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1 // Copyright (c) 1996-2009 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 the License "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 // f32\sfat32\ram_fat_table32.cpp |
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15 // FAT16/32 File Allocation Table classes implementation for the RAM media |
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16 // |
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17 // |
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18 |
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19 /** |
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20 @file |
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21 @internalTechnology |
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22 */ |
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23 |
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24 |
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25 |
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26 #include "sl_std.h" |
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27 #include "sl_fatcache32.h" |
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28 #include "fat_table32.h" |
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29 |
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30 |
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31 //--------------------------------------------------------------------------------------------------------------------------------------- |
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32 |
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33 //####################################################################################################################################### |
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34 //# CRamFatTable class implementation |
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35 //####################################################################################################################################### |
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36 |
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37 /** |
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38 Constructor, the RamFatTable allows disk compression by redirecting the FAT |
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39 |
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40 @param aOwner Owning mount. |
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41 */ |
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42 CRamFatTable::CRamFatTable(CFatMountCB& aOwner) |
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43 :CFatTable(aOwner) |
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44 { |
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45 iFatTablePos=aOwner.FirstFatSector()<<aOwner.SectorSizeLog2(); |
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46 iIndirectionTablePos=iFatTablePos+aOwner.FatSizeInBytes(); |
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47 } |
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48 |
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49 /** factory method */ |
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50 CRamFatTable* CRamFatTable::NewL(CFatMountCB& aOwner) |
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51 { |
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52 __PRINT1(_L("CRamFatTable::NewL() drv:%d"),aOwner.DriveNumber()); |
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53 |
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54 CRamFatTable* pSelf = new (ELeave) CRamFatTable(aOwner); |
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55 |
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56 CleanupStack::PushL(pSelf); |
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57 pSelf->InitializeL(); |
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58 CleanupStack::Pop(); |
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59 |
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60 return pSelf; |
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61 } |
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62 |
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63 |
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64 void CRamFatTable::InitializeL() |
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65 { |
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66 CFatTable::InitializeL(); |
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67 |
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68 ASSERT(iMediaAtt & KMediaAttVariableSize); |
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69 ASSERT(FatType() == EFat16 || FatType()== EFat32); |
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70 |
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71 iFatTablePos=iOwner->FirstFatSector()<<iOwner->SectorSizeLog2(); |
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72 iIndirectionTablePos=iFatTablePos+iOwner->FatSizeInBytes(); |
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73 |
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74 //-- set RAM disk base |
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75 TLocalDriveCapsV2 caps; |
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76 TPckg<TLocalDriveCapsV2> capsPckg(caps); |
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77 User::LeaveIfError(iOwner->LocalDrive()->Caps(capsPckg)); |
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78 |
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79 iRamDiskBase = caps.iBaseAddress; |
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80 } |
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81 |
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82 /** |
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83 Just Count free clusters in the FAT |
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84 */ |
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85 void CRamFatTable::MountL(const TMountParams& /*aMountParam*/) |
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86 { |
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87 CountFreeClustersL(); |
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88 } |
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89 |
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90 |
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91 /** |
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92 Return the start address of the Ram Drive |
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93 @return start address of the Ram Drive |
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94 */ |
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95 TUint8 *CRamFatTable::RamDiskBase() const |
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96 { |
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97 return(iRamDiskBase); |
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98 } |
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99 |
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100 |
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101 /** |
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102 Allocate a new cluster number |
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103 |
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104 @return New cluster number |
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105 */ |
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106 TInt CRamFatTable::AllocateClusterNumber() |
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107 { |
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108 return(iOwner->MaxClusterNumber()-NumberOfFreeClusters()); |
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109 } |
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110 |
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111 /** |
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112 Write a value to the FAT (indirection table) |
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113 |
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114 @param aFatIndex Cluster to write to |
