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_allocated && this->_M_buf_size)
49 // Allocate internal buffer.
50 this->_M_buf = new char_type[this->_M_buf_size];
51 _M_buf_allocated = true;
55 // Both close and setbuf need to deallocate internal buffers, if it exists.
56 template<typename _CharT, typename _Traits>
58 basic_filebuf<_CharT, _Traits>::
59 _M_destroy_internal_buffer() throw()
63 delete [] this->_M_buf;
65 _M_buf_allocated = false;
69 template<typename _CharT, typename _Traits>
70 basic_filebuf<_CharT, _Traits>::
71 basic_filebuf() : __streambuf_type(), _M_file(&_M_lock),
72 _M_state_cur(__state_type()), _M_state_beg(__state_type()),
73 _M_buf(NULL), _M_buf_size(BUFSIZ), _M_buf_allocated(false),
74 _M_reading(false), _M_writing(false), _M_last_overflowed(false),
75 _M_pback_cur_save(0), _M_pback_end_save(0), _M_pback_init(false),
78 if (has_facet<__codecvt_type>(this->_M_buf_locale))
79 _M_codecvt = &use_facet<__codecvt_type>(this->_M_buf_locale);
82 template<typename _CharT, typename _Traits>
83 typename basic_filebuf<_CharT, _Traits>::__filebuf_type*
84 basic_filebuf<_CharT, _Traits>::
85 open(const char* __s, ios_base::openmode __mode)
87 __filebuf_type *__ret = NULL;
90 _M_file.open(__s, __mode);
93 _M_allocate_internal_buffer();
94 this->_M_mode = __mode;
96 // Setup initial buffer to 'uncommitted' mode.
101 if ((__mode & ios_base::ate)
102 && this->seekoff(0, ios_base::end, __mode) < 0)
112 template<typename _CharT, typename _Traits>
113 typename basic_filebuf<_CharT, _Traits>::__filebuf_type*
114 basic_filebuf<_CharT, _Traits>::
117 __filebuf_type* __ret = NULL;
120 bool __testfail = false;
123 if (this->pbase() < this->pptr()
124 && traits_type::eq_int_type(this->overflow(),
129 if (_M_last_overflowed)
141 // NB: Do this here so that re-opened filebufs will be cool...
142 this->_M_mode = ios_base::openmode(0);
143 this->_M_pback_init = false;
144 _M_destroy_internal_buffer();
149 if (!_M_file.close())
155 _M_last_overflowed = false;
159 template<typename _CharT, typename _Traits>
161 basic_filebuf<_CharT, _Traits>::
164 streamsize __ret = -1;
165 const bool __testin = this->_M_mode & ios_base::in;
167 if (__testin && this->is_open())
169 // For a stateful encoding (-1) the pending sequence might be just
170 // shift and unshift prefixes with no actual character.
171 __ret = this->egptr() - this->gptr();
172 if (__check_facet(_M_codecvt).encoding() >= 0)
173 __ret += _M_file.showmanyc() / _M_codecvt->max_length();
176 _M_last_overflowed = false;
180 template<typename _CharT, typename _Traits>
181 typename basic_filebuf<_CharT, _Traits>::int_type
182 basic_filebuf<_CharT, _Traits>::
183 _M_underflow(bool __bump)
185 int_type __ret = traits_type::eof();
186 const bool __testin = this->_M_mode & ios_base::in;
187 const bool __testout = this->_M_mode & ios_base::out;
189 if (__testin && !_M_writing)
191 // Check for pback madness, and if so swich back to the
192 // normal buffers and jet outta here before expensive
196 if (this->gptr() < this->egptr())
198 __ret = traits_type::to_int_type(*this->gptr());
204 // Get and convert input sequence.
205 const size_t __buflen = this->_M_buf_size > 1
206 ? this->_M_buf_size - 1 : 1;
207 streamsize __elen = 0;
208 streamsize __ilen = 0;
209 if (__check_facet(_M_codecvt).always_noconv())
211 __elen = _M_file.xsgetn(reinterpret_cast<char*>(this->eback()), __buflen);
216 // Worst-case number of external bytes.
217 // XXX Not done encoding() == -1.
