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
36 #define _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;
74 template<typename _CharT, typename _Traits>
75 basic_filebuf<_CharT, _Traits>::
76 basic_filebuf() : __streambuf_type(), _M_file(&_M_lock),
77 _M_mode(ios_base::openmode(0)), _M_state_beg(), _M_state_cur(),
78 _M_state_last(), _M_buf(NULL), _M_buf_size(BUFSIZ),
79 _M_buf_allocated(false), _M_reading(false), _M_writing(false),
80 _M_pback_cur_save(0), _M_pback_end_save(0), _M_pback_init(false),
81 _M_codecvt(0), _M_ext_buf(0), _M_ext_buf_size(0), _M_ext_next(0),
84 if (has_facet<__codecvt_type>(this->_M_buf_locale))
85 _M_codecvt = &use_facet<__codecvt_type>(this->_M_buf_locale);
88 template<typename _CharT, typename _Traits>
89 typename basic_filebuf<_CharT, _Traits>::__filebuf_type*
90 basic_filebuf<_CharT, _Traits>::
91 open(const char* __s, ios_base::openmode __mode)
93 __filebuf_type *__ret = NULL;
96 _M_file.open(__s, __mode);
99 _M_allocate_internal_buffer();
100 this->_M_mode = __mode;
102 // Setup initial buffer to 'uncommitted' mode.
107 // Reset to initial state.
108 _M_state_last = _M_state_cur = _M_state_beg;
111 if ((__mode & ios_base::ate)
112 && this->seekoff(0, ios_base::end, __mode)
113 == pos_type(off_type(-1)))
122 template<typename _CharT, typename _Traits>
123 typename basic_filebuf<_CharT, _Traits>::__filebuf_type*
124 basic_filebuf<_CharT, _Traits>::
127 __filebuf_type* __ret = NULL;
130 bool __testfail = false;
133 if (!_M_terminate_output())
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();
148 _M_state_last = _M_state_cur = _M_state_beg;
150 if (!_M_file.close())
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();
179 template<typename _CharT, typename _Traits>
180 typename basic_filebuf<_CharT, _Traits>::int_type
181 basic_filebuf<_CharT, _Traits>::
184 int_type __ret = traits_type::eof();
185 const bool __testin = this->_M_mode & ios_base::in;
186 const bool __testout = this->_M_mode & ios_base::out;
188 if (__testin && !_M_writing)
190 // Check for pback madness, and if so swich back to the
191 // normal buffers and jet outta here before expensive
195 if (this->gptr() < this->egptr())
196 return traits_type::to_int_type(*this->gptr());
198 // Get and convert input sequence.
199 const size_t __buflen = this->_M_buf_size > 1
200 ? this->_M_buf_size - 1 : 1;
202 // Will be set to true if ::read() returns 0 indicating EOF.
203 bool __got_eof = false;
204 // Number of internal characters produced.
205 streamsize __ilen = 0;
206 if (__check_facet(_M_codecvt).always_noconv())
208 __ilen = _M_file.xsgetn(reinterpret_cast<char*>(this->eback()),
215 // Worst-case number of external bytes.
216 // XXX Not done encoding() == -1.
217 const int __enc = _M_codecvt->encoding();
218 streamsize __blen; // Minimum buffer size.
219 streamsize __rlen; // Number of chars to read.
221 __blen = __rlen = __buflen * __enc;
224 __blen = __buflen + _M_codecvt->max_length() - 1;
227 const streamsize __remainder = _M_ext_end - _M_ext_next;
228 __rlen = __rlen > __remainder ? __rlen - __remainder : 0;
230 // Allocate buffer if necessary and move unconverted
232 if (_M_ext_buf_size < __blen)
234 char* __buf = new char[__blen];
236 std::memcpy(__buf, _M_ext_next, __remainder);
238 delete [] _M_ext_buf;
240 _M_ext_buf_size = __blen;
242 else if (__remainder > 0)
243 std::memmove(_M_ext_buf, _M_ext_next, __remainder);
245 _M_ext_next = _M_ext_buf;
246 _M_ext_end = _M_ext_buf + __remainder;
247 _M_state_last = _M_state_cur;
254 // This may fail if the return value of
255 // codecvt::max_length() is bogus.
