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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\sl_fatcache.cpp |
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15 // FAT12 and FAT16 cache implementation |
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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 */ |
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22 |
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23 #include "sl_std.h" |
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24 #include "sl_fatcache.h" |
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25 |
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26 |
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27 //################################################################################################################################# |
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28 // CFatCacheBase implementation |
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29 // Base class for all types of FAT cache |
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30 //################################################################################################################################# |
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31 |
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32 CFatCacheBase::~CFatCacheBase() |
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33 { |
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34 Close(ETrue); //-- deallocate cache's memory discarding any dirty data |
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35 } |
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36 |
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37 CFatCacheBase::CFatCacheBase() |
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38 { |
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39 iCurrentFatNo = KInvalidFatNo; |
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40 SetDirty(EFalse); |
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41 } |
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42 |
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43 |
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44 /** |
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45 FAT cache initialisation. |
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46 |
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47 @param aOwner pointer to the owning FAT mount |
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48 */ |
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49 void CFatCacheBase::InitialiseL(CFatMountCB* aOwner) |
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50 { |
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51 ASSERT(aOwner); |
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52 |
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53 Close(ETrue); //-- deallocate cache's memory discarding any dirty data |
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54 |
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55 //-- populate parameters from the owning mount |
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56 iFatType = aOwner->FatType(); |
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57 __ASSERT_ALWAYS((iFatType == EFat12 || iFatType == EFat16 || iFatType == EFat32), User::Leave(KErrCorrupt)); |
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58 |
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59 ipDrive = &aOwner->DriveInterface(); |
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60 iFatStartPos = aOwner->FirstFatSector() << aOwner->SectorSizeLog2(); |
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61 iFatSize = aOwner->FatSizeInBytes(); |
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62 iNumFATs = (TUint16)aOwner->NumberOfFats(); |
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63 iFatSecSzLog2 = (TUint16)aOwner->SectorSizeLog2(); |
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64 iFatClustSzLog2 = (TUint16)aOwner->ClusterSizeLog2(); |
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65 |
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66 __ASSERT_ALWAYS(iNumFATs >=1, User::Leave(KErrCorrupt)); |
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67 |
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68 __PRINT3(_L("#-CFatCacheBase::InitialiseL() FatStart:%u, FatSz:%d, drv:%d"),iFatStartPos, iFatSize, aOwner->DriveNumber()); |
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69 } |
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70 |
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71 //----------------------------------------------------------------------------- |
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72 /** |
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73 This method shall be called to check if we are allowed to invalidate dirty cache, i.e. discard non-flushed data. |
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74 The behaviour is hardcoded (see KAllowInvalidateDirtyCache constant) |
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75 |
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76 @return ETrue if invalidating dirty cache is allowed. Otherwise panics the current thread |
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77 */ |
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78 TBool CFatCacheBase::CheckInvalidatingDirtyCache() const |
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79 { |
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80 |
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81 //-- If not EFalse, invalidating dirty cache (pages) is allowed. This shall be OK, because |
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82 //-- invalidating the cache is required only after direct media writes to the FAT by RawWrite, which can corrupt it anyway. |
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83 TBool KAllowInvalidateDirtyCache = ETrue; |
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84 |
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85 if(!IsDirty()) |
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86 return KAllowInvalidateDirtyCache; |
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87 |
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88 __PRINT(_L("#-CFatCacheBase::Invalidating dirty cache !")); |
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89 |
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90 if(!KAllowInvalidateDirtyCache) |
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91 { |
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92 __ASSERT_ALWAYS(0, Fault(EFatCache_DiscardingDirtyData)); |
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93 } |
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94 |
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95 return KAllowInvalidateDirtyCache; |
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96 } |
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97 |
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98 //----------------------------------------------------------------------------- |
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99 |
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100 /** |
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101 Read portion of raw data from 1st FAT copy. |
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102 |
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103 @param aPos media position in the _FIRST_ FAT to start reading with |
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104 @param aLen number of bytes to read |
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105 @param aData data descriptor |
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106 |
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107 @return standard error code. |
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108 */ |
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109 TInt CFatCacheBase::ReadFatData(TUint32 aPos, TUint32 aLen, TDes8& aData) const |
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110 { |
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111 //__PRINT2(_L("#-CFatCacheNew::ReadFatData() pos:%u, Len:%d"), aPos, aLen); |
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112 |
