CFileStream.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/CFileStream.h>
#include <mrpt/system/os.h>

using namespace mrpt::utils;
using namespace std;

/*---------------------------------------------------------------
                                                        Constructor
 ---------------------------------------------------------------*/
CFileStream::CFileStream() : m_f()
{
}

/*---------------------------------------------------------------
                                                        Constructor
 ---------------------------------------------------------------*/
CFileStream::CFileStream( const string &fileName, TFileOpenModes mode_ ) : m_f()
{
        MRPT_START

        std::ios_base::openmode mode = std::ios_base::in;
        if (mode_==fomRead) mode = std::ios_base::in;
        else if (mode_==fomWrite) mode  = std::ios_base::out | std::ios_base::trunc;
        else if (mode_==fomAppend) mode = std::ios_base::app | std::ios_base::out;
        else if (mode_==(fomRead|fomWrite))   mode = std::ios_base::in | std::ios_base::out | std::ios_base::trunc;
        else if (mode_==(fomAppend|fomWrite)) mode = std::ios_base::in | std::ios_base::out | std::ios_base::app;

        // Try to open the file:
        m_f.open(fileName.c_str(), mode);
        if (!m_f.is_open())
                THROW_EXCEPTION_FMT( "Error creating/opening: '%s'",fileName.c_str() );
        MRPT_END
}

/*---------------------------------------------------------------
                                                        open
 ---------------------------------------------------------------*/
bool CFileStream::open(const std::string &fileName, TFileOpenModes mode_)
{
        MRPT_START

        std::ios_base::openmode mode = std::ios_base::in;
        if (mode_==fomRead) mode = std::ios_base::in;
        else if (mode_==fomWrite) mode  = std::ios_base::out | std::ios_base::trunc;
        else if (mode_==fomAppend) mode = std::ios_base::app | std::ios_base::out;
        else if (mode_==(fomRead|fomWrite))   mode = std::ios_base::in | std::ios_base::out | std::ios_base::trunc;
        else if (mode_==(fomAppend|fomWrite)) mode = std::ios_base::in | std::ios_base::out | std::ios_base::app;

        if (m_f.is_open())
                m_f.close();

        m_f.open(fileName.c_str(), ios_base::binary | mode );
        return m_f.is_open();

        MRPT_END
}

/*---------------------------------------------------------------
                                                        close
 ---------------------------------------------------------------*/
void CFileStream::close()
{
        m_f.close();
}

/*---------------------------------------------------------------
                                                        Destructor
 ---------------------------------------------------------------*/
CFileStream::~CFileStream()
{
        m_f.close();
}


/*---------------------------------------------------------------
                                                        Read
                        Reads bytes from the stream into Buffer
 ---------------------------------------------------------------*/
size_t  CFileStream::Read(void *Buffer, size_t Count)
{
        if (! m_f.is_open()) return 0;
        m_f.read(static_cast<char*>(Buffer),Count);
        return m_f.fail() ? 0:Count;
}

/*---------------------------------------------------------------
                                                        Write
                        Writes a block of bytes to the stream.
 ---------------------------------------------------------------*/
size_t  CFileStream::Write(const void *Buffer, size_t Count)
{
        if (!m_f.is_open()) return 0;

        m_f.write( static_cast<const char*>(Buffer),Count);
        return m_f.fail() ? 0:Count;
}

/*---------------------------------------------------------------
                                                        Seek
        Method for moving to a specified position in the streamed resource.
         See documentation of CStream::Seek
 ---------------------------------------------------------------*/
uint64_t CFileStream::Seek(int64_t Offset, CStream::TSeekOrigin Origin)
{
        if (!m_f.is_open()) return 0;

        fstream::off_type  offset = Offset;
        fstream::seekdir   way;

        switch(Origin)
        {
        case sFromBeginning: way = ios_base::beg; break;
        case sFromCurrent: way = ios_base::cur; break;
        case sFromEnd: way = ios_base::end; break;
        default: THROW_EXCEPTION("Invalid value for 'Origin'");
        }

        m_f.seekp(offset, way);
        m_f.seekg(offset, way);

        return getPosition();
}

/*---------------------------------------------------------------
                                                getTotalBytesCount
 ---------------------------------------------------------------*/
uint64_t CFileStream::getTotalBytesCount()
{
        if (!fileOpenCorrectly()) return 0;

        uint64_t previousPos = getPosition();
        uint64_t fileSize = Seek(0,sFromEnd);
        Seek(previousPos);
        return fileSize;
}

/*---------------------------------------------------------------
                                                getPosition
 ---------------------------------------------------------------*/
uint64_t CFileStream::getPosition()
{
        if (m_f.is_open())
                        return m_f.tellg();
        else    return 0;
}

/*---------------------------------------------------------------
                                                getPositionI
 ---------------------------------------------------------------*/
uint64_t CFileStream::getPositionI()
{
        if (m_f.is_open())
                        return m_f.tellg();
        else    return 0;
}

/*---------------------------------------------------------------
                                                getPositionO
 ---------------------------------------------------------------*/
uint64_t CFileStream::getPositionO()
{
        if (m_f.is_open())
                        return m_f.tellp();
        else    return 0;
}

/*---------------------------------------------------------------
                                                fileOpenCorrectly
 ---------------------------------------------------------------*/
bool  CFileStream::fileOpenCorrectly()
{
        return m_f.is_open();
}

/*---------------------------------------------------------------
                                                readLine
 ---------------------------------------------------------------*/
bool CFileStream::readLine( string &str )
{
        str = string(); // clear() is not defined in VC6
        if (!m_f.is_open()) return false;

        std::getline( m_f, str );
        return !m_f.fail() && !m_f.eof();
}


/*---------------------------------------------------------------
                                                checkEOF
 ---------------------------------------------------------------*/
bool CFileStream::checkEOF()
{
        if (!m_f.is_open())
                        return true;
        return  m_f.eof();
}