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115 @param aValue value to write to Fat |
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116 */ |
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117 void CRamFatTable::WriteL(TUint32 aFatIndex, TUint32 aValue) |
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118 { |
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119 //__PRINT(_L("CRamFatTable::WriteL")); |
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120 |
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121 // __ASSERT_ALWAYS(aFatIndex>=2 && (aValue>=2 || aValue==0) && aValue<=0xFFFF,User::Leave(KErrCorrupt)); |
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122 TUint32 indirectCluster=aFatIndex; |
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123 TUint32 indirectClusterNewVal=0; |
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124 ReadIndirectionTable(indirectCluster); |
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125 // If value in indirection table!=0 we assume we have already written to the indirection table |
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126 // So just update the FAT table |
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127 if (indirectCluster!=0 && aValue!=0) |
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128 { |
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129 WriteFatTable(aFatIndex,aValue); |
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130 return; |
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131 } |
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132 // If value in indirection table is 0, we haven't written to it yet, though the memory has |
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133 // already been allocated by the EnlargeL() function |
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134 if (indirectCluster==0 && aValue!=0) // Assumes memory has already been allocated |
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135 indirectClusterNewVal=AllocateClusterNumber(); |
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136 // Write aValue into aFaxIndex and indirectClusterNewVal into the corresponding position |
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137 // in the indirection table |
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138 WriteFatTable(aFatIndex,aValue,indirectClusterNewVal); |
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139 } |
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140 |
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141 /** |
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142 Read the value of a cluster in the Fat |
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143 |
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144 @param aFatIndex A cluster to read |
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145 @return The cluster value read |
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146 */ |
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147 TUint32 CRamFatTable::ReadL(TUint32 aFatIndex) const |
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148 { |
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149 __ASSERT_ALWAYS(aFatIndex>=KFatFirstSearchCluster,User::Leave(KErrCorrupt)); |
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150 |
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151 TUint32 clusterVal; |
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152 |
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153 switch(FatType()) |
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154 { |
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155 case EFat16: |
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156 clusterVal=*(TUint16*)(RamDiskBase()+PosInBytes(aFatIndex)+iFatTablePos); |
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157 break; |
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158 |
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159 case EFat32: |
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160 clusterVal=*(TUint32*)(RamDiskBase()+PosInBytes(aFatIndex)+iFatTablePos); |
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161 break; |
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162 |
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163 default: |
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164 ASSERT(0); |
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165 return 0; |
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166 } |
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167 |
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168 return clusterVal; |
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169 } |
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170 |
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171 /** |
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172 Write a value to the FAT and indirection table |
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173 |
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174 @param aFatIndex Cluster number to write to |
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175 @param aFatValue Cluster value for Fat |
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176 @param anIndirectionValue Value for indirection table |
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177 */ |
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178 void CRamFatTable::WriteFatTable(TInt aFatIndex,TInt aFatValue,TInt anIndirectionValue) |
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179 { |
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180 const TUint8* pos=RamDiskBase()+PosInBytes(aFatIndex); |
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181 |
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182 switch(FatType()) |
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183 { |
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184 case EFat16: |
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185 *(TUint16*)(pos+iFatTablePos)=(TUint16)aFatValue; |
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186 *(TUint16*)(pos+iIndirectionTablePos)=(TUint16)anIndirectionValue; |
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187 break; |
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188 |
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189 case EFat32: |
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190 *(TUint32*)(pos+iFatTablePos)=(TUint32)aFatValue; |
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191 *(TUint32*)(pos+iIndirectionTablePos)=(TUint32)anIndirectionValue; |
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192 break; |
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193 |
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194 default: |
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195 ASSERT(0); |
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196 return; |
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197 } |
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198 |
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199 } |
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200 |
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201 /** |
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202 Write to just the fat table |
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203 |
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204 @param aFatIndex Cluster number to write to |
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205 @param aFatValue Cluster value for Fat |
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206 */ |
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207 void CRamFatTable::WriteFatTable(TInt aFatIndex,TInt aFatValue) |
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208 { |
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209 |
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210 switch(FatType()) |
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211 { |
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212 case EFat16: |
