C++ (Cpp) QRingBuffer::free示例

示例#1

void tst_qringbuffer::free()
{
    QRingBuffer ringBuffer;
    QBENCHMARK {
        ringBuffer.reserve(4096);
        ringBuffer.reserve(2048);
        ringBuffer.append(QByteArray("01234", 5));

        ringBuffer.free(1);
        ringBuffer.free(4096);
        ringBuffer.free(48);
        ringBuffer.free(2000);
    }
}

示例#2

文件： tst_qringbuffer.cpp 项目： Mr-Kumar-Abhishek/qt

void tst_QRingBuffer::readPointerAtPositionWithHead()
{
    QRingBuffer ringBuffer;
    char *buf = ringBuffer.reserve(4);
    memcpy (buf, "0123", 4);
    ringBuffer.free(2);

    // ringBuffer should have stayed the same except
    // its head it had moved to position 2
    qint64 length;
    const char* buf2 = ringBuffer.readPointerAtPosition(0, length);

    QCOMPARE(length, qint64(2));
    QVERIFY(*buf2 == '2');
    QVERIFY(*(buf2+1) == '3');

    // advance 2 more, ringBuffer should be empty then
    ringBuffer.free(2);
    buf2 = ringBuffer.readPointerAtPosition(0, length);
    QCOMPARE(length, qint64(0));
    QVERIFY(buf2 == 0);
}

示例#3

文件： qprocess.cpp 项目： psi-im/neatstuff

/*! \reimp
*/
qint64 QProcess::readData(char *data, qint64 maxlen)
{
    Q_D(QProcess);
    QRingBuffer *readBuffer = (d->processChannel == QProcess::StandardError)
                              ? &d->errorReadBuffer
                              : &d->outputReadBuffer;

    if (maxlen == 1) {
        int c = readBuffer->getChar();
        if (c == -1) {
#if defined QPROCESS_DEBUG
            qDebug("QProcess::readData(%p \"%s\", %d) == -1",
                   data, qt_prettyDebug(data, maxlen, 1).constData(), 1);
#endif
            return -1;
        }
        *data = (char) c;
#if defined QPROCESS_DEBUG
        qDebug("QProcess::readData(%p \"%s\", %d) == 1",
               data, qt_prettyDebug(data, maxlen, 1).constData(), 1);
#endif
        return 1;
    }

    qint64 bytesToRead = qint64(qMin(readBuffer->size(), (int)maxlen));
    qint64 readSoFar = 0;
    while (readSoFar < bytesToRead) {
        char *ptr = readBuffer->readPointer();
        int bytesToReadFromThisBlock = qMin<qint64>(bytesToRead - readSoFar,
                                            readBuffer->nextDataBlockSize());
        memcpy(data + readSoFar, ptr, bytesToReadFromThisBlock);
        readSoFar += bytesToReadFromThisBlock;
        readBuffer->free(bytesToReadFromThisBlock);
    }

#if defined QPROCESS_DEBUG
    qDebug("QProcess::readData(%p \"%s\", %lld) == %lld",
           data, qt_prettyDebug(data, readSoFar, 16).constData(), maxlen, readSoFar);
#endif
    return readSoFar;
}