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/* vim:set ts=3 sw=3 sts=3 et: */
#ifndef MOOST_IO_FILE_OPERATIONS_HPP__
#define MOOST_IO_FILE_OPERATIONS_HPP__

#include <errno.h>
#include <stdexcept>
#include <string>
#include <cstring>
#include <boost/cstdint.hpp>

#if defined(__GNUC__)
#include <unistd.h>
#elif defined(_MSC_VER)
#include <io.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <stdio.h>
#include <share.h>
#endif

namespace moost { namespace io {

class file_operations
{
private:

  static std::string get_error_string(int err)
  {
    char buf[512];
#if defined(__GNUC__)
    strerror_r(err, buf, sizeof(buf));
#elif defined(_MSC_VER)
    strerror_s(buf, sizeof(buf), err);
#endif
    return std::string(buf);
  }

public:

  static void change_size(const std::string & path, boost::int64_t length)
  {
#if defined(__GNUC__)
    if (truncate(path.c_str(), length) != 0)
      throw std::runtime_error("could not change size: " + get_error_string(errno));
#elif defined(_MSC_VER)
    int fh;

    if( _sopen_s( &fh, path.c_str(), _O_RDWR, _SH_DENYNO, _S_IREAD | _S_IWRITE ) == 0 )
    {
      int result = _chsize_s( fh, length );
      if (result != 0)
      {
        _close( fh );
        throw std::runtime_error( std::string("could not change size: ") + get_error_string(errno) );
      }
      _close( fh );
    }
    else
      throw std::runtime_error("could not open file: " + get_error_string(errno));
#endif
  }
};

}} // moost::io

#endif // MOOST_IO_FILE_OPERATIONS_HPP__