CFileGZOutputStream.cpp

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/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          http://www.mrpt.org/                          |
   |                                                                        |
   | Copyright (c) 2005-2017, Individual contributors, see AUTHORS file     |
   | See: http://www.mrpt.org/Authors - All rights reserved.                |
   | Released under BSD License. See details in http://www.mrpt.org/License |
   +------------------------------------------------------------------------+ */

#include "base-precomp.h"  // Precompiled headers

#ifdef _MSC_VER
#define _SCL_SECURE_NO_WARNINGS
#endif

#include <mrpt/utils/CFileGZOutputStream.h>
#include <mrpt/system/os.h>

#if MRPT_HAS_GZ_STREAMS

#include <zlib.h>

#define THE_GZFILE reinterpret_cast<gzFile>(m_f)

using namespace mrpt::utils;
using namespace std;

/*---------------------------------------------------------------
                                                        Constructor
 ---------------------------------------------------------------*/
CFileGZOutputStream::CFileGZOutputStream(const string& fileName) : m_f(nullptr)
{
        MRPT_START
        if (!open(fileName))
                THROW_EXCEPTION_FMT(
                        "Error trying to open file: '%s'", fileName.c_str());
        MRPT_END
}

/*---------------------------------------------------------------
                                Constructor
 ---------------------------------------------------------------*/
CFileGZOutputStream::CFileGZOutputStream() : m_f(nullptr) {}
/*---------------------------------------------------------------
                                                        open
 ---------------------------------------------------------------*/
bool CFileGZOutputStream::open(const string& fileName, int compress_level)
{
        MRPT_START

        if (m_f) gzclose(THE_GZFILE);

        // Open gz stream:
        m_f = gzopen(fileName.c_str(), format("wb%i", compress_level).c_str());
        return m_f != nullptr;

        MRPT_END
}

/*---------------------------------------------------------------
                                                        Destructor
 ---------------------------------------------------------------*/
CFileGZOutputStream::~CFileGZOutputStream() { close(); }
/*---------------------------------------------------------------
                                                        close
 ---------------------------------------------------------------*/
void CFileGZOutputStream::close()
{
        if (m_f)
        {
                gzclose(THE_GZFILE);
                m_f = nullptr;
        }
}

/*---------------------------------------------------------------
                                                        Read
                        Reads bytes from the stream into Buffer
 ---------------------------------------------------------------*/
size_t CFileGZOutputStream::Read(void* Buffer, size_t Count)
{
        MRPT_UNUSED_PARAM(Buffer);
        MRPT_UNUSED_PARAM(Count);
        THROW_EXCEPTION("Trying to read from an output file stream.");
}

/*---------------------------------------------------------------
                                                        Write
                        Writes a block of bytes to the stream.
 ---------------------------------------------------------------*/
size_t CFileGZOutputStream::Write(const void* Buffer, size_t Count)
{
        if (!m_f)
        {
                THROW_EXCEPTION("File is not open.");
        }
        return gzwrite(THE_GZFILE, const_cast<void*>(Buffer), Count);
}

/*---------------------------------------------------------------
                                                getPosition
 ---------------------------------------------------------------*/
uint64_t CFileGZOutputStream::getPosition()
{
        if (!m_f)
        {
                THROW_EXCEPTION("File is not open.");
        }
        return gztell(THE_GZFILE);
}

/*---------------------------------------------------------------
                                                fileOpenCorrectly
 ---------------------------------------------------------------*/
bool CFileGZOutputStream::fileOpenCorrectly() { return m_f != nullptr; }
#endif  // MRPT_HAS_GZ_STREAMS