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/*
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* Copyright (c) 1996,1997
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* Silicon Graphics Computer Systems, Inc.
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*
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* Copyright (c) 1999
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* Boris Fomitchev
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*
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* This material is provided "as is", with absolutely no warranty expressed
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* or implied. Any use is at your own risk.
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*
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* Permission to use or copy this software for any purpose is hereby granted
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* without fee, provided the above notices are retained on all copies.
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* Permission to modify the code and to distribute modified code is granted,
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* provided the above notices are retained, and a notice that the code was
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* modified is included with the above copyright notice.
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*
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*/
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#ifndef _STLP_FSTREAM_C
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#define _STLP_FSTREAM_C
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#ifndef _STLP_INTERNAL_FSTREAM_H
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# include <stl/_fstream.h>
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#endif
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#ifndef _STLP_INTERNAL_LIMITS
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# include <stl/_limits.h>
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#endif
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_STLP_BEGIN_NAMESPACE
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# if defined ( _STLP_NESTED_TYPE_PARAM_BUG )
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// no wchar_t is supported for this mode
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# define __BF_int_type__ int
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# define __BF_pos_type__ streampos
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# define __BF_off_type__ streamoff
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# else
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# define __BF_int_type__ _STLP_TYPENAME_ON_RETURN_TYPE basic_filebuf<_CharT, _Traits>::int_type
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# define __BF_pos_type__ _STLP_TYPENAME_ON_RETURN_TYPE basic_filebuf<_CharT, _Traits>::pos_type
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# define __BF_off_type__ _STLP_TYPENAME_ON_RETURN_TYPE basic_filebuf<_CharT, _Traits>::off_type
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# endif
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//----------------------------------------------------------------------
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// Public basic_filebuf<> member functions
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template <class _CharT, class _Traits>
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basic_filebuf<_CharT, _Traits>::basic_filebuf()
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: basic_streambuf<_CharT, _Traits>(), _M_base(),
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_M_constant_width(false), _M_always_noconv(false),
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_M_int_buf_dynamic(false),
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_M_in_input_mode(false), _M_in_output_mode(false),
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_M_in_error_mode(false), _M_in_putback_mode(false),
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_M_int_buf(0), _M_int_buf_EOS(0),
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_M_ext_buf(0), _M_ext_buf_EOS(0),
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_M_ext_buf_converted(0), _M_ext_buf_end(0),
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_M_state(_STLP_DEFAULT_CONSTRUCTED(_State_type)),
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_M_end_state(_STLP_DEFAULT_CONSTRUCTED(_State_type)),
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_M_mmap_base(0), _M_mmap_len(0),
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_M_saved_eback(0), _M_saved_gptr(0), _M_saved_egptr(0),
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_M_codecvt(0),
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_M_width(1), _M_max_width(1)
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{
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this->_M_setup_codecvt(locale(), false);
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}
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template <class _CharT, class _Traits>
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basic_filebuf<_CharT, _Traits>*
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basic_filebuf<_CharT, _Traits>::close() {
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bool __ok = this->is_open();
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if (_M_in_output_mode) {
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__ok = __ok && !_Traits::eq_int_type(this->overflow(traits_type::eof()),
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traits_type::eof());
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__ok == __ok && this->_M_unshift();
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}
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else if (_M_in_input_mode)
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this->_M_exit_input_mode();
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// Note order of arguments. We close the file even if __ok is false.
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__ok = _M_base._M_close() && __ok;
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// Restore the initial state, except that we don't deallocate the buffer
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// or mess with the cached codecvt information.
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_M_state = _M_end_state = _State_type();
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_M_ext_buf_converted = _M_ext_buf_end = 0;
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_M_mmap_base = 0;
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_M_mmap_len = 0;
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this->setg(0, 0, 0);
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this->setp(0, 0);
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_M_saved_eback = _M_saved_gptr = _M_saved_egptr = 0;
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_M_in_input_mode = _M_in_output_mode = _M_in_error_mode = _M_in_putback_mode
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= false;
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return __ok ? this : 0;
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}
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// This member function is called whenever we exit input mode.
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// It unmaps the memory-mapped file, if any, and sets
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// _M_in_input_mode to false.
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template <class _CharT, class _Traits>
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void basic_filebuf<_CharT, _Traits>::_M_exit_input_mode() {
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if (_M_mmap_base != 0)
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_M_base._M_unmap(_M_mmap_base, _M_mmap_len);
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_M_in_input_mode = false;
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_M_mmap_base = 0;
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}
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//----------------------------------------------------------------------
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// basic_filebuf<> helper functions.
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//----------------------------------------
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// Helper functions for switching between modes.
