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   1 /**
   2  * @file Common/inifile_p.h
   3  * @brief Internal implementation of the class for reading and writing parameter values in INI files.
   4  * @author Enar Vaikene
   5  *
   6  * Copyright (c) 2011-2019 Enar Vaikene
   7  *
   8  * This file is part of the eVaf C++ cross-platform application development framework.
   9  *
  10  * This file can be used under the terms of the GNU General Public License
  11  * version 3.0 as published by the Free Software Foundation and appearing in
  12  * the file LICENSE included in the packaging of this file. Please review the
  13  * the following information to ensure the GNU General Public License version
  14  * 3.0 requirements will be met: http://www.gnu.org/copyleft/gpl.html.
  15  *
  16  * Alternatively, this file may be used in accordance with the Commercial License
  17  * Agreement provided with the Software.
  18  */
  19
  20 #ifndef __COMMON_INIFILE_P_H
  21 #define   __COMMON_INIFILE_P_H
  22
  23 #include <QSharedData>
  24 #include <QExplicitlySharedDataPointer>
  25 #include <QHash>
  26 #include <QString>
  27 #include <QVariant>
  28 #include <QDateTime>
  29 #include <QFile>
  30
  31
  32 namespace eVaf {
  33 namespace Common {
  34 namespace Internal {
  35
  36 /**
  37  * INI file value in the internal cache
  38  */
  39 class IniFileValue : public QSharedData
  40 {
  41 public:
  42
  43     IniFileValue(quint64 pos)
  44         : QSharedData()
  45         , filePos(pos)
  46         , thisOsOnly(false)
  47     {}
  48
  49     /**
  50      * File position
  51      *
  52      * Offset of the parameter in the INI file. By seeking the file to this offset value,
  53      * the next character read or written will be the beginning of the key name.
  54      */
  55     quint64 filePos;
  56
  57     /**
  58      * Key name of the parameter
  59      */
  60     QByteArray name;
  61
  62     /**
  63      * Value from the INI file
  64      */
  65     QByteArray paramValue;
  66
  67     /**
  68      * Value converted to the final type (defaults to QVariant::Invalid
  69      */
  70     QVariant value;
  71
  72     /**
  73      * Flag indicating that this value is valid on this OS only
  74      */
  75     bool thisOsOnly;
  76 };
  77
  78 /**
  79  * INI file section in the internal cache
  80  */
  81 class IniFileSection : public QSharedData
  82 {
  83 public:
  84
  85     IniFileSection(quint64 pos)
  86         : QSharedData()
  87         , filePos(pos)
  88     {}
  89
  90     /**
  91      * File position
  92      *
  93      * Offset of the section in the INI file. By seeking the file to this offset value,
  94      * the next character read or written will be the first character of the section.
  95      */
  96     quint64 filePos;
  97
  98     /**
  99      * Name of the section
 100      */
 101     QByteArray name;
 102
 103     /**
 104      * List of all the known parameter values in this section
 105      *
 106      * The key to the hash table is the name of the key for the parameters value.
 107      */
 108     QHash<QByteArray, QExplicitlySharedDataPointer<IniFileValue> > values;
 109
 110 };
 111
 112 /**
 113  * Internal implementation of the IniFile class.
 114  */
 115 class IniFileImpl
 116 {
 117 public:
 118
 119     IniFileImpl(QString const & fileName, QIODevice::OpenMode mode);
 120
 121     ~IniFileImpl();
 122
 123     QVariant getValue(QByteArray const & paramName, QVariant const & defaultValue);
 124
 125     bool setValue(QByteArray const & paramName, QVariant const & value);
 126
 127     inline bool isValid() const { return mValid; }
 128
 129     inline QString const & fileName() const { return mFileName; }
 130
 131     inline QString const & errorString() const { return mErrorString; }
 132
 133
 134 private: // Members
 135
 136     /// Flag indicating that the INI file object is valid and can be used to access the INI file
 137     bool mValid;
 138
 139     /// Name of the INI file
 140     QString mFileName;
 141
 142     /// INI file opening mode
 143     QIODevice::OpenMode mMode;
 144
 145     /// Last human-readable error message if an operation with the INI file failed
 146     QString mErrorString;
 147
 148     /**
 149      * Internal cache of sections and parameter values.
 150      *
 151      * The key to the hash table is the name of the section.
 152      */
 153     QHash<QByteArray, QExplicitlySharedDataPointer<IniFileSection> > mCache;
 154
 155     /// When was the INI file modified.
 156     QDateTime mLastModified;
 157
 158
 159 private: /// Methods
 160
 161     /**
 162      * Updates items in the internal cache after changes to the INI file
 163      * @param pos File offset from where the cache should be updated
 164      * @param diff Difference between old and new file offsets
 165      *
 166      * When a parameter value is modified or a new value inserted, the length of the INI file changes.
 167      * Sections and parameters that come after the modified parameter value are shifted and their file
 168      * positions changed. This method updates items in the internal cache after changes to the INI file.
 169      */
 170     void updateCache(quint64 pos, qint64 diff);
 171
 172     /**
 173      * Looks for a section in the INI file
 174      * @param file The file object
 175      * @param sectionName Name of the section
 176      * @return The section object or an invalid object if not found
 177      *
 178      * This method reads the INI file and looks for the section with the given name. If found, returns the section
 179      * object and seeks the file to the first character after the section name.
 180      *
 181      * If the section is not found, returns an invalid section object and seeks the file to the end of the file.
 182      *
 183      * The file object is expected to be opened if the mValid flag is true. If the mValid flag is false, looks
 184      * only in the cache.
 185      */
 186     QExplicitlySharedDataPointer<IniFileSection> getSection(QFile & file, QByteArray const & sectionName);
 187
 188     /**
 189      * Looks for a parameter in the INI file
 190      * @param file The file object
 191      * @param section The section object
 192      * @param paramName Name of the parameter
 193      * @return The value object or an invalid object if not found
 194      *
 195      * This method reads the INI file and looks for the parameter with the given name. If found, returns the value
 196      * object and seeks the file to the beginning of the line containing the parameter.
 197      *
 198      * If not found, returns an invalid value object and seeks the file to the end of the section.
 199      *
 200      * The file object is expected to be opened if the mValid flag is true. If the mValid flag is false, looks
 201      * only in the cache.
 202      */
 203     QExplicitlySharedDataPointer<IniFileValue> getParameter(QFile & file, IniFileSection & section, QByteArray const & paramName);
 204
 205 };
 206
 207
 208 } // namespace eVaf::Common::Internal
 209 } // namespace eVaf::Common
 210 } // namespace eVaf
 211
 212 #endif // inifile_p.h