| // -*- C++ -*- |
| /*************************************************************************** |
| * |
| * fstream.cc - Definition for the Standard Library file streams |
| * |
| * $Id$ |
| * |
| *************************************************************************** |
| * |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed |
| * with this work for additional information regarding copyright |
| * ownership. The ASF licenses this file to you under the Apache |
| * License, Version 2.0 (the "License"); you may not use this file |
| * except in compliance with the License. You may obtain a copy of |
| * the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or |
| * implied. See the License for the specific language governing |
| * permissions and limitations under the License. |
| * |
| * Copyright 1997-2008 Rogue Wave Software, Inc. |
| * |
| **************************************************************************/ |
| |
| _RWSTD_NAMESPACE (std) { |
| |
| |
| template<class _CharT, class _Traits> |
| basic_filebuf<_CharT, _Traits>* |
| basic_filebuf<_CharT, _Traits>:: |
| open (const char *__name, ios_base::openmode __mode, long __prot) |
| { |
| _RWSTD_ASSERT (this->_C_is_valid ()); |
| |
| // fail if `mode' has invalid bits set or if the file is already open |
| if ((__mode & ~_RWSTD_IOS_OPENMODE_MASK) || is_open ()) |
| return 0; |
| |
| _C_file = _RW::__rw_fopen (__name, __mode, __prot); |
| |
| if (!_C_file) |
| return 0; |
| |
| pos_type __pos = pos_type (); |
| |
| if (__mode & ios_base::ate) { |
| |
| // the end of a file is assumed to be in the initial shift state |
| // this assumption is safe as long as the file has been properly |
| // closed (or unshifted) after the last write operation on it |
| __pos = _RW::__rw_fseek (_C_file, 0, 0, ios_base::end); |
| |
| if (-1L == __pos) { |
| _RW::__rw_fclose (_C_file, 0); |
| _C_file = 0; |
| return 0; |
| } |
| } |
| |
| _C_beg_pos = _C_cur_pos = __pos; |
| |
| this->_C_state &= ~_RWSTD_IOS_OPENMODE_MASK; |
| this->_C_state |= __mode; |
| |
| return this; |
| } |
| |
| |
| template<class _CharT, class _Traits> |
| basic_filebuf<_CharT, _Traits>* |
| basic_filebuf<_CharT, _Traits>:: |
| close (bool __close_file /* = true */) |
| { |
| // close_file is false when close() is called from detach() |
| |
| _RWSTD_ASSERT (this->_C_is_valid ()); |
| |
| if (!is_open ()) |
| return 0; // failure |
| |
| // close() returns this on success, 0 on failure |
| basic_filebuf *__retval = this; |
| |
| _TRY { |
| // avoid expensive call to overflow() unless necessary |
| if (this->pptr () != this->pbase () && this->_C_is_eof (overflow ())) |
| __retval = 0; // failure |
| |
| // write out any unshift sequence if necessary |
| // (applies to multibyte, state dependent encodings only) |
| if (__retval && this->_C_out_last () && !_C_unshift ()) |
| __retval = 0; // failure |
| } |
| _CATCH (...) { |
| // either overflow() or codecvt::unshift() threw |
| |
| if (__close_file) { |
| _RW::__rw_fclose (_C_file, this->_C_state); |
| |
| // zero out the file pointer except when detaching fd |
| _C_file = 0; |
| _C_cur_pos = _C_beg_pos = pos_type (off_type (-1)); |
| |
| // reset input/output sequences to prevent any |
| // subsequent I/O attempts on closed file |
| this->setg (0, 0, 0); |
| this->setp (0, 0); |
| } |
| |
| // rethrow the caught exception |
| _RETHROW; |
| } |
| |
| if (__close_file) { |
| if (_RW::__rw_fclose (_C_file, this->_C_state)) |
| __retval = 0; |
| |
| // zero out the file pointer except when detaching fd |
| _C_file = 0; |
| _C_cur_pos = _C_beg_pos = pos_type (off_type (-1)); |
| |
| // reset input/output sequences to prevent any |
| // subsequent I/O attempts on closed file |
