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