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1 // Copyright (c) 1997-2009 Nokia Corporation and/or its subsidiary(-ies). |
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2 // All rights reserved. |
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3 // This component and the accompanying materials are made available |
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4 // under the terms of "Eclipse Public License v1.0" |
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5 // which accompanies this distribution, and is available |
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6 // at the URL "http://www.eclipse.org/legal/epl-v10.html". |
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7 // |
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8 // Initial Contributors: |
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9 // Nokia Corporation - initial contribution. |
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10 // |
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11 // Contributors: |
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12 // |
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13 // Description: |
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14 // Buffer Manager for Protocols (MBuf Chains) |
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15 // |
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16 // |
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17 |
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18 /** |
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19 @file |
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20 @internalComponent |
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21 */ |
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22 |
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23 #include <es_mbman.h> |
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24 #include "MBufPoolChain.h" |
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25 #include "MBufPoolManager.h" |
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26 #include <cflog.h> |
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27 |
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28 |
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29 // |
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30 // MBUF CHAIN |
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31 // |
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32 |
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33 #ifdef __CFLOG_ACTIVE |
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34 __CFLOG_STMT(_LIT8(KSubsysMBufMgr, "MBufMgr");) // subsystem name |
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35 __CFLOG_STMT(_LIT8(KComponentPerformance, "performance");) // component name - used for any sub-optimal performance behaviuor |
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36 #endif |
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37 |
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38 __IMPLEMENT_CLEANUP(RMBufChain, Free) |
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39 |
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40 |
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41 EXPORT_C void RMBufChain::AllocL(TInt aLen) |
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42 /** |
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43 Allocate sufficient mbufs to hold specfied amount of data, |
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44 optionally zeroing the buffers. |
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45 - Overloaded min/max variants (eg. refer RMBufChain::Alloc) deliberately do not exist because; |
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46 a. Intention is to ultimately deprecate (or at least discourage) the leaving variants since their usage is not typically (but not always |
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47 the case) recommended because they the throw/catch mechanism can hinder performance if used in appopriately. |
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48 b. Intention is to ultimately deprecate (or at least discourage) this class as it will likely be superceded by a generic system wide |
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49 equivalent. |
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50 c. If they shown to useful for this API, they can easily be added in the future... but the same can not be said for removing them in the future! |
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51 @param aLen A length of the cell |
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52 */ |
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53 { |
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54 RMBufAllocator allocator; |
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55 return AllocL(aLen, allocator); |
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56 } |
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57 |
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58 EXPORT_C TInt RMBufChain::Alloc(TInt aLen) |
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59 /** |
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60 Allocate sufficient mbufs to hold specfied amount of data, |
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61 optionally zeroing the buffers. |
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62 @param aLen A length of the cell |
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63 */ |
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64 { |
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65 RMBufAllocator allocator; |
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66 return Alloc(aLen, allocator); |
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67 } |
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68 TInt RMBufChain::Alloc(TInt aLen, const RMBufChain &aMBufChain) |
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69 { |
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70 RMBufAllocator allocator; |
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71 return Alloc(aLen, aMBufChain, allocator); |
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72 } |
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73 EXPORT_C TInt RMBufChain::Alloc(TInt aLen, TInt aMinMBufSize) |
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74 { |
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75 RMBufAllocator allocator; |
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76 return Alloc(aLen, aMinMBufSize, allocator); |
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77 } |
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78 EXPORT_C TInt RMBufChain::Alloc(TInt aLen, TInt aMinMBufSize, TInt aMaxMBufSize) |
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79 { |
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80 RMBufAllocator allocator; |
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81 return Alloc(aLen, aMinMBufSize, aMaxMBufSize, allocator); |