256 if (_M_ext_end - _M_ext_buf + __rlen > _M_ext_buf_size)
258 __throw_ios_failure("codecvt::max_length() "
261 streamsize __elen = _M_file.xsgetn(_M_ext_end, __rlen);
264 _M_ext_end += __elen;
268 codecvt_base::result __r;
269 __r = _M_codecvt->in(_M_state_cur, _M_ext_next,
270 _M_ext_end, _M_ext_next, this->eback(),
271 this->eback() + __buflen, __iend);
272 if (__r == codecvt_base::ok || __r == codecvt_base::partial)
273 __ilen = __iend - this->eback();
274 else if (__r == codecvt_base::noconv)
276 size_t __avail = _M_ext_end - _M_ext_buf;
277 __ilen = std::min(__avail, __buflen);
278 traits_type::copy(this->eback(),
279 reinterpret_cast<char_type*>(_M_ext_buf), __ilen);
280 _M_ext_next = _M_ext_buf + __ilen;
289 while (!__got_eof && __ilen == 0);
294 _M_set_buffer(__ilen);
296 __ret = traits_type::to_int_type(*this->gptr());
300 // If the actual end of file is reached, set 'uncommitted'
301 // mode, thus allowing an immediate write without an
310 template<typename _CharT, typename _Traits>
311 typename basic_filebuf<_CharT, _Traits>::int_type
312 basic_filebuf<_CharT, _Traits>::
313 pbackfail(int_type __i)
315 int_type __ret = traits_type::eof();
316 const bool __testin = this->_M_mode & ios_base::in;
318 if (__testin && !_M_writing)
320 // Remember whether the pback buffer is active, otherwise below
321 // we may try to store in it a second char (libstdc++/9761).
322 const bool __testpb = this->_M_pback_init;
323 const bool __testeof = traits_type::eq_int_type(__i, __ret);
326 if (this->eback() < this->gptr())
329 __tmp = traits_type::to_int_type(*this->gptr());
331 else if (this->seekoff(-1, ios_base::cur) != pos_type(off_type(-1)))
333 __tmp = this->underflow();
334 if (traits_type::eq_int_type(__tmp, __ret))
339 // At the beginning of the buffer, need to make a
340 // putback position available. But the seek may fail
341 // (f.i., at the beginning of a file, see
342 // libstdc++/9439) and in that case we return
343 // traits_type::eof().
347 // Try to put back __i into input sequence in one of three ways.
348 // Order these tests done in is unspecified by the standard.
349 if (!__testeof && traits_type::eq_int_type(__i, __tmp))
352 __ret = traits_type::not_eof(__i);
357 *this->gptr() = traits_type::to_char_type(__i);
364 template<typename _CharT, typename _Traits>
365 typename basic_filebuf<_CharT, _Traits>::int_type
366 basic_filebuf<_CharT, _Traits>::
367 overflow(int_type __c)
369 int_type __ret = traits_type::eof();
370 const bool __testeof = traits_type::eq_int_type(__c, __ret);
371 const bool __testout = this->_M_mode & ios_base::out;
373 if (__testout && !_M_reading)
375 if (this->pbase() < this->pptr())
377 // If appropriate, append the overflow char.
380 *this->pptr() = traits_type::to_char_type(__c);
384 // Convert pending sequence to external representation,
386 if (_M_convert_to_external(this->pbase(),
387 this->pptr() - this->pbase())
388 && (!__testeof || (__testeof && !_M_file.sync())))
391 __ret = traits_type::not_eof(__c);
394 else if (this->_M_buf_size > 1)
396 // Overflow in 'uncommitted' mode: set _M_writing, set
397 // the buffer to the initial 'write' mode, and put __c
403 *this->pptr() = traits_type::to_char_type(__c);
406 __ret = traits_type::not_eof(__c);
411 char_type __conv = traits_type::to_char_type(__c);
412 if (__testeof || _M_convert_to_external(&__conv, 1))
415 __ret = traits_type::not_eof(__c);
422 template<typename _CharT, typename _Traits>
424 basic_filebuf<_CharT, _Traits>::
425 _M_convert_to_external(_CharT* __ibuf, streamsize __ilen)
427 // Sizes of external and pending output.
428 streamsize __elen = 0;
429 streamsize __plen = 0;
431 if (__check_facet(_M_codecvt).always_noconv())
433 __elen += _M_file.xsputn(reinterpret_cast<char*>(__ibuf), __ilen);
438 // Worst-case number of external bytes needed.
439 // XXX Not done encoding() == -1.
440 streamsize __blen = __ilen * _M_codecvt->max_length();
441 char* __buf = static_cast<char*>(__builtin_alloca(__blen));
444 const char_type* __iend;
445 codecvt_base::result __r;
446 __r = _M_codecvt->out(_M_state_cur, __ibuf, __ibuf + __ilen,
447 __iend, __buf, __buf + __blen, __bend);
449 if (__r == codecvt_base::ok || __r == codecvt_base::partial)
450 __blen = __bend - __buf;
451 else if (__r == codecvt_base::noconv)
453 // Same as the always_noconv case above.
454 __buf = reinterpret_cast<char*>(__ibuf);
465 __elen += _M_file.xsputn(__buf, __blen);
469 // Try once more for partial conversions.