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213 *(TUint16*)(RamDiskBase()+PosInBytes(aFatIndex)+iFatTablePos)=(TUint16)aFatValue; |
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214 break; |
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215 |
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216 case EFat32: |
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217 *(TUint32*)(RamDiskBase()+PosInBytes(aFatIndex)+iFatTablePos)=(TUint32)aFatValue; |
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218 break; |
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219 |
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220 default: |
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221 ASSERT(0); |
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222 return; |
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223 } |
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224 |
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225 } |
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226 |
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227 /** |
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228 Write to just the fat table |
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229 |
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230 @param aFatIndex Cluster number to write to |
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231 @param aFatValue Value for indirection table |
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232 */ |
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233 void CRamFatTable::WriteIndirectionTable(TInt aFatIndex,TInt aFatValue) |
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234 { |
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235 switch(FatType()) |
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236 { |
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237 case EFat16: |
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238 *(TUint16*)(RamDiskBase()+PosInBytes(aFatIndex)+iIndirectionTablePos)=(TUint16)aFatValue; |
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239 break; |
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240 |
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241 case EFat32: |
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242 *(TUint32*)(RamDiskBase()+PosInBytes(aFatIndex)+iIndirectionTablePos)=(TUint32)aFatValue; |
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243 break; |
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244 |
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245 default: |
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246 ASSERT(0); |
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247 return; |
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248 } |
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249 } |
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250 |
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251 /** |
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252 Find the real location of aCluster |
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253 @param aCluster Cluster to read, contians cluster value upon return |
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254 */ |
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255 void CRamFatTable::ReadIndirectionTable(TUint32& aCluster) const |
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256 { |
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257 switch(FatType()) |
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258 { |
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259 case EFat16: |
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260 aCluster=*(TUint16*)(RamDiskBase()+PosInBytes(aCluster)+iIndirectionTablePos); |
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261 break; |
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262 |
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263 case EFat32: |
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264 aCluster=*(TUint32*)(RamDiskBase()+PosInBytes(aCluster)+iIndirectionTablePos); |
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265 break; |
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266 |
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267 default: |
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268 ASSERT(0); |
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269 return; |
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270 } |
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271 |
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272 } |
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273 |
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274 /** |
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275 Copy memory in RAM drive area, unlocking required |
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276 |
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277 @param aTrg Pointer to destination location |
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278 @param aSrc Pointer to source location |
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279 @param aLength Length of data to copy |
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280 @return Pointer to end of data copied |
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281 */ |
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282 TUint8* CRamFatTable::MemCopy(TAny* aTrg,const TAny* aSrc,TInt aLength) |
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283 { |
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284 TUint8* p=Mem::Copy(aTrg,aSrc,aLength); |
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285 return(p); |
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286 } |
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287 |
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288 /** |
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289 Copy memory with filling the source buffer with zeroes. Target and source buffers can overlap. |
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290 Used on RAMDrive srinking in order to wipe data from the file that is being deleted. |
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291 |
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292 @param aTrg pointer to the target address |
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293 @param aSrc pointer to the destination address |
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294 @param aLength how many bytes to copy |
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295 @return A pointer to a location aLength bytes beyond aTrg (i.e. the location aTrg+aLength). |
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296 */ |
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297 TUint8* CRamFatTable::MemCopyFillZ(TAny* aTrg, TAny* aSrc,TInt aLength) |
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298 { |
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299 //-- just copy src to the trg, the memory areas can overlap. |
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300 TUint8* p=Mem::Copy(aTrg, aSrc, aLength); |
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301 |
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302 //-- now zero-fill the source memory area taking into account possible overlap. |
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303 TUint8* pSrc = static_cast<TUint8*>(aSrc); |
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304 TUint8* pTrg = static_cast<TUint8*>(aTrg); |
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305 |
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306 TUint8* pZFill = NULL; //-- pointer to the beginning of zerofilled area |
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307 TInt zFillLen = 0; //-- a number of bytes to zero-fill |
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308 |
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309 if(aTrg < aSrc) |
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310 { |
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311 if(pTrg+aLength < pSrc) |
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312 {//-- target and source areas do not overlap |