| this->setg (0, 0, 0); |
| this->setp (0, 0); |
| } |
| |
| return __retval; |
| } |
| |
| |
| template<class _CharT, class _Traits> |
| streamsize |
| basic_filebuf<_CharT, _Traits>:: |
| showmanyc () |
| { |
| _RWSTD_ASSERT (this->_C_is_valid ()); |
| |
| if ( !this->_C_is_in () || !is_open () |
| || _C_cur_pos == pos_type (off_type (-1))) |
| return -1; |
| |
| // start with the number of chars in get area |
| _RWSTD_STREAMSIZE __retval = this->egptr () - this->gptr (); |
| |
| // no prob if this fails for non-seekable devices |
| const pos_type __end_pos = |
| _RW::__rw_fseek (_C_file, this->_C_state, 0, ios_base::end); |
| |
| if (__end_pos != pos_type (off_type (-1))) { |
| |
| // restore position within file only if seek succeeded |
| _RW::__rw_fseek (_C_file, this->_C_state, _C_cur_pos, ios_base::beg); |
| |
| typedef typename traits_type::state_type _StateT; |
| typedef codecvt<char_type, char, _StateT> _Codecvt; |
| |
| const _Codecvt &__cvt = _USE_FACET (_Codecvt, this->getloc ()); |
| |
| if (__cvt.always_noconv ()) |
| __retval += __end_pos - _C_cur_pos; |
| else |
| // make most pessimistic conversion estimate |
| __retval += (__end_pos - _C_cur_pos) / __cvt.max_length (); |
| } |
| |
| return __retval > 0 ? __retval : 0; |
| } |
| |
| |
| template<class _CharT, class _Traits> |
| typename basic_filebuf<_CharT, _Traits>::int_type |
| basic_filebuf<_CharT, _Traits>:: |
| underflow () |
| { |
| _RWSTD_ASSERT (this->_C_is_valid ()); |
| |
| this->setp (0, 0); // invalidate put area |
| |
| this->_C_out_last (false); // needed by close () |
| |
| if (!this->_C_is_in () || !is_open()) |
| return traits_type::eof (); |
| |
| char_type* const __to_end = this->_C_buffer + this->_C_bufsize; |
| |
| typedef typename traits_type::int_type _IntType; |
| |
| _IntType __ret = _IntType (); |
| |
| // fill the buffer if it's empty |
| |
| if (this->gptr () == this->egptr()) { // N.B.: gptr() could be null here |
| |
| // determine the maximum possible size of putback area (if any) |
| // make sure putback area isn't too big - try to honor |
| // _RWSTD_PBACK_SIZE if possible, otherwise shrink |
| |
| const _RWSTD_SIZE_T __pbackavail = this->_C_putback_avail (); |
| _C_pbacksize = __pbackavail < _RWSTD_PBACK_SIZE ? |
| __pbackavail : _RWSTD_PBACK_SIZE; |
| |
| _RWSTD_ASSERT (0 != this->_C_bufsize); |
| |
| if (_C_pbacksize == this->_C_bufsize) |
| _C_pbacksize = this->_C_bufsize - 1; |
| |
| traits_type::move (this->eback(), this->gptr () - _C_pbacksize, |
| _C_pbacksize); |
| |
| // fill the get area from the file, performing code conversion if |
| // necessary |
| |
| _RWSTD_STREAMSIZE __nread = 0; // number of bytes read from file |
| |
| _C_beg_pos = _C_cur_pos; |
| |
| typedef typename traits_type::state_type _StateT; |
| typedef codecvt<char_type, char, _StateT> _Codecvt; |
| |
| const _Codecvt &__cvt = _USE_FACET (_Codecvt, this->getloc ()); |
| |
| if (__cvt.always_noconv ()) { |
| // no conversion required |
| __nread = (__to_end - this->_C_buffer) - _C_pbacksize; |
| __nread = _RW::__rw_fread (_C_file, this->_C_state, |
| this->_C_buffer + _C_pbacksize, |
| sizeof (char_type) * __nread); |
| if (__nread < 0) |
| return traits_type::eof (); // error while reading |
| |
| this->setg (this->_C_buffer, |
| this->_C_buffer + _C_pbacksize, |
| this->_C_buffer + _C_pbacksize + __nread); |
| |
| // adjust the current position in the file, |
| // taking into account CR/LF conversion on windows |
| __nread += _C_crlf_intern_count (this->gptr (), |
| this->gptr () + __nread); |
| } |
| else { // conversion required |
| |
| char __xbuf [_RWSTD_DEFAULT_BUFSIZE]; |
| char* __from_base = __xbuf; |
| const char* __from_next = 0; |
