void tst_QRingBuffer::readPointerAtPositionWriteRead()
{
//create some data
QBuffer inData;
inData.open(QIODevice::ReadWrite);
inData.putChar(0x42);
inData.putChar(0x23);
inData.write("Qt rocks!");
for (int i = 0; i < 5000; i++)
inData.write(QString("Number %1").arg(i).toUtf8());
inData.reset();
QVERIFY(inData.size() > 0);
//put the inData in the QRingBuffer
QRingBuffer ringBuffer;
qint64 remaining = inData.size();
while (remaining > 0) {
// write in chunks of 50 bytes
// this ensures there will be multiple QByteArrays inside the QRingBuffer
// since QRingBuffer is then only using individual arrays of around 4000 bytes
qint64 thisWrite = qMin(remaining, qint64(50));
char *pos = ringBuffer.reserve(thisWrite);
inData.read(pos, thisWrite);
remaining -= thisWrite;
}
// was data put into it?
QVERIFY(ringBuffer.size() > 0);
QCOMPARE(qint64(ringBuffer.size()), inData.size());
//read from the QRingBuffer in loop, put back into another QBuffer
QBuffer outData;
outData.open(QIODevice::ReadWrite);
remaining = ringBuffer.size();
while (remaining > 0) {
qint64 thisRead;
// always try to read as much as possible
const char *buf = ringBuffer.readPointerAtPosition(ringBuffer.size() - remaining, thisRead);
outData.write(buf, thisRead);
remaining -= thisRead;
}
outData.reset();
QVERIFY(outData.size() > 0);
// was the data read from the QRingBuffer the same as the one written into it?
QCOMPARE(outData.size(), inData.size());
QVERIFY(outData.buffer().startsWith(inData.buffer()));
}