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313 pZFill = pSrc; |
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314 zFillLen = aLength; |
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315 } |
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316 else |
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317 {//-- target and source areas overlap, try not to corrupt the target area |
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318 zFillLen = pSrc-pTrg; |
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319 pZFill = pTrg+aLength; |
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320 } |
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321 } |
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322 else |
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323 { |
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324 if(pSrc+aLength < pTrg) |
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325 {//-- target and source areas do not overlap |
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326 pZFill = pSrc; |
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327 zFillLen = aLength; |
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328 } |
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329 else |
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330 {//-- target and source areas overlap, try not to corrupt the target area |
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331 zFillLen = pSrc+aLength-pTrg; |
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332 pZFill = pSrc; |
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333 } |
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334 } |
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335 |
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336 Mem::FillZ(pZFill, zFillLen); |
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337 |
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338 return(p); |
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339 } |
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340 |
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341 |
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342 /** |
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343 Zero fill RAM area corresponding to the cluster number aCluster |
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344 @param aCluster a cluster number to be zero-filled |
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345 */ |
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346 void CRamFatTable::ZeroFillCluster(TInt aCluster) |
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347 { |
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348 TLinAddr clusterPos= I64LOW(DataPositionInBytes(aCluster)); |
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349 Mem::FillZ(iRamDiskBase+clusterPos, 1<< iOwner->ClusterSizeLog2()); |
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350 } |
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351 |
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352 |
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353 /** |
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354 Return the location of a Cluster in the data section of the media |
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355 |
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356 @param aCluster to find location of |
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357 @return Byte offset of the cluster data |
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358 */ |
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359 TInt64 CRamFatTable::DataPositionInBytes(TUint32 aCluster) const |
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360 { |
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361 //__PRINT(_L("CRamFatTable::DataPositionInBytes")); |
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362 ReadIndirectionTable(aCluster); |
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363 return(aCluster<<iOwner->ClusterSizeLog2()); |
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364 } |
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365 |
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366 /** |
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367 Allocate and mark as EOF a single cluster as close as possible to aNearestCluster, |
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368 calls base class implementation but must Enlarge the RAM drive first. Allocated cluster RAM area will be zero-filled. |
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369 |
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370 @param aNearestCluster Cluster the new cluster should be nearest to |
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371 @leave System wide error codes |
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372 @return The cluster number allocated |
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373 */ |
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374 TUint32 CRamFatTable::AllocateSingleClusterL(TUint32 aNearestCluster) |
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375 { |
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376 __PRINT(_L("CRamFatTable::AllocateSingleClusterL")); |
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377 iOwner->EnlargeL(1<<iOwner->ClusterSizeLog2()); // First enlarge the RAM drive |
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378 TInt fileAllocated=CFatTable::AllocateSingleClusterL(aNearestCluster); // Now update the free cluster and fat/fit |
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379 ZeroFillCluster(fileAllocated); //-- zero-fill allocated cluster |
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380 return(fileAllocated); |
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381 } |
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382 |
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383 |
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384 /** |
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385 Extend a file or directory cluster chain, enlarging RAM drive first. Allocated clusters are zero-filled. |
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386 Leaves if there are no free clusters (the disk is full). |
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387 Note that method now doesn't call CFatTable::ExtendClusterListL() from its base class, be careful making changes there. |
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388 |
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389 @param aNumber number of clusters to allocate |
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390 @param aCluster starting cluster number / ending cluster number after |
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391 @leave KErrDiskFull + system wide error codes |
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392 */ |
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393 void CRamFatTable::ExtendClusterListL(TUint32 aNumber, TInt& aCluster) |
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394 { |
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395 __PRINT(_L("CRamFatTable::ExtendClusterListL")); |
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396 __ASSERT_DEBUG(aNumber>0,Fault(EFatBadParameter)); |
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397 |
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398 iOwner->EnlargeL(aNumber<<iOwner->ClusterSizeLog2()); |
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399 |
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400 while(aNumber && GetNextClusterL(aCluster)) |
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401 aNumber--; |
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402 |
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403 if(!aNumber) |
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404 return; |
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405 |
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406 if (NumberOfFreeClusters() < aNumber) |
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407 { |