218 const streamsize __blen = __buflen * _M_codecvt->max_length();
219 char* __buf = static_cast<char*>(__builtin_alloca(__blen));
220 __elen = _M_file.xsgetn(__buf, __blen);
224 codecvt_base::result __r;
225 __r = _M_codecvt->in(_M_state_cur, __buf, __buf + __elen,
226 __eend, this->eback(),
227 this->eback() + __buflen, __iend);
228 if (__r == codecvt_base::ok || __r == codecvt_base::partial)
229 __ilen = __iend - this->eback();
230 else if (__r == codecvt_base::noconv)
232 traits_type::copy(this->eback(),
233 reinterpret_cast<char_type*>(__buf),
241 _M_file.seekoff(-__elen, ios_base::cur, ios_base::in);
247 _M_set_buffer(__ilen);
249 __ret = traits_type::to_int_type(*this->gptr());
253 else if (__elen == 0)
255 // If the actual end of file is reached, set 'uncommitted'
256 // mode, thus allowing an immediate write without an
262 _M_last_overflowed = false;
266 template<typename _CharT, typename _Traits>
267 typename basic_filebuf<_CharT, _Traits>::int_type
268 basic_filebuf<_CharT, _Traits>::
269 pbackfail(int_type __i)
271 int_type __ret = traits_type::eof();
272 const bool __testin = this->_M_mode & ios_base::in;
274 if (__testin && !_M_writing)
276 // Remember whether the pback buffer is active, otherwise below
277 // we may try to store in it a second char (libstdc++/9761).
278 const bool __testpb = this->_M_pback_init;
279 const bool __testeof = traits_type::eq_int_type(__i, __ret);
282 if (this->eback() < this->gptr())
285 __tmp = traits_type::to_int_type(*this->gptr());
287 else if (this->seekoff(-1, ios_base::cur) >= 0)
289 __tmp = this->underflow();
290 if (traits_type::eq_int_type(__tmp, __ret))
295 // At the beginning of the buffer, need to make a
296 // putback position available. But the seek may fail
297 // (f.i., at the beginning of a file, see
298 // libstdc++/9439) and in that case we return
299 // traits_type::eof().
303 // Try to put back __i into input sequence in one of three ways.
304 // Order these tests done in is unspecified by the standard.
305 if (!__testeof && traits_type::eq_int_type(__i, __tmp))
308 __ret = traits_type::not_eof(__i);
313 *this->gptr() = traits_type::to_char_type(__i);
317 _M_last_overflowed = false;
321 template<typename _CharT, typename _Traits>
322 typename basic_filebuf<_CharT, _Traits>::int_type
323 basic_filebuf<_CharT, _Traits>::
324 overflow(int_type __c)
326 int_type __ret = traits_type::eof();
327 const bool __testeof = traits_type::eq_int_type(__c, __ret);
328 const bool __testout = this->_M_mode & ios_base::out;
330 if (__testout && !_M_reading)
332 if (this->pbase() < this->pptr())
334 // If appropriate, append the overflow char.
337 *this->pptr() = traits_type::to_char_type(__c);
341 // Convert pending sequence to external representation,
343 if (_M_convert_to_external(this->pbase(),
344 this->pptr() - this->pbase())
345 && (!__testeof || (__testeof && !_M_file.sync())))
348 __ret = traits_type::not_eof(__c);
351 else if (this->_M_buf_size > 1)
353 // Overflow in 'uncommitted' mode: set _M_writing, set
354 // the buffer to the initial 'write' mode, and put __c
360 *this->pptr() = traits_type::to_char_type(__c);
363 __ret = traits_type::not_eof(__c);
368 char_type __conv = traits_type::to_char_type(__c);
369 if (__testeof || _M_convert_to_external(&__conv, 1))
372 __ret = traits_type::not_eof(__c);
376 _M_last_overflowed = true;
380 template<typename _CharT, typename _Traits>
382 basic_filebuf<_CharT, _Traits>::
383 _M_convert_to_external(_CharT* __ibuf, streamsize __ilen)
385 // Sizes of external and pending output.
386 streamsize __elen = 0;
387 streamsize __plen = 0;
389 if (__check_facet(_M_codecvt).always_noconv())
391 __elen += _M_file.xsputn(reinterpret_cast<char*>(__ibuf), __ilen);
396 // Worst-case number of external bytes needed.
397 // XXX Not done encoding() == -1.
398 streamsize __blen = __ilen * _M_codecvt->max_length();
399 char* __buf = static_cast<char*>(__builtin_alloca(__blen));
402 const char_type* __iend;
403 codecvt_base::result __r;
404 __r = _M_codecvt->out(_M_state_cur, __ibuf, __ibuf + __ilen,
405 __iend, __buf, __buf + __blen, __bend);
407 if (__r == codecvt_base::ok || __r == codecvt_base::partial)
408 __blen = __bend - __buf;
409 else if (__r == codecvt_base::noconv)
411 // Same as the always_noconv case above.
412 __buf = reinterpret_cast<char*>(__ibuf);
423 __elen += _M_file.xsputn(__buf, __blen);
427 // Try once more for partial conversions.
