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1 /* | 1 /* |
2 * Copyright (C) 2013 Google Inc. All rights reserved. | 2 * Copyright (C) 2013 Google Inc. All rights reserved. |
3 * | 3 * |
4 * Redistribution and use in source and binary forms, with or without | 4 * Redistribution and use in source and binary forms, with or without |
5 * modification, are permitted provided that the following conditions are | 5 * modification, are permitted provided that the following conditions are |
6 * met: | 6 * met: |
7 * | 7 * |
8 * * Redistributions of source code must retain the above copyright | 8 * * Redistributions of source code must retain the above copyright |
9 * notice, this list of conditions and the following disclaimer. | 9 * notice, this list of conditions and the following disclaimer. |
10 * * Redistributions in binary form must reproduce the above | 10 * * Redistributions in binary form must reproduce the above |
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35 #include <limits> | 35 #include <limits> |
36 | 36 |
37 namespace WTF { | 37 namespace WTF { |
38 | 38 |
39 static const int defaultBufferCapacity = 32768; | 39 static const int defaultBufferCapacity = 32768; |
40 | 40 |
41 ArrayBufferBuilder::ArrayBufferBuilder() | 41 ArrayBufferBuilder::ArrayBufferBuilder() |
42 : m_bytesUsed(0) | 42 : m_bytesUsed(0) |
43 , m_variableCapacity(true) | 43 , m_variableCapacity(true) |
44 { | 44 { |
45 m_buffer = ArrayBuffer::create(defaultBufferCapacity, 1); | 45 m_buffer = ArrayBuffer::createOrNull(defaultBufferCapacity, 1); |
46 } | 46 } |
47 | 47 |
48 bool ArrayBufferBuilder::expandCapacity(unsigned sizeToIncrease) | 48 bool ArrayBufferBuilder::expandCapacity(unsigned sizeToIncrease) |
49 { | 49 { |
| 50 ASSERT(isValid()); |
50 unsigned currentBufferSize = m_buffer->byteLength(); | 51 unsigned currentBufferSize = m_buffer->byteLength(); |
51 | 52 |
52 // If the size of the buffer exceeds max of unsigned, it can't be grown any | 53 // If the size of the buffer exceeds max of unsigned, it can't be grown any |
53 // more. | 54 // more. |
54 if (sizeToIncrease > std::numeric_limits<unsigned>::max() - m_bytesUsed) | 55 if (sizeToIncrease > std::numeric_limits<unsigned>::max() - m_bytesUsed) |
55 return false; | 56 return false; |
56 | 57 |
57 unsigned newBufferSize = m_bytesUsed + sizeToIncrease; | 58 unsigned newBufferSize = m_bytesUsed + sizeToIncrease; |
58 | 59 |
59 // Grow exponentially if possible. | 60 // Grow exponentially if possible. |
60 unsigned exponentialGrowthNewBufferSize = std::numeric_limits<unsigned>::max
(); | 61 unsigned exponentialGrowthNewBufferSize = std::numeric_limits<unsigned>::max
(); |
61 if (currentBufferSize <= std::numeric_limits<unsigned>::max() / 2) | 62 if (currentBufferSize <= std::numeric_limits<unsigned>::max() / 2) |
62 exponentialGrowthNewBufferSize = currentBufferSize * 2; | 63 exponentialGrowthNewBufferSize = currentBufferSize * 2; |
63 if (exponentialGrowthNewBufferSize > newBufferSize) | 64 if (exponentialGrowthNewBufferSize > newBufferSize) |
64 newBufferSize = exponentialGrowthNewBufferSize; | 65 newBufferSize = exponentialGrowthNewBufferSize; |
65 | 66 |
66 // Copy existing data in current buffer to new buffer. | 67 // Copy existing data in current buffer to new buffer. |
67 RefPtr<ArrayBuffer> newBuffer = ArrayBuffer::create(newBufferSize, 1); | 68 RefPtr<ArrayBuffer> newBuffer = ArrayBuffer::createOrNull(newBufferSize, 1); |
