 200 end = 0; 201 if (static_cast<unsigned>(end) > arraySize) 202 end = arraySize; 203 if (end < start) 204 end = start; 205 *offset = static_cast<unsigned>(start); 206 *length = static_cast<unsigned>(end - start); 207} 208 209} // namespace JSC 210 211using JSC::ArrayBufferView; 212 213#endif // ArrayBufferView_h 214