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 // Allocate internal buffer only if one doesn't already exist
48 // (either allocated or provided by the user via setbuf).
49 if (!_M_buf_allocated && !this->_M_buf)
51 this->_M_buf = new char_type[this->_M_buf_size];
52 _M_buf_allocated = true;
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())
137 { __testfail = true; }
139 // NB: Do this here so that re-opened filebufs will be cool...
140 this->_M_mode = ios_base::openmode(0);
141 this->_M_pback_init = false;
142 _M_destroy_internal_buffer();
146 _M_state_last = _M_state_cur = _M_state_beg;
148 if (!_M_file.close())
157 template<typename _CharT, typename _Traits>
159 basic_filebuf<_CharT, _Traits>::
162 streamsize __ret = -1;
163 const bool __testin = this->_M_mode & ios_base::in;
165 if (__testin && this->is_open())
167 // For a stateful encoding (-1) the pending sequence might be just
168 // shift and unshift prefixes with no actual character.
169 __ret = this->egptr() - this->gptr();
170 if (__check_facet(_M_codecvt).encoding() >= 0)
171 __ret += _M_file.showmanyc() / _M_codecvt->max_length();
177 template<typename _CharT, typename _Traits>
178 typename basic_filebuf<_CharT, _Traits>::int_type
179 basic_filebuf<_CharT, _Traits>::
182 int_type __ret = traits_type::eof();
183 const bool __testin = this->_M_mode & ios_base::in;
184 const bool __testout = this->_M_mode & ios_base::out;
186 if (__testin && !_M_writing)
188 // Check for pback madness, and if so swich back to the
189 // normal buffers and jet outta here before expensive
193 if (this->gptr() < this->egptr())
194 return traits_type::to_int_type(*this->gptr());
196 // Get and convert input sequence.
197 const size_t __buflen = this->_M_buf_size > 1
198 ? this->_M_buf_size - 1 : 1;
200 // Will be set to true if ::read() returns 0 indicating EOF.
201 bool __got_eof = false;
202 // Number of internal characters produced.
203 streamsize __ilen = 0;
204 codecvt_base::result __r = codecvt_base::ok;
205 if (__check_facet(_M_codecvt).always_noconv())
207 __ilen = _M_file.xsgetn(reinterpret_cast<char*>(this->eback()),
214 // Worst-case number of external bytes.
215 // XXX Not done encoding() == -1.
216 const int __enc = _M_codecvt->encoding();
217 streamsize __blen; // Minimum buffer size.
218 streamsize __rlen; // Number of chars to read.
220 __blen = __rlen = __buflen * __enc;
223 __blen = __buflen + _M_codecvt->max_length() - 1;
226 const streamsize __remainder = _M_ext_end - _M_ext_next;
227 __rlen = __rlen > __remainder ? __rlen - __remainder : 0;
229 // Allocate buffer if necessary and move unconverted
231 if (_M_ext_buf_size < __blen)
233 char* __buf = new char[__blen];
235 std::memcpy(__buf, _M_ext_next, __remainder);
237 delete [] _M_ext_buf;
239 _M_ext_buf_size = __blen;
241 else if (__remainder > 0)
242 std::memmove(_M_ext_buf, _M_ext_next, __remainder);
244 _M_ext_next = _M_ext_buf;
245 _M_ext_end = _M_ext_buf + __remainder;
246 _M_state_last = _M_state_cur;
253 // This may fail if the return value of
254 // codecvt::max_length() is bogus.
255 if (_M_ext_end - _M_ext_buf + __rlen > _M_ext_buf_size)
257 __throw_ios_failure("basic_filebuf::underflow "
258 "codecvt::max_length() "
261 streamsize __elen = _M_file.xsgetn(_M_ext_end, __rlen);
264 _M_ext_end += __elen;
268 __r = _M_codecvt->in(_M_state_cur, _M_ext_next,
269 _M_ext_end, _M_ext_next, this->eback(),
270 this->eback() + __buflen, __iend);
271 if (__r == codecvt_base::noconv)
273 size_t __avail = _M_ext_end - _M_ext_buf;
274 __ilen = std::min(__avail, __buflen);
275 traits_type::copy(this->eback(),
276 reinterpret_cast<char_type*>(_M_ext_buf), __ilen);
277 _M_ext_next = _M_ext_buf + __ilen;
280 __ilen = __iend - this->eback();
282 // _M_codecvt->in may return error while __ilen > 0: this is
283 // ok, and actually occurs in case of mixed encodings (e.g.,
285 if (__r == codecvt_base::error)
290 while (__ilen == 0 && !__got_eof);
295 _M_set_buffer(__ilen);
297 __ret = traits_type::to_int_type(*this->gptr());
301 // If the actual end of file is reached, set 'uncommitted'
302 // mode, thus allowing an immediate write without an
306 // However, reaching it while looping on partial means that
307 // the file has got an incomplete character.