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82 } |
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83 |
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84 |
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85 // overloading for TLS |
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86 EXPORT_C void RMBufChain::AllocL(TInt aLen, RMBufAllocator& aRMBufAllocator) |
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87 { |
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88 __ASSERT_ALWAYS(iNext==NULL, CMBufManager::Panic(EMBuf_NotEmptyChain)); |
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89 |
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90 iNext = aRMBufAllocator.MBufManager().AllocL(aLen); |
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91 } |
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92 EXPORT_C TInt RMBufChain::Alloc(TInt aLen, RMBufAllocator& aRMBufAllocator) |
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93 { |
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94 __ASSERT_ALWAYS(iNext==NULL, CMBufManager::Panic(EMBuf_NotEmptyChain)); |
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95 |
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96 iNext = aRMBufAllocator.MBufManager().Alloc(aLen); |
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97 return iNext? KErrNone: KErrNoMBufs; |
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98 } |
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99 TInt RMBufChain::Alloc(TInt aLen, const RMBufChain& aMBufChain, RMBufAllocator& aRMBufAllocator) |
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100 { |
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101 __ASSERT_ALWAYS(iNext==NULL, CMBufManager::Panic(EMBuf_NotEmptyChain)); |
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102 |
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103 iNext = aRMBufAllocator.MBufManager().Alloc(aLen, aMBufChain); |
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104 return iNext? KErrNone: KErrNoMBufs; |
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105 } |
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106 EXPORT_C TInt RMBufChain::Alloc(TInt aLen, TInt aMinMBufSize, RMBufAllocator& aRMBufAllocator) |
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107 { |
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108 __ASSERT_ALWAYS(iNext==NULL, CMBufManager::Panic(EMBuf_NotEmptyChain)); |
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109 |
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110 iNext = aRMBufAllocator.MBufManager().Alloc(aLen, aMinMBufSize); |
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111 return iNext? KErrNone: KErrNoMBufs; |
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112 } |
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113 EXPORT_C TInt RMBufChain::Alloc(TInt aLen, TInt aMinMBufSize, TInt aMaxMBufSize, RMBufAllocator& aRMBufAllocator) |
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114 { |
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115 __ASSERT_ALWAYS(iNext==NULL, CMBufManager::Panic(EMBuf_NotEmptyChain)); |
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116 |
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117 iNext = aRMBufAllocator.MBufManager().Alloc(aLen, aMinMBufSize, aMaxMBufSize); |
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118 return iNext? KErrNone: KErrNoMBufs; |
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119 } |
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120 |
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121 EXPORT_C TInt RMBufChain::ReAlloc(TInt aLen) |
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122 /** |
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123 Adjust the size of a chain, allocates a new memory for the chain |
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124 - refer RMBufChain::AllocL notes regarding the deliberate decision not to provide an overloaded min/max mbuf size variant |
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125 @param aLen A new length |
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126 */ |
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127 { |
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128 __ASSERT_ALWAYS(aLen>=0, CMBufManager::Panic(EMBuf_NegativeLength)); |
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129 |
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130 TInt currLen = Length(); |
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131 if(aLen < currLen) |
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132 TrimEnd(aLen); |
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133 else if(aLen > currLen) |
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134 { |
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135 TInt extraReq = aLen - currLen; |
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136 if(currLen > 0) |
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137 { |
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138 // Extend the final buf to consume any idle space |
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139 RMBuf* pLast = Last(); |
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140 TInt idleSpace = pLast->Size() - pLast->End(); |
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141 ASSERT(idleSpace >= 0); |
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142 if(idleSpace) |
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143 { |
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144 TInt useSpace = Min(idleSpace, extraReq); |
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145 pLast->AdjustEnd(useSpace); |
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146 extraReq -= useSpace; |
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147 // Did this yield enough? |
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148 if(!extraReq) |
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149 return KErrNone; |
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150 } |
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151 } |
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152 // Need additional allocation |
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153 RMBufChain extraChain; |
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154 TInt err = extraChain.Alloc(extraReq, *this); |
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155 if(err != KErrNone) |
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156 { |
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157 return err; |
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158 } |
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159 Append(extraChain); |
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160 } |
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161 return KErrNone; |
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162 } |
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163 |
