qbuffer.cpp

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#include "qbuffer.h"
#include "private/qiodevice_p.h"

QT_BEGIN_NAMESPACE

class QBufferPrivate : public QIODevicePrivate
{
    Q_DECLARE_PUBLIC(QBuffer)

public:
    QBufferPrivate()
    : buf(0)
#ifndef QT_NO_QOBJECT
        , writtenSinceLastEmit(0), signalConnectionCount(0), signalsEmitted(false)
#endif
    { }
    ~QBufferPrivate() { }

    QByteArray *buf;
    QByteArray defaultBuf;
    int ioIndex;

    virtual qint64 peek(char *data, qint64 maxSize);
    virtual QByteArray peek(qint64 maxSize);

#ifndef QT_NO_QOBJECT
    // private slots
    void _q_emitSignals();

    qint64 writtenSinceLastEmit;
    int signalConnectionCount;
    bool signalsEmitted;
#endif
};

#ifndef QT_NO_QOBJECT
void QBufferPrivate::_q_emitSignals()
{
    Q_Q(QBuffer);
    emit q->bytesWritten(writtenSinceLastEmit);
    writtenSinceLastEmit = 0;
    emit q->readyRead();
    signalsEmitted = false;
}
#endif

qint64 QBufferPrivate::peek(char *data, qint64 maxSize)
{
    qint64 readBytes = qMin(maxSize, static_cast<qint64>(buf->size()) - pos);
    memcpy(data, buf->constData() + pos, readBytes);
    return readBytes;
}

QByteArray QBufferPrivate::peek(qint64 maxSize)
{
    qint64 readBytes = qMin(maxSize, static_cast<qint64>(buf->size()) - pos);
    if (pos == 0 && maxSize >= buf->size())
        return *buf;
    return QByteArray(buf->constData() + pos, readBytes);
}

#ifdef QT_NO_QOBJECT
QBuffer::QBuffer()
    : QIODevice(*new QBufferPrivate)
{
    Q_D(QBuffer);
    d->buf = &d->defaultBuf;
    d->ioIndex = 0;
}
QBuffer::QBuffer(QByteArray *buf)
    : QIODevice(*new QBufferPrivate)
{
    Q_D(QBuffer);
    d->buf = buf ? buf : &d->defaultBuf;
    d->ioIndex = 0;
    d->defaultBuf.clear();
}
#else

QBuffer::QBuffer(QObject *parent)
    : QIODevice(*new QBufferPrivate, parent)
{
    Q_D(QBuffer);
    d->buf = &d->defaultBuf;
    d->ioIndex = 0;
}

QBuffer::QBuffer(QByteArray *byteArray, QObject *parent)
    : QIODevice(*new QBufferPrivate, parent)
{
    Q_D(QBuffer);
    d->buf = byteArray ? byteArray : &d->defaultBuf;
    d->defaultBuf.clear();
    d->ioIndex = 0;
}
#endif

QBuffer::~QBuffer()
{
}

void QBuffer::setBuffer(QByteArray *byteArray)
{
    Q_D(QBuffer);
    if (isOpen()) {
        qWarning("QBuffer::setBuffer: Buffer is open");
        return;
    }
    if (byteArray) {
        d->buf = byteArray;
    } else {
        d->buf = &d->defaultBuf;
    }
    d->defaultBuf.clear();
    d->ioIndex = 0;
}

QByteArray &QBuffer::buffer()
{
    Q_D(QBuffer);
    return *d->buf;
}

const QByteArray &QBuffer::buffer() const
{
    Q_D(const QBuffer);
    return *d->buf;
}


const QByteArray &QBuffer::data() const
{
    Q_D(const QBuffer);
    return *d->buf;
}

void QBuffer::setData(const QByteArray &data)
{
    Q_D(QBuffer);
    if (isOpen()) {
        qWarning("QBuffer::setData: Buffer is open");
        return;
    }
    *d->buf = data;
    d->ioIndex = 0;
}

bool QBuffer::open(OpenMode flags)
{
    Q_D(QBuffer);

    if ((flags & (Append | Truncate)) != 0)
        flags |= WriteOnly;
    if ((flags & (ReadOnly | WriteOnly)) == 0) {
        qWarning("QBuffer::open: Buffer access not specified");
        return false;
    }

    if ((flags & Truncate) == Truncate)
        d->buf->resize(0);
    d->ioIndex = (flags & Append) == Append ? d->buf->size() : 0;

    return QIODevice::open(flags);
}

void QBuffer::close()
{
    QIODevice::close();
}

qint64 QBuffer::pos() const
{
    return QIODevice::pos();
}

qint64 QBuffer::size() const
{
    Q_D(const QBuffer);
    return qint64(d->buf->size());
}

bool QBuffer::seek(qint64 pos)
{
    Q_D(QBuffer);
    if (pos > d->buf->size() && isWritable()) {
        if (seek(d->buf->size())) {
            const qint64 gapSize = pos - d->buf->size();
            if (write(QByteArray(gapSize, 0)) != gapSize) {
                qWarning("QBuffer::seek: Unable to fill gap");
                return false;
            }
        } else {
            return false;
        }
    } else if (pos > d->buf->size() || pos < 0) {
        qWarning("QBuffer::seek: Invalid pos: %d", int(pos));
        return false;
    }
    d->ioIndex = int(pos);
    return QIODevice::seek(pos);
}

bool QBuffer::atEnd() const
{
    return QIODevice::atEnd();
}

bool QBuffer::canReadLine() const
{
    Q_D(const QBuffer);
    if (!isOpen())
        return false;

    return d->buf->indexOf('\n', int(pos())) != -1 || QIODevice::canReadLine();
}

qint64 QBuffer::readData(char *data, qint64 len)
{
    Q_D(QBuffer);
    if ((len = qMin(len, qint64(d->buf->size()) - d->ioIndex)) <= 0)
        return qint64(0);
    memcpy(data, d->buf->constData() + d->ioIndex, len);
    d->ioIndex += int(len);
    return len;
}

qint64 QBuffer::writeData(const char *data, qint64 len)
{
    Q_D(QBuffer);
    int extraBytes = d->ioIndex + len - d->buf->size();
    if (extraBytes > 0) { // overflow
        int newSize = d->buf->size() + extraBytes;
        d->buf->resize(newSize);
        if (d->buf->size() != newSize) { // could not resize
            qWarning("QBuffer::writeData: Memory allocation error");
            return -1;
        }
    }

    memcpy(d->buf->data() + d->ioIndex, (uchar *)data, int(len));
    d->ioIndex += int(len);

#ifndef QT_NO_QOBJECT
    d->writtenSinceLastEmit += len;
    if (d->signalConnectionCount && !d->signalsEmitted && !signalsBlocked()) {
        d->signalsEmitted = true;
        QMetaObject::invokeMethod(this, "_q_emitSignals", Qt::QueuedConnection);
    }
#endif
    return len;
}

#ifndef QT_NO_QOBJECT

void QBuffer::connectNotify(const char *signal)
{
    if (strcmp(signal + 1, "readyRead()") == 0 || strcmp(signal + 1, "bytesWritten(qint64)") == 0)
        d_func()->signalConnectionCount++;
}

void QBuffer::disconnectNotify(const char *signal)
{
    if (!signal || strcmp(signal + 1, "readyRead()") == 0 || strcmp(signal + 1, "bytesWritten(qint64)") == 0)
        d_func()->signalConnectionCount--;
}
#endif

QT_END_NAMESPACE

#ifndef QT_NO_QOBJECT
# include "moc_qbuffer.cpp"
#endif