308 if (__r == codecvt_base::partial)
309 __throw_ios_failure("basic_filebuf::underflow "
310 "incomplete character in file");
313 __throw_ios_failure("basic_filebuf::underflow "
314 "invalid byte sequence in file");
319 template<typename _CharT, typename _Traits>
320 typename basic_filebuf<_CharT, _Traits>::int_type
321 basic_filebuf<_CharT, _Traits>::
322 pbackfail(int_type __i)
324 int_type __ret = traits_type::eof();
325 const bool __testin = this->_M_mode & ios_base::in;
327 if (__testin && !_M_writing)
329 // Remember whether the pback buffer is active, otherwise below
330 // we may try to store in it a second char (libstdc++/9761).
331 const bool __testpb = this->_M_pback_init;
332 const bool __testeof = traits_type::eq_int_type(__i, __ret);
335 if (this->eback() < this->gptr())
338 __tmp = traits_type::to_int_type(*this->gptr());
340 else if (this->seekoff(-1, ios_base::cur) != pos_type(off_type(-1)))
342 __tmp = this->underflow();
343 if (traits_type::eq_int_type(__tmp, __ret))
348 // At the beginning of the buffer, need to make a
349 // putback position available. But the seek may fail
350 // (f.i., at the beginning of a file, see
351 // libstdc++/9439) and in that case we return
352 // traits_type::eof().
356 // Try to put back __i into input sequence in one of three ways.
357 // Order these tests done in is unspecified by the standard.
358 if (!__testeof && traits_type::eq_int_type(__i, __tmp))
361 __ret = traits_type::not_eof(__i);
366 *this->gptr() = traits_type::to_char_type(__i);
373 template<typename _CharT, typename _Traits>
374 typename basic_filebuf<_CharT, _Traits>::int_type
375 basic_filebuf<_CharT, _Traits>::
376 overflow(int_type __c)
378 int_type __ret = traits_type::eof();
379 const bool __testeof = traits_type::eq_int_type(__c, __ret);
380 const bool __testout = this->_M_mode & ios_base::out;
382 if (__testout && !_M_reading)
384 if (this->pbase() < this->pptr())
386 // If appropriate, append the overflow char.
389 *this->pptr() = traits_type::to_char_type(__c);
393 // Convert pending sequence to external representation,
395 if (_M_convert_to_external(this->pbase(),
396 this->pptr() - this->pbase())
397 && (!__testeof || (__testeof && !_M_file.sync())))
400 __ret = traits_type::not_eof(__c);
403 else if (this->_M_buf_size > 1)
405 // Overflow in 'uncommitted' mode: set _M_writing, set
406 // the buffer to the initial 'write' mode, and put __c
412 *this->pptr() = traits_type::to_char_type(__c);
415 __ret = traits_type::not_eof(__c);
420 char_type __conv = traits_type::to_char_type(__c);
421 if (__testeof || _M_convert_to_external(&__conv, 1))
424 __ret = traits_type::not_eof(__c);
431 template<typename _CharT, typename _Traits>
433 basic_filebuf<_CharT, _Traits>::
434 _M_convert_to_external(_CharT* __ibuf, streamsize __ilen)
436 // Sizes of external and pending output.
437 streamsize __elen = 0;
438 streamsize __plen = 0;
440 if (__check_facet(_M_codecvt).always_noconv())
442 __elen += _M_file.xsputn(reinterpret_cast<char*>(__ibuf), __ilen);
447 // Worst-case number of external bytes needed.
448 // XXX Not done encoding() == -1.
449 streamsize __blen = __ilen * _M_codecvt->max_length();
450 char* __buf = static_cast<char*>(__builtin_alloca(__blen));
453 const char_type* __iend;
454 codecvt_base::result __r;
455 __r = _M_codecvt->out(_M_state_cur, __ibuf, __ibuf + __ilen,
456 __iend, __buf, __buf + __blen, __bend);
458 if (__r == codecvt_base::ok || __r == codecvt_base::partial)
459 __blen = __bend - __buf;
460 else if (__r == codecvt_base::noconv)
462 // Same as the always_noconv case above.