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113 //-- this method can pick up data corresponding to invalid FAT entries, like FAT[0], FAT[1] and |
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114 //-- the last portion beyond FAT because of read granularity. This isn't a problem, because the data there |
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115 //-- won't be written on disk. |
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116 ASSERT(aPos >= FatStartPos()); |
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117 |
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118 return ipDrive->ReadNonCritical(aPos, aLen, aData); |
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119 } |
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120 |
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121 //----------------------------------------------------------------------------- |
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122 |
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123 /** |
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124 Writes data to the FAT table, which number is set in iCurrentFatNo member variable. |
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125 @param aPos data media position in the _FIRST_ FAT copy |
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126 @param aData data descriptor |
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127 @return standard error code. |
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128 */ |
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129 TInt CFatCacheBase::WriteFatData(TUint32 aPos, const TDesC8& aData) const |
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130 { |
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131 //__PRINT3(_L("#-CFatCacheBase::WriteFatData() pos:%u, Len:%d, FAT:%d"), aPos, aData.Length(), iCurrentFatNo); |
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132 |
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133 #ifdef _DEBUG |
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134 //-- FAT[0] and FAT[1] entries are reserved and we must not write data there. It's up to the caller of this method to |
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135 //-- calculate correct data position in FAT |
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136 TInt reserved_Entries_Offset=0; |
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137 switch(iFatType) |
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138 { |
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139 case EFat32: reserved_Entries_Offset = KFatFirstSearchCluster*sizeof(TFat32Entry); break; //-- FAT32 |
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140 case EFat16: reserved_Entries_Offset = KFatFirstSearchCluster*sizeof(TFat16Entry); break; //-- FAT16 |
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141 case EFat12: reserved_Entries_Offset = 3; break; //-- FAT12 |
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142 default: ASSERT(0); break; |
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143 } |
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144 ASSERT(aPos >= FatStartPos()+reserved_Entries_Offset); |
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145 ASSERT((aPos+aData.Length()) <= FatStartPos()+FatSize()); |
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146 ASSERT(iCurrentFatNo < iNumFATs); |
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147 #endif |
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148 |
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149 //-- goto the required FAT copy. iCurrentFatNo shall contain FAT number we are writing to. |
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150 aPos+=iCurrentFatNo*FatSize(); |
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151 |
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152 return ipDrive->WriteCritical(aPos, aData); |
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153 } |
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154 |
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155 //----------------------------------------------------------------------------- |
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156 /** |
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157 get a pointer to the CFatBitCache interface. |
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158 @return NULL because it is not present here |
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159 */ |
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160 CFatBitCache* CFatCacheBase::BitCacheInterface() |
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161 { |
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162 return NULL; |
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163 } |
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164 |
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165 |
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166 //################################################################################################################################# |
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167 // CFatPagedCacheBase implementation |
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168 // Base class for all paged FAT caches |
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169 //################################################################################################################################# |
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170 |
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171 CFatPagedCacheBase::CFatPagedCacheBase() |
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172 :CFatCacheBase() |
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173 { |
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174 } |
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175 |
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176 |
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177 //################################################################################################################################# |
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178 // CFatCachePageBase implementation |
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179 // Base class for FAT cache pages (FAT16 fixed and FAT32 LRU) |
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180 //################################################################################################################################# |
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181 |
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182 CFatCachePageBase::CFatCachePageBase(CFatPagedCacheBase& aCache) |
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183 :iCache(aCache) |
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184 { |
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185 ASSERT(IsPowerOf2(aCache.PageSize())); |
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186 iStartIndexInFAT = KMaxTUint; |
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187 |
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188 //-- calculate number of FAT entries in the page, it depends on FAT type |
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189 switch(aCache.FatType()) |
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190 { |
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191 case EFat32: |
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192 iFatEntriesInPage = PageSize() >> KFat32EntrySzLog2; |
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193 break; |
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194 |
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195 case EFat16: |
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196 iFatEntriesInPage = PageSize() >> KFat16EntrySzLog2; |
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197 break; |
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198 |
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199 default: |
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200 ASSERT(0); |
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201 Fault(EFatCache_BadFatType); |
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202 break; |
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203 |