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// This member function is called if we're performing the first I/O
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// operation on a filebuf, or if we're performing an input operation
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// immediately after a seek.
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template <class _CharT, class _Traits>
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bool basic_filebuf<_CharT, _Traits>::_M_switch_to_input_mode() {
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if (this->is_open() && (((int)_M_base.__o_mode() & (int)ios_base::in) != 0)
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&& (_M_in_output_mode == 0) && (_M_in_error_mode == 0)) {
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if (!_M_int_buf && !_M_allocate_buffers())
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return false;
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_M_ext_buf_converted = _M_ext_buf;
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_M_ext_buf_end = _M_ext_buf;
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_M_end_state = _M_state;
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_M_in_input_mode = true;
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return true;
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}
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return false;
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}
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// This member function is called if we're performing the first I/O
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// operation on a filebuf, or if we're performing an output operation
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// immediately after a seek.
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template <class _CharT, class _Traits>
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bool basic_filebuf<_CharT, _Traits>::_M_switch_to_output_mode() {
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if (this->is_open() && (_M_base.__o_mode() & (int)ios_base::out) &&
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_M_in_input_mode == 0 && _M_in_error_mode == 0) {
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if (!_M_int_buf && !_M_allocate_buffers())
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return false;
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// In append mode, every write does an implicit seek to the end
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// of the file. Whenever leaving output mode, the end of file
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// get put in the initial shift state.
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if (_M_base.__o_mode() & ios_base::app)
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_M_state = _State_type();
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this->setp(_M_int_buf, _M_int_buf_EOS - 1);
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_M_in_output_mode = true;
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return true;
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}
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return false;
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}
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//----------------------------------------
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// Helper functions for input
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// This member function is called if there is an error during input.
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// It puts the filebuf in error mode, clear the get area buffer, and
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// returns eof.
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// returns eof. Error mode is sticky; it is cleared only by close or
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// seek.
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template <class _CharT, class _Traits>
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__BF_int_type__
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basic_filebuf<_CharT, _Traits>::_M_input_error() {
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this->_M_exit_input_mode();
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_M_in_output_mode = false;
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_M_in_error_mode = true;
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this->setg(0, 0, 0);
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return traits_type::eof();
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}
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template <class _CharT, class _Traits>
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__BF_int_type__
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basic_filebuf<_CharT, _Traits>::_M_underflow_aux() {
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// We have the state and file position from the end of the internal
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// buffer. This round, they become the beginning of the internal buffer.
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_M_state = _M_end_state;
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// Fill the external buffer. Start with any leftover characters that
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// didn't get converted last time.
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if (_M_ext_buf_end > _M_ext_buf_converted)
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_M_ext_buf_end = copy(_M_ext_buf_converted, _M_ext_buf_end, _M_ext_buf);
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// boris : copy_backward did not work
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//_M_ext_buf_end = copy_backward(_M_ext_buf_converted, _M_ext_buf_end,
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//_M_ext_buf+ (_M_ext_buf_end - _M_ext_buf_converted));
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else
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_M_ext_buf_end = _M_ext_buf;
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// Now fill the external buffer with characters from the file. This is
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// a loop because occasionally we don't get enough external characters
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// to make progress.
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for (;;) {
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ptrdiff_t __n = _M_base._M_read(_M_ext_buf_end, _M_ext_buf_EOS - _M_ext_buf_end);
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// Don't enter error mode for a failed read. Error mode is sticky,
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// and we might succeed if we try again.
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if (__n <= 0)
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return traits_type::eof();
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// Convert the external buffer to internal characters.
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_M_ext_buf_end += __n;
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const char* __enext;
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_CharT* __inext;
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typename _Codecvt::result __status
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= _M_codecvt->in(_M_end_state,
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_M_ext_buf, _M_ext_buf_end, __enext,
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_M_int_buf, _M_int_buf_EOS, __inext);
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// Error conditions: (1) Return value of error. (2) Producing internal
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// characters without consuming external characters. (3) In fixed-width
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// encodings, producing an internal sequence whose length is inconsistent
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// with that of the internal sequence. (4) Failure to produce any
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// characters if we have enough characters in the external buffer, where
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// "enough" means the largest possible width of a single character.
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if (__status == _Codecvt::noconv)
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return _Noconv_input<_Traits>::_M_doit(this);
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else if (__status == _Codecvt::error ||
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(__inext != _M_int_buf && __enext == _M_ext_buf) ||
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(_M_constant_width &&
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// __inext - _M_int_buf != _M_width * (__enext - _M_ext_buf)) ||
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(__inext - _M_int_buf) * _M_width != (__enext - _M_ext_buf)) ||
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(__inext == _M_int_buf && __enext - _M_ext_buf >= _M_max_width))
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return _M_input_error();
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else if (__inext != _M_int_buf) {
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_M_ext_buf_converted = _M_ext_buf + (__enext - _M_ext_buf);
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this->setg(_M_int_buf, _M_int_buf, __inext);
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return traits_type::to_int_type(*_M_int_buf);
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}
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// We need to go around the loop again to get more external characters.
