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;
164 if (__testin && this->is_open())
166 // For a stateful encoding (-1) the pending sequence might be just
167 // shift and unshift prefixes with no actual character.
168 __ret = this->egptr() - this->gptr();
169 if (__check_facet(_M_codecvt).encoding() >= 0)
170 __ret += _M_file.showmanyc() / _M_codecvt->max_length();
175 template<typename _CharT, typename _Traits>
176 typename basic_filebuf<_CharT, _Traits>::int_type
177 basic_filebuf<_CharT, _Traits>::
180 int_type __ret = traits_type::eof();
181 const bool __testin = this->_M_mode & ios_base::in;
182 const bool __testout = this->_M_mode & ios_base::out;
183 if (__testin && !_M_writing)
185 // Check for pback madness, and if so swich back to the
186 // normal buffers and jet outta here before expensive
190 if (this->gptr() < this->egptr())
191 return traits_type::to_int_type(*this->gptr());
193 // Get and convert input sequence.
194 const size_t __buflen = this->_M_buf_size > 1
195 ? this->_M_buf_size - 1 : 1;
197 // Will be set to true if ::read() returns 0 indicating EOF.
198 bool __got_eof = false;
199 // Number of internal characters produced.
200 streamsize __ilen = 0;
201 codecvt_base::result __r = codecvt_base::ok;
202 if (__check_facet(_M_codecvt).always_noconv())
204 __ilen = _M_file.xsgetn(reinterpret_cast<char*>(this->eback()),
211 // Worst-case number of external bytes.
212 // XXX Not done encoding() == -1.
213 const int __enc = _M_codecvt->encoding();
214 streamsize __blen; // Minimum buffer size.
215 streamsize __rlen; // Number of chars to read.
217 __blen = __rlen = __buflen * __enc;
220 __blen = __buflen + _M_codecvt->max_length() - 1;
223 const streamsize __remainder = _M_ext_end - _M_ext_next;
224 __rlen = __rlen > __remainder ? __rlen - __remainder : 0;
226 // Allocate buffer if necessary and move unconverted
228 if (_M_ext_buf_size < __blen)
230 char* __buf = new char[__blen];
232 std::memcpy(__buf, _M_ext_next, __remainder);
234 delete [] _M_ext_buf;
236 _M_ext_buf_size = __blen;
238 else if (__remainder > 0)
239 std::memmove(_M_ext_buf, _M_ext_next, __remainder);
241 _M_ext_next = _M_ext_buf;
242 _M_ext_end = _M_ext_buf + __remainder;
243 _M_state_last = _M_state_cur;
250 // This may fail if the return value of
251 // codecvt::max_length() is bogus.
252 if (_M_ext_end - _M_ext_buf + __rlen > _M_ext_buf_size)
254 __throw_ios_failure("basic_filebuf::underflow "
255 "codecvt::max_length() "
258 streamsize __elen = _M_file.xsgetn(_M_ext_end, __rlen);
261 else if (__elen == -1)
263 _M_ext_end += __elen;
267 __r = _M_codecvt->in(_M_state_cur, _M_ext_next,
268 _M_ext_end, _M_ext_next, this->eback(),
269 this->eback() + __buflen, __iend);
270 if (__r == codecvt_base::noconv)
272 size_t __avail = _M_ext_end - _M_ext_buf;
273 __ilen = std::min(__avail, __buflen);
274 traits_type::copy(this->eback(),
275 reinterpret_cast<char_type*>(_M_ext_buf), __ilen);
276 _M_ext_next = _M_ext_buf + __ilen;
279 __ilen = __iend - this->eback();
281 // _M_codecvt->in may return error while __ilen > 0: this is
282 // ok, and actually occurs in case of mixed encodings (e.g.,
284 if (__r == codecvt_base::error)
289 while (__ilen == 0 && !__got_eof);
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
305 // However, reaching it while looping on partial means that
306 // the file has got an incomplete character.
