CFileStream.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/io/CFileStream.h>
#include <iomanip>
#include <iostream>
#include <string>  // std::getline()

using namespace mrpt::io;
using namespace std;

static_assert(
    !std::is_copy_constructible_v<CFileStream> &&
        !std::is_copy_assignable_v<CFileStream>,
    "Copy Check");

/*---------------------------------------------------------------
                            Constructor
 ---------------------------------------------------------------*/
CFileStream::CFileStream() : m_f() {}
/*---------------------------------------------------------------
                            Constructor
 ---------------------------------------------------------------*/
CFileStream::CFileStream(const string& fileName, TFileOpenModes mode_) : m_f()
{
    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 std::runtime_error(
            std::string("CFileStream: Error creating/opening: ") + fileName);
}

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

/*---------------------------------------------------------------
                            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 std::runtime_error(
                "[CFileStream::Seek] Invalid value for 'Origin'");
    }

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

    return getPosition();
}

uint64_t CFileStream::getTotalBytesCount() const
{
    if (!fileOpenCorrectly()) return 0;

    auto& f = const_cast<std::fstream&>(m_f);

    const uint64_t previousPos = f.tellg();
    f.seekg(0, ios_base::end);
    uint64_t fileSize = f.tellg();
    f.seekg(previousPos, ios_base::beg);
    return fileSize;
}

uint64_t CFileStream::getPosition() const
{
    auto& f = const_cast<std::fstream&>(m_f);
    if (m_f.is_open())
        return 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() const { 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();
}

void CFileStream::clearError()
{
    if (m_f.is_open()) m_f.clear();
}