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164 EXPORT_C void RMBufChain::ReAllocL(TInt aLen) |
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165 /** |
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166 Adjust the size of a chain, allocates a new memory for the chain |
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167 @param aLen A new length |
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168 */ |
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169 { |
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170 User::LeaveIfError(ReAlloc(aLen)); |
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171 } |
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172 |
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173 |
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174 |
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175 EXPORT_C TInt RMBufChain::Create(const TDesC8& aDes, TInt aHdrLen) |
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176 /** |
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177 Create an Mbuf chain from a descriptor optionally allowing room at front for a protocol header. |
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178 - refer RMBufChain::AllocL notes regarding the deliberate decision not to provide an overloaded min/max mbuf size variant |
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179 @param aDes |
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180 @param aHdrLen A header length |
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181 */ |
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182 { |
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183 TInt err = Alloc(aDes.Length() + aHdrLen); |
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184 if(err == KErrNone) |
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185 { |
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186 CopyIn(aDes, aHdrLen); // NB! old version prepended explicit buf. wonder if that matters? |
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187 } |
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188 return err; |
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189 } |
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190 |
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191 |
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192 EXPORT_C void RMBufChain::CreateL(const TDesC8& aDes, TInt aHdrLen) |
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193 /** |
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194 Create an Mbuf chain from a descriptor optionally allowing room at front for a protocol header. |
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195 @param aDes |
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196 @param aHdrLen A header length |
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197 */ |
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198 { |
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199 User::LeaveIfError(Create(aDes, aHdrLen)); |
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200 } |
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201 |
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202 |
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203 EXPORT_C void RMBufChain::Free() |
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204 /** |
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205 Free an MBuf chain, returning it to the free Pool |
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206 A pointer to the first mbuf of the next packet is returned. |
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207 */ |
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208 { |
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209 if (iNext!=NULL) |
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210 iNext->Free(); |
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211 Init(); |
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212 } |
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213 |
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214 |
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215 EXPORT_C void RMBufChain::FillZ(TInt aLen) |
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216 /** |
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217 Zero fill the first aLen bytes of an mbuf chain |
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218 @param aLen the length (how many byte to be appended to the end) |
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219 */ |
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220 { |
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221 __ASSERT_ALWAYS(iNext!=NULL, CMBufManager::Panic(EMBuf_EmptyChain)); |
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222 |
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223 TInt n; |
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224 RMBuf* m = iNext; |
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225 |
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226 while (aLen>0 && m!=NULL) |
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227 { |
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228 n = aLen < m->Length() ? aLen : m->Length(); |
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229 Mem::FillZ(m->Ptr(), n); |
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230 aLen -= n; |
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231 m = m->Next(); |
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232 } |
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233 } |
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234 |
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235 |
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236 EXPORT_C void RMBufChain::CopyL(RMBufChain& newChain, TInt anOffset, TInt aLen) const |
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237 /** |
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238 Copy data into a new chain starting at a given offset |
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239 into this chain. |
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240 Allocate sufficient mbufs to hold specfied amount of data, |
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241 optionally zeroing the buffers. |
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242 @param aLen A length of the cell |
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243 */ |
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244 { |
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245 User::LeaveIfError(Copy(newChain, anOffset, aLen)); |
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246 } |
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247 |
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248 EXPORT_C TInt RMBufChain::Copy(RMBufChain &newChain, TInt anOffset, TInt aLen) const |
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249 /** |
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250 Copy data into a new chain starting at a given offset |
