1 // File based streams -*- C++ -*-
3 // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003
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() throw()
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 if ((__mode & ios_base::ate)
98 && this->seekoff(0, ios_base::end, __mode) < 0)
111 template<typename _CharT, typename _Traits>
112 typename basic_filebuf<_CharT, _Traits>::__filebuf_type*
113 basic_filebuf<_CharT, _Traits>::
116 __filebuf_type* __ret = NULL;
119 bool __testfail = false;
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),
131 if (_M_last_overflowed)
134 _M_really_overflow(__eof);
143 // NB: Do this here so that re-opened filebufs will be cool...
144 this->_M_mode = ios_base::openmode(0);
145 _M_destroy_internal_buffer();
148 if (!_M_file.close())
154 _M_last_overflowed = false;
158 template<typename _CharT, typename _Traits>
160 basic_filebuf<_CharT, _Traits>::
163 streamsize __ret = -1;
164 bool __testin = _M_mode & ios_base::in;
165 const locale __loc = this->getloc();
166 const __codecvt_type& __cvt = use_facet<__codecvt_type>(__loc);
168 if (__testin && this->is_open())
170 __ret = _M_in_end - _M_in_cur;
171 if (__cvt.always_noconv())
172 __ret += _M_file.showmanyc_helper();
175 _M_last_overflowed = false;
179 template<typename _CharT, typename _Traits>
180 typename basic_filebuf<_CharT, _Traits>::int_type
181 basic_filebuf<_CharT, _Traits>::
182 pbackfail(int_type __i)
184 int_type __ret = traits_type::eof();
185 bool __testin = _M_mode & ios_base::in;
189 bool __testpb = _M_in_beg < _M_in_cur;
190 char_type __c = traits_type::to_char_type(__i);
191 bool __testeof = traits_type::eq_int_type(__i, __ret);
195 bool __testout = _M_mode & ios_base::out;
196 bool __testeq = traits_type::eq(__c, this->gptr()[-1]);
198 // Try to put back __c into input sequence in one of three ways.
199 // Order these tests done in is unspecified by the standard.
200 if (!__testeof && __testeq)
212 __ret = traits_type::not_eof(__i);
226 // At the beginning of the buffer, need to make a
227 // putback position available.
228 // But the seek may fail (f.i., at the beginning of
229 // a file, see libstdc++/9439) and in that case
230 // we return traits_type::eof()
231 if (this->seekoff(-1, ios_base::cur) >= 0)
236 if (!traits_type::eq(__c, *_M_in_cur))
244 __ret = traits_type::not_eof(__i);
248 _M_last_overflowed = false;
252 template<typename _CharT, typename _Traits>
253 typename basic_filebuf<_CharT, _Traits>::int_type
254 basic_filebuf<_CharT, _Traits>::
255 overflow(int_type __c)
257 int_type __ret = traits_type::eof();
258 bool __testput = _M_out_cur && _M_out_cur < _M_buf + _M_buf_size;
259 bool __testout = _M_mode & ios_base::out;
263 if (traits_type::eq_int_type(__c, traits_type::eof()))
264 __ret = traits_type::not_eof(__c);
267 *_M_out_cur = traits_type::to_char_type(__c);
269 __ret = traits_type::not_eof(__c);
272 __ret = this->_M_really_overflow(__c);
275 _M_last_overflowed = false; // Set in _M_really_overflow, below.
279 template<typename _CharT, typename _Traits>
281 basic_filebuf<_CharT, _Traits>::
282 _M_convert_to_external(_CharT* __ibuf, streamsize __ilen,
283 streamsize& __elen, streamsize& __plen)
285 const locale __loc = this->getloc();
286 const __codecvt_type& __cvt = use_facet<__codecvt_type>(__loc);
288 if (__cvt.always_noconv() && __ilen)
290 __elen += _M_file.xsputn(reinterpret_cast<char*>(__ibuf), __ilen);
295 // Worst-case number of external bytes needed.
