1 // Copyright (c) 2010 Nokia Corporation and/or its subsidiary(-ies). |
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2 // All rights reserved. |
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3 // This component and the accompanying materials are made available |
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4 // under the terms of "Eclipse Public License v1.0" |
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5 // which accompanies this distribution, and is available |
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6 // at the URL "http://www.eclipse.org/legal/epl-v10.html". |
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7 // |
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8 // Initial Contributors: |
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9 // Nokia Corporation - initial contribution. |
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10 // |
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11 // Contributors: |
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12 // |
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13 // Description: |
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14 // Hexadecimal trees - implementation |
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15 // |
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16 |
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17 #include <hextree.h> |
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18 #include <e32atomics.h> |
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19 |
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20 EXPORT_C RHexTreeBase::RHexTreeBase(RHeap* aHeap) |
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21 : iHeap(aHeap) |
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22 { |
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23 Mem::FillZ(iRootOffsets, sizeof(iRootOffsets)); |
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24 } |
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25 |
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26 EXPORT_C TInt RHexTreeBase::SetAt(TUint aKey, TAny* aValue) |
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27 { |
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28 TUint mask = 0xF0000000; |
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29 for (TInt height = EMaxNumHexDigits; height > 1; --height) |
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30 { |
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31 if ((aKey & mask) != 0) |
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32 { |
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33 return SetAt(aKey, aValue, height); |
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34 } |
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35 mask >>= 4; |
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36 } |
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37 return SetAt(aKey, aValue, 1); |
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38 } |
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39 |
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40 EXPORT_C TAny* RHexTreeBase::At(TUint aKey) const |
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41 { |
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42 TUint mask = 0xF0000000; |
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43 for (TInt height = EMaxNumHexDigits; height > 1; --height) |
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44 { |
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45 if ((aKey & mask) != 0) |
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46 { |
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47 return At(aKey, height); |
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48 } |
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49 mask >>= 4; |
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50 } |
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51 return At(aKey, 1); |
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52 } |
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53 |
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54 /** |
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55 Empties this associative array and frees all memory allocated both for the |
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56 associative array implementation and for the values that have been added to |
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57 this associative array. |
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58 |
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59 The internal state of this associative array is reset so that it can be reused |
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60 or allowed to go out of scope after a call to this function. |
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61 */ |
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62 EXPORT_C void RHexTreeBase::ResetAndDestroy() |
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63 { |
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64 for (TInt height = 1; height <= EMaxNumHexDigits; ++height) |
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65 { |
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66 TInt offset = iRootOffsets[height - 1]; |
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67 if (offset != 0) |
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68 { |
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69 TAny* root = PtrAdd(this, offset); |
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70 ResetAndDestroy(height, root, 1); |
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71 iRootOffsets[height - 1] = 0; |
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72 } |
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73 } |
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74 } |
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75 |
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76 TInt RHexTreeBase::SetAt(TUint aKey, TAny* aLeaf, TInt aHeight) |
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77 { |
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78 TInt err; |
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79 TInt offset = iRootOffsets[aHeight - 1]; |
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80 if (offset == 0) |
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81 { |
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82 TAny* root = iHeap->AllocZ(aHeight > 1 ? sizeof(TInt) * 15 : sizeof(TInt) * 16); |
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83 if (!root) |
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84 { |
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85 return KErrNoMemory; |
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86 } |
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87 err = SetAt(aKey, aLeaf, aHeight, root, 1); |
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88 if (err == KErrNone) |
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89 { |
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90 __e32_atomic_store_rel32(&iRootOffsets[aHeight - 1], reinterpret_cast<TInt>(root) - reinterpret_cast<TInt>(this)); |
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91 } |
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92 else |
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93 { |
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94 iHeap->Free(root); |
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95 } |
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96 } |
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97 else |
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98 { |