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408 __PRINT(_L("CRamFatTable::ExtendClusterListL - leaving KErrDirFull")); |
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409 User::Leave(KErrDiskFull); |
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410 } |
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411 |
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412 while(aNumber--) |
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413 { |
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414 const TInt freeCluster=FindClosestFreeClusterL(aCluster); |
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415 |
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416 WriteFatEntryEofL(freeCluster); // Must write EOF for FindClosestFreeCluster to work again |
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417 DecrementFreeClusterCount(1); |
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418 WriteL(aCluster,freeCluster); |
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419 aCluster=freeCluster; |
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420 ZeroFillCluster(freeCluster); //-- zero fill just allocated cluster (RAM area) |
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421 } |
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422 |
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423 SetFreeClusterHint(aCluster); |
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424 |
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425 } |
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426 |
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427 /** |
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428 Mark a chain of clusters as free in the FAT. Shrinks the RAM drive once the |
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429 clusters are free |
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430 |
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431 @param aCluster Start cluster of cluster chain to free |
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432 @leave System wide error codes |
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433 */ |
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434 void CRamFatTable::FreeClusterListL(TUint32 aCluster) |
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435 { |
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436 __PRINT1(_L("CRamFatTable::FreeClusterListL aCluster=%d"),aCluster); |
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437 if (aCluster==0) |
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438 return; // File has no cluster allocated |
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439 |
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440 const TInt clusterShift=iOwner->ClusterSizeLog2(); |
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441 TInt startCluster=aCluster; |
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442 TInt endCluster=0; |
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443 TInt totalFreed=0; |
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444 TLinAddr srcEnd=0; |
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445 |
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446 if(IsFat32()) |
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447 { |
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448 while(endCluster!=EOF_32Bit) |
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449 { |
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450 TInt num=CountContiguousClustersL(startCluster,endCluster,KMaxTInt); |
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451 if (GetNextClusterL(endCluster)==EFalse || endCluster==0) |
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452 endCluster=EOF_32Bit; // endCluster==0 -> file contained FAT loop |
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453 |
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454 // Real position in bytes of the start cluster in the data area |
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455 TLinAddr startClusterPos=I64LOW(DataPositionInBytes(startCluster)); |
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456 // Sliding value when more than one block is freed |
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457 TLinAddr trg=startClusterPos-(totalFreed<<clusterShift); |
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458 __PRINT1(_L("trg=0x%x"),trg); |
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459 |
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460 // Beginning of data area to move |
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461 TLinAddr srcStart=startClusterPos+(num<<clusterShift); |
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462 __PRINT1(_L("srcStart=0x%x"),srcStart); |
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463 // Position of next part of cluster chain or position of end of ram drive |
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464 if (endCluster==EOF_32Bit) // Last cluster is the end of the chain |
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465 { |
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466 |
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467 |
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468 // Fixed to use the genuine RAM drive size rather than the number |
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469 // of free clusters - though they *should* be the same |
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470 // It avoids the problem of iFreeClusters getting out of sync with |
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471 // the RAM drive size but doesn't solve the issue of why it can happen... |
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472 |
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473 srcEnd=I64LOW(iOwner->Size()); |
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474 __PRINT1(_L("srcEnd=0x%x"),srcEnd); |
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475 } |
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476 else // Just move up to the next part of the chain |
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477 srcEnd=I64LOW(DataPositionInBytes(endCluster)); |
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478 |
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479 //-- Copy (srcEnd-srcStart) bytes from iRamDiskBase+srcStart onto iRamDiskBase+trg |
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480 //-- zero-filling free space to avoid leaving something important there |
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481 ASSERT(srcEnd >= srcStart); |
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482 if(srcEnd-srcStart > 0) |
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483 { |
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484 MemCopyFillZ(iRamDiskBase+trg,iRamDiskBase+srcStart,srcEnd-srcStart); |
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485 } |
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486 else |
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487 {//-- we are freeing the cluster chain at the end of the RAM drive; Nothing to copy to the drive space that has become free, |
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488 //-- but nevertheless zero fill this space. |
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489 Mem::FillZ(iRamDiskBase+trg, num<<clusterShift); |
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490 } |
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491 |
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492 |
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493 totalFreed+=num; |
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494 startCluster=endCluster; |
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495 UpdateIndirectionTable(srcStart>>clusterShift,srcEnd>>clusterShift,totalFreed); |
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496 } |
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497 } |
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498 else |
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499 { |