463 __buf = reinterpret_cast<char*>(__ibuf);
474 __elen += _M_file.xsputn(__buf, __blen);
478 // Try once more for partial conversions.
479 if (__r == codecvt_base::partial)
481 const char_type* __iresume = __iend;
482 streamsize __rlen = this->pptr() - __iend;
483 __r = _M_codecvt->out(_M_state_cur, __iresume,
484 __iresume + __rlen, __iend, __buf,
485 __buf + __blen, __bend);
486 if (__r != codecvt_base::error)
488 __rlen = __bend - __buf;
489 __elen += _M_file.xsputn(__buf, __rlen);
494 return __elen && __elen == __plen;
497 template<typename _CharT, typename _Traits>
499 basic_filebuf<_CharT, _Traits>::
500 xsputn(const _CharT* __s, streamsize __n)
502 streamsize __ret = 0;
504 // Optimization in the always_noconv() case, to be generalized in the
505 // future: when __n is sufficiently large we write directly instead of
507 const bool __testout = this->_M_mode & ios_base::out;
508 if (__testout && !_M_reading
509 && __check_facet(_M_codecvt).always_noconv())
511 // Measurement would reveal the best choice.
512 const streamsize __chunk = 1ul << 10;
513 streamsize __bufavail = this->epptr() - this->pptr();
515 // Don't mistake 'uncommitted' mode buffered with unbuffered.
516 if (!_M_writing && this->_M_buf_size > 1)
517 __bufavail = this->_M_buf_size - 1;
519 const streamsize __limit = std::min(__chunk, __bufavail);
522 const streamsize __buffill = this->pptr() - this->pbase();
523 const char* __buf = reinterpret_cast<const char*>(this->pbase());
524 __ret = _M_file.xsputn_2(__buf, __buffill,
525 reinterpret_cast<const char*>(__s),
527 if (__ret == __buffill + __n)
532 if (__ret > __buffill)
538 __ret = __streambuf_type::xsputn(__s, __n);
541 __ret = __streambuf_type::xsputn(__s, __n);
546 template<typename _CharT, typename _Traits>
547 typename basic_filebuf<_CharT, _Traits>::__streambuf_type*
548 basic_filebuf<_CharT, _Traits>::
549 setbuf(char_type* __s, streamsize __n)
551 if (!this->is_open())
552 if (__s == 0 && __n == 0)
553 this->_M_buf_size = 1;
554 else if (__s && __n > 0)
556 // This is implementation-defined behavior, and assumes that
557 // an external char_type array of length __n exists and has
558 // been pre-allocated. If this is not the case, things will
559 // quickly blow up. When __n > 1, __n - 1 positions will be
560 // used for the get area, __n - 1 for the put area and 1
561 // position to host the overflow char of a full put area.
562 // When __n == 1, 1 position will be used for the get area
563 // and 0 for the put area, as in the unbuffered case above.
565 this->_M_buf_size = __n;
571 // According to 27.8.1.4 p11 - 13, seekoff should ignore the last
572 // argument (of type openmode).
573 template<typename _CharT, typename _Traits>
574 typename basic_filebuf<_CharT, _Traits>::pos_type
575 basic_filebuf<_CharT, _Traits>::
576 seekoff(off_type __off, ios_base::seekdir __way, ios_base::openmode)
578 pos_type __ret = pos_type(off_type(-1));
582 __width = _M_codecvt->encoding();
586 const bool __testfail = __off != 0 && __width <= 0;
587 if (this->is_open() && !__testfail)
589 // Ditch any pback buffers to avoid confusion.
592 // Correct state at destination. Note that this is the correct
593 // state for the current position during output, because
594 // codecvt::unshift() returns the state to the initial state.
595 // This is also the correct state at the end of the file because
596 // an unshift sequence should have been written at the end.
597 __state_type __state = _M_state_beg;
598 off_type __computed_off = __off * __width;
599 if (_M_reading && __way == ios_base::cur)
601 if (_M_codecvt->always_noconv())
602 __computed_off += this->gptr() - this->egptr();
605 // Calculate offset from _M_ext_buf that corresponds
606 // to gptr(). Note: uses _M_state_last, which
607 // corresponds to eback().
608 const int __gptr_off =
609 _M_codecvt->length(_M_state_last, _M_ext_buf, _M_ext_next,
610 this->gptr() - this->eback());
611 __computed_off += _M_ext_buf + __gptr_off - _M_ext_end;
613 // _M_state_last is modified by codecvt::length() so
614 // it now corresponds to gptr().