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99 TAny* root = PtrAdd(this, offset); |
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100 err = SetAt(aKey, aLeaf, aHeight, root, 1); |
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101 } |
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102 return err; |
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103 } |
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104 |
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105 TInt RHexTreeBase::SetAt(TUint aKey, TAny* aLeaf, TInt aHeight, TAny* aNode, TInt aLevel) |
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106 { |
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107 TInt err = KErrNone; |
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108 TInt branch = (aKey >> ((aHeight - aLevel) << 2)) & 0xF; |
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109 if (aLevel == 1 && aHeight > 1) |
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110 { |
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111 --branch; |
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112 } |
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113 TInt offset = static_cast<TInt*>(aNode)[branch]; |
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114 if (aLevel == aHeight) |
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115 { |
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116 if (offset == 0) |
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117 { |
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118 __e32_atomic_store_rel32(&static_cast<TInt*>(aNode)[branch], reinterpret_cast<TInt>(aLeaf) - reinterpret_cast<TInt>(aNode)); |
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119 } |
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120 else |
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121 { |
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122 err = KErrAlreadyExists; |
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123 } |
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124 } |
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125 else if (offset == 0) |
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126 { |
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127 TAny* newNode = iHeap->AllocZ(sizeof(TInt) * 16); |
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128 if (!newNode) |
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129 { |
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130 return KErrNoMemory; |
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131 } |
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132 err = SetAt(aKey, aLeaf, aHeight, newNode, aLevel + 1); |
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133 if (err == KErrNone) |
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134 { |
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135 __e32_atomic_store_rel32(&static_cast<TInt*>(aNode)[branch], reinterpret_cast<TInt>(newNode) - reinterpret_cast<TInt>(aNode)); |
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136 } |
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137 else |
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138 { |
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139 iHeap->Free(newNode); |
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140 } |
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141 } |
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142 else |
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143 { |
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144 TAny* nextNode = PtrAdd(aNode, offset); |
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145 err = SetAt(aKey, aLeaf, aHeight, nextNode, aLevel + 1); |
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146 } |
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147 return err; |
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148 } |
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149 |
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150 TAny* RHexTreeBase::At(TUint aKey, TInt aHeight) const |
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151 { |
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152 TInt offset = __e32_atomic_load_acq32(&iRootOffsets[aHeight - 1]); |
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153 if (offset == 0) |
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154 { |
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155 return NULL; |
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156 } |
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157 const TAny* node = PtrAdd(this, offset); |
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158 for (TInt level = 1; level <= aHeight; ++level) |
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159 { |
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160 TInt branch = (aKey >> ((aHeight - level) << 2)) & 0xF; |
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161 if (level == 1 && aHeight > 1) |
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162 { |
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163 --branch; |
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164 } |
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165 offset = __e32_atomic_load_acq32(&static_cast<const TInt*>(node)[branch]); |
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166 if (offset == 0) |
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167 { |
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168 return NULL; |
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169 } |
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170 node = PtrAdd(node, offset); |
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171 } |
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172 return const_cast<TAny*>(node); |
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173 } |
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174 |
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175 void RHexTreeBase::ResetAndDestroy(TInt aHeight, TAny* aNode, TInt aLevel) |
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176 { |
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177 TInt maxNumBranches = (aLevel == 1 && aHeight > 1 ? 15 : 16); |
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178 for (TInt branch = 0; branch < maxNumBranches; ++branch) |
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179 { |
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180 TInt offset = static_cast<TInt*>(aNode)[branch]; |
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181 if (offset != 0) |
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182 { |
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183 TAny* nextNode = PtrAdd(aNode, offset); |
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184 if (aLevel == aHeight) |
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185 { |
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186 iHeap->Free(nextNode); |
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187 } |
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188 else |
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189 { |
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190 ResetAndDestroy(aHeight, nextNode, aLevel + 1); |
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191 } |
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192 } |
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193 } |
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194 iHeap->Free(aNode); |
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195 } |
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