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204 }; |
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205 |
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206 SetState(EInvalid); |
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207 } |
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208 |
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209 CFatCachePageBase::~CFatCachePageBase() |
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210 { |
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211 iData.Close(); |
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212 } |
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213 |
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214 //----------------------------------------------------------------------------- |
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215 /** |
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216 Mark the page as "invalid". I.e containing inalid data. |
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217 On the first read/write access to such page it will be re-read from the media |
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218 |
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219 @param aIgnoreDirtyData if ETrue, it is allowed to ignore the fact that the page contains dirty (not flushed) data. |
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220 */ |
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221 void CFatCachePageBase::Invalidate(TBool aIgnoreDirtyData /*= EFalse*/) |
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222 { |
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223 if(!aIgnoreDirtyData && IsDirty()) |
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224 { |
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225 __PRINT1(_L("#-CFatCachePageBase::Invalidate() dirty page! FAT idx:%d"), iStartIndexInFAT); |
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226 __ASSERT_ALWAYS(0, Fault(EFatCache_DiscardingDirtyData)); |
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227 } |
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228 |
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229 iDirtySectors.Clear(); //-- clear dirty sectors bitmap |
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230 SetState(EInvalid); |
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231 } |
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232 |
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233 //----------------------------------------------------------------------------- |
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234 /** |
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235 Flush all dirty page sectors to the media and mark the page as "clean" if required. |
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236 If the page is "clean" i.e doesn't contain changed data, does nothing. |
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237 |
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238 @param aKeepDirty if ETrue, the "dirty" flag isn't reset after page flushing. |
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239 */ |
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240 void CFatCachePageBase::FlushL(TBool aKeepDirty) |
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241 { |
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242 if(!IsDirty()) |
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243 return; |
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244 |
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245 if(!IsValid()) |
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246 { |
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247 __PRINT1(_L("#-CFatCachePageBase::FlushL() Invalid page! FAT idx:%d"), iStartIndexInFAT); |
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248 ASSERT(0); |
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249 User::Leave(KErrCorrupt); |
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250 return; |
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251 } |
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252 |
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253 //__PRINT1(_L("#-CFatCachePageBase::FlushL() FAT idx:%d"), iStartIndexInFAT); |
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254 |
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255 //-- write dirty FAT sectors to the media one by one. |
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256 //-- merging adjacent dirty subsectors into larger clusters and writing them at once looks like a good idea, but |
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257 //-- in reality it showed FAT performance degradation, at least on MMC/SD media. |
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258 |
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259 const TInt MaxSectors = iCache.SectorsInPage(); |
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260 |
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261 for(TInt i=0; i<MaxSectors; ++i) |
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262 { |
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263 if(iDirtySectors[i]) |
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264 { |
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265 DoWriteSectorL(i); |
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266 } |
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267 } |
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268 |
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269 //-- All data flushed; mark page as clean if it isn't required not to do. |
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270 if(!aKeepDirty) |
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271 SetClean(); |
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272 |
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273 } |
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274 |
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275 |
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276 //################################################################################################################################# |
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277 // CFat16FixedCache implementation |
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278 // Fixed cache (caches all FAT16) but organised as an array of pages |
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279 //################################################################################################################################# |
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280 |
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281 CFat16FixedCache::CFat16FixedCache() |
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282 :CFatPagedCacheBase(),iPages(1) //-- array granularity is 1 |
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283 { |
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284 } |
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285 |
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286 //----------------------------------------------------------------------------- |
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287 /** |
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288 FAT16 fixed cache factory function. |
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289 @param aOwner pointer to the owning FAT mount |
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290 @param aFatSize size of the FAT table in bytes |
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291 @param aRdGranularityLog2 Log2(read granularity) |
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292 @param aWrGranularityLog2 Log2(write granularity) |
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293 |
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294 @return pointer to the constructed object. |
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295 */ |
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296 CFat16FixedCache* CFat16FixedCache::NewL(CFatMountCB* aOwner, TUint32 aFatSize, TUint32 aRdGranularityLog2, TUint32 aWrGranularityLog2) |
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297 { |
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298 __PRINT(_L("#-CFat16FixedCache::NewL()")); |
