The Tor Browser / file comparison
comparison: xpcom/io/nsSegmentedBuffer.cpp
xpcom/io/nsSegmentedBuffer.cpp
- branch
- TOR_BUG_3246
- changeset 4
- fc2d59ddac77
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replaced
| -1:000000000000 | 0:ed09b0552e46 |
|---|---|
| 1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ | |
| 2 /* This Source Code Form is subject to the terms of the Mozilla Public | |
| 3 * License, v. 2.0. If a copy of the MPL was not distributed with this | |
| 4 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ | |
| 5 | |
| 6 #include "nsSegmentedBuffer.h" | |
| 7 #include "nsMemory.h" | |
| 8 | |
| 9 nsresult | |
| 10 nsSegmentedBuffer::Init(uint32_t segmentSize, uint32_t maxSize) | |
| 11 { | |
| 12 if (mSegmentArrayCount != 0) | |
| 13 return NS_ERROR_FAILURE; // initialized more than once | |
| 14 mSegmentSize = segmentSize; | |
| 15 mMaxSize = maxSize; | |
| 16 #if 0 // testing... | |
| 17 mSegmentArrayCount = 2; | |
| 18 #else | |
| 19 mSegmentArrayCount = NS_SEGMENTARRAY_INITIAL_COUNT; | |
| 20 #endif | |
| 21 return NS_OK; | |
| 22 } | |
| 23 | |
| 24 char* | |
| 25 nsSegmentedBuffer::AppendNewSegment() | |
| 26 { | |
| 27 if (GetSize() >= mMaxSize) | |
| 28 return nullptr; | |
| 29 | |
| 30 if (mSegmentArray == nullptr) { | |
| 31 uint32_t bytes = mSegmentArrayCount * sizeof(char*); | |
| 32 mSegmentArray = (char**)nsMemory::Alloc(bytes); | |
| 33 if (mSegmentArray == nullptr) | |
| 34 return nullptr; | |
| 35 memset(mSegmentArray, 0, bytes); | |
| 36 } | |
| 37 | |
| 38 if (IsFull()) { | |
| 39 uint32_t newArraySize = mSegmentArrayCount * 2; | |
| 40 uint32_t bytes = newArraySize * sizeof(char*); | |
| 41 char** newSegArray = (char**)nsMemory::Realloc(mSegmentArray, bytes); | |
| 42 if (newSegArray == nullptr) | |
| 43 return nullptr; | |
| 44 mSegmentArray = newSegArray; | |
| 45 // copy wrapped content to new extension | |
| 46 if (mFirstSegmentIndex > mLastSegmentIndex) { | |
| 47 // deal with wrap around case | |
| 48 memcpy(&mSegmentArray[mSegmentArrayCount], | |
| 49 mSegmentArray, | |
| 50 mLastSegmentIndex * sizeof(char*)); | |
| 51 memset(mSegmentArray, 0, mLastSegmentIndex * sizeof(char*)); | |
| 52 mLastSegmentIndex += mSegmentArrayCount; | |
| 53 memset(&mSegmentArray[mLastSegmentIndex], 0, | |
| 54 (newArraySize - mLastSegmentIndex) * sizeof(char*)); | |
| 55 } | |
| 56 else { | |
| 57 memset(&mSegmentArray[mLastSegmentIndex], 0, | |
| 58 (newArraySize - mLastSegmentIndex) * sizeof(char*)); | |
| 59 } | |
| 60 mSegmentArrayCount = newArraySize; | |
| 61 } | |
| 62 | |
| 63 char* seg = (char*)moz_malloc(mSegmentSize); | |
| 64 if (seg == nullptr) { | |
| 65 return nullptr; | |
| 66 } | |
| 67 mSegmentArray[mLastSegmentIndex] = seg; | |
| 68 mLastSegmentIndex = ModSegArraySize(mLastSegmentIndex + 1); | |
| 69 return seg; | |
| 70 } | |
| 71 | |
| 72 bool | |
| 73 nsSegmentedBuffer::DeleteFirstSegment() | |
| 74 { | |
| 75 NS_ASSERTION(mSegmentArray[mFirstSegmentIndex] != nullptr, "deleting bad segment"); | |
| 76 moz_free(mSegmentArray[mFirstSegmentIndex]); | |
| 77 mSegmentArray[mFirstSegmentIndex] = nullptr; | |
| 78 int32_t last = ModSegArraySize(mLastSegmentIndex - 1); | |
| 79 if (mFirstSegmentIndex == last) { | |