| char_type* __to_base = this->_C_buffer + _C_pbacksize; |
| char_type* __to_next = __to_base; |
| |
| _StateT __state = _C_cur_pos.state (); |
| |
| codecvt_base::result __res = codecvt_base::ok; |
| |
| const ctype<char_type> &__ctp = |
| _USE_FACET (ctype<char_type>, this->getloc ()); |
| |
| while (__to_next != __to_end && codecvt_base::error != __res) { |
| |
| // read only as many characters as we have positions left in |
| // internal buffer - guarantees we won't read more characters |
| // than we can put into the internal buffer after conversion |
| // and ending file position isn't in the middle of a shift |
| // sequence |
| // N.B.: area between __xbuf and __from_base contains partially |
| // converted sequences left from previous read |
| _RWSTD_STREAMSIZE __n = __to_end - __to_next; |
| if (_RWSTD_DEFAULT_BUFSIZE - (__from_base - __xbuf) < __n) |
| __n = _RWSTD_DEFAULT_BUFSIZE - (__from_base - __xbuf); |
| |
| __n = _RW::__rw_fread (_C_file, this->_C_state, |
| __from_base, __n); |
| |
| if (0 > __n) |
| return traits_type::eof (); // error while reading |
| |
| if (0 == __n) |
| break; // reached eof |
| |
| // take into account CR/LF conversion on Win32 |
| __nread += __n + |
| _C_crlf_extern_count (__from_base, __from_base + __n); |
| |
| // adjust 'n' to hold the number of external chars in buffer |
| __n += __from_base - __xbuf; |
| |
| // convert any partially converted sequence from the previous |
| // iteration (possibly empty) plus what we just read in |
| __res = __cvt.in (__state, __xbuf, __xbuf + __n, __from_next, |
| __to_base, __to_end, __to_next); |
| |
| switch (__res) { |
| case codecvt_base::ok: |
| // there may be yet unconverted elements at the end |
| // of the source sequence, fall through and treat |
| // as partial (`n' below may be 0) |
| |
| case codecvt_base::partial: |
| // compute the length of partially converted sequence |
| __n -= __from_next - __xbuf; |
| |
| typedef char_traits<char> CharTraits; |
| |
| // copy the sequence to beginning of xbuf |
| CharTraits::move (__xbuf, __from_next, __n); |
| |
| // will append external chars to end of the sequence |
| __from_base = __xbuf + __n; |
| break; |
| |
| case codecvt_base::noconv: |
| // note that according to lwg issue 19, codecvt<wchar_t, |
| // char>::in() may not return noconv since internT and |
| // externT are not the same type |
| |
| // since codecvt<char, char>::always_noconv() is required |
| // to return true, this branch only executes for a user- |
| // defined codecvt<T, T> facet with internT and externT |
| // being the same type |
| |
| // FIXME: do not widen external buffer just memcpy it |
| // to internal buffer (externT == internT) |
| __ctp.widen (__xbuf, __xbuf + __n, __to_base); |
| __to_next = __to_base + __n; |
| break; |
| |
| case codecvt_base::error: |
| // failed to convert part of the buffer |
| // retain the part that has been successfully |
| // converted, and disregard the rest |
| __ret = traits_type::eof (); |
| break; |
| |
| default: |
| // bad return value from codecvt |
| return traits_type::eof (); |
| } |
| __to_base = __to_next; // continue at end of converted seq |
| } |
| |
| _C_cur_pos.state (__state); |
| |
| this->setg (this->_C_buffer, this->_C_buffer + _C_pbacksize, |
| __to_next); |
| } // end conversion block |
| |
| if (__nread == 0) |
| return traits_type::eof (); |
| |
| _C_cur_pos += __nread; |
| } |
| |
| return traits_type::eq_int_type (__ret, _IntType ()) ? |
| traits_type::to_int_type (*this->gptr ()) : __ret; |
| } |
| |
| |
| template<class _CharT, class _Traits> |
| typename basic_filebuf<_CharT, _Traits>::int_type |
| basic_filebuf<_CharT, _Traits>:: |
