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1 // Copyright (c) 1998-2009 Nokia Corporation and/or its subsidiary(-ies). |
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2 // All rights reserved. |
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3 // This component and the accompanying materials are made available |
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4 // under the terms of "Eclipse Public License v1.0" |
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5 // which accompanies this distribution, and is available |
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6 // at the URL "http://www.eclipse.org/legal/epl-v10.html". |
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7 // |
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8 // Initial Contributors: |
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9 // Nokia Corporation - initial contribution. |
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10 // |
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11 // Contributors: |
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12 // |
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13 // Description: |
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14 // |
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15 |
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16 #include "US_STD.H" |
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17 |
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18 EXPORT_C TStreamFilter::TStreamFilter() |
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19 : iHost(NULL),iMode(0) |
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20 /** Constructs an empty stream filter object. */ |
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21 {} |
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22 |
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23 EXPORT_C void TStreamFilter::EmitL(const TAny* aPtr,TInt aLength) |
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24 /** Writes data from the specified memory location directly to the host without |
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25 filtering. |
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26 |
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27 This is useful for sending any final data, when flushing the filter as part |
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28 of DoSynchL(). |
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29 |
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30 In debug mode: the filter must be in write mode, otherwise the function raises |
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31 a STORE-Stream 11 panic. |
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32 |
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33 In debug mode, a host stream must have been set before calling this function, |
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34 otherwise it raises a STORE-Stream 0 panic. |
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35 |
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36 @param aPtr A pointer to the memory location from which data is to be written |
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37 to the host stream. |
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38 @param aLength The number of bytes to be written. |
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39 @see DoSynchL() */ |
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40 { |
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41 __ASSERT_DEBUG(iMode&EWrite,Panic(EStreamCannotWrite)); |
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42 __ASSERT_DEBUG(iHost!=NULL,Panic(EStreamNotOpen)); |
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43 iHost->WriteL(aPtr,aLength); |
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44 } |
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45 |
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46 EXPORT_C void TStreamFilter::DoRelease() |
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47 /** Frees the host stream's resources. |
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48 |
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49 @see MStreamBuf::DoRelease() */ |
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50 { |
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51 if (iHost!=NULL&&(iMode&EAttached)) |
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52 iHost->Release(); |
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53 iHost=NULL; |
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54 } |
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55 |
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56 EXPORT_C void TStreamFilter::DoSynchL() |
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57 /** Synchronizes the host's intermediate buffer with its stream, leaving if any |
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58 error occurs. |
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59 |
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60 @see MStreamBuf::DoSynchL() */ |
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61 { |
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62 if (iHost!=NULL&&(iMode&EAttached)) |
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63 iHost->SynchL(); |
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64 } |
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65 |
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66 EXPORT_C TInt TStreamFilter::DoReadL(TAny* aPtr,TInt aMaxLength) |
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67 /** Reads data from the host stream through the filter into the specified memory |
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68 location. |
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69 |
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70 In debug mode: the filter must be in read mode, otherwise the function raises |
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71 a STORE-Stream 10 panic. |
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72 |
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73 In debug mode, a host stream must have been set before calling this function, |
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74 otherwise it raises a STORE-Stream 0 panic. |
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75 |
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76 @param aPtr A pointer to the target memory location for the filtered data. |
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77 @param aMaxLength The maximum number of bytes to be read. In debug mode: if |
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78 this value is negative then the function raises a STORE-Stream 1 panic; if |
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79 this value is zero, then the function raises a STORE-Stream 3 panic. |
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80 @return The number of bytes read. */ |
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81 { |
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82 __ASSERT_DEBUG(aMaxLength>=0,Panic(EStreamReadLengthNegative)); |
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83 __ASSERT_DEBUG(aMaxLength>0,Panic(EStreamReadNoTransfer)); |
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84 __ASSERT_DEBUG(iMode&ERead,Panic(EStreamCannotRead)); |
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85 __ASSERT_DEBUG(iHost!=NULL,Panic(EStreamNotOpen)); |
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86 TFilterInput input(*this,aPtr,aMaxLength); |
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87 do |
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88 { |
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89 iHost->ReadL(input); |
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90 } while (!(input.Done()||input.Eof())); |
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91 return aMaxLength-input.Left(); |
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92 } |
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93 |
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94 EXPORT_C void TStreamFilter::DoWriteL(const TAny* aPtr,TInt aLength) |
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95 /** Writes data to the host stream through the filter from the specified memory |
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96 location. |
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97 |
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98 In debug mode: the filter must be in write mode, otherwise the function raises |
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99 a STORE-Stream 11 panic. |
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100 |
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101 In debug mode, a host stream must have been set before calling this function, |
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102 otherwise it raises a STORE-Stream 0 panic. |
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103 |
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104 @param aPtr A pointer to the source memory location. |
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105 @param aLength The number of bytes to be written. In debug mode: if this value |
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106 is negative then the function raises a STORE-Stream 1 panic; if this value |
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107 is zero, then the function raises a STORE-Stream 7 panic. */ |
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108 { |
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109 __ASSERT_DEBUG(aLength>=0,Panic(EStreamWriteLengthNegative)); |
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110 __ASSERT_DEBUG(aLength>0,Panic(EStreamWriteNoTransfer)); |
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111 __ASSERT_DEBUG(iMode&EWrite,Panic(EStreamCannotWrite)); |
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112 __ASSERT_DEBUG(iHost!=NULL,Panic(EStreamNotOpen)); |
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113 TFilterOutput output(*this,aPtr,aLength); |
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114 do |
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115 { |
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116 iHost->WriteL(output); |
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117 } while (!output.Done()); |
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118 } |
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119 |
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120 EXPORT_C void TStreamFilter::__DbgChkMode(TInt aMode) |
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121 // |
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122 // Check mode allows either reading or writing, but not both. |
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123 // |
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124 { |
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125 __ASSERT_ALWAYS((aMode&(ERead|EWrite))&&(aMode&(ERead|EWrite))!=(ERead|EWrite),Panic(EStreamModeInvalid)); |
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126 } |
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127 |