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#ifndef QBYTEDATA_P_H
#define QBYTEDATA_P_H
//
// W A R N I N G
// -------------
//
// This file is not part of the Qt API. It exists purely as an
// implementation detail. This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.
//
#include <QtCore/private/qglobal_p.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;
qint64 firstPos;
public:
QByteDataBuffer() : bufferCompleteSize(0), firstPos(0)
{
}
~QByteDataBuffer()
{
clear();
}
static inline void popFront(QByteArray &ba, qint64 n)
{
ba = QByteArray(ba.constData() + n, ba.size() - n);
}
inline void squeezeFirst()
{
if (!buffers.isEmpty() && firstPos > 0) {
popFront(buffers.first(), firstPos);
firstPos = 0;
}
}
inline void append(const QByteDataBuffer& other)
{
if (other.isEmpty())
return;
buffers.append(other.buffers);
bufferCompleteSize += other.byteAmount();
if (other.firstPos > 0)
popFront(buffers[bufferCount() - other.bufferCount()], other.firstPos);
}
inline void append(const QByteArray& bd)
{
if (bd.isEmpty())
return;
buffers.append(bd);
bufferCompleteSize += bd.size();
}
inline void prepend(const QByteArray& bd)
{
if (bd.isEmpty())
return;
squeezeFirst();
buffers.prepend(bd);
bufferCompleteSize += bd.size();
}
// return the first QByteData. User of this function has to free() its .data!
// preferably use this function to read data.
inline QByteArray read()
{
squeezeFirst();
bufferCompleteSize -= buffers.first().size();
return buffers.takeFirst();
}
// return everything. User of this function has to free() 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 free() 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 free() 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) {
const QByteArray &first = buffers.first();
qint64 firstSize = first.size() - firstPos;
if (amount >= firstSize) {
// take it completely
bufferCompleteSize -= firstSize;
amount -= firstSize;
memcpy(writeDst, first.constData() + firstPos, firstSize);
writeDst += firstSize;
firstPos = 0;
buffers.takeFirst();
} else {
// take a part of it & it is the last one to take
bufferCompleteSize -= amount;
memcpy(writeDst, first.constData() + firstPos, amount);
firstPos += amount;
amount = 0;
}
}
return originalAmount;
}
inline char getChar()
{
char c;
read(&c, 1);
return c;
}
inline void clear()
{
buffers.clear();
bufferCompleteSize = 0;
firstPos = 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() - firstPos;
}
inline QByteArray& operator[](int i)
{
if (i == 0)
squeezeFirst();
return buffers[i];
}
inline bool canReadLine() const {
int i = 0;
if (i < buffers.length()) {
if (buffers.at(i).indexOf('\n', firstPos) != -1)
return true;
++i;
for (; i < buffers.length(); i++)
if (buffers.at(i).contains('\n'))
return true;
}
return false;
}
};
QT_END_NAMESPACE
#endif // QBYTEDATA_P_H