| 80 mLastSegmentIndex = last; | |
| 81 return true; | |
| 82 } | |
| 83 else { | |
| 84 mFirstSegmentIndex = ModSegArraySize(mFirstSegmentIndex + 1); | |
| 85 return false; | |
| 86 } | |
| 87 } | |
| 88 | |
| 89 bool | |
| 90 nsSegmentedBuffer::DeleteLastSegment() | |
| 91 { | |
| 92 int32_t last = ModSegArraySize(mLastSegmentIndex - 1); | |
| 93 NS_ASSERTION(mSegmentArray[last] != nullptr, "deleting bad segment"); | |
| 94 moz_free(mSegmentArray[last]); | |
| 95 mSegmentArray[last] = nullptr; | |
| 96 mLastSegmentIndex = last; | |
| 97 return (bool)(mLastSegmentIndex == mFirstSegmentIndex); | |
| 98 } | |
| 99 | |
| 100 bool | |
| 101 nsSegmentedBuffer::ReallocLastSegment(size_t newSize) | |
| 102 { | |
| 103 int32_t last = ModSegArraySize(mLastSegmentIndex - 1); | |
| 104 NS_ASSERTION(mSegmentArray[last] != nullptr, "realloc'ing bad segment"); | |
| 105 char *newSegment = | |
| 106 (char*)moz_realloc(mSegmentArray[last], newSize); | |
| 107 if (newSegment) { | |
| 108 mSegmentArray[last] = newSegment; | |
| 109 return true; | |
| 110 } else { | |
| 111 return false; | |
| 112 } | |
| 113 } | |
| 114 | |
| 115 void | |
| 116 nsSegmentedBuffer::Empty() | |
| 117 { | |
| 118 if (mSegmentArray) { | |
| 119 for (uint32_t i = 0; i < mSegmentArrayCount; i++) { | |
| 120 if (mSegmentArray[i]) | |
| 121 moz_free(mSegmentArray[i]); | |
| 122 } | |
| 123 nsMemory::Free(mSegmentArray); | |
| 124 mSegmentArray = nullptr; | |
| 125 } | |
| 126 mSegmentArrayCount = NS_SEGMENTARRAY_INITIAL_COUNT; | |
| 127 mFirstSegmentIndex = mLastSegmentIndex = 0; | |
| 128 } | |
| 129 | |
| 130 #if 0 | |
| 131 void | |
| 132 TestSegmentedBuffer() | |
| 133 { | |
| 134 nsSegmentedBuffer* buf = new nsSegmentedBuffer(); | |
| 135 NS_ASSERTION(buf, "out of memory"); | |
| 136 buf->Init(4, 16); | |
| 137 char* seg; | |
| 138 bool empty; | |
| 139 seg = buf->AppendNewSegment(); | |
| 140 NS_ASSERTION(seg, "AppendNewSegment failed"); | |
| 141 seg = buf->AppendNewSegment(); | |
| 142 NS_ASSERTION(seg, "AppendNewSegment failed"); | |
| 143 seg = buf->AppendNewSegment(); | |
| 144 NS_ASSERTION(seg, "AppendNewSegment failed"); | |
| 145 empty = buf->DeleteFirstSegment(); | |
| 146 NS_ASSERTION(!empty, "DeleteFirstSegment failed"); | |
| 147 empty = buf->DeleteFirstSegment(); | |
| 148 NS_ASSERTION(!empty, "DeleteFirstSegment failed"); | |
| 149 seg = buf->AppendNewSegment(); | |
| 150 NS_ASSERTION(seg, "AppendNewSegment failed"); | |
| 151 seg = buf->AppendNewSegment(); | |
| 152 NS_ASSERTION(seg, "AppendNewSegment failed"); | |
| 153 seg = buf->AppendNewSegment(); | |
| 154 NS_ASSERTION(seg, "AppendNewSegment failed"); | |
| 155 empty = buf->DeleteFirstSegment(); | |
| 156 NS_ASSERTION(!empty, "DeleteFirstSegment failed"); | |
| 157 empty = buf->DeleteFirstSegment(); | |
| 158 NS_ASSERTION(!empty, "DeleteFirstSegment failed"); | |
| 159 empty = buf->DeleteFirstSegment(); | |
| 160 NS_ASSERTION(!empty, "DeleteFirstSegment failed"); | |
| 161 empty = buf->DeleteFirstSegment(); | |
| 162 NS_ASSERTION(empty, "DeleteFirstSegment failed"); | |
| 163 delete buf; | |
| 164 } | |
| 165 #endif | |
| 166 | |
| 167 //////////////////////////////////////////////////////////////////////////////// |
