CFileGZOutputStream.cpp

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/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          https://www.mrpt.org/                         |
   |                                                                        |
   | Copyright (c) 2005-2020, Individual contributors, see AUTHORS file     |
   | See: https://www.mrpt.org/Authors - All rights reserved.               |
   | Released under BSD License. See: https://www.mrpt.org/License          |
   +------------------------------------------------------------------------+ */

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

#include <mrpt/core/exceptions.h>
#include <mrpt/io/CFileGZOutputStream.h>
#include <cerrno>
#include <cstring>  // strerror

#include <zlib.h>

using namespace mrpt::io;
using namespace std;

struct CFileGZOutputStream::Impl
{
    gzFile f{nullptr};
};

CFileGZOutputStream::CFileGZOutputStream()
    : m_f(mrpt::make_impl<CFileGZOutputStream::Impl>())
{
}

CFileGZOutputStream::CFileGZOutputStream(const string& fileName)
    : CFileGZOutputStream()
{
    MRPT_START
    std::string err_msg;
    if (!open(fileName, 1, err_msg))
        THROW_EXCEPTION(mrpt::format(
            "Error trying to open file: '%s', error: '%s'", fileName.c_str(),
            err_msg.c_str()));
    MRPT_END
}

bool CFileGZOutputStream::open(
    const string& fileName, int compress_level,
    mrpt::optional_ref<std::string> error_msg)
{
    MRPT_START

    if (m_f->f) gzclose(m_f->f);

    // Open gz stream:
    m_f->f = gzopen(fileName.c_str(), format("wb%i", compress_level).c_str());
    if (m_f->f == nullptr && error_msg)
        error_msg.value().get() = std::string(strerror(errno));
    return m_f->f != nullptr;

    MRPT_END
}

CFileGZOutputStream::~CFileGZOutputStream() { close(); }
void CFileGZOutputStream::close()
{
    if (m_f->f)
    {
        gzclose(m_f->f);
        m_f->f = nullptr;
    }
}

size_t CFileGZOutputStream::Read(void*, size_t)
{
    THROW_EXCEPTION("Trying to read from an output file stream.");
}

size_t CFileGZOutputStream::Write(const void* Buffer, size_t Count)
{
    if (!m_f->f)
    {
        THROW_EXCEPTION("File is not open.");
    }
    return gzwrite(m_f->f, const_cast<void*>(Buffer), Count);
}

uint64_t CFileGZOutputStream::getPosition() const
{
    if (!m_f->f)
    {
        THROW_EXCEPTION("File is not open.");
    }
    return gztell(m_f->f);
}

bool CFileGZOutputStream::fileOpenCorrectly() const
{
    return m_f->f != nullptr;
}
uint64_t CFileGZOutputStream::Seek(int64_t, CStream::TSeekOrigin)
{
    THROW_EXCEPTION("Method not available in this class.");
}

uint64_t CFileGZOutputStream::getTotalBytesCount() const
{
    THROW_EXCEPTION("Method not available in this class.");
}