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299 |
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300 CFat16FixedCache* pSelf = NULL; |
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301 pSelf = new (ELeave) CFat16FixedCache; |
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302 |
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303 CleanupStack::PushL(pSelf); |
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304 pSelf->InitialiseL(aOwner, aFatSize, aRdGranularityLog2, aWrGranularityLog2); |
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305 CleanupStack::Pop(); |
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306 |
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307 return pSelf; |
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308 } |
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309 |
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310 //----------------------------------------------------------------------------- |
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311 /** |
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312 FAT16 fixed cache initialisation. |
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313 @param aOwner pointer to the owning FAT mount |
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314 @param aFatSize size of the FAT table in bytes |
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315 @param aRdGranularityLog2 Log2(read granularity) |
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316 @param aWrGranularityLog2 Log2(write granularity) |
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317 */ |
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318 void CFat16FixedCache::InitialiseL(CFatMountCB* aOwner, TUint32 aFatSize, TUint32 aRdGranularityLog2, TUint32 aWrGranularityLog2) |
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319 { |
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320 const TUint32 ReadGranularity = Pow2(aRdGranularityLog2); |
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321 const TUint32 WriteGranularity = Pow2(aWrGranularityLog2); |
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322 |
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323 __PRINT3(_L("#-CFat16FixedCache::InitialiseL FatSz:%u, RdGr:%d, WrGr:%d"),aFatSize, ReadGranularity, WriteGranularity); |
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324 (void)ReadGranularity; |
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325 (void)WriteGranularity; |
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326 |
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327 TBool bParamsValid = (aRdGranularityLog2 >= aWrGranularityLog2) && (aWrGranularityLog2 >= KDefSectorSzLog2); |
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328 __ASSERT_ALWAYS(bParamsValid, Fault(EFatCache_BadGranularity)); |
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329 |
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330 CFatPagedCacheBase::InitialiseL(aOwner); |
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331 |
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332 ASSERT(FatType() == EFat16); |
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333 |
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334 //-- See FAT specs, and round up the limit to the FAT sector boundary |
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335 const TUint32 KMaxFat16Size = ((65524*sizeof(TFat16Entry)+FAT_SectorSz()-1) >> FAT_SectorSzLog2()) << FAT_SectorSzLog2(); |
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336 const TUint32 KMinFat16Size = 4086*sizeof(TFat16Entry); //-- See FAT specs |
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337 |
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338 bParamsValid = aFatSize >= KMinFat16Size && aFatSize <= KMaxFat16Size; |
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339 __ASSERT_ALWAYS(bParamsValid, User::Leave(KErrCorrupt)); |
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340 |
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341 //-- cache page size is (2^aRdGranularityLog2) bytes and consists of 2^(aRdGranularityLog2-aWrGranularity) sectors. |
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342 iPageSizeLog2 = aRdGranularityLog2; |
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343 iSectorSizeLog2 = aWrGranularityLog2; //-- Log2(number of sectors in cache page) |
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344 |
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345 __ASSERT_ALWAYS(SectorsInPage() < KMaxSectorsInPage, Fault(EFatCache_BadGranularity)); |
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346 |
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347 const TUint numPages = (aFatSize+(PageSize()-1)) >> iPageSizeLog2; |
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348 __PRINT1(_L("#-CFat16FixedCache Num Pages:%d"), numPages); |
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349 |
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350 //-- prepare pointer array for pages. NULL entry in the array means that the page at this index isn't allocated. |
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351 for(TUint i=0; i<numPages; ++i) |
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352 iPages.Append(NULL); |
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353 |
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354 } |
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355 |
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356 |
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357 //----------------------------------------------------------------------------- |
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358 /** |
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359 Close the cache and deallocate its memory. |
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360 @param aDiscardDirtyData if ETrue, will ignore dirty data. If EFalse, will panic on atempt to close dirty cache. |
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361 */ |
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362 void CFat16FixedCache::Close(TBool aDiscardDirtyData) |
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363 { |
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364 __PRINT1(_L("#-CFat16FixedCache::Close(%d)"), aDiscardDirtyData); |
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365 |
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366 TInt cnt = iPages.Count(); |
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367 while(cnt--) |
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368 {//-- delete pages |
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369 CFat16FixedCachePage *pPage = iPages[cnt]; |
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370 if(pPage && (pPage->IsDirty())) |
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371 {//-- trying to destroy the cache that has dirty pages |
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372 __PRINT1(_L("#-CFat16FixedCache::Close() The page is dirty! Start idx:%d"), pPage->StartFatIndex()); |
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373 if(!aDiscardDirtyData) |
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374 { |
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375 __ASSERT_ALWAYS(0, Fault(EFatCache_DiscardingDirtyData)); |
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376 } |
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377 //-- ignore this fact if requested. |
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378 } |
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379 |
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380 delete pPage; |
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381 } |
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382 |
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383 iPages.Close(); |
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384 SetDirty(EFalse); |
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385 } |
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386 |
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387 //----------------------------------------------------------------------------- |
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388 /** |
