1 // File based streams -*- C++ -*-
3 // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002
4 // Free Software Foundation, Inc.
6 // This file is part of the GNU ISO C++ Library. This library is free
7 // software; you can redistribute it and/or modify it under the
8 // terms of the GNU General Public License as published by the
9 // Free Software Foundation; either version 2, or (at your option)
12 // This library is distributed in the hope that it will be useful,
13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 // GNU General Public License for more details.
17 // You should have received a copy of the GNU General Public License along
18 // with this library; see the file COPYING. If not, write to the Free
19 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
22 // As a special exception, you may use this file as part of a free software
23 // library without restriction. Specifically, if other files instantiate
24 // templates or use macros or inline functions from this file, or you compile
25 // this file and link it with other files to produce an executable, this
26 // file does not by itself cause the resulting executable to be covered by
27 // the GNU General Public License. This exception does not however
28 // invalidate any other reasons why the executable file might be covered by
29 // the GNU General Public License.
32 // ISO C++ 14882: 27.8 File-based streams
35 #ifndef _CPP_BITS_FSTREAM_TCC
36 #define _CPP_BITS_FSTREAM_TCC 1
38 #pragma GCC system_header
42 template<typename _CharT, typename _Traits>
44 basic_filebuf<_CharT, _Traits>::
45 _M_allocate_internal_buffer()
47 if (!_M_buf && _M_buf_size_opt)
49 _M_buf_size = _M_buf_size_opt;
51 // Allocate internal buffer.
52 _M_buf = new char_type[_M_buf_size];
53 _M_buf_allocated = true;
57 // Both close and setbuf need to deallocate internal buffers, if it exists.
58 template<typename _CharT, typename _Traits>
60 basic_filebuf<_CharT, _Traits>::
61 _M_destroy_internal_buffer()
67 _M_buf_allocated = false;
68 this->setg(NULL, NULL, NULL);
69 this->setp(NULL, NULL);
73 template<typename _CharT, typename _Traits>
74 basic_filebuf<_CharT, _Traits>::
75 basic_filebuf() : __streambuf_type(), _M_file(&_M_lock),
76 _M_state_cur(__state_type()), _M_state_beg(__state_type()),
77 _M_buf_allocated(false), _M_last_overflowed(false)
78 { _M_buf_unified = true; }
80 template<typename _CharT, typename _Traits>
81 typename basic_filebuf<_CharT, _Traits>::__filebuf_type*
82 basic_filebuf<_CharT, _Traits>::
83 open(const char* __s, ios_base::openmode __mode)
85 __filebuf_type *__ret = NULL;
88 _M_file.open(__s, __mode);
91 _M_allocate_internal_buffer();
94 // Setup initial position of buffer.
95 _M_set_indeterminate();
97 // Set input buffer to something real.
98 // NB: Must open in non-blocking way to do this, or must
99 // set the initial position in a different manner than
101 if (__mode & ios_base::in && _M_buf_allocated)
104 if ((__mode & ios_base::ate)
105 && this->seekoff(0, ios_base::end, __mode) < 0)
114 template<typename _CharT, typename _Traits>
115 typename basic_filebuf<_CharT, _Traits>::__filebuf_type*
116 basic_filebuf<_CharT, _Traits>::
119 __filebuf_type *__ret = NULL;
122 const int_type __eof = traits_type::eof();
123 bool __testput = _M_out_cur && _M_out_beg < _M_out_end;
125 && traits_type::eq_int_type(_M_really_overflow(__eof), __eof))
128 // NB: Do this here so that re-opened filebufs will be cool...
129 _M_mode = ios_base::openmode(0);
130 _M_destroy_internal_buffer();
135 if (_M_last_overflowed)
138 _M_really_overflow(__eof);
146 _M_last_overflowed = false;
150 template<typename _CharT, typename _Traits>
152 basic_filebuf<_CharT, _Traits>::
155 streamsize __ret = -1;
156 bool __testin = _M_mode & ios_base::in;
158 if (__testin && this->is_open())
159 __ret = _M_in_end - _M_in_cur;
160 _M_last_overflowed = false;
164 template<typename _CharT, typename _Traits>
165 typename basic_filebuf<_CharT, _Traits>::int_type
166 basic_filebuf<_CharT, _Traits>::
167 pbackfail(int_type __i)
169 int_type __ret = traits_type::eof();
170 bool __testin = _M_mode & ios_base::in;
174 bool __testpb = _M_in_beg < _M_in_cur;
175 char_type __c = traits_type::to_char_type(__i);
176 bool __testeof = traits_type::eq_int_type(__i, __ret);
180 bool __testout = _M_mode & ios_base::out;
181 bool __testeq = traits_type::eq(__c, this->gptr()[-1]);
183 // Try to put back __c into input sequence in one of three ways.