68 if (!newBuffer) | 69 if (!newBuffer) |
69 return false; | 70 return false; |
70 | 71 |
71 memcpy(newBuffer->data(), m_buffer->data(), m_bytesUsed); | 72 memcpy(newBuffer->data(), m_buffer->data(), m_bytesUsed); |
72 m_buffer = newBuffer; | 73 m_buffer = newBuffer; |
73 return true; | 74 return true; |
74 } | 75 } |
75 | 76 |
76 unsigned ArrayBufferBuilder::append(const char* data, unsigned length) | 77 unsigned ArrayBufferBuilder::append(const char* data, unsigned length) |
77 { | 78 { |
| 79 ASSERT(isValid()); |
78 ASSERT(length > 0); | 80 ASSERT(length > 0); |
79 | 81 |
80 unsigned currentBufferSize = m_buffer->byteLength(); | 82 unsigned currentBufferSize = m_buffer->byteLength(); |
81 | 83 |
82 ASSERT(m_bytesUsed <= currentBufferSize); | 84 ASSERT(m_bytesUsed <= currentBufferSize); |
83 | 85 |
84 unsigned remainingBufferSpace = currentBufferSize - m_bytesUsed; | 86 unsigned remainingBufferSpace = currentBufferSize - m_bytesUsed; |
85 | 87 |
86 unsigned bytesToSave = length; | 88 unsigned bytesToSave = length; |
87 | 89 |
88 if (length > remainingBufferSpace) { | 90 if (length > remainingBufferSpace) { |
89 if (m_variableCapacity) { | 91 if (m_variableCapacity) { |
90 if (!expandCapacity(length)) | 92 if (!expandCapacity(length)) |
91 return 0; | 93 return 0; |
92 } else { | 94 } else { |
93 bytesToSave = remainingBufferSpace; | 95 bytesToSave = remainingBufferSpace; |
94 } | 96 } |
95 } | 97 } |
96 | 98 |
97 memcpy(static_cast<char*>(m_buffer->data()) + m_bytesUsed, data, bytesToSave
); | 99 memcpy(static_cast<char*>(m_buffer->data()) + m_bytesUsed, data, bytesToSave
); |
98 m_bytesUsed += bytesToSave; | 100 m_bytesUsed += bytesToSave; |
99 | 101 |
100 return bytesToSave; | 102 return bytesToSave; |
101 } | 103 } |
102 | 104 |
103 PassRefPtr<ArrayBuffer> ArrayBufferBuilder::toArrayBuffer() | 105 PassRefPtr<ArrayBuffer> ArrayBufferBuilder::toArrayBuffer() |
104 { | 106 { |
| 107 ASSERT(isValid()); |
105 // Fully used. Return m_buffer as-is. | 108 // Fully used. Return m_buffer as-is. |
106 if (m_buffer->byteLength() == m_bytesUsed) | 109 if (m_buffer->byteLength() == m_bytesUsed) |
107 return m_buffer; | 110 return m_buffer; |
108 | 111 |
109 return m_buffer->slice(0, m_bytesUsed); | 112 RefPtr<ArrayBuffer> tmp = m_buffer->sliceOrNull(0, m_bytesUsed); |
| 113 if (tmp) |
| 114 return tmp; |
| 115 return m_buffer; |
110 } | 116 } |
111 | 117 |
112 String ArrayBufferBuilder::toString() | 118 String ArrayBufferBuilder::toString() |
113 { | 119 { |
| 120 ASSERT(isValid()); |
114 return String(static_cast<const char*>(m_buffer->data()), m_bytesUsed); | 121 return String(static_cast<const char*>(m_buffer->data()), m_bytesUsed); |
115 } | 122 } |
116 | 123 |
117 void ArrayBufferBuilder::shrinkToFit() | 124 void ArrayBufferBuilder::shrinkToFit() |
118 { | 125 { |
| 126 ASSERT(isValid()); |
119 ASSERT(m_bytesUsed <= m_buffer->byteLength()); | 127 ASSERT(m_bytesUsed <= m_buffer->byteLength()); |
120 | 128 |
121 if (m_buffer->byteLength() > m_bytesUsed) | 129 if (m_buffer->byteLength() > m_bytesUsed) { |
122 m_buffer = m_buffer->slice(0, m_bytesUsed); | 130 RefPtr<ArrayBuffer> tmp = m_buffer->sliceOrNull(0, m_bytesUsed); |
| 131 if (tmp) |
| 132 m_buffer = tmp; |
| 133 } |
123 } | 134 } |
124 | 135 |
125 } // namespace WTF | 136 } // namespace WTF |
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