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1 // Copyright (c) 2005-2009 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 // |
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15 #include "byte_pair.h" |
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16 |
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17 // User includes |
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18 #include "e32errwrap.h" |
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19 |
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20 TInt UnpackBytePair(TUint8* dst, TInt dstSize, TUint8* src, TInt srcSize, TUint8*& srcNext) |
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21 { |
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22 TUint8* dstStart = dst; |
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23 TUint8* dstEnd = dst+dstSize; |
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24 TUint8* srcEnd = src+srcSize; |
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25 |
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26 TUint32 LUT[0x100/2]; |
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27 TUint8* LUT0 = (TUint8*)LUT; |
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28 TUint8* LUT1 = LUT0+0x100; |
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29 |
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30 TUint8 stack[0x100]; |
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31 TUint8* stackStart = stack+sizeof(stack); |
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32 TUint8* sp = stackStart; |
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33 |
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34 TUint32 marker = ~0u; |
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35 TInt numTokens; |
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36 TUint32 p1; |
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37 TUint32 p2; |
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38 |
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39 TUint32* l = (TUint32*)LUT; |
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40 TUint32 b = 0x03020100; |
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41 TUint32 step = 0x04040404; |
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42 do |
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43 { |
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44 *l++ = b; |
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45 b += step; |
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46 } |
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47 while(b>step); |
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48 |
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49 if(src>=srcEnd) |
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50 goto error; |
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51 numTokens = *src++; |
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52 if(numTokens) |
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53 { |
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54 if(src>=srcEnd) |
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55 goto error; |
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56 marker = *src++; |
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57 LUT0[marker] = (TUint8)~marker; |
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58 |
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59 if(numTokens<32) |
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60 { |
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61 TUint8* tokenEnd = src+3*numTokens; |
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62 if(tokenEnd>srcEnd) |
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63 goto error; |
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64 do |
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65 { |
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66 TInt b = *src++; |
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67 TInt p1 = *src++; |
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68 TInt p2 = *src++; |
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69 LUT0[b] = (TUint8)p1; |
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70 LUT1[b] = (TUint8)p2; |
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71 } |
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72 while(src<tokenEnd); |
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73 } |
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74 else |
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75 { |
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76 TUint8* bitMask = src; |
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77 src += 32; |
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78 if(src>srcEnd) |
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79 goto error; |
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80 TInt b=0; |
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81 do |
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82 { |
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83 TUint8 mask = bitMask[b>>3]; |
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84 if(mask&(1<<(b&7))) |
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85 { |
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86 if(src>srcEnd) |
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87 goto error; |
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88 TInt p1 = *src++; |
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89 if(src>srcEnd) |
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90 goto error; |
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91 TInt p2 = *src++; |
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92 LUT0[b] = (TUint8)p1; |
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93 LUT1[b] = (TUint8)p2; |
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94 --numTokens; |
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95 } |
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96 ++b; |
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97 } |
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98 while(b<0x100); |
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99 if(numTokens) |
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100 goto error; |
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101 } |
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102 } |
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103 |
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104 if(src>=srcEnd) |
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105 goto error; |
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106 b = *src++; |
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107 if(dst>=dstEnd) |
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108 goto error; |
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109 p1 = LUT0[b]; |
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110 if(p1!=b) |
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111 goto not_single; |
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112 next: |
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113 if(src>=srcEnd) |
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114 goto done_s; |
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115 b = *src++; |
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116 *dst++ = (TUint8)p1; |
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117 if(dst>=dstEnd) |
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118 goto done_d; |
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119 p1 = LUT0[b]; |
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120 if(p1==b) |
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121 goto next; |
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122 |
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123 not_single: |
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124 if(b==marker) |
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125 goto do_marker; |
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126 |
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127 do_pair: |
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128 p2 = LUT1[b]; |
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129 b = p1; |
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130 p1 = LUT0[b]; |
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131 if(sp<=stack) |
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132 goto error; |
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133 *--sp = (TUint8)p2; |
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134 |
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135 recurse: |
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136 if(b!=p1) |
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137 goto do_pair; |
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138 |
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139 if(sp==stackStart) |
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140 goto next; |
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141 b = *sp++; |
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142 if(dst>=dstEnd) |
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143 goto error; |
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144 *dst++ = (TUint8)p1; |
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145 p1 = LUT0[b]; |
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146 goto recurse; |
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147 |
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148 do_marker: |
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149 if(src>=srcEnd) |
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150 goto error; |
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151 p1 = *src++; |
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152 goto next; |
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153 |
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154 error: |
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155 srcNext = 0; |
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156 return KErrCorrupt; |
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157 |
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158 done_s: |
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159 *dst++ = (TUint8)p1; |
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160 srcNext = src; |
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161 return dst-dstStart; |
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162 |
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163 done_d: |
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164 if(dst>=dstEnd) |
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165 --src; |
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166 srcNext = src; |
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167 return dst-dstStart; |
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168 } |
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169 |
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170 |
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171 |