470 if (__r == codecvt_base::partial)
472 const char_type* __iresume = __iend;
473 streamsize __rlen = this->pptr() - __iend;
474 __r = _M_codecvt->out(_M_state_cur, __iresume,
475 __iresume + __rlen, __iend, __buf,
476 __buf + __blen, __bend);
477 if (__r != codecvt_base::error)
479 __rlen = __bend - __buf;
480 __elen += _M_file.xsputn(__buf, __rlen);
485 return __elen && __elen == __plen;
488 template<typename _CharT, typename _Traits>
490 basic_filebuf<_CharT, _Traits>::
491 xsputn(const _CharT* __s, streamsize __n)
493 streamsize __ret = 0;
495 // Optimization in the always_noconv() case, to be generalized in the
496 // future: when __n is sufficiently large we write directly instead of
498 const bool __testout = this->_M_mode & ios_base::out;
499 if (__testout && !_M_reading
500 && __check_facet(_M_codecvt).always_noconv())
502 // Measurement would reveal the best choice.
503 const streamsize __chunk = 1ul << 10;
504 streamsize __bufavail = this->epptr() - this->pptr();
506 // Don't mistake 'uncommitted' mode buffered with unbuffered.
507 if (!_M_writing && this->_M_buf_size > 1)
508 __bufavail = this->_M_buf_size - 1;
510 const streamsize __limit = std::min(__chunk, __bufavail);
513 const streamsize __buffill = this->pptr() - this->pbase();
514 const char* __buf = reinterpret_cast<const char*>(this->pbase());
515 __ret = _M_file.xsputn_2(__buf, __buffill,
516 reinterpret_cast<const char*>(__s),
518 if (__ret == __buffill + __n)
523 if (__ret > __buffill)
529 __ret = __streambuf_type::xsputn(__s, __n);
532 __ret = __streambuf_type::xsputn(__s, __n);
537 template<typename _CharT, typename _Traits>
538 typename basic_filebuf<_CharT, _Traits>::__streambuf_type*
539 basic_filebuf<_CharT, _Traits>::
540 setbuf(char_type* __s, streamsize __n)
542 if (!this->is_open() && __s == 0 && __n == 0)
543 this->_M_buf_size = 1;
544 else if (__s && __n > 0)
546 // This is implementation-defined behavior, and assumes that
547 // an external char_type array of length __n exists and has
548 // been pre-allocated. If this is not the case, things will
549 // quickly blow up. When __n > 1, __n - 1 positions will be
550 // used for the get area, __n - 1 for the put area and 1
551 // position to host the overflow char of a full put area.
552 // When __n == 1, 1 position will be used for the get area
553 // and 0 for the put area, as in the unbuffered case above.
555 // Step 1: Destroy the current internal array.
556 _M_destroy_internal_buffer();
558 // Step 2: Use the external array.
560 this->_M_buf_size = __n;
569 // According to 27.8.1.4 p11 - 13, seekoff should ignore the last
570 // argument (of type openmode).
571 template<typename _CharT, typename _Traits>
572 typename basic_filebuf<_CharT, _Traits>::pos_type
573 basic_filebuf<_CharT, _Traits>::
574 seekoff(off_type __off, ios_base::seekdir __way, ios_base::openmode)
576 pos_type __ret = pos_type(off_type(-1));
580 __width = _M_codecvt->encoding();
584 const bool __testfail = __off != 0 && __width <= 0;
585 if (this->is_open() && !__testfail)
587 // Ditch any pback buffers to avoid confusion.
590 // Correct state at destination. Note that this is the correct
591 // state for the current position during output, because
592 // codecvt::unshift() returns the state to the initial state.
593 // This is also the correct state at the end of the file because
594 // an unshift sequence should have been written at the end.
595 __state_type __state = _M_state_beg;
596 off_type __computed_off = __off * __width;
597 if (_M_reading && __way == ios_base::cur)
599 if (_M_codecvt->always_noconv())
600 __computed_off += this->gptr() - this->egptr();
603 // Calculate offset from _M_ext_buf that corresponds
604 // to gptr(). Note: uses _M_state_last, which
605 // corresponds to eback().
606 const int __gptr_off =
607 _M_codecvt->length(_M_state_last, _M_ext_buf, _M_ext_next,
608 this->gptr() - this->eback());
609 __computed_off += _M_ext_buf + __gptr_off - _M_ext_end;
611 // _M_state_last is modified by codecvt::length() so
612 // it now corresponds to gptr().
613 __state = _M_state_last;
616 __ret = _M_seek(__computed_off, __way, __state);
621 // _GLIBCXX_RESOLVE_LIB_DEFECTS
622 // 171. Strange seekpos() semantics due to joint position
623 // According to the resolution of DR 171, seekpos should ignore the last
624 // argument (of type openmode).