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251 into this chain. |
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252 - refer RMBufChain::AllocL notes regarding the deliberate decision not to provide an overloaded min/max mbuf size variant |
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253 @param newChain A new chain, where the data is copied to |
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254 @param anOffset A offset, |
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255 @param aLen the length of the data to be copied |
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256 */ |
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257 { |
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258 __ASSERT_ALWAYS(iNext!=NULL, CMBufManager::Panic(EMBuf_EmptyChain)); |
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259 __ASSERT_ALWAYS(aLen>=0, CMBufManager::Panic(EMBuf_NegativeLength)); |
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260 __ASSERT_ALWAYS(anOffset>=0, CMBufManager::Panic(EMBuf_NegativeOffset)); |
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261 |
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262 TInt n, n1, n2; |
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263 TUint8* p1, *p2; |
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264 RMBuf* m1, *m2; |
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265 |
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266 TInt len = Length(); |
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267 if (anOffset>0) |
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268 { |
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269 __ASSERT_ALWAYS(anOffset<len, CMBufManager::Panic(EMBuf_BadOffset)); |
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270 n = len - anOffset; |
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271 len = Min(aLen, n); |
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272 } |
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273 else |
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274 len = Min(aLen, len); |
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275 |
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276 TInt err = newChain.Alloc(len, *this); |
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277 if(err != KErrNone) |
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278 { |
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279 return err; |
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280 } |
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281 |
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282 if (anOffset>0) |
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283 { |
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284 if (!Goto(anOffset, m1, n, n1)) |
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285 return KErrNone; |
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286 p1 = m1->Buffer()+n; |
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287 } |
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288 else |
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289 { |
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290 m1 = iNext; |
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291 p1 = m1->Ptr(); |
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292 n1 = m1->Length(); |
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293 } |
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294 |
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295 m2 = newChain.iNext; |
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296 p2 = m2->Ptr(); |
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297 n2 = m2->Length(); |
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298 |
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299 while (len>0) |
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300 { |
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301 __ASSERT_DEBUG(n1>0 && n2>0, CMBufManager::Panic(EMBuf_NegativeLength)); |
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302 |
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303 n = n1 < n2 ? n1 : n2; |
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304 |
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305 Mem::Copy(p2, p1, n); |
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306 |
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307 if (n1 -= n, n1 == 0) |
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308 { |
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309 if (m1 = m1->Next(), m1==NULL) |
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310 break; |
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311 p1 = m1->Ptr(); |
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312 n1 = m1->Length(); |
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313 } |
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314 else |
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315 p1 += n; |
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316 |
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317 if (n2 -= n, n2 == 0) |
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318 { |
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319 if (m2 = m2->Next(), m2==NULL) |
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320 break; |
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321 p2 = m2->Ptr(); |
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322 n2 = m2->Length(); |
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323 } |
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324 else |
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325 p2 += n; |
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326 |
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327 len -= n; |
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328 } |
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329 return KErrNone; |
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330 } |
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331 |
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332 |
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333 EXPORT_C void RMBufChain::CopyIn(const TDesC8& aDes, TInt aOffset) |
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334 /** |
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335 Copy data into an mbuf chain from a linear buffer |
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336 starting at specified offset. |
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337 @param aDes The buffer from where data is copied to the chain |
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338 @param aOffset The offset |
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339 */ |
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340 { |
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341 __ASSERT_ALWAYS(iNext!=NULL, CMBufManager::Panic(EMBuf_EmptyChain)); |