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389 Read FAT entry from the cache. |
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390 |
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391 @param aIndex FAT entry index to read |
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392 @return FAT entry value at the index "aIndex" |
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393 */ |
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394 TUint32 CFat16FixedCache::ReadEntryL(TUint32 aIndex) |
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395 { |
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396 //__PRINT1(_L("#-CFat16FixedCache::ReadEntryL() FAT idx:%d"), aIndex); |
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397 ASSERT(aIndex >= KFatFirstSearchCluster && aIndex < (FatSize() >> KFat16EntrySzLog2)); |
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398 |
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399 //-- calculate page index in the array |
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400 const TInt pgIdx = aIndex >> (PageSizeLog2()-KFat16EntrySzLog2); |
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401 CFat16FixedCachePage *pPage = iPages[pgIdx]; |
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402 |
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403 TUint32 entry = KMaxTUint; |
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404 |
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405 if(!pPage) |
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406 {//-- page at this position isn't allocated yet |
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407 pPage = CFat16FixedCachePage::NewL(*this); |
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408 iPages[pgIdx] = pPage; |
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409 |
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410 //-- read the page from media |
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411 entry = pPage->ReadFromMediaL(aIndex); |
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412 } |
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413 else |
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414 {//-- get cached entry from the page |
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415 TBool bRes = pPage->ReadCachedEntryL(aIndex, entry); |
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416 ASSERT(bRes); |
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417 (void)bRes; |
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418 } |
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419 |
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420 return entry; |
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421 } |
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422 |
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423 //----------------------------------------------------------------------------- |
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424 /** |
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425 Write FAT entry to the cache. |
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426 Appropriate FAT cache sector will be marked as "dirty" and will be eventually flushed to the media. |
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427 |
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428 @param aIndex FAT entry index |
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429 @param aEntry FAT entry value |
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430 */ |
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431 void CFat16FixedCache::WriteEntryL(TUint32 aIndex, TUint32 aEntry) |
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432 { |
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433 //__PRINT2(_L("#-CFat16FixedCache::WriteEntryL() FAT idx:%d, val:%d"), aIndex, aEntry); |
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434 |
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435 ASSERT(aIndex >= KFatFirstSearchCluster && aIndex < (FatSize() >> KFat16EntrySzLog2)); |
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436 |
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437 SetDirty(ETrue); |
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438 |
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439 //-- calculate page index in the array |
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440 const TInt pgIdx = aIndex >> (PageSizeLog2()-KFat16EntrySzLog2); |
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441 CFat16FixedCachePage *pPage = iPages[pgIdx]; |
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442 |
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443 if(!pPage) |
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444 {//-- page at this position isn't allocated yet |
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445 pPage = CFat16FixedCachePage::NewL(*this); |
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446 iPages[pgIdx] = pPage; |
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447 |
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448 //-- read the page from media |
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449 pPage->ReadFromMediaL(aIndex); |
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450 } |
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451 |
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452 //-- overwrite entry in cache |
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453 TBool bRes = pPage->WriteCachedEntryL(aIndex, aEntry); |
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454 ASSERT(bRes); |
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455 (void)bRes; |
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456 } |
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457 |
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458 /** |
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459 A debug method that asserts that the cache is really clean |
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460 */ |
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461 void CFat16FixedCache::AssertCacheReallyClean() const |
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462 { |
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463 #ifdef _DEBUG |
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464 for(TUint i=0; i<NumPages(); ++i) |
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465 { |
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466 CFat16FixedCachePage* pPage = iPages[i]; |
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467 if(pPage && pPage->IsDirty()) |
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468 { |
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469 __PRINT(_L("#-CFat16FixedCache::AssertCacheReallyClean()")); |
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470 ASSERT(0); |
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471 } |
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472 } |
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473 #endif |
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474 } |
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475 |
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476 |
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477 //----------------------------------------------------------------------------- |
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478 /** |
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479 Flushes all dirty data to the media. |
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480 */ |
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481 void CFat16FixedCache::FlushL() |
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482 { |
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483 if(!IsDirty()) |
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484 { |
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485 AssertCacheReallyClean(); |
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486 return; |
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487 } |
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488 |
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489 |
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490 //-- flush dirty data to all copies of FAT |
