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/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the QtCore module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** No Commercial Usage
** This file contains pre-release code and may not be distributed.
** You may use this file in accordance with the terms and conditions
** contained in the either Technology Preview License Agreement or the
** Beta Release License Agreement.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain
** additional rights. These rights are described in the Nokia Qt LGPL
** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this
** package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
** If you are unsure which license is appropriate for your use, please
** contact the sales department at http://www.qtsoftware.com/contact.
** $QT_END_LICENSE$
**
****************************************************************************/
#ifndef QBYTEDATA_H
#define QBYTEDATA_H
#include <qbytearray.h>
QT_BEGIN_NAMESPACE
// this class handles a list of QByteArrays. It is a variant of QRingBuffer
// that avoid malloc/realloc/memcpy.
class QByteDataBuffer
{
private:
QList<QByteArray> buffers;
qint64 bufferCompleteSize;
public:
QByteDataBuffer() : bufferCompleteSize(0)
{
}
~QByteDataBuffer()
{
clear();
}
inline void append(QByteDataBuffer& other)
{
if (other.isEmpty())
return;
buffers.append(other.buffers);
bufferCompleteSize += other.byteAmount();
}
inline void append(QByteArray& bd)
{
if (bd.isEmpty())
return;
buffers.append(bd);
bufferCompleteSize += bd.size();
}
inline void prepend(QByteArray& bd)
{
if (bd.isEmpty())
return;
buffers.prepend(bd);
bufferCompleteSize += bd.size();
}
// return the first QByteData. User of this function has to qFree() its .data!
// preferably use this function to read data.
inline QByteArray read()
{
bufferCompleteSize -= buffers.first().size();
return buffers.takeFirst();
}
// return everything. User of this function has to qFree() its .data!
// avoid to use this, it might malloc and memcpy.
inline QByteArray readAll()
{
return read(byteAmount());
}
// return amount. User of this function has to qFree() its .data!
// avoid to use this, it might malloc and memcpy.
inline QByteArray read(qint64 amount)
{
amount = qMin(byteAmount(), amount);
QByteArray byteData;
byteData.resize(amount);
read(byteData.data(), byteData.size());
return byteData;
}
// return amount bytes. User of this function has to qFree() its .data!
// avoid to use this, it will memcpy.
qint64 read(char* dst, qint64 amount)
{
amount = qMin(amount, byteAmount());
qint64 originalAmount = amount;
char *writeDst = dst;
while (amount > 0) {
QByteArray first = buffers.takeFirst();
if (amount >= first.size()) {
// take it completely
bufferCompleteSize -= first.size();
amount -= first.size();
memcpy(writeDst, first.constData(), first.size());
writeDst += first.size();
first.clear();
} else {
// take a part of it & it is the last one to take
bufferCompleteSize -= amount;
memcpy(writeDst, first.constData(), amount);
qint64 newFirstSize = first.size() - amount;
QByteArray newFirstData;
newFirstData.resize(newFirstSize);
memcpy(newFirstData.data(), first.constData() + amount, newFirstSize);
buffers.prepend(newFirstData);
amount = 0;
first.clear();
}
}
return originalAmount;
}
inline char getChar()
{
char c;
read(&c, 1);
return c;
}
inline void clear()
{
buffers.clear();
bufferCompleteSize = 0;
}
// The byte count of all QByteArrays
inline qint64 byteAmount() const
{
return bufferCompleteSize;
}
// the number of QByteArrays
inline qint64 bufferCount() const
{
return buffers.length();
}
inline bool isEmpty() const
{
return byteAmount() == 0;
}
inline qint64 sizeNextBlock() const
{
if(buffers.isEmpty())
return 0;
else
return buffers.first().size();
}
inline QByteArray& operator[](int i)
{
return buffers[i];
}
};
QT_END_NAMESPACE
#endif // QBYTEDATA_H
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