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// File descriptor layer for filebuf -*- C++ -*-

// Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.

//

// This file is part of the GNU ISO C++ Library.  This library 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, or (at your option)

// any later version.

// This library 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 this library; see the file COPYING.  If not, write to the Free

// Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,

// USA.

// As a special exception, you may use this file as part of a free software

// library without restriction.  Specifically, if other files instantiate

// templates or use macros or inline functions from this file, or you compile

// this file and link it with other files to produce an executable, this

// file does not by itself cause the resulting executable to be covered by

// the GNU General Public License.  This exception does not however

// invalidate any other reasons why the executable file might be covered by

// the GNU General Public License.

/** @file ext/stdio_filebuf.h

 *  This file is a GNU extension to the Standard C++ Library.

 */

#ifndef _STDIO_FILEBUF_H

#define _STDIO_FILEBUF_H 1

#pragma GCC system_header

#include <fstream>

namespace __gnu_cxx

{

  /**

   *  @brief Provides a layer of compatibility for C/POSIX.

   *

   *  This GNU extension provides extensions for working with standard C

   *  FILE*'s and POSIX file descriptors.  It must be instantiated by the

   *  user with the type of character used in the file stream, e.g.,

   *  stdio_filebuf<char>.

  */

  template<typename _CharT, typename _Traits = std::char_traits<_CharT> >

    class stdio_filebuf : public std::basic_filebuf<_CharT, _Traits>

    {

    public:

      // Types:

      typedef _CharT                                    char_type;

      typedef _Traits                                   traits_type;

      typedef typename traits_type::int_type            int_type;

      typedef typename traits_type::pos_type            pos_type;

      typedef typename traits_type::off_type            off_type;

      typedef std::size_t                               size_t;

    public:

      /**

       * deferred initialization

      */

      stdio_filebuf() : std::basic_filebuf<_CharT, _Traits>() {}

      /**

       *  @param  fd  An open file descriptor.

       *  @param  mode  Same meaning as in a standard filebuf.

       *  @param  size  Optimal or preferred size of internal buffer, in chars.

       *

       *  This constructor associates a file stream buffer with an open

       *  POSIX file descriptor. The file descriptor will be automatically

       *  closed when the stdio_filebuf is closed/destroyed.

      */

      stdio_filebuf(int __fd, std::ios_base::openmode __mode,

                    size_t __size = static_cast<size_t>(BUFSIZ));

      /**

       *  @param  f  An open @c FILE*.

       *  @param  mode  Same meaning as in a standard filebuf.

       *  @param  size  Optimal or preferred size of internal buffer, in chars.

       *                Defaults to system's @c BUFSIZ.

       *

       *  This constructor associates a file stream buffer with an open

       *  C @c FILE*.  The @c FILE* will not be automatically closed when the

       *  stdio_filebuf is closed/destroyed.

      */

      stdio_filebuf(std::__c_file* __f, std::ios_base::openmode __mode,

                    size_t __size = static_cast<size_t>(BUFSIZ));

      /**

       *  Closes the external data stream if the file descriptor constructor

       *  was used.

      */

      virtual

      ~stdio_filebuf();

      /**

       *  @return  The underlying file descriptor.

       *

       *  Once associated with an external data stream, this function can be

       *  used to access the underlying POSIX file descriptor.  Note that

       *  there is no way for the library to track what you do with the

       *  descriptor, so be careful.

      */

      int

      fd() { return this->_M_file.fd(); }

      /**

       *  @return  The underlying FILE*.

       *

       *  This function can be used to access the underlying "C" file pointer.

       *  Note that there is no way for the library to track what you do

       *  with the file, so be careful.

       */

      std::__c_file*

      file() { return this->_M_file.file(); }

    };

  template<typename _CharT, typename _Traits>

    stdio_filebuf<_CharT, _Traits>::~stdio_filebuf()

    { }

  template<typename _CharT, typename _Traits>

    stdio_filebuf<_CharT, _Traits>::

    stdio_filebuf(int __fd, std::ios_base::openmode __mode, size_t __size)

    {

      this->_M_file.sys_open(__fd, __mode);

      if (this->is_open())

        {

          this->_M_mode = __mode;

          this->_M_buf_size = __size;

          this->_M_allocate_internal_buffer();

          this->_M_reading = false;

          this->_M_writing = false;

          this->_M_set_buffer(-1);

        }

    }

  template<typename _CharT, typename _Traits>

    stdio_filebuf<_CharT, _Traits>::

    stdio_filebuf(std::__c_file* __f, std::ios_base::openmode __mode,

                  size_t __size)

    {

      this->_M_file.sys_open(__f, __mode);

      if (this->is_open())

        {

          this->_M_mode = __mode;

          this->_M_buf_size = __size;

          this->_M_allocate_internal_buffer();

          this->_M_reading = false;

          this->_M_writing = false;

          this->_M_set_buffer(-1);

        }

    }

} // namespace __gnu_cxx

#endif