296 int __ext_multiplier = __cvt.encoding();
297 if (__ext_multiplier == -1 || __ext_multiplier == 0)
298 __ext_multiplier = sizeof(char_type);
299 streamsize __blen = __ilen * __ext_multiplier;
300 char* __buf = static_cast<char*>(__builtin_alloca(__blen));
302 const char_type* __iend;
303 codecvt_base::result __r;
304 __r = __cvt.out(_M_state_cur, __ibuf, __ibuf + __ilen,
305 __iend, __buf, __buf + __blen, __bend);
307 if (__r == codecvt_base::ok || __r == codecvt_base::partial)
308 __blen = __bend - __buf;
309 else if (__r == codecvt_base::noconv)
311 // Same as the always_noconv case above.
312 __buf = reinterpret_cast<char*>(__ibuf);
323 __elen += _M_file.xsputn(__buf, __blen);
327 // Try once more for partial conversions.
328 if (__r == codecvt_base::partial)
330 const char_type* __iresume = __iend;
331 streamsize __rlen = _M_out_end - __iend;
332 __r = __cvt.out(_M_state_cur, __iresume, __iresume + __rlen,
333 __iend, __buf, __buf + __blen, __bend);
334 if (__r != codecvt_base::error)
336 __rlen = __bend - __buf;
337 __elen += _M_file.xsputn(__buf, __rlen);
344 template<typename _CharT, typename _Traits>
345 typename basic_filebuf<_CharT, _Traits>::int_type
346 basic_filebuf<_CharT, _Traits>::
347 _M_really_overflow(int_type __c)
349 int_type __ret = traits_type::eof();
350 bool __testput = _M_out_cur && _M_out_beg < _M_out_end;
351 bool __testunbuffered = _M_file.is_open() && !_M_buf_size;
353 if (__testput || __testunbuffered)
355 // Sizes of external and pending output.
356 streamsize __elen = 0;
357 streamsize __plen = 0;
359 // Need to restore current position. The position of the external
360 // byte sequence (_M_file) corresponds to _M_filepos, and we need
361 // to move it to _M_out_beg for the write.
362 if (_M_filepos && _M_filepos != _M_out_beg)
364 off_type __off = _M_out_beg - _M_filepos;
365 _M_file.seekoff(__off, ios_base::cur);
368 // Convert internal buffer to external representation, output.
369 // NB: In the unbuffered case, no internal buffer exists.
370 if (!__testunbuffered)
371 _M_convert_to_external(_M_out_beg, _M_out_end - _M_out_beg,
374 // Checks for codecvt.out failures and _M_file.xsputn failures,
375 // respectively, inside _M_convert_to_external.
376 if (__testunbuffered || (__elen && __elen == __plen))
378 // Convert pending sequence to external representation, output.
379 // If eof, then just attempt sync.
380 if (!traits_type::eq_int_type(__c, traits_type::eof()))
382 char_type __pending = traits_type::to_char_type(__c);
383 _M_convert_to_external(&__pending, 1, __elen, __plen);
385 // User code must flush when switching modes (thus
387 if (__elen == __plen && __elen)
389 _M_set_indeterminate();
390 __ret = traits_type::not_eof(__c);
393 else if (!_M_file.sync())
395 _M_set_indeterminate();
396 __ret = traits_type::not_eof(__c);
400 _M_last_overflowed = true;
404 template<typename _CharT, typename _Traits>
405 typename basic_filebuf<_CharT, _Traits>::__streambuf_type*
406 basic_filebuf<_CharT, _Traits>::
407 setbuf(char_type* __s, streamsize __n)
409 if (!this->is_open() && __s == 0 && __n == 0)
413 // This is implementation-defined behavior, and assumes
414 // that an external char_type array of length (__s + __n)
415 // exists and has been pre-allocated. If this is not the
416 // case, things will quickly blow up.