| overflow (int_type __c /* = eof () */) |
| { |
| _RWSTD_ASSERT (this->_C_is_valid ()); |
| |
| if (!this->_C_is_out () || !is_open ()) |
| return traits_type::eof (); |
| |
| this->setg (0, 0, 0); // invalidate the get area |
| |
| const bool __unbuf = this->_C_is_unbuffered (); |
| |
| const char_type __c_to_char = traits_type::to_char_type (__c); |
| |
| if (this->pptr () == 0 && !__unbuf) { |
| // put area not valid yet - just need to initialize it |
| this->setp (this->_C_buffer, this->_C_buf_end ()); |
| } |
| else if ( this->pptr () == this->epptr () |
| || this->_C_is_eof (__c) |
| || __unbuf) { |
| |
| const char_type* __buf; |
| _RWSTD_STREAMSIZE __nchars; |
| |
| if (__unbuf) { |
| if (this->_C_is_eof (__c)){ |
| __buf = 0; |
| __nchars = 0; |
| } |
| else { |
| __buf = &__c_to_char; |
| __nchars = 1; |
| } |
| } |
| else { |
| // call xsputn() with a special value to have it flush |
| // the controlled sequence to the file |
| __buf = _RWSTD_REINTERPRET_CAST (char_type*, this); |
| __nchars = this->pptr () - this->pbase (); |
| } |
| |
| // typedef helps HP aCC 3.27 |
| typedef basic_filebuf _FileBuf; |
| |
| if (__nchars != _FileBuf::xsputn (__buf, __nchars)) |
| return traits_type::eof (); // error while writing |
| } |
| |
| // now that there's room in the buffer, call sputc() recursively |
| // to actually place the character in the buffer (unless we're |
| // in unbuffered mode because we just wrote it out) |
| if (!this->_C_is_eof (__c) && !__unbuf) |
| this->sputc (__c_to_char); |
| |
| this->_C_out_last (true); // needed by close () |
| |
| return traits_type::not_eof (__c); |
| } |
| |
| |
| template <class _CharT, class _Traits> |
| _RWSTD_STREAMSIZE |
| basic_filebuf<_CharT, _Traits>:: |
| xsputn (const char_type* __buf, _RWSTD_STREAMSIZE __nchars) |
| { |
| _RWSTD_ASSERT (0 != __buf || 0 == __nchars); |
| _RWSTD_ASSERT (this->_C_is_valid ()); |
| |
| if (0 == __nchars) |
| return 0; // not an error |
| |
| if (__nchars < 0 || !this->_C_is_out () || !is_open ()) |
| return -1; // error |
| |
| if (0 == this->pptr () && !this->_C_is_unbuffered ()) |
| // put area not valid yet - just need to initialize it |
| this->setp (this->_C_buffer, this->_C_buf_end ()); |
| |
| const _RWSTD_STREAMSIZE __navail = this->epptr () - this->pptr (); |
| |
| const char_type* const __special = |
| _RWSTD_REINTERPRET_CAST (char_type*, this); |
| |
| if (__buf == __special) { |
| __buf = this->pbase (); |
| } |
| else if (__nchars <= __navail) { |
| // the amount of available space is big enough |
| |
| // append the contents of the buffer to the controlled sequence |
| traits_type::copy (this->pptr (), __buf, __nchars); |
| |
| this->pbump (__nchars); |
| |
| return __nchars; |
| } |
| else { |
| // call self recursively to flush the controlled sequence first |
| const _RWSTD_STREAMSIZE __nwrite = this->pptr () - this->pbase (); |
| |
| // typedef helps HP aCC 3.27 |
| typedef basic_filebuf _FileBuf; |
| |
| // return -1 on error to flush the controlled sequence |
| if (__nwrite != _FileBuf::xsputn (__special, __nwrite)) |
| return -1; |
| } |
| |
| // flush buffer to file, performing code conversion if necessary |
| |
| _RWSTD_ASSERT (this->_C_is_valid ()); |
| _RWSTD_ASSERT (this->_C_is_out ()); |
| _RWSTD_ASSERT (is_open ()); |
| |
| const char_type* const __end = __buf + __nchars; |
| |
| typedef typename traits_type::state_type _StateT; |
| |
| _RWSTD_STREAMSIZE __nwrote = 0; // num chars to write |
| _StateT __state = _C_cur_pos.state (); // state of stream |
| |
| _C_beg_pos = _C_cur_pos; |
| |
| typedef codecvt<char_type, char, _StateT> _Codecvt; |
| |
| const _Codecvt &__cvt = _USE_FACET (_Codecvt, this->getloc ()); |
| |