184 // Order these tests done in is unspecified by the standard.
185 if (!__testeof && __testeq)
197 __ret = traits_type::not_eof(__i);
211 // At the beginning of the buffer, need to make a
212 // putback position available.
213 this->seekoff(-1, ios_base::cur);
217 if (!traits_type::eq(__c, *_M_in_cur))
225 __ret = traits_type::not_eof(__i);
228 _M_last_overflowed = false;
232 template<typename _CharT, typename _Traits>
233 typename basic_filebuf<_CharT, _Traits>::int_type
234 basic_filebuf<_CharT, _Traits>::
235 overflow(int_type __c)
237 int_type __ret = traits_type::eof();
238 bool __testput = _M_out_cur && _M_out_cur < _M_buf + _M_buf_size;
239 bool __testout = _M_mode & ios_base::out;
245 *_M_out_cur = traits_type::to_char_type(__c);
247 __ret = traits_type::not_eof(__c);
250 __ret = this->_M_really_overflow(__c);
253 _M_last_overflowed = false; // Set in _M_really_overflow, below.
257 template<typename _CharT, typename _Traits>
259 basic_filebuf<_CharT, _Traits>::
260 _M_convert_to_external(_CharT* __ibuf, streamsize __ilen,
261 streamsize& __elen, streamsize& __plen)
263 const locale __loc = this->getloc();
264 const __codecvt_type& __cvt = use_facet<__codecvt_type>(__loc);
266 if (__cvt.always_noconv() && __ilen)
268 __elen += _M_file.xsputn(reinterpret_cast<char*>(__ibuf), __ilen);
273 // Worst-case number of external bytes needed.
274 int __ext_multiplier = __cvt.encoding();
275 if (__ext_multiplier == -1 || __ext_multiplier == 0)
276 __ext_multiplier = sizeof(char_type);
277 streamsize __blen = __ilen * __ext_multiplier;
278 char* __buf = static_cast<char*>(__builtin_alloca(__blen));
280 const char_type* __iend;
281 __res_type __r = __cvt.out(_M_state_cur, __ibuf, __ibuf + __ilen,
282 __iend, __buf, __buf + __blen, __bend);
283 // Result == ok, partial, noconv
284 if (__r != codecvt_base::error)
285 __blen = __bend - __buf;
292 __elen += _M_file.xsputn(__buf, __blen);
296 // Try once more for partial conversions.
297 if (__r == codecvt_base::partial)
299 const char_type* __iresume = __iend;
300 streamsize __rlen = _M_out_end - __iend;
301 __r = __cvt.out(_M_state_cur, __iresume, __iresume + __rlen,
302 __iend, __buf, __buf + __blen, __bend);
303 if (__r != codecvt_base::error)
304 __rlen = __bend - __buf;
309 __elen += _M_file.xsputn(__buf, __rlen);
316 template<typename _CharT, typename _Traits>
317 typename basic_filebuf<_CharT, _Traits>::int_type
318 basic_filebuf<_CharT, _Traits>::
319 _M_really_overflow(int_type __c)
321 int_type __ret = traits_type::eof();
322 bool __testput = _M_out_cur && _M_out_beg < _M_out_end;
323 bool __testunbuffered = _M_file.is_open() && !_M_buf_size_opt;
325 if (__testput || __testunbuffered)
327 // Sizes of external and pending output.
328 streamsize __elen = 0;
329 streamsize __plen = 0;
331 // Need to restore current position. The position of the external
332 // byte sequence (_M_file) corresponds to _M_filepos, and we need
333 // to move it to _M_out_beg for the write.
334 if (_M_filepos && _M_filepos != _M_out_beg)
336 off_type __off = _M_out_beg - _M_filepos;
337 _M_file.seekoff(__off, ios_base::cur);
340 // Convert internal buffer to external representation, output.
341 // NB: In the unbuffered case, no internal buffer exists.
342 if (!__testunbuffered)
343 _M_convert_to_external(_M_out_beg, _M_out_end - _M_out_beg,
346 // Convert pending sequence to external representation, output.
347 // If eof, then just attempt sync.
348 if (!traits_type::eq_int_type(__c, traits_type::eof()))
350 char_type __pending = traits_type::to_char_type(__c);
351 _M_convert_to_external(&__pending, 1, __elen, __plen);
353 // User code must flush when switching modes (thus don't sync).