307 if (__r == codecvt_base::partial)
308 __throw_ios_failure("basic_filebuf::underflow "
309 "incomplete character in file");
311 else if (__r == codecvt_base::error)
312 __throw_ios_failure("basic_filebuf::underflow "
313 "invalid byte sequence in file");
315 __throw_ios_failure("basic_filebuf::underflow "
316 "error reading the file");
321 template<typename _CharT, typename _Traits>
322 typename basic_filebuf<_CharT, _Traits>::int_type
323 basic_filebuf<_CharT, _Traits>::
324 pbackfail(int_type __i)
326 int_type __ret = traits_type::eof();
327 const bool __testin = this->_M_mode & ios_base::in;
328 if (__testin && !_M_writing)
330 // Remember whether the pback buffer is active, otherwise below
331 // we may try to store in it a second char (libstdc++/9761).
332 const bool __testpb = this->_M_pback_init;
333 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;
381 if (__testout && !_M_reading)
383 if (this->pbase() < this->pptr())
385 // If appropriate, append the overflow char.
388 *this->pptr() = traits_type::to_char_type(__c);
392 // Convert pending sequence to external representation,
394 if (_M_convert_to_external(this->pbase(),
395 this->pptr() - this->pbase())
396 && (!__testeof || (__testeof && !_M_file.sync())))
399 __ret = traits_type::not_eof(__c);
402 else if (this->_M_buf_size > 1)
404 // Overflow in 'uncommitted' mode: set _M_writing, set
405 // the buffer to the initial 'write' mode, and put __c
411 *this->pptr() = traits_type::to_char_type(__c);
414 __ret = traits_type::not_eof(__c);
419 char_type __conv = traits_type::to_char_type(__c);
420 if (__testeof || _M_convert_to_external(&__conv, 1))
423 __ret = traits_type::not_eof(__c);
430 template<typename _CharT, typename _Traits>
432 basic_filebuf<_CharT, _Traits>::
433 _M_convert_to_external(_CharT* __ibuf, streamsize __ilen)
435 // Sizes of external and pending output.
436 streamsize __elen = 0;
437 streamsize __plen = 0;
438 if (__check_facet(_M_codecvt).always_noconv())
440 __elen += _M_file.xsputn(reinterpret_cast<char*>(__ibuf), __ilen);
445 // Worst-case number of external bytes needed.
446 // XXX Not done encoding() == -1.
447 streamsize __blen = __ilen * _M_codecvt->max_length();
448 char* __buf = static_cast<char*>(__builtin_alloca(__blen));
451 const char_type* __iend;
452 codecvt_base::result __r;
453 __r = _M_codecvt->out(_M_state_cur, __ibuf, __ibuf + __ilen,
454 __iend, __buf, __buf + __blen, __bend);
456 if (__r == codecvt_base::ok || __r == codecvt_base::partial)
457 __blen = __bend - __buf;
458 else if (__r == codecvt_base::noconv)
460 // Same as the always_noconv case above.
461 __buf = reinterpret_cast<char*>(__ibuf);
472 __elen += _M_file.xsputn(__buf, __blen);
476 // Try once more for partial conversions.
477 if (__r == codecvt_base::partial)
479 const char_type* __iresume = __iend;
480 streamsize __rlen = this->pptr() - __iend;
481 __r = _M_codecvt->out(_M_state_cur, __iresume,
482 __iresume + __rlen, __iend, __buf,
483 __buf + __blen, __bend);
484 if (__r != codecvt_base::error)
486 __rlen = __bend - __buf;
487 __elen += _M_file.xsputn(__buf, __rlen);
492 return __elen && __elen == __plen;
495 template<typename _CharT, typename _Traits>
497 basic_filebuf<_CharT, _Traits>::
498 xsputn(const _CharT* __s, streamsize __n)
500 // Optimization in the always_noconv() case, to be generalized in the
501 // future: when __n is sufficiently large we write directly instead of
503 streamsize __ret = 0;
504 const bool __testout = this->_M_mode & ios_base::out;
505 if (__testout && !_M_reading
506 && __check_facet(_M_codecvt).always_noconv())
508 // Measurement would reveal the best choice.
