sli_fdstream.cpp

/*
 *  fdstream.cc
 *
 *  This file is part of NEST.
 *
 *  Copyright (C) 2004 The NEST Initiative
 *
 *  NEST 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 2 of the License, or
 *  (at your option) any later version.
 *
 *  NEST 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 NEST.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

#include "sli_config.h"
#include "sli_fdstream.h"

std::streamsize const fdbuf::s_bufsiz;

fdbuf* fdbuf::open(const char* s, std::ios_base::openmode mode)
{
  if (is_open())
    {
      return 0;
    }

  
  int oflag;
  std::ios_base::openmode open_mode = 
    (mode&~std::ios_base::ate&~std::ios_base::binary);
  
  // the corresponding O_*-flags are as described in Josuttis Chap. 13 (p.632)
  if      (open_mode == std::ios_base::out) // corresponds to "w"
    oflag = (O_WRONLY | O_TRUNC | O_CREAT);
  else if (open_mode == (std::ios_base::out|std::ios_base::app))// corresponds to "a"
    oflag = (O_WRONLY | O_APPEND| O_CREAT);
  else if (open_mode == (std::ios_base::out|std::ios_base::trunc))// corresponds to "w"
    oflag = (O_WRONLY | O_TRUNC | O_CREAT);
  else if (open_mode == std::ios_base::in)// corresponds to "r"
    oflag = O_RDONLY;
  else if (open_mode == (std::ios_base::in|std::ios_base::out))// corresponds to "r+"
    oflag = O_RDWR;
  else if (open_mode == (std::ios_base::in|std::ios_base::out|std::ios_base::trunc))// corresponds to "w+"
    oflag = (O_RDWR | O_TRUNC | O_CREAT);
  else
    {
      return 0;
    }
  
  m_fd=::open(s, oflag, S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH); // these file permissions are required by POSIX.1 (see Stevens 5.5)

  if (m_fd==-1) 
    {
      // std::cerr<<"::open failed!"<<std::endl;
      // perror(0);
      return 0;
    }
  
  // beware of operator precedence --- HEP
  if ( ( mode & std::ios_base::ate ) != 0)
    {
      if (lseek(m_fd, 0, SEEK_END) == -1)
	{
	  close();
	  // std::cerr<<"seek failed!"<<std::endl;
	  // perror(0);
	  return 0;
	}
    };
  
  m_isopen=true;
  return this;
}

fdbuf* fdbuf::close()
{
  if (!is_open())
    {
      // std::cerr<<"File was not open."<<std::endl;
      return 0;
    }
  
  bool success=true;
  
  if (overflow(traits_type::eof()) == traits_type::eof())
    {
      // std::cerr<<"overflow failed!"<<std::endl;
      success=false;
    }
  if (::close(m_fd)==-1)
    {
      // std::cerr<<"::close failed: "<<std::endl;perror(0);
      success=false;
    }
  
  m_isopen=false;
  
  return (success ? this : 0);
}

void ofdstream::close()
{
  if (rdbuf()->close() == 0) 
    {
      setstate(failbit);
    }
}


void ifdstream::close()
{
  if (rdbuf()->close() == 0) 
    {
      setstate(failbit);
    }
}

void fdstream::close()
{
  if (rdbuf()->close() == 0) 
    {
      setstate(failbit);
    }
}