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342 __ASSERT_ALWAYS(aOffset>=0, CMBufManager::Panic(EMBuf_NegativeOffset)); |
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343 |
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344 TUint8* ptr = (TUint8*)aDes.Ptr(); |
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345 TInt len = aDes.Length(); |
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346 |
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347 TInt n; |
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348 RMBuf* m; |
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349 |
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350 if (aOffset>0) |
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351 { |
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352 TInt o; |
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353 |
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354 if (!Goto(aOffset, m, o, n)) |
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355 return; |
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356 |
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357 if (n>len) |
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358 n = len; |
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359 |
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360 Mem::Copy(m->Buffer()+o, ptr, n); |
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361 ptr += n; |
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362 len -= n; |
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363 m = m->Next(); |
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364 } |
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365 else |
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366 m = iNext; |
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367 |
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368 while (len>0 && m!=NULL) |
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369 { |
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370 n = len > m->Length() ? m->Length() : len; |
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371 Mem::Copy(m->Ptr(), ptr, n); |
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372 ptr += n; |
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373 len -= n; |
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374 m = m->Next(); |
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375 } |
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376 } |
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377 |
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378 |
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379 EXPORT_C void RMBufChain::CopyOut(TDes8& aDes, TInt aOffset) const |
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380 /** |
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381 Copy data from an mbuf chain into linear buffer |
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382 starting at specified offset. |
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383 @param aDes the buffer to copy in to |
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384 @param aOffset the offset |
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385 */ |
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386 { |
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387 //removed after internal discussion; generally unhelpful as empty == zero length is ok concept |
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388 // __ASSERT_ALWAYS(iNext!=NULL, CMBufManager::Panic(EMBuf_EmptyChain)); |
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389 __ASSERT_ALWAYS(aOffset>=0, CMBufManager::Panic(EMBuf_NegativeOffset)); |
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390 |
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391 TUint8* ptr = (TUint8*)aDes.Ptr(); |
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392 TInt len = aDes.Length(); |
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393 |
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394 TInt n; |
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395 RMBuf* m; |
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396 |
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397 if (aOffset>0) |
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398 { |
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399 TInt o; |
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400 |
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401 if (!Goto(aOffset, m, o, n)) |
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402 { |
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403 aDes.SetLength(0); |
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404 return; |
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405 } |
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406 |
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407 if (n>len) |
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408 n = len; |
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409 |
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410 Mem::Copy(ptr, m->Buffer()+o, n); |
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411 ptr += n; |
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412 len -= n; |
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413 m = m->Next(); |
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414 } |
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415 else |
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416 m = iNext; |
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417 |
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418 while (len>0 && m!=NULL) |
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419 { |
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420 n = len > m->Length() ? m->Length() : len; |
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421 Mem::Copy(ptr, m->Ptr(), n); |
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422 ptr += n; |
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423 len -= n; |
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424 m = m->Next(); |
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425 } |
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426 aDes.SetLength(ptr-aDes.Ptr()); |
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427 } |
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428 |
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429 |
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430 EXPORT_C void RMBufChain::Assign(RMBufQ& aQueue) |
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431 /** |
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432 Take ownership of Mbuf from a queue |
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433 Previously allocated data (e.g. by a call to RMBufChain::AllocL) in the chain must be |
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434 emptied (e.g. by calling RMBufChain::Free) before the assignment |
