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// Copyright (C) 2016 Jochen Becher
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0 WITH Qt-GPL-exception-1.0
#include "qcompressedfile.h"
#include "qmt/infrastructure/qmtassert.h"
// TODO create real compressed files that can be read by some archiver (gzip)
namespace qmt {
QCompressedDevice::QCompressedDevice(QObject *parent)
: QIODevice(parent)
{
}
QCompressedDevice::QCompressedDevice(QIODevice *targetDevice, QObject *parent)
: QIODevice(parent),
m_targetDevice(targetDevice)
{
}
QCompressedDevice::~QCompressedDevice()
{
flush();
}
void QCompressedDevice::setTargetDevice(QIODevice *targetDevice)
{
m_targetDevice = targetDevice;
}
void QCompressedDevice::close()
{
flush();
QIODevice::close();
}
qint64 QCompressedDevice::readData(char *data, qint64 maxlen)
{
QMT_ASSERT(m_targetDevice, return 0);
QMT_ASSERT(m_targetDevice->isOpen(), return 0);
QMT_ASSERT(m_targetDevice->openMode() == QIODevice::ReadOnly, return 0);
if (m_bytesInBuffer == 0) {
QByteArray compressedBuffer;
int compressedLen = 0;
if (m_targetDevice->read(reinterpret_cast<char *>(&compressedLen), sizeof(int)) != sizeof(int))
return -1;
compressedBuffer.resize(compressedLen);
qint64 compressedBytes = m_targetDevice->read(compressedBuffer.data(), compressedLen);
m_buffer = qUncompress((const uchar *) compressedBuffer.data(), compressedBytes);
m_bytesInBuffer = m_buffer.size();
if (m_bytesInBuffer == 0)
return 0;
m_indexInBuffer = 0;
}
qint64 n = std::min(maxlen, m_bytesInBuffer);
memcpy(data, m_buffer.data() + m_indexInBuffer, n);
m_bytesInBuffer -= n;
m_indexInBuffer += n;
return n;
}
qint64 QCompressedDevice::writeData(const char *data, qint64 len)
{
QMT_ASSERT(m_targetDevice, return 0);
QMT_ASSERT(m_targetDevice->isOpen(), return 0);
QMT_ASSERT(m_targetDevice->openMode() == QIODevice::WriteOnly, return 0);
m_buffer.append(data, len);
if (m_buffer.size() > 1024*1024) {
QByteArray compressedBuffer = qCompress(m_buffer);
int compressedLen = static_cast<int>(compressedBuffer.size());
if (m_targetDevice->write(reinterpret_cast<const char *>(&compressedLen), sizeof(int)) != sizeof(int))
return -1;
if (m_targetDevice->write(compressedBuffer.data(), compressedLen) != compressedBuffer.size())
return -1;
m_buffer.clear();
}
return len;
}
qint64 QCompressedDevice::flush()
{
if (openMode() == QIODevice::WriteOnly && !m_buffer.isEmpty()) {
QMT_ASSERT(m_targetDevice->isOpen(), return 0);
QMT_ASSERT(m_targetDevice->openMode() == QIODevice::WriteOnly, return 0);
QByteArray compressedBuffer = qCompress(m_buffer);
int compressedLen = static_cast<int>(compressedBuffer.size());
if (m_targetDevice->write(reinterpret_cast<const char *>(&compressedLen), sizeof(int)) != sizeof(int))
return -1;
return m_targetDevice->write(compressedBuffer.data(), compressedLen);
}
return 0;
}
} // namespace qmt
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