| if (__cvt.always_noconv ()) { |
| |
| // no conversion |
| |
| __nwrote = __end - __buf; |
| |
| const _RWSTD_STREAMSIZE __nbytes = sizeof (char_type) * __nwrote; |
| |
| if (__nbytes != _RW::__rw_fwrite (_C_file, this->_C_state, |
| __buf, __nbytes)) |
| return -1; // error while writing |
| } |
| else { |
| |
| // perform codeset conversion in chunks to avoid dynamic |
| // memory allocation |
| |
| char __xbuf [_RWSTD_DEFAULT_BUFSIZE]; |
| char* __xbuf_end = __xbuf + sizeof __xbuf; |
| char* __to_next = 0; |
| const char_type* __from_next = 0; |
| |
| for (const char_type* __base = __buf; __from_next != __end; |
| __base = __from_next) { |
| |
| // avoid using const codecvt_base::result here |
| // to prevent HP aCC 3.27 errors |
| const int __res = |
| __cvt.out (__state, __base, __end, __from_next, |
| __xbuf, __xbuf_end, __to_next); |
| |
| _RWSTD_STREAMSIZE __nbytes = |
| sizeof (char_type) * (__end - __base); |
| |
| switch (__res) { |
| case codecvt_base::error: |
| // write out the sequence successfully converted up |
| // to the point of the error in the internal sequence |
| // and fail |
| _RW::__rw_fwrite (_C_file, this->_C_state, __base, __nbytes); |
| return traits_type::eof (); |
| |
| case codecvt_base::noconv: |
| // write the entire sequence |
| if (__nbytes != _RW::__rw_fwrite (_C_file, this->_C_state, |
| __base, __nbytes)) |
| return traits_type::eof (); |
| |
| __nwrote += __end - __base |
| + _C_crlf_intern_count (__base, __end); |
| |
| __from_next = __end; // effectively 'break' |
| break; |
| |
| default: |
| _RWSTD_ASSERT ( codecvt_base::ok == __res |
| || codecvt_base::partial == __res); |
| |
| // partial conversion will result if there isn't enough |
| // space in the conversion buffer to hold the converted |
| // sequence, but we're O.K. since we'll be passing any |
| // remaining unconverted characters (starting at |
| // __from_next) in the next iteration |
| |
| __nbytes = __to_next - __xbuf; |
| |
| if (__nbytes != _RW::__rw_fwrite (_C_file, this->_C_state, |
| __xbuf, __nbytes)) |
| return -1; |
| |
| __nwrote += __nbytes |
| + _C_crlf_extern_count (__xbuf, __to_next); |
| } |
| } |
| } |
| |
| // adjust the current position in the file |
| _C_cur_pos += __nwrote; |
| _C_cur_pos.state (__state); |
| |
| // reset the put area |
| if (!this->_C_is_unbuffered ()) |
| this->setp (this->_C_buffer, this->_C_buf_end ()); |
| |
| this->_C_out_last (true); // needed by close () |
| |
| // return the number of characters (not bytes) in the buffer |
| // successfully written to the file |
| return __nchars; |
| } |
| |
| |
| template<class _CharT, class _Traits> |
| typename basic_filebuf<_CharT, _Traits>::int_type |
| basic_filebuf<_CharT, _Traits>:: |
| pbackfail (int_type __c) |
| { |
| _RWSTD_ASSERT (this->_C_is_valid ()); |
| |
| if (!is_open ()) |
| return traits_type::eof (); |
| |
| // we could get here if gptr = eback or if __c != *(gptr-1) |
| if (!this->_C_putback_avail ()) { |
| // try to make a putback area available |
| |
| if (this->seekoff (-1, ios_base::cur) == pos_type (off_type (-1))) |
| return traits_type::eof (); |
| |
| if (this->_C_is_eof (underflow ())) |
| return traits_type::eof (); |
| |
| this->gbump (1); |
| } |
| |
| if (traits_type::eq (traits_type::to_char_type (__c), *(this->gptr () - 1)) |
| || this->_C_is_eof (__c)) { |
| // "put back" original value |
| this->gbump (-1); |
| return traits_type::not_eof (__c); |
| } |
| else if (this->_C_is_out ()) { |
| // overwrite existing value with new value |
| this->gbump (-1); |
| *this->gptr () = traits_type::to_char_type (__c); |
| return __c; |
| } |
| else |
| return traits_type::eof (); |
| } |
| |
| |