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435 @param aQueue the queue |
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436 @see RMBufChain::IsEmpty() |
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437 @see RMBufChain::Free() |
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438 */ |
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439 { |
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440 __ASSERT_ALWAYS(iNext==NULL, CMBufManager::Panic(EMBuf_NotEmptyChain)); |
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441 iNext = aQueue.First(); |
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442 aQueue.Init(); |
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443 } |
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444 |
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445 |
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446 EXPORT_C void RMBufChain::Assign(RMBufChain& aChain) |
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447 /** |
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448 Take ownership of Mbuf from another chain |
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449 Previously allocated data (e.g. by a call to RMBufChain::AllocL) in the chain must be |
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450 emptied (e.g. by calling RMBufChain::Free) before the assignment |
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451 @param aChain the chain |
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452 @see RMBufChain::IsEmpty() |
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453 @see RMBufChain::Free() |
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454 */ |
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455 { |
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456 __ASSERT_ALWAYS(iNext==NULL, CMBufManager::Panic(EMBuf_NotEmptyChain)); |
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457 iNext = aChain.iNext; |
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458 aChain.Init(); |
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459 } |
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460 |
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461 |
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462 EXPORT_C void RMBufChain::Append(RMBufChain& aChain) |
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463 /** |
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464 Append an MBuf chain, taking ownership of the MBufs |
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465 @param aChain the chain to be appended |
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466 */ |
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467 { |
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468 __ASSERT_ALWAYS(iNext!=aChain.iNext, CMBufManager::Panic(EMBuf_CircularRef)); |
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469 |
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470 if (iNext!=NULL) |
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471 { |
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472 RMBuf* last = Last(); |
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473 last->Link(aChain.iNext); |
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474 } |
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475 else |
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476 iNext = aChain.iNext; |
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477 |
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478 aChain.Init(); |
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479 } |
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480 |
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481 |
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482 EXPORT_C void RMBufChain::AppendL(TInt aLen) |
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483 /** |
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484 Append space to the end of a MBuf chain |
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485 @param aLen the length (how many byte to be appended to the end) |
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486 */ |
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487 { |
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488 User::LeaveIfError(Append(aLen)); |
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489 } |
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490 |
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491 EXPORT_C TInt RMBufChain::Append(TInt aLen) |
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492 /** |
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493 Append space to the end of a MBuf chain |
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494 - refer RMBufChain::AllocL notes regarding the deliberate decision not to provide an overloaded min/max mbuf size variant |
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495 @param aLen the length (how many byte to be appended to the end) |
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496 */ |
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497 { |
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498 RMBufAllocator allocator; |
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499 return Append(aLen, allocator); |
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500 } |
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501 |
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502 // overloading for TLS |
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503 EXPORT_C TInt RMBufChain::Append(TInt aLen, RMBufAllocator& aRMBufAllocator) |
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504 { |
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505 if (iNext==NULL) |
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506 { |
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507 return Alloc(aLen, *this, aRMBufAllocator); |
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508 } |
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509 |
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510 RMBuf* last = Last(); |
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511 // Amount of space available on end of last Mbuf |
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512 TInt n = Min(last->Size()-(last->Offset()+last->Length()), aLen); |
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513 // Amount of space that needs to be Allocated in new buffers |
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514 TInt m = aLen-n; |
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515 |
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516 if (m>0) |
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517 { |
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518 RMBufChain chn; |
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519 TInt err = chn.Alloc(m, *this, aRMBufAllocator); |
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520 if(err != KErrNone) |
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521 { |
