File indexing completed on 2024-12-08 07:18:24
0001 /* This file is part of the KDE project 0002 Copyright (C) 2002 Lucijan Busch <lucijan@gmx.at> 0003 Copyright (C) 2003 Daniel Molkentin <molkentin@kde.org> 0004 Copyright (C) 2003-2016 Jarosław Staniek <staniek@kde.org> 0005 0006 This program is free software; you can redistribute it and/or 0007 modify it under the terms of the GNU Library General Public 0008 License as published by the Free Software Foundation; either 0009 version 2 of the License, or (at your option) any later version. 0010 0011 This program is distributed in the hope that it will be useful, 0012 but WITHOUT ANY WARRANTY; without even the implied warranty of 0013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 0014 Library General Public License for more details. 0015 0016 You should have received a copy of the GNU Library General Public License 0017 along with this program; see the file COPYING. If not, write to 0018 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, 0019 * Boston, MA 02110-1301, USA. 0020 0021 Original Author: Till Busch <till@bux.at> 0022 Original Project: buX (www.bux.at) 0023 */ 0024 0025 #ifndef KDB_RECORDDATA_H 0026 #define KDB_RECORDDATA_H 0027 0028 #include <QVariant> 0029 #include "kdb_export.h" 0030 0031 //! @short Structure for storing single record with type information. 0032 //! @todo consider forking QVariant to a non-shared Variant class, with type information stored elsewhere. 0033 //! @todo Variant should have toQVariant() method 0034 //! @todo look if we can have zero-copy strategy for SQLite and other backends 0035 //! @todo look if we can use memory allocator for strings, etc. 0036 class KDB_EXPORT KDbRecordData 0037 { 0038 public: 0039 /*! Creates a new empty record. */ 0040 inline KDbRecordData() : m_data(nullptr), m_numCols(0) {} 0041 0042 /*! Creates a new record data with @a numCols columns. 0043 Values are initialized to null. */ 0044 inline explicit KDbRecordData(int numCols) 0045 : m_numCols(numCols) 0046 { 0047 if (m_numCols > 0) { 0048 m_data = static_cast<QVariant **>(malloc(m_numCols * sizeof(QVariant *))); 0049 memset(m_data, 0, m_numCols * sizeof(QVariant *)); 0050 } else { 0051 m_data = nullptr; 0052 } 0053 } 0054 0055 inline ~KDbRecordData() { 0056 if (m_numCols > 0) { 0057 for (int i = 0; i < m_numCols; i++) 0058 delete m_data[i]; 0059 free(m_data); 0060 } 0061 } 0062 0063 inline bool isEmpty() const { return m_numCols == 0; } 0064 0065 inline int size() const { return m_numCols; } 0066 0067 inline int count() const { return m_numCols; } 0068 0069 /*! @return the value at position @a i. 0070 @a i must be a valid index. i.e. 0 <= i < size(). 0071 @see value(), operator[](). */ 0072 inline const QVariant& at(int i) const { 0073 if (!m_data[i]) 0074 return s_null; 0075 return *m_data[i]; 0076 } 0077 0078 /*! @return the value at position @a i as a modifiable reference. 0079 @a i must be a valid index, i.e. 0 <= i < size(). 0080 @see at(), value(). */ 0081 inline QVariant& operator[](int i) { 0082 if (!m_data[i]) { 0083 return *(m_data[i] = new QVariant); 0084 } 0085 return *m_data[i]; 0086 } 0087 0088 /*! @return true id value at position @a i is null. 0089 @a i must be a valid index, i.e. 0 <= i < size(). 0090 @see at(), value(). */ 0091 inline bool isNull(int i) const { return !m_data[i] || m_data[i]->isNull(); } 0092 0093 /*! Overloaded function.*/ 0094 inline const QVariant& operator[](int i) const { 0095 if (!m_data[i]) 0096 return s_null; 0097 return *m_data[i]; 0098 } 0099 0100 /*! @return the value at index position @a i in the vector. 0101 If the index @a i is out of bounds, the function returns a default-constructed value. 0102 If you are certain that @a i is within bounds, you can use at() or operator[] instead, which is 0103 slightly faster. */ 0104 inline QVariant value(int i) const { 0105 if (!m_data || i < 0 || i >= m_numCols || !m_data[i]) 0106 return QVariant(); 0107 return *m_data[i]; 0108 } 0109 0110 /*! @return the value at index position @a i in the vector. 0111 This is an overloaded function. 0112 If the index @a i is out of bounds, the function returns a @a defaultValue. 0113 If you are certain that i is within bounds, you can use at() instead, which is slightly faster. */ 0114 inline QVariant value(int i, const QVariant& defaultValue) const { 0115 if (!m_data || i < 0 || i >= m_numCols) 0116 return defaultValue; 0117 if (!m_data[i]) 0118 return QVariant(); 0119 return *m_data[i]; 0120 } 0121 0122 /*! Sets all column values to null, current number of columns is preserved. */ 0123 void clearValues(); 0124 0125 /*! Clears all columns, the record is set empty. */ 0126 void clear(); 0127 0128 /*! Resizes the record to @a numCols. 0129 If @a numCols differ from size(), new with record with all values set to null is created. 0130 If @a numCols equals size() nothing is performed. */ 0131 void resize(int numCols); 0132 0133 //! Converts this record to QList<QVariant> 0134 QList<QVariant> toList() const; 0135 0136 private: 0137 Q_DISABLE_COPY(KDbRecordData) 0138 QVariant **m_data; 0139 int m_numCols; 0140 static QVariant s_null; 0141 }; 0142 0143 //! Sends information about record data @a data to debug output @a dbg. 0144 KDB_EXPORT QDebug operator<<(QDebug dbg, const KDbRecordData& data); 0145 0146 #endif