| template<class _CharT, class _Traits> |
| basic_streambuf<_CharT, _Traits>* |
| basic_filebuf<_CharT, _Traits>:: |
| setbuf (char_type *__buf, streamsize __ssize) |
| { |
| _RWSTD_ASSERT (this->_C_is_valid ()); |
| |
| if (__ssize < 0) |
| return 0; |
| |
| const _RWSTD_SIZE_T __bufsize = |
| _RWSTD_STATIC_CAST (_RWSTD_SIZE_T, __ssize); |
| |
| // sync the buffer to the external file so it can be deallocated |
| if ((this->gptr () || this->pptr ()) && is_open () && sync () != 0) |
| return 0; |
| |
| bool __reset = true; |
| |
| if (0 < __bufsize) { |
| |
| if (!__buf && (this->_C_bufsize < __bufsize || !this->_C_buffer)) { |
| // if `buf' is 0 and the requested size is greater than |
| // the size of the object's buffer, or of the object's |
| // buffer is 0, try to allocate a new buffer of the |
| // specified size |
| __buf = new char_type [__bufsize]; |
| |
| // delete old buffer if the object owns it |
| if (this->_C_own_buf ()) |
| delete [] this->_C_buffer; |
| |
| // take ownership of the newly allocated buffer |
| this->_C_own_buf (true); |
| } |
| else if (!__buf && __bufsize <= this->_C_bufsize) { |
| // if `buf' is 0 and the requested size is less than |
| // the size of the object's buffer, simply reuse the |
| // object's buffer |
| |
| __buf = this->_C_buffer; |
| __reset = false; |
| } |
| else if (__buf && __buf != this->_C_buffer) { |
| // if `buf' is non-0 and different from the existing |
| // buffer, use it |
| |
| // delete old buffer if the object owns it |
| if (this->_C_own_buf ()) |
| delete [] this->_C_buffer; |
| |
| // the object does not own of the new buffer |
| this->_C_own_buf (false); |
| } |
| |
| this->_C_buffer = __buf; |
| this->_C_bufsize = __bufsize; |
| this->_C_set_unbuffered (false); |
| } |
| else { |
| // unbuffer this stream object |
| |
| // character buffer is preserved (used as get area only), |
| // streambuf object unbuffered for writing |
| |
| // to put a streambuf object into an unbuffered mode (see 27.8.1.4, |
| // p10) and affect the size of the get area, setbuf() should first |
| // be called with the desired (non-zero) size and then again with |
| // both arguments being 0 |
| this->_C_set_unbuffered (true); |
| } |
| |
| if (__reset) { |
| this->setg (0, 0, 0); |
| this->setp (0, 0); |
| } |
| |
| // a character buffer of nonzero size must exist even in unbuffered mode |
| _RWSTD_ASSERT (0 != this->_C_buffer); |
| _RWSTD_ASSERT (0 != this->_C_bufsize); |
| |
| return this; |
| } |
| |
| |
| // 27.8.1.4, p 11 |
| template<class _CharT, class _Traits> |
| typename basic_filebuf<_CharT, _Traits>::pos_type |
| basic_filebuf<_CharT, _Traits>:: |
| seekoff (off_type __off, ios_base::seekdir __way, ios_base::openmode) |
| { |
| _RWSTD_ASSERT (this->_C_is_valid ()); |
| |
| if (!is_open ()) |
| return pos_type (off_type (-1)); |
| |
| typedef typename traits_type::state_type _StateT; |
| typedef codecvt<char_type, char, _StateT> _Codecvt; |
| |
| const int __width = _USE_FACET (_Codecvt, this->getloc ()).encoding (); |
| |
| // offset must be zero with state-dependent encoding |
| if (0 != __off && __width <= 0) |
| return pos_type (off_type (-1)); |
| |
| // sync the buffer... (this also invalidates the get/put area) |
| if (sync () != 0) |
| return pos_type (off_type (-1)); |
| |
| // ...and, if last operation was output, append an unshift sequence |
| if (this->_C_out_last ()) |
| _C_unshift (); |
| |
| if (__width > 1) |
| __off *= __width; |
| |
| // perform the seek and save the result |
| pos_type __pos = _RW::__rw_fseek (_C_file, this->_C_state, __off, __way); |
| |
| if (__pos != pos_type (off_type (-1))) { |
| |
| // preserve the current state if not changing position |