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522 return err; |
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523 } |
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524 last->Link(chn.iNext); |
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525 } |
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526 // Left to last to avoid modifying the chain unless the extension suceeds |
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527 last->AdjustEnd(n); |
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528 return KErrNone; |
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529 } |
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530 |
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531 |
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532 EXPORT_C RMBuf* RMBufChain::Remove() |
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533 /** |
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534 Remove 1st mbuf from chain |
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535 @param aChain the chain to be prepended |
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536 */ |
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537 { |
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538 if (IsEmpty()) |
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539 return NULL; |
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540 else |
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541 { |
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542 RMBuf* m = iNext; |
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543 iNext = iNext->Next(); |
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544 m->Unlink(); |
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545 return m; |
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546 } |
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547 } |
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548 |
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549 |
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550 EXPORT_C void RMBufChain::Prepend(RMBufChain& aChain) |
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551 /** |
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552 Prepend an MBuf chain, taking ownership of the MBufs |
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553 @param aChain the chain to be prepended |
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554 */ |
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555 { |
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556 if (iNext!=NULL) |
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557 { |
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558 RMBuf* last = aChain.Last(); |
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559 last->Link(iNext); |
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560 } |
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561 iNext = aChain.iNext; |
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562 aChain.Init(); |
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563 } |
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564 |
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565 |
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566 EXPORT_C void RMBufChain::Prepend(RMBuf* aBuf) |
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567 /** |
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568 Prepend an MBuf to a chain, taking ownership of the MBuf |
|
569 @param aBuf the buffer to be prepended |
|
570 */ |
|
571 { |
|
572 aBuf->Link(iNext); |
|
573 iNext = aBuf; |
|
574 } |
|
575 |
|
576 |
|
577 EXPORT_C void RMBufChain::PrependL(TInt aLen) |
|
578 /** |
|
579 Prepend space onto the front of a chain |
|
580 @param aLen the length of the space |
|
581 */ |
|
582 { |
|
583 User::LeaveIfError(Prepend(aLen)); |
|
584 } |
|
585 |
|
586 EXPORT_C TInt RMBufChain::Prepend(TInt aLen) |
|
587 /** |
|
588 Prepend space onto the front of a chain |
|
589 - refer RMBufChain::AllocL notes regarding the deliberate decision not to provide an overloaded min/max mbuf size variant |
|
590 @param aLen the length of the space |
|
591 */ |
|
592 { |
|
593 RMBufAllocator allocator; |
|
594 return Prepend(aLen, allocator); |
|
595 } |
|
596 |
|
597 // overloading for TLS |
|
598 EXPORT_C TInt RMBufChain::Prepend(TInt aLen, RMBufAllocator& aRMBufAllocator) |
|
599 { |
|
600 __ASSERT_ALWAYS(aLen>=0, CMBufManager::Panic(EMBuf_NegativeLength)); |
|
601 |
|
602 // If can fit and the start would remain aligned |
|
603 // then prepend by moving offset and length |
|
604 // if (iNext->Offset()>=aLen && IS_ALIGNED(iNext->Offset()-aLen)) |
|
605 if (iNext && iNext->Offset()>=aLen) |
|
606 { |
|
607 iNext->AdjustStart(-aLen); |
|
608 return KErrNone; |
|
609 } |
|
610 |
|
611 // else allocation required |
|
612 #ifdef __CFLOG_ACTIVE |
|
613 __CFLOG_VAR((KSubsysMBufMgr, KComponentPerformance, _L8("RMBufChain::Prepend() - Warning! sub-optimal performance; prepend required to alloc a new mbuf/chain, iOffset=%d reqLen=%d"), |
|
614 iNext?iNext->Offset():0, aLen)); |
|
615 #endif |
|
616 RMBuf* m=NULL; |
|
617 |
|
618 m = aRMBufAllocator.MBufManager().Alloc(aLen); |
|
619 if(!m) |
|
620 { |
|
621 return KErrNoMBufs; |
|
622 } |
|
623 |
|
624 // Iterate along the mbuf chain to determine the size and find the last in the chain. |
|
625 RMBuf* next = m; |
|
626 RMBuf* last; |
|
627 do |
|
628 { |
|
629 last = next; |
|
630 aLen -= last->Length(); |
|
631 next = last->Next(); |
|
632 } |
|
633 while(next); |
|
634 |
|
635 // Performance enhancement - most of these prepends are 20 byes or so |
|
636 // This allows the next one to use this MBuf |
|
637 if (aLen<0) |
|
638 { |
|
639 m->SetData(-aLen, m->Length()+aLen); |
|
640 } |
|
641 |
|
642 last->Link(iNext); |
|
643 iNext = m; |
|
644 return KErrNone; |
|
645 } |
|
646 |
|
647 EXPORT_C TInt RMBufChain::NumBufs() const |
|
648 /** |
|
649 Count the number of buffers in a chain |
|
650 */ |
|
651 { |
|
652 __ASSERT_ALWAYS(iNext!=NULL, CMBufManager::Panic(EMBuf_EmptyChain)); |
|
653 |
|
654 TInt len = 0; |
|
655 RMBuf* m; |
|
656 for (m = iNext; m!=NULL; m = m->Next()) |
|
657 len++; |
|
658 |
|
659 return len; |
|
660 } |
|
661 |
|
662 |
|
663 EXPORT_C TInt RMBufChain::Length() const |
|
664 /** |
|
665 Return the number of bytes of actual data contained |
|
666 in an MBuf chain |
|
667 */ |
|
668 { |
|
669 //removed after internal & 3rd party discussion; generally unhelpful as empty == zero length is ok concept |
|
670 // __ASSERT_ALWAYS(iNext!=NULL, CMBufManager::Panic(EMBuf_EmptyChain)); |
|
671 |
|
672 TInt len = 0; |
|
673 RMBuf* m; |
|
674 for (m = iNext; m!=NULL; m = m->Next()) |
|
675 len += m->Length(); |
|
676 |
|
677 return len; |
|
678 } |
|
679 |
|
680 |
|
681 EXPORT_C void RMBufChain::SplitL(TInt anOffset, RMBufChain& newChain) |
|
682 /** |
|
683 Split a chain into two new chains |
|
684 Original chain gets the 1st half |
|
685 newChain gets the other half. |
|
686 @param anOffset The offset |
|
687 @param newChain The result chain |
|
688 */ |
|
689 { |
|