428 if (__r == codecvt_base::partial)
430 const char_type* __iresume = __iend;
431 streamsize __rlen = this->pptr() - __iend;
432 __r = _M_codecvt->out(_M_state_cur, __iresume,
433 __iresume + __rlen, __iend, __buf,
434 __buf + __blen, __bend);
435 if (__r != codecvt_base::error)
437 __rlen = __bend - __buf;
438 __elen += _M_file.xsputn(__buf, __rlen);
443 return __elen && __elen == __plen;
446 template<typename _CharT, typename _Traits>
447 typename basic_filebuf<_CharT, _Traits>::__streambuf_type*
448 basic_filebuf<_CharT, _Traits>::
449 setbuf(char_type* __s, streamsize __n)
451 if (!this->is_open() && __s == 0 && __n == 0)
452 this->_M_buf_size = 1;
453 else if (__s && __n > 0)
455 // This is implementation-defined behavior, and assumes that
456 // an external char_type array of length __n exists and has
457 // been pre-allocated. If this is not the case, things will
458 // quickly blow up. When __n > 1, __n - 1 positions will be
459 // used for the get area, __n - 1 for the put area and 1
460 // position to host the overflow char of a full put area.
461 // When __n == 1, 1 position will be used for the get area
462 // and 0 for the put area, as in the unbuffered case above.
464 // Step 1: Destroy the current internal array.
465 _M_destroy_internal_buffer();
467 // Step 2: Use the external array.
469 this->_M_buf_size = __n;
474 _M_last_overflowed = false;
478 template<typename _CharT, typename _Traits>
479 typename basic_filebuf<_CharT, _Traits>::pos_type
480 basic_filebuf<_CharT, _Traits>::
481 seekoff(off_type __off, ios_base::seekdir __way, ios_base::openmode __mode)
483 pos_type __ret = pos_type(off_type(-1));
484 const bool __testin = (ios_base::in & this->_M_mode & __mode) != 0;
485 const bool __testout = (ios_base::out & this->_M_mode & __mode) != 0;
489 __width = _M_codecvt->encoding();
493 const bool __testfail = __off != 0 && __width <= 0;
494 if (this->is_open() && !__testfail && (__testin || __testout))
496 // Ditch any pback buffers to avoid confusion.
499 // Sync the internal and external streams.
500 off_type __computed_off = __width * __off;
502 if (this->pbase() < this->pptr()
503 || _M_last_overflowed)
505 // Part one: update the output sequence.
508 // Part two: output unshift sequence.
511 else if (_M_reading && __way == ios_base::cur)
512 __computed_off += this->gptr() - this->egptr();
514 // Return pos_type(off_type(-1)) in case of failure.
515 __ret = _M_file.seekoff(__computed_off, __way, __mode);
520 _M_last_overflowed = false;
524 template<typename _CharT, typename _Traits>
525 typename basic_filebuf<_CharT, _Traits>::pos_type
526 basic_filebuf<_CharT, _Traits>::
527 seekpos(pos_type __pos, ios_base::openmode __mode)
529 #ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
530 // 171. Strange seekpos() semantics due to joint position
531 return this->seekoff(off_type(__pos), ios_base::beg, __mode);
535 template<typename _CharT, typename _Traits>
537 basic_filebuf<_CharT, _Traits>::
541 template<typename _CharT, typename _Traits>
543 basic_filebuf<_CharT, _Traits>::
544 imbue(const locale& __loc)
546 const bool __testbeg = !this->seekoff(0, ios_base::cur, this->_M_mode);
547 const bool __teststate = __check_facet(_M_codecvt).encoding() == -1;
549 if (this->_M_buf_locale != __loc
550 && (!this->is_open() || (__testbeg && !__teststate)))
552 this->_M_buf_locale = __loc;
553 if (__builtin_expect(has_facet<__codecvt_type>(__loc), true))
554 _M_codecvt = &use_facet<__codecvt_type>(__loc);
556 // NB This may require the reconversion of previously
557 // converted chars. This in turn may cause the
558 // reconstruction of the original file. YIKES!! This
559 // implementation interprets this requirement as requiring
560 // the file position be at the beginning, and a stateless
561 // encoding, or that the filebuf be closed. Opinions may differ.
563 _M_last_overflowed = false;
566 // Inhibit implicit instantiations for required instantiations,
567 // which are defined via explicit instantiations elsewhere.
568 // NB: This syntax is a GNU extension.
569 #if _GLIBCPP_EXTERN_TEMPLATE
570 extern template class basic_filebuf<char>;
571 extern template class basic_ifstream<char>;
572 extern template class basic_ofstream<char>;
573 extern template class basic_fstream<char>;
575 #ifdef _GLIBCPP_USE_WCHAR_T
576 extern template class basic_filebuf<wchar_t>;
577 extern template class basic_ifstream<wchar_t>;
578 extern template class basic_ofstream<wchar_t>;
579 extern template class basic_fstream<wchar_t>;