| // (only matters for state-dependent encodings for which |
| // the offset is required and guaranteed to be 0) |
| if (__way == ios_base::cur) |
| __pos.state (_C_cur_pos.state ()); |
| |
| _C_beg_pos = _C_cur_pos = __pos; |
| } |
| |
| this->_C_out_last (false); // needed by close() |
| |
| return __pos; |
| } |
| |
| |
| template<class _CharT, class _Traits> |
| typename basic_filebuf<_CharT, _Traits>::pos_type |
| basic_filebuf<_CharT, _Traits>:: |
| seekpos (pos_type __pos, ios_base::openmode) |
| { |
| _RWSTD_ASSERT (this->_C_is_valid ()); |
| |
| if (!is_open ()) |
| return pos_type (off_type (-1)); |
| |
| // flush the output area if it exists |
| if (this->pptr () != 0) { |
| if (this->_C_is_eof (this->overflow (traits_type::eof ()))) |
| return pos_type (off_type (-1)); |
| } |
| |
| if ( _RW::__rw_fseek (_C_file, this->_C_state, __pos, ios_base::beg) |
| == pos_type (off_type (-1))) |
| return pos_type (off_type (-1)); |
| |
| _C_cur_pos = _C_beg_pos = __pos; |
| |
| this->setg (0, 0, 0); |
| this->setp (0, 0); |
| |
| this->_C_out_last (false); // needed by close() |
| |
| return __pos; |
| } |
| |
| |
| template<class _CharT, class _Traits> |
| int |
| basic_filebuf<_CharT, _Traits>:: |
| sync () |
| { |
| _RWSTD_ASSERT (this->_C_is_valid ()); |
| |
| // put area active |
| if (this->pptr () != 0) { |
| // flush the buffer to the file |
| if (this->_C_is_eof (overflow (traits_type::eof ()))) |
| return -1; |
| |
| if (this->_C_state & _RWSTD_IOS_STDIO) |
| _RW::__rw_fflush (_C_file, this->_C_state); |
| } |
| |
| // get area active |
| if (this->gptr () != 0) { |
| |
| // pbacksize may need to be adjusted if it's greater than |
| // the available putback area (e.g., after calling putback() |
| // at the end of the buffer) |
| const _RWSTD_SIZE_T __pbackavail = this->_C_putback_avail (); |
| if (__pbackavail < _C_pbacksize) |
| _C_pbacksize = __pbackavail; |
| |
| _RWSTD_ASSERT (0 != this->_C_bufsize); |
| |
| if (_C_pbacksize == this->_C_bufsize) |
| _C_pbacksize = this->_C_bufsize - 1; |
| |
| typedef typename traits_type::state_type _StateT; |
| typedef codecvt<char_type, char, _StateT> _Codecvt; |
| |
| const _Codecvt &__cvt = _USE_FACET (_Codecvt, this->getloc ()); |
| int __width = __cvt.encoding (); |
| |
| if (__width > 0) { |
| // get the number of chars consumed in the buffer |
| const off_type __consumed = |
| this->gptr () - this->eback () - _C_pbacksize; |
| |
| // constant width conversion: |
| // adjust the current position/state in the file, |
| // taking into account CR/LF conversion on Win32 |
| _C_cur_pos = _C_beg_pos; |
| _C_cur_pos += (__width * __consumed) |
| + _C_crlf_intern_count (this->eback () + _C_pbacksize, |
| this->gptr()); |
| } |
| else { |
| // This gets a bit tricky here because we don't know the external |
| // file position corresponding to the position in the |
| // internal buffer. To figure this out, we'll use the known |
| // file position/state corresponding to the start of the buffer |
| // (which we have carefully saved in _C_beg_pos) and |
| // convert the characters up to the current position in the |
| // buffer, counting how many external chars result. We can |
| // then use the offset from _C_beg_pos and the state |
| // returned from codecvt::out() to construct the current file |
| // position |
| |
| off_type __ext_chars = 0; // converted external chars |
| |
| char __xbuf [_RWSTD_DEFAULT_BUFSIZE]; |
| char* __xbuf_end = __xbuf + sizeof __xbuf; |
| char* __to_next = 0; |
| const char_type* __from_next = 0; |
| const char_type* __from_end = this->gptr (); |
| _StateT __state = _C_beg_pos.state (); |
| const char_type* __base = this->eback () + _C_pbacksize; |
| |
