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1 /**************************************************************************** |
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2 ** |
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3 ** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). |
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4 ** All rights reserved. |
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5 ** Contact: Nokia Corporation (qt-info@nokia.com) |
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6 ** |
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7 ** This file is part of the QtXmlPatterns module of the Qt Toolkit. |
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8 ** |
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9 ** $QT_BEGIN_LICENSE:LGPL$ |
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10 ** No Commercial Usage |
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11 ** This file contains pre-release code and may not be distributed. |
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12 ** You may use this file in accordance with the terms and conditions |
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13 ** contained in the Technology Preview License Agreement accompanying |
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14 ** this package. |
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15 ** |
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16 ** GNU Lesser General Public License Usage |
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17 ** Alternatively, this file may be used under the terms of the GNU Lesser |
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18 ** General Public License version 2.1 as published by the Free Software |
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19 ** Foundation and appearing in the file LICENSE.LGPL included in the |
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20 ** packaging of this file. Please review the following information to |
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21 ** ensure the GNU Lesser General Public License version 2.1 requirements |
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22 ** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. |
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23 ** |
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24 ** In addition, as a special exception, Nokia gives you certain additional |
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25 ** rights. These rights are described in the Nokia Qt LGPL Exception |
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26 ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. |
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27 ** |
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28 ** If you have questions regarding the use of this file, please contact |
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29 ** Nokia at qt-info@nokia.com. |
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30 ** |
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31 ** |
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32 ** |
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33 ** |
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34 ** |
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35 ** |
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36 ** |
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37 ** |
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38 ** $QT_END_LICENSE$ |
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39 ** |
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40 ****************************************************************************/ |
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41 |
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42 // |
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43 // W A R N I N G |
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44 // ------------- |
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45 // |
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46 // This file is not part of the Qt API. It exists purely as an |
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47 // implementation detail. This header file may change from version to |
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48 // version without notice, or even be removed. |
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49 // |
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50 // We mean it. |
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51 |
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52 #ifndef Patternist_CacheCells_H |
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53 #define Patternist_CacheCells_H |
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54 |
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55 #include <QList> |
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56 #include <QVector> |
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57 |
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58 #include "qitem_p.h" |
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59 |
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60 QT_BEGIN_HEADER |
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61 |
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62 QT_BEGIN_NAMESPACE |
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63 |
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64 namespace QPatternist |
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65 { |
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66 |
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67 /** |
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68 * @short Represents a cache entry for a single Item, |
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69 * as opposed to for a sequence of items. |
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70 * |
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71 * A characteristic of the ItemCacheCell is that it has two states: |
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72 * either its full or it's not, since it only deals with a single |
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73 * item. |
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74 * |
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75 * Remember that cachedItem doesn't tell the state of the ItemCacheCell. |
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76 * For instance, it can have a null pointer, the empty sequence, and that |
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77 * can be the value of its cache. |
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78 * |
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79 * @author Frans Englich <frans.englich@nokia.com> |
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80 */ |
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81 class ItemCacheCell |
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82 { |
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83 public: |
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84 typedef QList<ItemCacheCell> List; |
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85 typedef QVector<ItemCacheCell> Vector; |
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86 enum CacheState |
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87 { |
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88 Full, |
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89 Empty |
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90 }; |
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91 |
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92 inline ItemCacheCell() : cacheState(Empty) |
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93 { |
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94 } |
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95 |
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96 Item cachedItem; |
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97 CacheState cacheState; |
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98 }; |
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99 |
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100 /** |
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101 * @short Represents a cache entry for a sequence of items. |
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102 * |
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103 * As opposed to ItemCacheCell, ItemSequenceCacheCell can be partially |
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104 * populated: e.g, four items is in the cache while three remains in the |
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105 * source. For that reason ItemSequenceCacheCell in addition to the source |
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106 * also carried an QAbstractXmlForwardIterator which is the source, such |
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107 * that it can continue to populate the cache when it runs out. |
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108 * |
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109 * @author Frans Englich <frans.englich@nokia.com> |
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110 */ |
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111 class ItemSequenceCacheCell |
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112 { |
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113 public: |
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114 typedef QList<ItemSequenceCacheCell> List; |
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115 typedef QVector<ItemSequenceCacheCell> Vector; |
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116 |
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117 enum CacheState |
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118 { |
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119 Full, |
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120 Empty, |
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121 PartiallyPopulated |
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122 }; |
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123 |
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124 inline ItemSequenceCacheCell() : cacheState(Empty) |
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125 , inUse(false) |
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126 { |
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127 } |
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128 |
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129 Item::List cachedItems; |
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130 Item::Iterator::Ptr sourceIterator; |
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131 CacheState cacheState; |
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132 /** |
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133 * In XSL-T, we can have circularity which we cannot detect statically. |
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134 * For instance, a global variable invokes a template, and the template |
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135 * uses the variable. We can't detect that, because we can't figure out |
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136 * what template will be invoked. |
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137 * |
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138 * For solution we have this toggle, which is set temporarily on the |
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139 * cell such that EvaluationCache can detect whether it's trashing |
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140 * itself. |
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141 * |
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142 * One might think that it would be sufficient to flag usage of the |
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143 * variable in an arbitrary template, but that would also flag valid |
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144 * cases. |
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145 */ |
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146 bool inUse; |
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147 }; |
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148 } |
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149 |
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150 Q_DECLARE_TYPEINFO(QPatternist::ItemCacheCell, Q_MOVABLE_TYPE); |
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151 Q_DECLARE_TYPEINFO(QPatternist::ItemSequenceCacheCell, Q_MOVABLE_TYPE); |
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152 |
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153 QT_END_NAMESPACE |
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154 |
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155 QT_END_HEADER |
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156 |
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157 #endif |