417 // Step 1: Destroy the current internal array.
418 _M_destroy_internal_buffer();
420 // Step 2: Use the external array.
422 _M_buf_size_opt = _M_buf_size = __n;
423 _M_set_indeterminate();
425 _M_last_overflowed = false;
429 template<typename _CharT, typename _Traits>
430 typename basic_filebuf<_CharT, _Traits>::pos_type
431 basic_filebuf<_CharT, _Traits>::
432 seekoff(off_type __off, ios_base::seekdir __way, ios_base::openmode __mode)
434 pos_type __ret = pos_type(off_type(-1));
435 bool __testin = (ios_base::in & _M_mode & __mode) != 0;
436 bool __testout = (ios_base::out & _M_mode & __mode) != 0;
439 if (has_facet<__codecvt_type>(this->_M_buf_locale))
440 __width = use_facet<__codecvt_type>(this->_M_buf_locale).encoding();
444 bool __testfail = __off != 0 && __width <= 0;
445 if (this->is_open() && !__testfail && (__testin || __testout))
447 // Ditch any pback buffers to avoid confusion.
450 if (__way != ios_base::cur || __off != 0)
452 off_type __computed_off = __width * __off;
454 bool __testget = _M_in_cur && _M_in_beg < _M_in_end;
455 bool __testput = _M_out_cur && _M_out_beg < _M_out_end;
456 // Sync the internal and external streams.
458 if (__testput || _M_last_overflowed)
460 // Part one: update the output sequence.
462 // Part two: output unshift sequence.
466 else if (__testget && __way == ios_base::cur)
467 __computed_off += _M_in_cur - _M_filepos;
469 // Return pos_type(off_type(-1)) in case of failure.
470 __ret = _M_file.seekoff(__computed_off, __way, __mode);
471 _M_set_indeterminate();
473 // NB: Need to do this in case _M_file in indeterminate
474 // state, ie _M_file._offset == -1
478 _M_file.seekoff(__off, ios_base::cur, __mode);
483 __ret += max(_M_out_cur, _M_in_cur) - _M_filepos;
487 _M_last_overflowed = false;
491 template<typename _CharT, typename _Traits>
492 typename basic_filebuf<_CharT, _Traits>::pos_type
493 basic_filebuf<_CharT, _Traits>::
494 seekpos(pos_type __pos, ios_base::openmode __mode)
496 #ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
497 // 171. Strange seekpos() semantics due to joint position
498 return this->seekoff(off_type(__pos), ios_base::beg, __mode);
502 template<typename _CharT, typename _Traits>
504 basic_filebuf<_CharT, _Traits>::
508 template<typename _CharT, typename _Traits>
510 basic_filebuf<_CharT, _Traits>::
511 imbue(const locale& __loc)
513 bool __testbeg = gptr() == eback() && pptr() == pbase();
515 if (__testbeg && _M_buf_locale != __loc)
516 _M_buf_locale = __loc;
518 // NB this may require the reconversion of previously
519 // converted chars. This in turn may cause the reconstruction
520 // of the original file. YIKES!!
521 // XXX The part in the above comment is not done.
522 _M_last_overflowed = false;
525 // Inhibit implicit instantiations for required instantiations,
526 // which are defined via explicit instantiations elsewhere.
527 // NB: This syntax is a GNU extension.
528 #if _GLIBCPP_EXTERN_TEMPLATE
529 extern template class basic_filebuf<char>;
530 extern template class basic_ifstream<char>;
531 extern template class basic_ofstream<char>;
532 extern template class basic_fstream<char>;
534 #ifdef _GLIBCPP_USE_WCHAR_T
535 extern template class basic_filebuf<wchar_t>;
536 extern template class basic_ifstream<wchar_t>;
537 extern template class basic_ofstream<wchar_t>;
538 extern template class basic_fstream<wchar_t>;