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500 while(endCluster!=EOF_16Bit) |
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501 { |
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502 TInt num=CountContiguousClustersL(startCluster,endCluster,KMaxTInt); |
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503 if (GetNextClusterL(endCluster)==EFalse || endCluster==0) |
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504 endCluster=EOF_16Bit; // endCluster==0 -> file contained FAT loop |
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505 |
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506 // Real position in bytes of the start cluster in the data area |
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507 TLinAddr startClusterPos=I64LOW(DataPositionInBytes(startCluster)); |
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508 // Sliding value when more than one block is freed |
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509 TLinAddr trg=startClusterPos-(totalFreed<<clusterShift); |
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510 __PRINT1(_L("trg=0x%x"),trg); |
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511 |
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512 // Beginning of data area to move |
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513 TLinAddr srcStart=startClusterPos+(num<<clusterShift); |
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514 __PRINT1(_L("srcStart=0x%x"),srcStart); |
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515 // Position of next part of cluster chain or position of end of ram drive |
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516 if (endCluster==EOF_16Bit) // Last cluster is the end of the chain |
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517 { |
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518 |
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519 |
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520 // Fixed to use the genuine RAM drive size rather than the number |
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521 // of free clusters - though they *should* be the same |
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522 // It avoids the problem of iFreeClusters getting out of sync with |
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523 // the RAM drive size but doesn't solve the issue of why it can happen... |
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524 |
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525 srcEnd=I64LOW(iOwner->Size()); |
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526 __PRINT1(_L("srcEnd=0x%x"),srcEnd); |
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527 } |
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528 else // Just move up to the next part of the chain |
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529 srcEnd=I64LOW(DataPositionInBytes(endCluster)); |
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530 |
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531 //-- Copy (srcEnd-srcStart) bytes from iRamDiskBase+srcStart onto iRamDiskBase+trg |
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532 //-- zero-filling free space to avoid leaving something important there |
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533 ASSERT(srcEnd >= srcStart); |
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534 if(srcEnd-srcStart > 0) |
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535 { |
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536 MemCopyFillZ(iRamDiskBase+trg,iRamDiskBase+srcStart,srcEnd-srcStart); |
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537 } |
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538 else |
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539 {//-- we are freeing the cluster chain at the end of the RAMdrive; Nothing to copy to the drive space that has become free, |
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540 //-- but nevertheless zero fill this space. |
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541 Mem::FillZ(iRamDiskBase+trg, num<<clusterShift); |
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542 } |
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543 |
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544 totalFreed+=num; |
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545 startCluster=endCluster; |
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546 UpdateIndirectionTable(srcStart>>clusterShift,srcEnd>>clusterShift,totalFreed); |
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547 } |
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548 } |
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549 TInt bytesFreed=totalFreed<<clusterShift; |
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550 |
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551 // First free the cluster list |
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552 CFatTable::FreeClusterListL(aCluster); |
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553 // Now reduce the size of the RAM drive |
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554 iOwner->ReduceSizeL(srcEnd-bytesFreed,bytesFreed); |
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555 } |
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556 |
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557 /** |
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558 Shift any clusters between aStart and anEnd backwards by aClusterShift |
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559 |
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560 @param aStart Start of shift region |
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561 @param anEnd End of shift region |
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562 @param aClusterShift amount to shift cluster by |
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563 */ |
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564 void CRamFatTable::UpdateIndirectionTable(TUint32 aStart,TUint32 anEnd,TInt aClusterShift) |
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565 { |
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566 __PRINT(_L("CRamFatTable::UpdateIndirectionTable")); |
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567 #if defined(__WINS__) |
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568 TUint32 count=iOwner->MaxClusterNumber(); |
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569 while (count--) |
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570 { |
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571 TUint32 cluster=count; |
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572 ReadIndirectionTable(cluster); |
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573 if (cluster>=aStart && cluster<anEnd) |
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574 WriteIndirectionTable(count,cluster-aClusterShift); |
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575 } |
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576 #else |
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577 TUint16* table=(TUint16*)(RamDiskBase()+iIndirectionTablePos); |
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578 TUint16* entry=table+iOwner->MaxClusterNumber(); |
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579 while (entry>table) |
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580 { |
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581 TUint32 cluster=*--entry; |
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582 if (cluster<aStart) |
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583 continue; |
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584 if (cluster<anEnd) |
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585 *entry=TUint16(cluster-aClusterShift); |
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586 } |
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587 #endif |
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588 } |
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589 |
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590 |
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591 |