509 const streamsize __chunk = 1ul << 10;
510 streamsize __bufavail = this->epptr() - this->pptr();
512 // Don't mistake 'uncommitted' mode buffered with unbuffered.
513 if (!_M_writing && this->_M_buf_size > 1)
514 __bufavail = this->_M_buf_size - 1;
516 const streamsize __limit = std::min(__chunk, __bufavail);
519 const streamsize __buffill = this->pptr() - this->pbase();
520 const char* __buf = reinterpret_cast<const char*>(this->pbase());
521 __ret = _M_file.xsputn_2(__buf, __buffill,
522 reinterpret_cast<const char*>(__s),
524 if (__ret == __buffill + __n)
529 if (__ret > __buffill)
535 __ret = __streambuf_type::xsputn(__s, __n);
538 __ret = __streambuf_type::xsputn(__s, __n);
542 template<typename _CharT, typename _Traits>
543 typename basic_filebuf<_CharT, _Traits>::__streambuf_type*
544 basic_filebuf<_CharT, _Traits>::
545 setbuf(char_type* __s, streamsize __n)
547 if (!this->is_open())
548 if (__s == 0 && __n == 0)
549 this->_M_buf_size = 1;
550 else if (__s && __n > 0)
552 // This is implementation-defined behavior, and assumes that
553 // an external char_type array of length __n exists and has
554 // been pre-allocated. If this is not the case, things will
555 // quickly blow up. When __n > 1, __n - 1 positions will be
556 // used for the get area, __n - 1 for the put area and 1
557 // position to host the overflow char of a full put area.
558 // When __n == 1, 1 position will be used for the get area
559 // and 0 for the put area, as in the unbuffered case above.
561 this->_M_buf_size = __n;
567 // According to 27.8.1.4 p11 - 13, seekoff should ignore the last
568 // argument (of type openmode).
569 template<typename _CharT, typename _Traits>
570 typename basic_filebuf<_CharT, _Traits>::pos_type
571 basic_filebuf<_CharT, _Traits>::
572 seekoff(off_type __off, ios_base::seekdir __way, ios_base::openmode)
576 __width = _M_codecvt->encoding();
580 pos_type __ret = pos_type(off_type(-1));
581 const bool __testfail = __off != 0 && __width <= 0;
582 if (this->is_open() && !__testfail)
584 // Ditch any pback buffers to avoid confusion.
587 // Correct state at destination. Note that this is the correct
588 // state for the current position during output, because
589 // codecvt::unshift() returns the state to the initial state.
590 // This is also the correct state at the end of the file because
591 // an unshift sequence should have been written at the end.
592 __state_type __state = _M_state_beg;
593 off_type __computed_off = __off * __width;
594 if (_M_reading && __way == ios_base::cur)
596 if (_M_codecvt->always_noconv())
597 __computed_off += this->gptr() - this->egptr();
600 // Calculate offset from _M_ext_buf that corresponds
601 // to gptr(). Note: uses _M_state_last, which
602 // corresponds to eback().
603 const int __gptr_off =
604 _M_codecvt->length(_M_state_last, _M_ext_buf, _M_ext_next,
605 this->gptr() - this->eback());
606 __computed_off += _M_ext_buf + __gptr_off - _M_ext_end;
608 // _M_state_last is modified by codecvt::length() so
609 // it now corresponds to gptr().
610 __state = _M_state_last;
613 __ret = _M_seek(__computed_off, __way, __state);
618 // _GLIBCXX_RESOLVE_LIB_DEFECTS
619 // 171. Strange seekpos() semantics due to joint position
620 // According to the resolution of DR 171, seekpos should ignore the last
621 // argument (of type openmode).
622 template<typename _CharT, typename _Traits>
623 typename basic_filebuf<_CharT, _Traits>::pos_type
624 basic_filebuf<_CharT, _Traits>::
625 seekpos(pos_type __pos, ios_base::openmode)
627 pos_type __ret = pos_type(off_type(-1));
630 // Ditch any pback buffers to avoid confusion.