615 __state = _M_state_last;
618 __ret = _M_seek(__computed_off, __way, __state);
623 // _GLIBCXX_RESOLVE_LIB_DEFECTS
624 // 171. Strange seekpos() semantics due to joint position
625 // According to the resolution of DR 171, seekpos should ignore the last
626 // argument (of type openmode).
627 template<typename _CharT, typename _Traits>
628 typename basic_filebuf<_CharT, _Traits>::pos_type
629 basic_filebuf<_CharT, _Traits>::
630 seekpos(pos_type __pos, ios_base::openmode)
632 pos_type __ret = pos_type(off_type(-1));
636 // Ditch any pback buffers to avoid confusion.
639 __ret = _M_seek(off_type(__pos), ios_base::beg, __pos.state());
644 template<typename _CharT, typename _Traits>
645 typename basic_filebuf<_CharT, _Traits>::pos_type
646 basic_filebuf<_CharT, _Traits>::
647 _M_seek(off_type __off, ios_base::seekdir __way, __state_type __state)
649 pos_type __ret = pos_type(off_type(-1));
650 if (_M_terminate_output())
652 // Returns pos_type(off_type(-1)) in case of failure.
653 __ret = pos_type(_M_file.seekoff(__off, __way));
657 _M_ext_next = _M_ext_end = _M_ext_buf;
659 _M_state_cur = __state;
660 __ret.state(_M_state_cur);
665 template<typename _CharT, typename _Traits>
667 basic_filebuf<_CharT, _Traits>::
668 _M_terminate_output()
670 bool __testvalid = true;
672 // Part one: update the output sequence.
673 if (this->pbase() < this->pptr())
675 const int_type __tmp = this->overflow();
676 if (traits_type::eq_int_type(__tmp, traits_type::eof()))
680 // Part two: output unshift sequence.
681 if (_M_writing && !__check_facet(_M_codecvt).always_noconv()
684 // Note: this value is arbitrary, since there is no way to
685 // get the length of the unshift sequence from codecvt,
686 // without calling unshift.
687 const size_t __blen = 128;
690 codecvt_base::result __r;
691 streamsize __ilen = 0;
696 __r = _M_codecvt->unshift(_M_state_cur, __buf,
697 __buf + __blen, __next);
698 if (__r == codecvt_base::error)
700 else if (__r == codecvt_base::ok ||
701 __r == codecvt_base::partial)
703 __ilen = __next - __buf;
707 const streamsize __elen = _M_file.xsputn(__buf, __ilen);
708 if (__elen != __ilen)
713 while (__r == codecvt_base::partial && __ilen > 0 && __testvalid);
717 // This second call to overflow() is required by the standard,
718 // but it's not clear why it's needed, since the output buffer
719 // should be empty by this point (it should have been emptied
720 // in the first call to overflow()).
721 const int_type __tmp = this->overflow();
722 if (traits_type::eq_int_type(__tmp, traits_type::eof()))
729 template<typename _CharT, typename _Traits>
731 basic_filebuf<_CharT, _Traits>::
736 // Make sure that the internal buffer resyncs its idea of
737 // the file position with the external file.
738 // NB: _M_file.sync() will be called within.
739 if (this->pbase() < this->pptr())
741 const int_type __tmp = this->overflow();
742 if (traits_type::eq_int_type(__tmp, traits_type::eof()))
749 template<typename _CharT, typename _Traits>
751 basic_filebuf<_CharT, _Traits>::
752 imbue(const locale& __loc)
754 bool __testfail = false;
758 const pos_type __ret = this->seekoff(0, ios_base::cur,
760 const bool __teststate = __check_facet(_M_codecvt).encoding() == -1;
761 __testfail = __teststate && __ret != pos_type(off_type(0));
766 if (__builtin_expect(has_facet<__codecvt_type>(__loc), true))
767 _M_codecvt = &use_facet<__codecvt_type>(__loc);
773 // Inhibit implicit instantiations for required instantiations,
774 // which are defined via explicit instantiations elsewhere.
775 // NB: This syntax is a GNU extension.
776 #if _GLIBCXX_EXTERN_TEMPLATE
777 extern template class basic_filebuf<char>;
778 extern template class basic_ifstream<char>;
779 extern template class basic_ofstream<char>;
780 extern template class basic_fstream<char>;
782 #ifdef _GLIBCXX_USE_WCHAR_T
783 extern template class basic_filebuf<wchar_t>;
784 extern template class basic_ifstream<wchar_t>;
785 extern template class basic_ofstream<wchar_t>;
786 extern template class basic_fstream<wchar_t>;