rawBinary.hpp

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/** \file rawBinary.hpp
  * \author Jared R. Males (jaredmales@gmail.com)
  * \brief Provides functions for working with raw binary files.
  * \ingroup utils_files
  *
  */
 
//***********************************************************************//
// Copyright 2018 Jared R. Males (jaredmales@gmail.com)
//
// This file is part of mxlib.
//
// mxlib is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// mxlib is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with mxlib.  If not, see <http://www.gnu.org/licenses/>.
//***********************************************************************//
 
#ifndef rawBinary_hpp
#define rawBinary_hpp
 
#include <cstdio>
#include <string>
 
#include "../mxlib.hpp"
#include "../mxException.hpp"
 
namespace mx
{
namespace ioutils
{
 
/// Read an array of data from a file as raw binary.
/** Here raw binary means no formatting or metadata.
  *
  * \ingroup ioutils
  *
  * \returns 0 on success
  * \returns -1 on error
  */
template<typename T>
int readRawBinary( T * data,                    ///< [out] the data pointer
                   size_t szData,               ///< [in] number of elements of sizeof(T) to read
                   const std::string & fileName ///< [in] the file to read from
                 )
{
   FILE * fout;
 
   fout = fopen(fileName.c_str(), "rb");
   if(fout == 0)
   {
      mxThrowExceptionErrno(mx::err::fileoerr, errno, "readRawBinary", "Error from fopen [" + fileName + "]");
   }
 
   int nrd = fread( data, sizeof(T), szData, fout);
 
   if(nrd != szData)
   {
      int en = errno; //get this before fclose
      fclose(fout);
      //Have to handle case where EOF reached but no error.
      if(en != 0)
      {
         mxThrowExceptionErrno(mx::err::filererr, en, "readRawBinary", "Error from file [" + fileName + "]");
      }
      else
      {
         mxThrowException(mx::err::filererr,"readRawBinary", "Error reading from file, did not read all elements. [" + fileName+ "]");
      }
   }
 
   int res = fclose(fout);
 
   if(res != 0)
   {
      mxThrowExceptionErrno(mx::err::filecerr, errno, "readRawBinary", "Error closing file [" + fileName+ "]");
   }
 
   return 0;
}
 
/// Write an array of data to file as raw binary.
/** Here raw binary means no formatting or metadata,
  * just the bytes pointed to by the array are written to
  * disk.
  *
  * \ingroup ioutils
  *
  * \returns 0 on success
  * \returns -1 on error
  */
template<typename T>
int writeRawBinary( const std::string & fileName, ///< [in] the file to write to
                    T * data,                     ///< [in] the data pointer
                    size_t szData)                ///< [in] number of elements of sizeof(T) to write
{
   FILE * fout;
 
   fout = fopen(fileName.c_str(), "wb");
   if(fout == 0)
   {
      mxThrowExceptionErrno(mx::err::fileoerr, errno, "writeRawBinary", "Error from fopen [" + fileName + "]");
   }
 
 
   int nwr = fwrite( data, sizeof(T), szData, fout);
 
   if(nwr != szData)
   {
      int en = errno; //save before close call
      fclose(fout);
      
      //Have to handle case where EOF reached but no error.
      if(en != 0)
      {
         mxThrowExceptionErrno(mx::err::filewerr, en, "writeRawBinary", "Error writing to file [" + fileName + "]");
      }
      else
      {
         mxThrowException(mx::err::filewerr, "writeRawBinary", "Error writing to file, did not write all elements. [" + fileName+ "]");
      }
      
   }
 
   int res = fclose(fout);
 
   if(res != 0)
   {
      mxThrowExceptionErrno(mx::err::filecerr, errno, "writeRawBinary", "Error closing file [" + fileName+ "]");
   }
 
   return 0;
}
 
} //namespace ioutils
} //namespace mx
 
#endif //rawBinary_hpp