625 template<typename _CharT, typename _Traits>
626 typename basic_filebuf<_CharT, _Traits>::pos_type
627 basic_filebuf<_CharT, _Traits>::
628 seekpos(pos_type __pos, ios_base::openmode)
630 pos_type __ret = pos_type(off_type(-1));
634 // Ditch any pback buffers to avoid confusion.
637 __ret = _M_seek(off_type(__pos), ios_base::beg, __pos.state());
642 template<typename _CharT, typename _Traits>
643 typename basic_filebuf<_CharT, _Traits>::pos_type
644 basic_filebuf<_CharT, _Traits>::
645 _M_seek(off_type __off, ios_base::seekdir __way, __state_type __state)
647 pos_type __ret = pos_type(off_type(-1));
648 if (_M_terminate_output())
650 // Returns pos_type(off_type(-1)) in case of failure.
651 __ret = pos_type(_M_file.seekoff(__off, __way));
655 _M_ext_next = _M_ext_end = _M_ext_buf;
657 _M_state_cur = __state;
658 __ret.state(_M_state_cur);
663 template<typename _CharT, typename _Traits>
665 basic_filebuf<_CharT, _Traits>::
666 _M_terminate_output()
668 bool __testvalid = true;
670 // Part one: update the output sequence.
671 if (this->pbase() < this->pptr())
673 const int_type __tmp = this->overflow();
674 if (traits_type::eq_int_type(__tmp, traits_type::eof()))
678 // Part two: output unshift sequence.
679 if (_M_writing && !__check_facet(_M_codecvt).always_noconv()
682 // Note: this value is arbitrary, since there is no way to
683 // get the length of the unshift sequence from codecvt,
684 // without calling unshift.
685 const size_t __blen = 128;
688 codecvt_base::result __r;
689 streamsize __ilen = 0;
694 __r = _M_codecvt->unshift(_M_state_cur, __buf,
695 __buf + __blen, __next);
696 if (__r == codecvt_base::error)
698 else if (__r == codecvt_base::ok ||
699 __r == codecvt_base::partial)
701 __ilen = __next - __buf;
705 const streamsize __elen = _M_file.xsputn(__buf, __ilen);
706 if (__elen != __ilen)
711 while (__r == codecvt_base::partial && __ilen > 0 && __testvalid);
715 // This second call to overflow() is required by the standard,
716 // but it's not clear why it's needed, since the output buffer
717 // should be empty by this point (it should have been emptied
718 // in the first call to overflow()).
719 const int_type __tmp = this->overflow();
720 if (traits_type::eq_int_type(__tmp, traits_type::eof()))
727 template<typename _CharT, typename _Traits>
729 basic_filebuf<_CharT, _Traits>::
734 // Make sure that the internal buffer resyncs its idea of
735 // the file position with the external file.
736 // NB: _M_file.sync() will be called within.
737 if (this->pbase() < this->pptr())
739 const int_type __tmp = this->overflow();
740 if (traits_type::eq_int_type(__tmp, traits_type::eof()))
747 template<typename _CharT, typename _Traits>
749 basic_filebuf<_CharT, _Traits>::
750 imbue(const locale& __loc)
752 if (this->_M_buf_locale != __loc)
754 bool __testfail = false;
757 const bool __testbeg =
758 this->seekoff(0, ios_base::cur, this->_M_mode) ==
759 pos_type(off_type(0));
760 const bool __teststate =
761 __check_facet(_M_codecvt).encoding() == -1;
763 __testfail = !__testbeg || __teststate;
768 this->_M_buf_locale = __loc;
769 if (__builtin_expect(has_facet<__codecvt_type>(__loc), true))
770 _M_codecvt = &use_facet<__codecvt_type>(__loc);
774 // NB This may require the reconversion of previously
775 // converted chars. This in turn may cause the
776 // reconstruction of the original file. YIKES!! This
777 // implementation interprets this requirement as requiring
778 // the file position be at the beginning, and a stateless
779 // encoding, or that the filebuf be closed. Opinions may differ.
784 // Inhibit implicit instantiations for required instantiations,
785 // which are defined via explicit instantiations elsewhere.
786 // NB: This syntax is a GNU extension.
787 #if _GLIBCXX_EXTERN_TEMPLATE
788 extern template class basic_filebuf<char>;
789 extern template class basic_ifstream<char>;
790 extern template class basic_ofstream<char>;
791 extern template class basic_fstream<char>;
793 #ifdef _GLIBCXX_USE_WCHAR_T
794 extern template class basic_filebuf<wchar_t>;
795 extern template class basic_ifstream<wchar_t>;
796 extern template class basic_ofstream<wchar_t>;
797 extern template class basic_fstream<wchar_t>;