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 ArrayBufferView_h 27 #define ArrayBufferView_h 28 29 #include "ArrayBuffer.h" 30 #include "ExceptionCode.h" 31 32 #include <algorithm> 33 #include <limits.h> 34 #include <wtf/PassRefPtr.h> 35 #include <wtf/RefCounted.h> 36 #include <wtf/RefPtr.h> 37 38 namespace WebCore { 39 40 class ArrayBufferView : public RefCounted<ArrayBufferView> { 41 public: isByteArray()42 virtual bool isByteArray() const { return false; } isUnsignedByteArray()43 virtual bool isUnsignedByteArray() const { return false; } isShortArray()44 virtual bool isShortArray() const { return false; } isUnsignedShortArray()45 virtual bool isUnsignedShortArray() const { return false; } isIntArray()46 virtual bool isIntArray() const { return false; } isUnsignedIntArray()47 virtual bool isUnsignedIntArray() const { return false; } isFloatArray()48 virtual bool isFloatArray() const { return false; } isDoubleArray()49 virtual bool isDoubleArray() const { return false; } isDataView()50 virtual bool isDataView() const { return false; } 51 buffer()52 PassRefPtr<ArrayBuffer> buffer() const 53 { 54 return m_buffer; 55 } 56 baseAddress()57 void* baseAddress() const 58 { 59 return m_baseAddress; 60 } 61 byteOffset()62 unsigned byteOffset() const 63 { 64 return m_byteOffset; 65 } 66 67 virtual unsigned byteLength() const = 0; 68 69 virtual ~ArrayBufferView(); 70 71 protected: 72 ArrayBufferView(PassRefPtr<ArrayBuffer> buffer, unsigned byteOffset); 73 74 void setImpl(ArrayBufferView* array, unsigned byteOffset, ExceptionCode& ec); 75 76 void setRangeImpl(const char* data, size_t dataByteLength, unsigned byteOffset, ExceptionCode& ec); 77 78 void zeroRangeImpl(unsigned byteOffset, size_t rangeByteLength, ExceptionCode& ec); 79 80 static void calculateOffsetAndLength(int start, int end, unsigned arraySize, 81 unsigned* offset, unsigned* length); 82 83 // Helper to verify that a given sub-range of an ArrayBuffer is 84 // within range. 85 template <typename T> verifySubRange(PassRefPtr<ArrayBuffer> buffer,unsigned byteOffset,unsigned numElements)86 static bool verifySubRange(PassRefPtr<ArrayBuffer> buffer, 87 unsigned byteOffset, 88 unsigned numElements) 89 { 90 if (!buffer) 91 return false; 92 if (sizeof(T) > 1 && byteOffset % sizeof(T)) 93 return false; 94 if (byteOffset > buffer->byteLength()) 95 return false; 96 unsigned remainingElements = (buffer->byteLength() - byteOffset) / sizeof(T); 97 if (numElements > remainingElements) 98 return false; 99 return true; 100 } 101 102 // Input offset is in number of elements from this array's view; 103 // output offset is in number of bytes from the underlying buffer's view. 104 template <typename T> clampOffsetAndNumElements(PassRefPtr<ArrayBuffer> buffer,unsigned arrayByteOffset,unsigned * offset,unsigned * numElements)105 static void clampOffsetAndNumElements(PassRefPtr<ArrayBuffer> buffer, 106 unsigned arrayByteOffset, 107 unsigned *offset, 108 unsigned *numElements) 109 { 110 unsigned maxOffset = (UINT_MAX - arrayByteOffset) / sizeof(T); 111 if (*offset > maxOffset) { 112 *offset = buffer->byteLength(); 113 *numElements = 0; 114 return; 115 } 116 *offset = arrayByteOffset + *offset * sizeof(T); 117 *offset = std::min(buffer->byteLength(), *offset); 118 unsigned remainingElements = (buffer->byteLength() - *offset) / sizeof(T); 119 *numElements = std::min(remainingElements, *numElements); 120 } 121 122 // This is the address of the ArrayBuffer's storage, plus the byte offset. 123 void* m_baseAddress; 124 125 unsigned m_byteOffset; 126 127 private: 128 RefPtr<ArrayBuffer> m_buffer; 129 }; 130 131 } // namespace WebCore 132 133 #endif // ArrayBufferView_h 134