| while (__from_next != __from_end) { |
| const int __res = |
| __cvt.out (__state, __base, __from_end, __from_next, |
| __xbuf, __xbuf_end, __to_next); |
| |
| switch (__res) { |
| case codecvt_base::error: |
| return -1; |
| |
| case codecvt_base::noconv: |
| __ext_chars += __from_end - __base |
| + _C_crlf_intern_count (__base, __from_end); |
| __from_next = __from_end; // break out of the loop |
| break; |
| |
| default: // __res = ok or partial |
| // take into account CR/LF conversion on Win32 |
| __ext_chars += __to_next - __xbuf |
| + _C_crlf_extern_count (__xbuf, __to_next); |
| } |
| // repeat with next chunk |
| __base = __from_next; |
| } |
| |
| _C_cur_pos = _C_beg_pos; |
| _C_cur_pos += __ext_chars; |
| _C_cur_pos.state (__state); |
| } |
| |
| // seek within the external file to the position |
| // corresponding to the future beginning of the buffer |
| const off_type __off = |
| _RW::__rw_fseek (_C_file, this->_C_state, |
| _C_cur_pos, ios_base::beg); |
| |
| if (-1L == __off) |
| return -1; |
| |
| traits_type::move (this->eback (), this->gptr () - _C_pbacksize, |
| _C_pbacksize); |
| |
| this->setg (this->eback (), this->eback () + _C_pbacksize, |
| this->eback () + _C_pbacksize); |
| } |
| |
| _C_beg_pos = _C_cur_pos; |
| |
| this->setp (0, 0); |
| |
| return 0; |
| } |
| |
| |
| template<class _CharT, class _Traits> |
| basic_filebuf<_CharT, _Traits>* |
| basic_filebuf<_CharT, _Traits>:: |
| _C_open (int __fd, void *__file, char_type *__buf, streamsize __n) |
| { |
| if (is_open () || !__file && -1 == __fd || !setbuf (__buf, __n)) |
| return 0; |
| |
| if (__file) { |
| _RWSTD_ASSERT (-1 == __fd); |
| |
| _C_file = __file; |
| |
| this->_C_state |= this->_C_stdio; |
| } |
| else { |
| _RWSTD_ASSERT (!__file); |
| |
| _C_file = _RW::__rw_fdopen (__fd); |
| |
| if (!_C_file) |
| return 0; |
| |
| this->_C_state &= ~this->_C_stdio; |
| } |
| |
| this->_C_state |= _RW::__rw_fmode (_C_file, this->_C_state); |
| |
| this->setg (0, 0, 0); |
| this->setp (0, 0); |
| |
| _C_cur_pos = _C_beg_pos = pos_type (); |
| |
| return this; |
| } |
| |
| |
| // write out an unshift sequence if not in initial shift state |
| template<class _CharT, class _Traits> |
| bool |
| basic_filebuf<_CharT, _Traits>:: |
| _C_unshift () |
| { |
| typedef typename traits_type::state_type _StateT; |
| typedef codecvt<char_type, char, _StateT> _Codecvt; |
| |
| const _Codecvt &__cvt = _USE_FACET (_Codecvt, this->getloc ()); |
| |
| // unshifting isn't necessary if encoding isn't state dependent |
| // or if the state is equivalent to initial state (determined |
| // by codecvt::unshift()) |
| if (__cvt.encoding () >= 0) |
| return true; |
| |
| // buf to hold unshift sequence - assumes that the shift |
| // sequence will be less than 64 chars (we can't safely |
| // use dynamic allocation because this function could be |
| // called as a result of memory allocation exception) |
| |
| char __useq [64]; |
| char* __useq_end = 0; |
| |
| _StateT __state = _C_cur_pos.state (); |
| |
| const int __res = |
| __cvt.unshift (__state, __useq, __useq + sizeof __useq, __useq_end); |
| |
| const _RWSTD_STREAMSIZE __nbytes = __useq_end - __useq; |
| |
| // in the unlikely event that the buffer isn't big enough, assert |
| _RWSTD_ASSERT (__res != codecvt_base::partial); |
| |
| if (__res == codecvt_base::error) |
| return false; |
| |
| if (__res == codecvt_base::noconv) |
| return true; |
| |
| const off_type __nwrote = |
| _RW::__rw_fwrite (_C_file, this->_C_state, __useq, __nbytes); |
| |
| if (__nwrote < 0) |
| return false; |
| |
| _C_cur_pos += __nwrote; // CR/LF conversion not an issue here |
| |
| return __nwrote == __nbytes; |
| } |
| |
| |
| } // namespace std |
