11.2.0/ext/stdio_filebuf.h

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

// Copyright (C) 2002-2021 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 3, 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.

// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.

// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
// <http://www.gnu.org/licenses/>.

/** @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 _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION

  /**
   *  @brief Provides a layer of compatibility for C/POSIX.
   *  @ingroup io
   *
   *  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>(_GLIBCXX_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>(_GLIBCXX_BUFSIZ));

      /**
       *  Closes the external data stream if the file descriptor constructor
       *  was used.
      */
      virtual
      ~stdio_filebuf();

#if __cplusplus >= 201103L
      stdio_filebuf(stdio_filebuf&&) = default;
      stdio_filebuf& operator=(stdio_filebuf&&) = default;

      void
      swap(stdio_filebuf& __fb)
      { std::basic_filebuf<_CharT, _Traits>::swap(__fb); }
#endif

      /**
       *  @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);
        }
    }

_GLIBCXX_END_NAMESPACE_VERSION
} // namespace

#endif
Revision:	1166
Committed:	Tue Oct 26 14:22:36 2021 UTC (4 years ago) by rossy
Content type:	text/x-chdr
File size:	5688 byte(s)
Log Message:	Daodan: Replace MinGW build env with an up-to-date MSYS2 env
#	Content
1	// File descriptor layer for filebuf -- C++ --
2
3	// Copyright (C) 2002-2021 Free Software Foundation, Inc.
4	//
5	// This file is part of the GNU ISO C++ Library. This library is free
6	// software; you can redistribute it and/or modify it under the
7	// terms of the GNU General Public License as published by the
8	// Free Software Foundation; either version 3, or (at your option)
9	// any later version.
10
11	// This library is distributed in the hope that it will be useful,
12	// but WITHOUT ANY WARRANTY; without even the implied warranty of
13	// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14	// GNU General Public License for more details.
15
16	// Under Section 7 of GPL version 3, you are granted additional
17	// permissions described in the GCC Runtime Library Exception, version
18	// 3.1, as published by the Free Software Foundation.
19
20	// You should have received a copy of the GNU General Public License and
21	// a copy of the GCC Runtime Library Exception along with this program;
22	// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23	// <http://www.gnu.org/licenses/>.
24
25	/** @file ext/stdio_filebuf.h
26	* This file is a GNU extension to the Standard C++ Library.
27	*/
28
29	#ifndef _STDIO_FILEBUF_H
30	#define _STDIO_FILEBUF_H 1
31
32	#pragma GCC system_header
33
34	#include <fstream>
35
36	namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
37	{
38	_GLIBCXX_BEGIN_NAMESPACE_VERSION
39
40	/**
41	* @brief Provides a layer of compatibility for C/POSIX.
42	* @ingroup io
43	*
44	* This GNU extension provides extensions for working with standard C
45	* FILE*'s and POSIX file descriptors. It must be instantiated by the
46	* user with the type of character used in the file stream, e.g.,
47	* stdio_filebuf<char>.
48	*/
49	template<typename _CharT, typename _Traits = std::char_traits<_CharT> >
50	class stdio_filebuf : public std::basic_filebuf<_CharT, _Traits>
51	{
52	public:
53	// Types:
54	typedef _CharT char_type;
55	typedef _Traits traits_type;
56	typedef typename traits_type::int_type int_type;
57	typedef typename traits_type::pos_type pos_type;
58	typedef typename traits_type::off_type off_type;
59	typedef std::size_t size_t;
60
61	public:
62	/**
63	* deferred initialization
64	*/
65	stdio_filebuf() : std::basic_filebuf<_CharT, _Traits>() {}
66
67	/**
68	* @param __fd An open file descriptor.
69	* @param __mode Same meaning as in a standard filebuf.
70	* @param __size Optimal or preferred size of internal buffer,
71	* in chars.
72	*
73	* This constructor associates a file stream buffer with an open
74	* POSIX file descriptor. The file descriptor will be automatically
75	* closed when the stdio_filebuf is closed/destroyed.
76	*/
77	stdio_filebuf(int __fd, std::ios_base::openmode __mode,
78	size_t __size = static_cast<size_t>(_GLIBCXX_BUFSIZ));
79
80	/**
81	* @param __f An open @c FILE*.
82	* @param __mode Same meaning as in a standard filebuf.
83	* @param __size Optimal or preferred size of internal buffer,
84	* in chars. Defaults to system's @c BUFSIZ.
85	*
86	* This constructor associates a file stream buffer with an open
87	* C @c FILE. The @c FILE will not be automatically closed when the
88	* stdio_filebuf is closed/destroyed.
89	*/
90	stdio_filebuf(std::__c_file* __f, std::ios_base::openmode __mode,
91	size_t __size = static_cast<size_t>(_GLIBCXX_BUFSIZ));
92
93	/**
94	* Closes the external data stream if the file descriptor constructor
95	* was used.
96	*/
97	virtual
98	~stdio_filebuf();
99
100	#if __cplusplus >= 201103L
101	stdio_filebuf(stdio_filebuf&&) = default;
102	stdio_filebuf& operator=(stdio_filebuf&&) = default;
103
104	void
105	swap(stdio_filebuf& __fb)
106	{ std::basic_filebuf<_CharT, _Traits>::swap(__fb); }
107	#endif
108
109	/**
110	* @return The underlying file descriptor.
111	*
112	* Once associated with an external data stream, this function can be
113	* used to access the underlying POSIX file descriptor. Note that
114	* there is no way for the library to track what you do with the
115	* descriptor, so be careful.
116	*/
117	int
118	fd() { return this->_M_file.fd(); }
119
120	/**
121	* @return The underlying FILE*.
122	*
123	* This function can be used to access the underlying "C" file pointer.
124	* Note that there is no way for the library to track what you do
125	* with the file, so be careful.
126	*/
127	std::__c_file*
128	file() { return this->_M_file.file(); }
129	};
130
131	template<typename _CharT, typename _Traits>
132	stdio_filebuf<_CharT, _Traits>::~stdio_filebuf()
133	{ }
134
135	template<typename _CharT, typename _Traits>
136	stdio_filebuf<_CharT, _Traits>::
137	stdio_filebuf(int __fd, std::ios_base::openmode __mode, size_t __size)
138	{
139	this->_M_file.sys_open(__fd, __mode);
140	if (this->is_open())
141	{
142	this->_M_mode = __mode;
143	this->_M_buf_size = __size;
144	this->_M_allocate_internal_buffer();
145	this->_M_reading = false;
146	this->_M_writing = false;
147	this->_M_set_buffer(-1);
148	}
149	}
150
151	template<typename _CharT, typename _Traits>
152	stdio_filebuf<_CharT, _Traits>::
153	stdio_filebuf(std::__c_file* __f, std::ios_base::openmode __mode,
154	size_t __size)
155	{
156	this->_M_file.sys_open(__f, __mode);
157	if (this->is_open())
158	{
159	this->_M_mode = __mode;
160	this->_M_buf_size = __size;
161	this->_M_allocate_internal_buffer();
162	this->_M_reading = false;
163	this->_M_writing = false;
164	this->_M_set_buffer(-1);
165	}
166	}
167
168	_GLIBCXX_END_NAMESPACE_VERSION
169	} // namespace
170
171	#endif