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491 for(iCurrentFatNo=0; iCurrentFatNo < NumFATs(); ++iCurrentFatNo) |
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492 { |
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493 const TInt nPages = NumPages(); |
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494 for(TInt i=0; i<nPages; ++i) |
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495 { |
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496 const TBool keepDirty = iCurrentFatNo < (NumFATs() - 1); |
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497 |
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498 CFat16FixedCachePage* pPage = iPages[i]; |
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499 if(pPage) |
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500 pPage->FlushL(keepDirty); |
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501 } |
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502 |
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503 } |
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504 |
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505 iCurrentFatNo = KInvalidFatNo; |
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506 SetDirty(EFalse); |
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507 } |
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508 |
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509 //----------------------------------------------------------------------------- |
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510 /** |
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511 Invalidate whole cache. All pages will be marked as invalid and will be re-read from the media on first access to them. |
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512 @return always KErrNone |
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513 */ |
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514 TInt CFat16FixedCache::Invalidate() |
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515 { |
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516 __PRINT(_L("#-CFat16FixedCache::Invalidate()")); |
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517 const TBool bIgnoreDirtyData = CheckInvalidatingDirtyCache(); |
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518 |
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519 //-- iterate through the array of pages marking invalidating every page |
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520 TInt cnt = iPages.Count(); |
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521 while(cnt--) |
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522 {//-- delete pages |
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523 CFat16FixedCachePage *pPage = iPages[cnt]; |
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524 if(pPage) |
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525 pPage->Invalidate(bIgnoreDirtyData); |
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526 } |
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527 |
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528 |
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529 SetDirty(EFalse); |
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530 |
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531 return KErrNone; |
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532 } |
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533 |
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534 //----------------------------------------------------------------------------- |
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535 /** |
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536 Invalidate FAT cache pages that contain FAT entries from aStartIndex to (aStartIndex+aNumEntries) |
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537 These pages will be marked as invalid and will be re-read from the media on first access to them. |
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538 |
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539 @param aStartIndex FAT start index of the region being invalidated |
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540 @param aNumEntries number of entries to invalidate |
|
541 @return always KErrNone |
|
542 */ |
|
543 TInt CFat16FixedCache::InvalidateRegion(TUint32 aStartIndex, TUint32 aNumEntries) |
|
544 { |
|
545 __PRINT2(_L("#-CFat16FixedCache::InvalidateRegion() startIndex:%d, entries:%d"),aStartIndex, aNumEntries); |
|
546 ASSERT(aStartIndex >= KFatFirstSearchCluster && aStartIndex < (FatSize() >> KFat16EntrySzLog2)); |
|
547 |
|
548 if(!aNumEntries) |
|
549 { |
|
550 ASSERT(0); |
|
551 return KErrNone; |
|
552 } |
|
553 |
|
554 const TBool bIgnoreDirtyData = CheckInvalidatingDirtyCache(); |
|
555 const TUint startPgIdx = aStartIndex >> (PageSizeLog2()-KFat16EntrySzLog2); |
|
556 const TUint nPagesToInv = 1+(aNumEntries >> (PageSizeLog2()-KFat16EntrySzLog2)); |
|
557 |
|
558 TUint i; |
|
559 //-- invalidate pages that contain [aStartIndex ... aStartIndex+aNumEntries] entries |
|
560 for(i=0; i<nPagesToInv; ++i) |
|
561 { |
|
562 const TUint pageIdx = i+startPgIdx; |
|
563 if(pageIdx >= NumPages()) |
|
564 break; |
|
565 |
|
566 CFat16FixedCachePage* pPage = iPages[pageIdx]; |
|
567 if(pPage) |
|
568 pPage->Invalidate(bIgnoreDirtyData); |
|
569 } |
|
570 |
|
571 SetDirty(EFalse); |
|
572 |
|
573 //-- check if the cache still has dirty pages |
|
574 for(i=0; i<NumPages(); ++i) |
|
575 { |
|
576 CFat16FixedCachePage* pPage = iPages[i]; |
|
577 if(pPage && pPage->IsDirty()) |
|
578 { |
|
579 SetDirty(ETrue); |
|
580 break; |
|
581 } |
|
582 } |
|
583 |
|
584 return KErrNone; |
|
585 } |
|
586 |
|
587 //################################################################################################################################# |
|
588 // CFat16FixedCachePage implementation |
|
589 // Page for the FAT16 fixed cache |
|
590 //################################################################################################################################# |
|
591 |
|
592 //----------------------------------------------------------------------------- |
|
593 |
|
594 CFat16FixedCachePage::CFat16FixedCachePage(CFatPagedCacheBase& aCache) |
|
595 :CFatCachePageBase(aCache) |
|
596 { |
|
597 ASSERT(IsPowerOf2(EntriesInPage())); |
|
598 } |
|
599 |
|
600 |
|
601 /** |
|
602 Factory function. |
|
603 @param aCache reference to the owning cache. |
|
604 @return pointer to the constructed object or NULL on error |
|
605 */ |
|
606 CFat16FixedCachePage* CFat16FixedCachePage::NewL(CFatPagedCacheBase& aCache) |
|
607 { |
|
608 CFat16FixedCachePage* pSelf = NULL; |
|
609 pSelf = new (ELeave) CFat16FixedCachePage(aCache); |
|
610 |
|
611 CleanupStack::PushL(pSelf); |
|
612 |
|
613 pSelf->iData.CreateMaxL(aCache.PageSize()); //-- allocate memory for the page |
|
614 |
|
615 CleanupStack::Pop(); |
|
616 |
|
617 return pSelf; |
|
618 } |
|
619 |
|
620 |
|
621 //----------------------------------------------------------------------------- |
|
622 /** |
|
623 Read FAT16 entry from the cache. |
|
624 |
|
625 1. If page's data are valid, just extracts data from the page buffer. |
|
626 2. If page's data are invalid firstly reads data from the media and goto 1 |
|
627 |
|
628 @param aFatIndex entry's absolute FAT index (from the FAT start) |
|
629 @param aResult on sucess there will be FAT16 entry value |
|
630 @return ETrue, because FAT16 cache pages never get eviched. |
|
631 */ |
|
632 TBool CFat16FixedCachePage::ReadCachedEntryL (TUint32 aFatIndex, TUint32& aResult) |
|
633 { |
|
634 if(IsValid()) |
|
635 {//-- read entry directly from page buffer, the cached data are valid |
|
636 aResult = (*GetEntryPtr(aFatIndex)) & KFat16EntryMask; |
|
637 } |
|
638 else |
|
639 {//-- aFatIndex belongs to this page, but the page is invalid and needs to be read from the media |
|
640 //__PRINT(_L("#-CFat16FixedCachePage::ReadCachedEntry() The page is invalid, reading from the media")); |
|
641 aResult = ReadFromMediaL(aFatIndex); |
|
642 } |
|
643 |
|
644 return ETrue; |
|
645 } |
|
646 |
|
647 //----------------------------------------------------------------------------- |
|
648 |
|
649 /** |
|
650 Writes FAT cache page sector to the media (to all copies of the FAT) |
|
651 @param aSector sector number winthin this page |
|
652 */ |
|
653 void CFat16FixedCachePage::DoWriteSectorL(TUint32 aSector) |
