/* This file is part of the KDE libraries

   SPDX-FileCopyrightText: 2001, 2002, 2007 David Faure <faure@kde.org>

   SPDX-License-Identifier: LGPL-2.0-or-later

*/

#include "klimitediodevice_p.h"

#include "loggingcategory.h"

#ifdef TEST_MODE

#define WARNING qWarning()

#else

#define WARNING qCWarning(KArchiveLog)

#endif

KLimitedIODevice::KLimitedIODevice(QIODevice *dev, qint64 start, qint64 length)

    : m_dev(dev)

    , m_start(start)

    , m_length(length)

{

    // qCDebug(KArchiveLog) << "start=" << start << "length=" << length;

    const bool res = open(QIODevice::ReadOnly); // krazy:exclude=syscalls

    // KLimitedIODevice always returns true

    Q_ASSERT(res);

    if(!res) {

        WARNING << "failed to open LimitedIO device for reading.";

    }

}

bool KLimitedIODevice::open(QIODevice::OpenMode m)

{

    // qCDebug(KArchiveLog) << "m=" << m;

    if (m & QIODevice::ReadOnly) {

        /*bool ok = false;

          if ( m_dev->isOpen() )

          ok = ( m_dev->mode() == QIODevice::ReadOnly );

          else

          ok = m_dev->open( m );

          if ( ok )*/

        m_dev->seek(m_start); // No concurrent access !

    } else {

        WARNING << "KLimitedIODevice::open only supports QIODevice::ReadOnly!";

    }

    setOpenMode(QIODevice::ReadOnly);

    return true;

}

void KLimitedIODevice::close()

{

}

qint64 KLimitedIODevice::size() const

{

    return m_length;

}

qint64 KLimitedIODevice::readData(char *data, qint64 maxlen)

{

    maxlen = qMin(maxlen, m_length - pos()); // Apply upper limit

    return m_dev->read(data, maxlen);

}

bool KLimitedIODevice::seek(qint64 pos)

{

    Q_ASSERT(pos <= m_length);

    pos = qMin(pos, m_length); // Apply upper limit

    bool ret = m_dev->seek(m_start + pos);

    if (ret) {

        QIODevice::seek(pos);

    }

    return ret;

}

qint64 KLimitedIODevice::bytesAvailable() const

{

    return QIODevice::bytesAvailable();

}

bool KLimitedIODevice::isSequential() const

{

    return m_dev->isSequential();

}

#include "moc_klimitediodevice_p.cpp"