632 __ret = _M_seek(off_type(__pos), ios_base::beg, __pos.state());
637 template<typename _CharT, typename _Traits>
638 typename basic_filebuf<_CharT, _Traits>::pos_type
639 basic_filebuf<_CharT, _Traits>::
640 _M_seek(off_type __off, ios_base::seekdir __way, __state_type __state)
642 pos_type __ret = pos_type(off_type(-1));
643 if (_M_terminate_output())
645 // Returns pos_type(off_type(-1)) in case of failure.
646 __ret = pos_type(_M_file.seekoff(__off, __way));
649 _M_ext_next = _M_ext_end = _M_ext_buf;
651 _M_state_cur = __state;
652 __ret.state(_M_state_cur);
657 template<typename _CharT, typename _Traits>
659 basic_filebuf<_CharT, _Traits>::
660 _M_terminate_output()
662 // Part one: update the output sequence.
663 bool __testvalid = true;
664 if (this->pbase() < this->pptr())
666 const int_type __tmp = this->overflow();
667 if (traits_type::eq_int_type(__tmp, traits_type::eof()))
671 // Part two: output unshift sequence.
672 if (_M_writing && !__check_facet(_M_codecvt).always_noconv()
675 // Note: this value is arbitrary, since there is no way to
676 // get the length of the unshift sequence from codecvt,
677 // without calling unshift.
678 const size_t __blen = 128;
680 codecvt_base::result __r;
681 streamsize __ilen = 0;
686 __r = _M_codecvt->unshift(_M_state_cur, __buf,
687 __buf + __blen, __next);
688 if (__r == codecvt_base::error)
690 else if (__r == codecvt_base::ok ||
691 __r == codecvt_base::partial)
693 __ilen = __next - __buf;
696 const streamsize __elen = _M_file.xsputn(__buf, __ilen);
697 if (__elen != __ilen)
702 while (__r == codecvt_base::partial && __ilen > 0 && __testvalid);
706 // This second call to overflow() is required by the standard,
707 // but it's not clear why it's needed, since the output buffer
708 // should be empty by this point (it should have been emptied
709 // in the first call to overflow()).
710 const int_type __tmp = this->overflow();
711 if (traits_type::eq_int_type(__tmp, traits_type::eof()))
718 template<typename _CharT, typename _Traits>
720 basic_filebuf<_CharT, _Traits>::
723 // Make sure that the internal buffer resyncs its idea of
724 // the file position with the external file.
725 // NB: _M_file.sync() will be called within.
727 if (this->pbase() < this->pptr())
729 const int_type __tmp = this->overflow();
730 if (traits_type::eq_int_type(__tmp, traits_type::eof()))
736 template<typename _CharT, typename _Traits>
738 basic_filebuf<_CharT, _Traits>::
739 imbue(const locale& __loc)
741 bool __testfail = false;
744 const pos_type __ret = this->seekoff(0, ios_base::cur,
746 const bool __teststate = __check_facet(_M_codecvt).encoding() == -1;
747 __testfail = __teststate && __ret != pos_type(off_type(0));
752 if (__builtin_expect(has_facet<__codecvt_type>(__loc), true))
753 _M_codecvt = &use_facet<__codecvt_type>(__loc);
759 // Inhibit implicit instantiations for required instantiations,
760 // which are defined via explicit instantiations elsewhere.
761 // NB: This syntax is a GNU extension.
762 #if _GLIBCXX_EXTERN_TEMPLATE
763 extern template class basic_filebuf<char>;
764 extern template class basic_ifstream<char>;
765 extern template class basic_ofstream<char>;
766 extern template class basic_fstream<char>;
768 #ifdef _GLIBCXX_USE_WCHAR_T
769 extern template class basic_filebuf<wchar_t>;
770 extern template class basic_ifstream<wchar_t>;
771 extern template class basic_ofstream<wchar_t>;
772 extern template class basic_fstream<wchar_t>;