|
654 { |
|
655 //__PRINT1(_L("#-CFat16FixedCachePage::DoWriteSectorL() startSec:%d, cnt:%d"), aSector); |
|
656 |
|
657 ASSERT(aSector < iCache.SectorsInPage()); |
|
658 |
|
659 TInt offset = 0; |
|
660 |
|
661 if(iStartIndexInFAT == 0 && aSector == 0) |
|
662 {//-- this is the very beginning of FAT16. We must skip FAT[0] & FAT[1] entries and do not write them to media. |
|
663 offset = KFatFirstSearchCluster << KFat16EntrySzLog2; |
|
664 } |
|
665 |
|
666 const TUint8* pData = iData.Ptr()+offset+(aSector << iCache.SectorSizeLog2()); |
|
667 |
|
668 TUint32 dataLen = (1 << iCache.SectorSizeLog2()) - offset; |
|
669 |
|
670 const TUint32 mediaPosStart = iCache.FatStartPos() + (iStartIndexInFAT << KFat16EntrySzLog2) + (aSector << iCache.SectorSizeLog2()) + offset; |
|
671 const TUint32 mediaPosEnd = mediaPosStart + dataLen; |
|
672 |
|
673 //-- check if we are going to write beyond FAT. It can happen if the write granularity is bigger that the sector size. |
|
674 const TUint32 posFatEnd = iCache.FatStartPos() + iCache.FatSize(); |
|
675 if(mediaPosEnd > posFatEnd) |
|
676 {//-- correct the leength of the data to write. |
|
677 dataLen -= (mediaPosEnd-posFatEnd); |
|
678 } |
|
679 |
|
680 TPtrC8 ptrData(pData, dataLen); //-- source data descriptor |
|
681 |
|
682 TInt nRes = iCache.WriteFatData(mediaPosStart, ptrData); |
|
683 |
|
684 if(nRes != KErrNone) |
|
685 { |
|
686 __PRINT1(_L("#-CFat16FixedCachePage::DoWriteSectorsL() failed! code:%d"), nRes); |
|
687 User::Leave(nRes); |
|
688 } |
|
689 |
|
690 } |
|
691 |
|
692 //----------------------------------------------------------------------------- |
|
693 /** |
|
694 Write FAT16 entry at aFatIndex to the cache. Note that the data are not written to the media, only to the cache page. |
|
695 Corresponding page sector is marked as dirty and will be flushed on FlushL() call later. |
|
696 |
|
697 1. If page's data are valid, copies data to the page buffer and marks sector as dirty. |
|
698 2. If page's data are invalid, firstly reads data from the media and goto 1 |
|
699 |
|
700 @param aFatIndex entry's absolute FAT index (from the FAT start) |
|
701 @param aFatEntry FAT16 entry value |
|
702 @return ETrue because FAT16 cache pages never get eviched. |
|
703 */ |
|
704 TBool CFat16FixedCachePage::WriteCachedEntryL(TUint32 aFatIndex, TUint32 aFatEntry) |
|
705 { |
|
706 |
|
707 ASSERT(IsEntryCached(aFatIndex)); |
|
708 |
|
709 if(!IsValid()) |
|
710 {//-- we are trying to write data to the page that has invalid data. //-- read the data from the media first. |
|
711 ReadFromMediaL(aFatIndex); |
|
712 } |
|
713 |
|
714 TFat16Entry* pEntry = GetEntryPtr(aFatIndex); |
|
715 |
|
716 const TFat16Entry orgEntry = *pEntry; |
|
717 *pEntry = (TFat16Entry)((orgEntry & ~KFat16EntryMask) | (aFatEntry & KFat16EntryMask)); |
|
718 |
|
719 //-- mark corresponding sector of the cache page as dirty |
|
720 const TUint entryIndexInPage = aFatIndex & (EntriesInPage()-1); //-- number of entries in page is always a power of 2 |
|
721 const TUint dirtySectorNum = entryIndexInPage >> (iCache.SectorSizeLog2() - KFat16EntrySzLog2); |
|
722 |
|
723 ASSERT(dirtySectorNum < iCache.SectorsInPage()); |
|
724 |
|
725 iDirtySectors.SetBit(dirtySectorNum); |
|
726 SetState(EDirty); //-- mark page as dirty. |
|
727 |
|
728 return ETrue; |
|
729 } |
|
730 |
|
731 //----------------------------------------------------------------------------- |
|
732 |
|
733 /** |
|
734 Get a pointer to the FAT16 entry in the page buffer. |
|
735 The page 's data shall be valid and the entry shall belong to this page. |
|
736 |
|
737 @param aFatIndex absolute FAT index (from the FAT start) of the entry |
|
738 @return pointer to the FAT16 entry in the page buffer. |
|
739 */ |
|
740 TFat16Entry* CFat16FixedCachePage::GetEntryPtr(TUint32 aFatIndex) const |
|
741 { |
|
742 ASSERT(IsValid() && IsEntryCached(aFatIndex)); |
|
743 |
|
744 const TUint KEntryIndexInPage = aFatIndex & (EntriesInPage()-1); //-- number of entries in page is always a power of 2 |
|
745 TFat16Entry* pEntry = ((TFat16Entry*)iData.Ptr()) + KEntryIndexInPage; |
|
746 |
|
747 return pEntry; |
|
748 } |
|
749 |
|
750 //----------------------------------------------------------------------------- |
|
751 /** |
|
752 Read the FAT16 cache page from the media and returns required FAT16 entry. |
|
753 |
|
754 @param aFatIndex entry's absolute FAT index (from the FAT start) |
|
755 @return entry value at aFatIndex. |
|
756 */ |
|
757 TUint32 CFat16FixedCachePage::ReadFromMediaL(TUint32 aFatIndex) |
|
758 { |
|
759 //__PRINT1(_L("#-CFat16FixedCachePage::ReadFromMediaL() FAT idx:%d"), aFatIndex); |
|
760 const TUint KFat16EntriesInPageLog2 = iCache.PageSizeLog2()-KFat16EntrySzLog2; //-- number of FAT16 entries in page is always a power of 2 |
|
761 |
|
762 //-- find out index in FAT this page starts from |
|
763 iStartIndexInFAT = (aFatIndex >> KFat16EntriesInPageLog2) << KFat16EntriesInPageLog2; |
|
764 SetState(EInvalid); //-- mark the page as invalid just in case if the read fails. |
|
765 |
|
766 //-- read page from the media |
|
767 const TUint32 pageStartPos = iCache.FatStartPos() + (iStartIndexInFAT << KFat16EntrySzLog2); |
|
768 |
|
769 TInt nRes = iCache.ReadFatData(pageStartPos, iCache.PageSize(), iData); |
|
770 if(nRes != KErrNone) |
|
771 { |
|
772 __PRINT1(_L("#-CFat16FixedCachePage::ReadFromMediaL() failed! code:%d"), nRes); |
|
773 User::Leave(nRes); |
|
774 } |
|
775 |
|
776 SetClean(); //-- mark this page as clean |
|
777 |
|
778 const TFat16Entry entry = (TFat16Entry)((*GetEntryPtr(aFatIndex)) & KFat16EntryMask); |
|
779 |
|
780 return entry; |
|
781 } |
|
782 |
|
783 |
|
784 //----------------------------------------------------------------------------- |
|
785 |
|
786 //################################################################################################################################# |
|
787 // CFat12Cache implementation |
|
788 // FAT12 non-paged fixed cache. This cache consists from only 1 page, logically divided up to 32 sectors (write granularity unit) |
|
789 //################################################################################################################################# |
|
790 |
|
791 CFat12Cache::CFat12Cache() |
|
792 :CFatCacheBase() |
|
793 { |
|
794 } |
|
795 |
|
796 //----------------------------------------------------------------------------- |
|
797 /** |
|
798 FAT12 fixed cache factory function. |
|
799 @param aOwner pointer to the owning FAT mount |
|
800 @param aFatSize size of the FAT table in bytes |
|
801 |
|
802 @return pointer to the constructed object. |
|
803 */ |
|
804 CFat12Cache* CFat12Cache::NewL(CFatMountCB* aOwner, TUint32 aFatSize) |
|
805 { |
|
806 __PRINT(_L("#-CFat12Cache::NewL()")); |
|
807 CFat12Cache* pSelf = NULL; |
|
808 pSelf = new (ELeave) CFat12Cache; |
|
809 |
|
810 CleanupStack::PushL(pSelf); |
|
811 pSelf->InitialiseL(aOwner, aFatSize); |
|
812 CleanupStack::Pop(); |
|
813 |
|
814 return pSelf; |
|
815 } |
|
816 |
|
817 //----------------------------------------------------------------------------- |
|
818 /** |
|
819 FAT16 fixed cache initialisation. |
|
820 @param aOwner pointer to the owning FAT mount |
|
821 @param aFatSize size of the FAT table in bytes |
|
822 */ |
|
823 void CFat12Cache::InitialiseL(CFatMountCB* aOwner, TUint32 aFatSize) |
|
824 { |
|
825 __PRINT1(_L("#-CFat12Cache::InitialiseL FatSz:%u"),aFatSize); |
|
826 |
|
827 CFatCacheBase::InitialiseL(aOwner); |
|
828 ASSERT(FatType() == EFat12); |
|
829 |
|
830 //-- see FAT specs; 4084 is a max. number of clusters, fat12 entry is 1.5 bytes; but we need to round up FAT12 size to the sector size |
|
831 const TUint32 KMaxFat12Size = ( ((TUint32)(4084*1.5+FAT_SectorSz()-1)) >> FAT_SectorSzLog2()) << FAT_SectorSzLog2(); |
|
832 const TUint32 KMinFat12Size = FAT_SectorSz(); //-- 1 FAT sector |
|
833 __ASSERT_ALWAYS(aFatSize >= KMinFat12Size && aFatSize <= KMaxFat12Size, User::Leave(KErrCorrupt)); |
|
834 (void)KMaxFat12Size; |
|
835 (void)KMinFat12Size; |
|
836 |
|
837 //-- as soon as FAT12 max size is 4084 entries or 6126 bytes, the cache is contiguous and divided |
|
838 //-- to logical sectors (write granularity). |
|
839 |
|
840 //-- calculate number write cache sector in the cache |
|
841 iSectorsInCache = (aFatSize + (FAT_SectorSz()-1)) >> FAT_SectorSzLog2(); |
|
842 __ASSERT_ALWAYS(NumSectors() <= KMaxSectorsInCache, Fault(EFatCache_BadGranularity)); |
|
843 |
|