354 if (__elen == __plen)
356 _M_set_indeterminate();
357 __ret = traits_type::not_eof(__c);
360 else if (!_M_file.sync())
362 _M_set_indeterminate();
363 __ret = traits_type::not_eof(__c);
366 _M_last_overflowed = true;
370 template<typename _CharT, typename _Traits>
371 typename basic_filebuf<_CharT, _Traits>::__streambuf_type*
372 basic_filebuf<_CharT, _Traits>::
373 setbuf(char_type* __s, streamsize __n)
375 if (!this->is_open() && __s == 0 && __n == 0)
379 // This is implementation-defined behavior, and assumes
380 // that an external char_type array of length (__s + __n)
381 // exists and has been pre-allocated. If this is not the
382 // case, things will quickly blow up.
383 // Step 1: Destroy the current internal array.
384 _M_destroy_internal_buffer();
386 // Step 2: Use the external array.
388 _M_buf_size_opt = _M_buf_size = __n;
389 _M_set_indeterminate();
391 _M_last_overflowed = false;
395 template<typename _CharT, typename _Traits>
396 typename basic_filebuf<_CharT, _Traits>::pos_type
397 basic_filebuf<_CharT, _Traits>::
398 seekoff(off_type __off, ios_base::seekdir __way, ios_base::openmode __mode)
400 pos_type __ret = pos_type(off_type(-1));
401 bool __testin = (ios_base::in & _M_mode & __mode) != 0;
402 bool __testout = (ios_base::out & _M_mode & __mode) != 0;
404 // Should probably do has_facet checks here.
405 int __width = use_facet<__codecvt_type>(_M_buf_locale).encoding();
408 bool __testfail = __off != 0 && __width <= 0;
410 if (this->is_open() && !__testfail && (__testin || __testout))
412 // Ditch any pback buffers to avoid confusion.
415 if (__way != ios_base::cur || __off != 0)
417 off_type __computed_off = __width * __off;
419 bool __testget = _M_in_cur && _M_in_beg < _M_in_end;
420 bool __testput = _M_out_cur && _M_out_beg < _M_out_end;
421 // Sync the internal and external streams.
423 if (__testput || _M_last_overflowed)
425 // Part one: update the output sequence.
427 // Part two: output unshift sequence.
431 else if (__testget && __way == ios_base::cur)
432 __computed_off += _M_in_cur - _M_filepos;
434 __ret = _M_file.seekoff(__computed_off, __way, __mode);
435 _M_set_indeterminate();
437 // NB: Need to do this in case _M_file in indeterminate
438 // state, ie _M_file._offset == -1
441 __ret = _M_file.seekoff(__off, ios_base::cur, __mode);
442 __ret += max(_M_out_cur, _M_in_cur) - _M_filepos;
445 _M_last_overflowed = false;
449 template<typename _CharT, typename _Traits>
450 typename basic_filebuf<_CharT, _Traits>::pos_type
451 basic_filebuf<_CharT, _Traits>::
452 seekpos(pos_type __pos, ios_base::openmode __mode)
454 #ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
455 // 171. Strange seekpos() semantics due to joint position
456 return this->seekoff(off_type(__pos), ios_base::beg, __mode);
460 template<typename _CharT, typename _Traits>
462 basic_filebuf<_CharT, _Traits>::
466 template<typename _CharT, typename _Traits>
468 basic_filebuf<_CharT, _Traits>::
469 imbue(const locale& __loc)
471 bool __testbeg = gptr() == eback() && pptr() == pbase();
473 if (__testbeg && _M_buf_locale != __loc)
475 _M_buf_locale = __loc;
476 _M_buf_locale_init = true;
479 // NB this may require the reconversion of previously
480 // converted chars. This in turn may cause the reconstruction
481 // of the original file. YIKES!!
482 // XXX The part in the above comment is not done.
483 _M_last_overflowed = false;
486 // Inhibit implicit instantiations for required instantiations,
487 // which are defined via explicit instantiations elsewhere.
488 // NB: This syntax is a GNU extension.
489 extern template class basic_filebuf<char>;
490 extern template class basic_ifstream<char>;
491 extern template class basic_ofstream<char>;
492 extern template class basic_fstream<char>;
494 #ifdef _GLIBCPP_USE_WCHAR_T
495 extern template class basic_filebuf<wchar_t>;
496 extern template class basic_ifstream<wchar_t>;
497 extern template class basic_ofstream<wchar_t>;
498 extern template class basic_fstream<wchar_t>;