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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 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     QString name;
  61
  62     /**
  63      * Value from the INI file
  64      */
  65     QString paramValue;
  66
  67     /**
  68      * Flag indicating that this value is valid on this OS only
  69      */
  70     bool thisOsOnly;
  71 };
  72
  73 /**
  74  * INI file section in the internal cache
  75  */
  76 class IniFileSection : public QSharedData
  77 {
  78 public:
  79
  80     IniFileSection(quint64 pos)
  81         : QSharedData()
  82         , filePos(pos)
  83     {}
  84
  85     /**
  86      * File position
  87      *
  88      * Offset of the section in the INI file. By seeking the file to this offset value,
  89      * the next character read or written will be the first character of the section.
  90      */
  91     quint64 filePos;
  92
  93     /**
  94      * Name of the section
  95      */
  96     QString name;
  97
  98     /**
  99      * List of all the known parameter values in this section
 100      *
 101      * The key to the hash table is the name of the key for the parameters value.
 102      */
 103     QHash<QString, QExplicitlySharedDataPointer<IniFileValue> > values;
 104
 105 };
 106
 107 /**
 108  * Internal implementation of the IniFile class.
 109  */
 110 class IniFileImpl
 111 {
 112 public:
 113
 114     IniFileImpl(QString const & fileName, QIODevice::OpenMode mode);
 115
 116     ~IniFileImpl();
 117
 118     QVariant getValue(QString const & paramName, QVariant const & defaultValue);
 119
 120     bool setValue(QString const & paramName, QVariant const & value);
 121
 122     inline bool isValid() const { return mValid; }
 123
 124     inline QString const & fileName() const { return mFileName; }
 125
 126     inline QString const & errorString() const { return mErrorString; }
 127
 128
 129 private: // Members
 130
 131     /// Flag indicating that the INI file object is valid and can be used to access the INI file
 132     bool mValid;
 133
 134     /// Name of the INI file
 135     QString mFileName;
 136
 137     /// INI file opening mode
 138     QIODevice::OpenMode mMode;
 139
 140     /// Last human-readable error message if an operation with the INI file failed
 141     QString mErrorString;
 142
 143     /**
 144      * Internal cache of sections and parameter values.
 145      *
 146      * The key to the hash table is the name of the section.
 147      */
 148     QHash<QString, QExplicitlySharedDataPointer<IniFileSection> > mCache;
 149
 150     /// When was the INI file modified.
 151     QDateTime mLastModified;
 152
 153
 154 private: /// Methods
 155
 156     /**
 157      * Updates items in the internal cache after changes to the INI file
 158      * @param pos File offset from where the cache should be updated
 159      * @param diff Difference between old and new file offsets
 160      *
 161      * When a parameter value is modified or a new value inserted, the length of the INI file changes.
 162      * Sections and parameters that come after the modified parameter value are shifted and their file
 163      * positions changed. This method updates items in the internal cache after changes to the INI file.
 164      */
 165     void updateCache(quint64 pos, qint64 diff);
 166
 167     /**
 168      * Looks for a section in the INI file
 169      * @param file The file object
 170      * @param sectionName Name of the section
 171      * @return The section object or an invalid object if not found
 172      *
 173      * This method reads the INI file and looks for the section with the given name. If found, returns the section
 174      * object and seeks the file to the first character after the section name.
 175      *
 176      * If the section is not found, returns an invalid section object and seeks the file to the end of the file.
 177      *
 178      * The file object is expected to be opened if the mValid flag is true. If the mValid flag is false, looks
 179      * only in the cache.
 180      */
 181     QExplicitlySharedDataPointer<IniFileSection> getSection(QFile & file, QString const & sectionName);
 182
 183     /**
 184      * Looks for a parameter in the INI file
 185      * @param file The file object
 186      * @param section The section object
 187      * @param paramName Name of the parameter
 188      * @return The value object or an invalid object if not found
 189      *
 190      * This method reads the INI file and looks for the parameter with the given name. If found, returns the value
 191      * object and seeks the file to the beginning of the line containing the parameter.
 192      *
 193      * If not found, returns an invalid value object and seeks the file to the end of the section.
 194      *
 195      * The file object is expected to be opened if the mValid flag is true. If the mValid flag is false, looks
 196      * only in the cache.
 197      */
 198     QExplicitlySharedDataPointer<IniFileValue> getParameter(QFile & file, IniFileSection & section, QString const & paramName);
 199
 200 };
 201
 202
 203 } // namespace eVaf::Common::Internal
 204 } // namespace eVaf::Common
 205 } // namespace eVaf
 206
 207 #endif // inifile_p.h