844 //-- round up cache size to write granularity (sector size) |
|
845 const TUint32 cacheSize = NumSectors() << FAT_SectorSzLog2(); |
|
846 |
|
847 //-- create buffer for the whole FAT12 |
|
848 iData.CreateMaxL(cacheSize); |
|
849 |
|
850 //-- this will read whole FAT into the cache |
|
851 User::LeaveIfError(Invalidate()); |
|
852 } |
|
853 |
|
854 //----------------------------------------------------------------------------- |
|
855 /** |
|
856 Close the cache and deallocate its memory. |
|
857 @param aDiscardDirtyData if ETrue, will ignore dirty data. If EFalse, will panic on atempt to close dirty cache. |
|
858 */ |
|
859 void CFat12Cache::Close(TBool aDiscardDirtyData) |
|
860 { |
|
861 __PRINT1(_L("#-CFat12Cache::Close(%d)"), aDiscardDirtyData); |
|
862 |
|
863 for(TUint32 i=0; i<NumSectors(); ++i) |
|
864 { |
|
865 if(iDirtySectors[i]) |
|
866 {//-- trying to destroy the cache that has dirty sectors |
|
867 __PRINT1(_L("#-CFat12Cache::Close() The cache is dirty! cache sector:%d"), i); |
|
868 if(!aDiscardDirtyData) |
|
869 { |
|
870 __ASSERT_ALWAYS(0, Fault(EFatCache_DiscardingDirtyData)); |
|
871 } |
|
872 //-- ignore this fact if requested. |
|
873 } |
|
874 } |
|
875 |
|
876 iData.Close(); |
|
877 SetDirty(EFalse); |
|
878 } |
|
879 |
|
880 //----------------------------------------------------------------------------- |
|
881 /** |
|
882 Read FAT entry from the cache. |
|
883 |
|
884 @param aIndex FAT entry index to read |
|
885 @return FAT entry value at the index "aIndex" |
|
886 */ |
|
887 TUint32 CFat12Cache::ReadEntryL(TUint32 aIndex) |
|
888 { |
|
889 //__PRINT1(_L("#-CFat12Cache::ReadEntryL() FAT idx:%d"), aIndex); |
|
890 ASSERT(aIndex >= KFatFirstSearchCluster && aIndex < (FatSize() + FatSize()/2)); //-- FAT12 entry is 1.5 bytes long |
|
891 |
|
892 TUint32 entry; |
|
893 |
|
894 if(aIndex & 0x01) |
|
895 {//-- odd index |
|
896 --aIndex; |
|
897 const TUint32 byteIdx = 1 + aIndex + (aIndex >> 1); //-- byteIdx = 1+(aIndex-1)*1.5 |
|
898 Mem::Copy(&entry, iData.Ptr()+byteIdx, 2); |
|
899 entry >>= 4; |
|
900 } |
|
901 else |
|
902 {//-- even index |
|
903 const TUint32 byteIdx = aIndex + (aIndex >> 1); //-- byteIdx = aIndex*1.5 |
|
904 Mem::Copy(&entry, iData.Ptr()+byteIdx, 2); |
|
905 } |
|
906 |
|
907 entry &= KFat12EntryMask; |
|
908 |
|
909 return entry; |
|
910 } |
|
911 |
|
912 //----------------------------------------------------------------------------- |
|
913 /** |
|
914 Write FAT entry to the cache. |
|
915 Appropriate FAT cache sector will be marked as "dirty" and will be eventually flushed to the media. |
|
916 |
|
917 @param aIndex FAT entry index |
|
918 @param aEntry FAT entry value |
|
919 */ |
|
920 void CFat12Cache::WriteEntryL(TUint32 aIndex, TUint32 aEntry) |
|
921 { |
|
922 //__PRINT2(_L("#-CFat12Cache::WriteEntryL() FAT idx:%d, entry:%u"), aIndex, aEntry); |
|
923 ASSERT(aIndex >= KFatFirstSearchCluster && aIndex < (FatSize() + FatSize()/2)); //-- FAT12 entry is 1.5 bytes long |
|
924 |
|
925 aEntry &= KFat12EntryMask; |
|
926 |
|
927 TUint32 byteIdx = 0; |
|
928 TUint8 tmp; |
|
929 |
|
930 if(aIndex & 0x01) |
|
931 {//-- odd index |
|
932 --aIndex; |
|
933 byteIdx = 1 + aIndex + (aIndex >> 1); //-- byteIdx = 1+(aIndex-1)*1.5 |
|
934 tmp = (TUint8)(iData[byteIdx] & 0x0F); //-- we modifying a higher nibble |
|
935 tmp |= (TUint8) ((aEntry & 0x0F)<<4); |
|
936 iData[byteIdx] = tmp; |
|
937 |
|
938 iData[byteIdx+1] = (TUint8)(aEntry >> 4); |
|
939 } |
|
940 else |
|
941 {//-- even index |
|
942 byteIdx = aIndex + (aIndex >> 1); //-- byteIdx = aIndex*1.5 |
|
943 iData[byteIdx] = (TUint8)aEntry; |
|
944 |
|
945 const TUint32 nextIdx = byteIdx+1; |
|
946 tmp = (TUint8)(iData[nextIdx] & 0xF0); //-- we modifying a lower nibble |
|
947 tmp |= (TUint8)((aEntry >> 8) & 0x0F); |
|
948 iData[nextIdx] = tmp; |
|
949 |
|
950 } |
|
951 |
|
952 //-- mark changed sectors dirty. We modified 2 bytes at [byteIdx] and [byteIdx+1] |
|
953 iDirtySectors.SetBit(byteIdx >> FAT_SectorSzLog2()); |
|
954 iDirtySectors.SetBit((byteIdx+1) >> FAT_SectorSzLog2()); |
|
955 |
|
956 SetDirty(ETrue); |
|
957 } |
|
958 |
|
959 //----------------------------------------------------------------------------- |
|
960 /** |
|
961 A debug method that asserts that the cache is really clean |
|
962 */ |
|
963 void CFat12Cache::AssertCacheReallyClean() const |
|
964 { |
|
965 #ifdef _DEBUG |
|
966 if(iDirtySectors.HasBitsSet()) |
|
967 { |
|
968 __PRINT(_L("#-CFat12Cache::AssertCacheReallyClean()")); |
|
969 ASSERT(0); |
|
970 } |
|
971 |
|
972 #endif |
|
973 } |
|
974 |
|
975 //----------------------------------------------------------------------------- |
|
976 /** |
|
977 Flushes all dirty data to the media. |
|
978 Walks through all sectors in this cache and flushes dirty ones. |
|
979 */ |
|
980 void CFat12Cache::FlushL() |
|
981 { |
|
982 if(!IsDirty()) |
|
983 { |
|
984 AssertCacheReallyClean(); |
|
985 return; |
|
986 } |
|
987 |
|
988 //-- write all dirty sectors to the media (into all copies of FAT) |
|
989 for(iCurrentFatNo=0; iCurrentFatNo < NumFATs(); ++iCurrentFatNo) |
|
990 { |
|
991 for(TUint secNo=0; secNo<NumSectors(); ++secNo) |
|
992 { |
|
993 if(iDirtySectors[secNo]) |
|
994 {//-- this sector is dirty, write it to the media |
|
995 |
|
996 TInt offset = 0; |
|
997 if(secNo == 0) |
|
998 {//-- this is a first sector in FAT. We must skip FAT[0] & FAT[1] entries and do not write them to the media. |
|
999 offset = 3; //-- 2 FAT12 entries |
|
1000 } |
|
1001 |
|
1002 const TUint32 secPos = secNo << FAT_SectorSzLog2(); //-- relative sector position in FAT |
|
1003 const TUint8* pData = iData.Ptr()+offset+secPos; //-- pointer to the data in cache buffer |
|
1004 const TUint32 len = FAT_SectorSz() - offset; |
|
1005 TPtrC8 ptrData(pData, len); //-- source data descriptor |
|
1006 const TUint32 mediaPos = FatStartPos() + secPos + offset; |
|
1007 |
|
1008 TInt nRes = WriteFatData(mediaPos, ptrData); |
|
1009 |
|
1010 if(nRes != KErrNone) |
|
1011 { |
|
1012 __PRINT1(_L("#-CFat12Cache::FlushL() failed! code:%d"), nRes); |
|
1013 User::Leave(nRes); |
|
1014 } |
|
1015 |
|
1016 }//if(iDirtySectors[secNo]) |
|
1017 } |
|
1018 |
|
1019 } |
|
1020 |
|
1021 iCurrentFatNo = KInvalidFatNo; |
|
1022 |
|
1023 //-- mark the cache as clean |
|
1024 iDirtySectors.Clear(); |
|
1025 SetDirty(EFalse); |
|
1026 |
|
1027 } |
|
1028 |
|
1029 //----------------------------------------------------------------------------- |
|
1030 /** |
|
1031 Invalidates whole cache. Because FAT12 is tiny, just re-reads data from the media to the cache |
|
1032 @return Media read result code. |
|
1033 */ |
|
1034 TInt CFat12Cache::Invalidate() |
|
1035 { |
|
1036 __PRINT(_L("#-CFat12Cache::Invalidate()")); |
|
1037 CheckInvalidatingDirtyCache(); |
|
1038 |
|
1039 //-- read whole cache from the media |
|
1040 const TUint32 posStart = FatStartPos(); |
|
1041 const TUint32 len = NumSectors() << FAT_SectorSzLog2(); |
|
1042 |
|
1043 TInt nRes = ReadFatData(posStart, len, iData); |
|
1044 if(nRes != KErrNone) |
|
1045 return nRes; |
|
1046 |
|
1047 //-- mark the cache as clean |
|
1048 SetDirty(EFalse); |
|
1049 iDirtySectors.Clear(); |
|
1050 |
|
1051 return KErrNone; |
|
1052 } |
|
1053 |
|
1054 //----------------------------------------------------------------------------- |
|
1055 /** |
|
1056 Invalidate wholes cache. Because FAT12 is tiny, just re-reads data from the media to the cache |
|
1057 @param aStartIndex ignored |
|
1058 @param aNumEntries ignored |
|
1059 @return Media read result code. |
|
1060 */ |
|
1061 TInt CFat12Cache::InvalidateRegion(TUint32 aStartIndex, TUint32 aNumEntries) |
|
1062 { |
|
1063 __PRINT2(_L("#-CFat12Cache::InvalidateRegion() startIndex:%d, entries:%d"),aStartIndex, aNumEntries); |
|
1064 ASSERT(aStartIndex >= KFatFirstSearchCluster && aStartIndex < (FatSize() + FatSize()/2)); //-- FAT12 entry is 1.5 bytes long |
|
1065 (void)aStartIndex; |
|
1066 (void)aNumEntries; |
|
1067 |
|
1068 //-- just re-read all FAT12, it is just 6K max and isn't worth calculating invalid sectors |
|
1069 return Invalidate(); |
|
1070 } |
|
1071 |
|
1072 |
|
1073 |
|
1074 |
|
1075 |
|
1076 |
|
1077 |
|
1078 |
|
1079 |
|
1080 |
|
1081 |
|
1082 |
|
1083 |
|
1084 |
|
1085 |
|
1086 |
|
1087 |
|
1088 |
|
1089 |
|
1090 |
|
1091 |
|
1092 |
|
1093 |
|
1094 |
|
1095 |
|
1096 |
|
1097 |
|
1098 |
|
1099 |
|
1100 |
|
1101 |
|
1102 |
|
1103 |
|
1104 |
|
1105 |
|
1106 |
|
1107 |
|
1108 |
|
1109 |
|
1110 |
|
1111 |
|
1112 |
|
1113 |