690 User::LeaveIfError(Split(anOffset, newChain)); |
|
691 } |
|
692 |
|
693 EXPORT_C TInt RMBufChain::Split(TInt anOffset, RMBufChain& newChain) |
|
694 /** |
|
695 Split a chain into two new chains |
|
696 Original chain gets the 1st half |
|
697 newChain gets the other half. |
|
698 - refer RMBufChain::AllocL notes regarding the deliberate decision not to provide an overloaded min/max mbuf size variant |
|
699 @param anOffset The offset |
|
700 @param newChain The result chain |
|
701 */ |
|
702 { |
|
703 RMBufAllocator allocator; |
|
704 return Split(anOffset, newChain, allocator); |
|
705 } |
|
706 |
|
707 // overloading for TLS |
|
708 EXPORT_C TInt RMBufChain::Split(TInt anOffset, RMBufChain& newChain, RMBufAllocator& aRMBufAllocator) |
|
709 { |
|
710 __ASSERT_ALWAYS(iNext!=NULL, CMBufManager::Panic(EMBuf_EmptyChain)); |
|
711 __ASSERT_ALWAYS(anOffset>=0, CMBufManager::Panic(EMBuf_NegativeOffset)); |
|
712 |
|
713 if (anOffset==0) |
|
714 { |
|
715 newChain.iNext = NULL; |
|
716 return KErrNone; |
|
717 } |
|
718 |
|
719 TInt o, n; |
|
720 RMBuf* m, *p; |
|
721 |
|
722 if (!Goto(anOffset, m, o, n, p)) |
|
723 return KErrNone; |
|
724 |
|
725 if (o!=m->Offset()) // Not on an mbuf boundary |
|
726 { |
|
727 // get another mbuf and copy extra data |
|
728 RMBuf* m2; |
|
729 m2 = aRMBufAllocator.MBufManager().Alloc(n, n); |
|
730 if(!m2) |
|
731 { |
|
732 return KErrNoMBufs; |
|
733 } |
|
734 |
|
735 __ASSERT_DEBUG(m2->Size() >= n, CMBufManager::Panic(EMBuf_TooSmall)); |
|
736 Mem::Copy(m2->Ptr(), m->Buffer()+o, n); // trs; possible future enhancement to optionally not split the mbuf unless requested, thus avoiding the copy, but kept as is to avoid a functional break |
|
737 m2->SetLength(n); |
|
738 m2->Link(m->Next()); |
|
739 m->AdjustEnd(-n); |
|
740 m->Unlink(); |
|
741 newChain = m2; |
|
742 } |
|
743 else |
|
744 { |
|
745 p->Unlink(); |
|
746 newChain = m; |
|
747 } |
|
748 return KErrNone; |
|
749 } |
|
750 |
|
751 EXPORT_C void RMBufChain::TrimStart(TInt anOffset) |
|
752 /** |
|
753 Trim chain upto offset |
|
754 @param anOffset The offset |
|
755 */ |
|
756 { |
|
757 __ASSERT_ALWAYS(iNext!=NULL, CMBufManager::Panic(EMBuf_EmptyChain)); |
|
758 __ASSERT_ALWAYS(anOffset>=0, CMBufManager::Panic(EMBuf_NegativeOffset)); |
|
759 |
|
760 if (anOffset==0) |
|
761 return; |
|
762 |
|
763 RMBuf* m, *p; |
|
764 TInt o, n; |
|
765 if (!Goto(anOffset, m, o, n, p)) |
|
766 { |
|
767 Free(); |
|
768 return; |
|
769 } |
|
770 |
|
771 if (p!=NULL) // m not first mbuf? |
|
772 { |
|
773 p->Unlink(); |
|
774 iNext->Free(); |
|
775 |
|
776 iNext = m; |
|
777 } |
|
778 |
|
779 if (o!=m->Offset()) // not at mbuf boundary? |
|
780 m->SetData(o, n); |
|
781 } |
|
782 |
|
783 EXPORT_C void RMBufChain::TrimEnd(TInt anOffset) |
|
784 /** |
|
785 Trim chain after offset |
|
786 @param anOffset The offset |
|
787 */ |
|
788 { |
|
789 __ASSERT_ALWAYS(iNext!=NULL, CMBufManager::Panic(EMBuf_EmptyChain)); |
|
790 __ASSERT_ALWAYS(anOffset>=0, CMBufManager::Panic(EMBuf_NegativeOffset)); |
|
791 |
|
792 if(anOffset==0) |
|
793 { |
|
794 Free(); |
|
795 return; |
|
796 } |
|
797 |
|
798 RMBuf* m, *p; |
|
799 TInt o, n; |
|
800 if (!Goto(anOffset, m, o, n, p)) |
|
801 return; |
|
802 |
|
803 if (o!=m->Offset()) // not at mbuf boundary? |
|
804 { |
|
805 m->AdjustEnd(-n); |
|
806 if (p = m->Next(), p!=NULL) |
|
807 { |
|
808 m->Unlink(); |
|
809 p->Free(); |
|
810 } |
|
811 } |
|
812 else |
|
813 { |
|
814 if (p!=NULL) |
|
815 p->Unlink(); |
|
816 m->Free(); |
|
817 } |
|
818 } |
|
819 |
|
820 |
|
821 EXPORT_C TBool RMBufChain::Goto(TInt anOffset, RMBuf* &resBuf, TInt& resOffset, TInt& resLength, RMBuf* &resPrevBuf) const |
|
822 /** |
|
823 Goto specified byte offset into an Mbuf chain |
|
824 Used as part of copyin/out, split etc to position |
|
825 MBuf pointer and offset from start of iBuffer. |
|
826 @param anOffset The offset |
|
827 @param resBuf result buffer |
|
828 @param resOffset result offset |
|
829 @param resLength result length |
|
830 @param resPrevBuf result previous Buf in the chain |
|
831 @return ETrue if successful |
|
832 */ |
|
833 { |
|
834 __ASSERT_ALWAYS(iNext!=NULL, CMBufManager::Panic(EMBuf_EmptyChain)); |
|
835 __ASSERT_ALWAYS(anOffset>=0, CMBufManager::Panic(EMBuf_NegativeOffset)); |
|
836 |
|
837 TInt o = 0; |
|
838 RMBuf* p = NULL, *m = iNext; |
|
839 |
|
840 while (m!=NULL) |
|
841 { |
|
842 if (o + m->Length() > anOffset) |
|
843 { |
|
844 resBuf = m; |
|
845 resOffset = (anOffset - o) + m->Offset(); |
|
846 resLength = m->Length() - (anOffset - o); |
|
847 resPrevBuf = p; |
|
848 return ETrue; |
|
849 } |
|
850 o += m->Length(); |
|
851 p = m; |
|
852 m = m->Next(); |
|
853 } |
|
854 |
|
855 // Attempt to goto beyond end of chain |
|
856 __ASSERT_ALWAYS(o==anOffset, CMBufManager::Panic(EMBuf_BadOffset)); |
|
857 return EFalse; |
|
858 } |
|
859 |
|
860 EXPORT_C RMBuf* RMBufChain::Last() const |
|
861 /** |
|
862 Find the last MBuf in a chain |
|
863 @return the last MBuf in the chain |
|
864 */ |
|
865 { |
|
866 __ASSERT_ALWAYS(iNext!=NULL, CMBufManager::Panic(EMBuf_EmptyChain)); |
|
867 |
|
868 return iNext->Last(); |
|
869 } |
|
870 |
|
871 |
|
872 EXPORT_C TInt RMBufChain::Align(TInt aSize) |
|
873 /** |
|
874 Ensure that the first aSize bytes can be safely cast |
|
875 to a structure of size aSize. |
|
876 @param aSize A size |
|
877 @return the number of bytes actually aligned. This will be the min of aSize and chain length. |
|
878 */ |
|
879 { |
|
880 __ASSERT_ALWAYS(iNext!=NULL, CMBufManager::Panic(EMBuf_EmptyChain)); |
|
881 __ASSERT_ALWAYS(aSize>=0, CMBufManager::Panic(EMBuf_NegativeLength)); |
|
882 |
|
883 // update length to the largest sized mbuf possible |
|
884 if (aSize == KMBufAll) // trs; does the KMBufAll concept (ie. 'largest sized' mbuf) really make sense? code kept as is to avoid a functional break |
|
885 { |
|
886 aSize = ((RMBufPoolChain*)iNext->MBufPoolChain())->MBufPoolManager().LargestMBufSize(); |
|
887 } |
|
888 |
|
889 // All data required is already in the first MBuf |
|
890 if (aSize <= iNext->Length()) |
|
891 { |
|
892 // Case 1 - allready aligned |
|
893 // Case 2 - it needs to be aligned |
|
894 if (!IS_ALIGNED(iNext->Offset())) |
|
895 { |
|
896 Mem::Copy(iNext->Buffer(), iNext->Ptr(), iNext->Length()); |
|
897 iNext->SetOffset(0); |
|
898 } |
|
899 return aSize; // already as required |
|
900 } |
|
901 |
|
902 // Get existing data at start |
|
903 if (iNext->Offset()!=0) |
|
904 { |
|
905 Mem::Copy(iNext->Buffer(), iNext->Ptr(), iNext->Length()); |
|
906 iNext->SetOffset(0); |
|
907 } |
|
908 |
|
909 RMBuf* m = iNext->Next(); |
|
910 TInt len = iNext->Length(); |
|
911 while (len<aSize && m!=NULL) |
|
912 { |
|
913 TInt n = aSize-len; |
|
914 if (n>m->Length()) |
|
915 n = m->Length(); |
|
916 Mem::Copy(iNext->EndPtr(), m->Ptr(), n); |
|
917 iNext->AdjustEnd(n); |
|
918 m->AdjustStart(n); |
|
919 len += n; |
|
920 |
|
921 // MBuf might now be empty so free it |
|
922 if (m->Length()==0) |
|
923 { |
|
924 iNext->Link(m->Next()); |
|
925 m->Unlink(); |
|
926 m->Free(); |
|
927 m = iNext->Next(); |
|
928 } |
|
929 } |
|
930 return len; |
|
931 } |