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}
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}
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//----------------------------------------
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// Helper functions for output
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// This member function is called if there is an error during output.
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// It puts the filebuf in error mode, clear the put area buffer, and
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// returns eof. Error mode is sticky; it is cleared only by close or
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// seek.
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template <class _CharT, class _Traits>
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__BF_int_type__
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basic_filebuf<_CharT, _Traits>::_M_output_error() {
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_M_in_output_mode = false;
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_M_in_input_mode = false;
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_M_in_error_mode = true;
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this->setp(0, 0);
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return traits_type::eof();
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}
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// Write whatever sequence of characters is necessary to get back to
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// the initial shift state. This function overwrites the external
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// buffer, changes the external file position, and changes the state.
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// Precondition: the internal buffer is empty.
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template <class _CharT, class _Traits>
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bool basic_filebuf<_CharT, _Traits>::_M_unshift() {
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if (_M_in_output_mode && !_M_constant_width) {
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typename _Codecvt::result __status;
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do {
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char* __enext = _M_ext_buf;
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__status = _M_codecvt->unshift(_M_state,
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_M_ext_buf, _M_ext_buf_EOS, __enext);
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if (__status == _Codecvt::noconv ||
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(__enext == _M_ext_buf && __status == _Codecvt::ok))
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return true;
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else if (__status == _Codecvt::error)
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return false;
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else if (!_M_write(_M_ext_buf, __enext - _M_ext_buf))
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return false;
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} while (__status == _Codecvt::partial);
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}
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return true;
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}
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//----------------------------------------
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// Helper functions for buffer allocation and deallocation
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// This member function is called when we're initializing a filebuf's
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// internal and external buffers. The argument is the size of the
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// internal buffer; the external buffer is sized using the character
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// width in the current encoding. Preconditions: the buffers are currently
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// null. __n >= 1. __buf is either a null pointer or a pointer to an
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// array show size is at least __n.
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// We need __n >= 1 for two different reasons. For input, the base
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// class always needs a buffer because of the semantics of underflow().
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// For output, we want to have an internal buffer that's larger by one
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// element than the buffer that the base class knows about. (See
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// basic_filebuf<>::overflow() for the reason.)
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template <class _CharT, class _Traits>
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bool basic_filebuf<_CharT, _Traits>::_M_allocate_buffers(_CharT* __buf, streamsize __n) {
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//The major hypothesis in the following implementation is that size_t is unsigned.
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//We also need streamsize byte representation to be larger or equal to the int
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//representation to correctly store the encoding information.
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_STLP_STATIC_ASSERT(!numeric_limits<size_t>::is_signed &&
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sizeof(streamsize) >= sizeof(int))
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318 |
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319 |
if (__buf == 0) {
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streamsize __bufsize = __n * sizeof(_CharT);
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//We first check that the streamsize representation can't overflow a size_t one.
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//If it can, we check that __bufsize is not higher than the size_t max value.
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if ((sizeof(streamsize) > sizeof(size_t)) &&
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(__bufsize > __STATIC_CAST(streamsize, (numeric_limits<size_t>::max)())))
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return false;
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_M_int_buf = __STATIC_CAST(_CharT*, malloc(__STATIC_CAST(size_t, __bufsize)));
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if (!_M_int_buf)
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return false;
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_M_int_buf_dynamic = true;
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}
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else {
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_M_int_buf = __buf;
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_M_int_buf_dynamic = false;
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}
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streamsize __ebufsiz = (max)(__n * __STATIC_CAST(streamsize, _M_width),
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__STATIC_CAST(streamsize, _M_codecvt->max_length()));
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_M_ext_buf = 0;
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if ((sizeof(streamsize) < sizeof(size_t)) ||
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((sizeof(streamsize) == sizeof(size_t)) && numeric_limits<streamsize>::is_signed) ||
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(__ebufsiz <= __STATIC_CAST(streamsize, (numeric_limits<size_t>::max)()))) {
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_M_ext_buf = __STATIC_CAST(char*, malloc(__STATIC_CAST(size_t, __ebufsiz)));
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}
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if (!_M_ext_buf) {
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_M_deallocate_buffers();
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return false;
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}
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_M_int_buf_EOS = _M_int_buf + __STATIC_CAST(ptrdiff_t, __n);
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_M_ext_buf_EOS = _M_ext_buf + __STATIC_CAST(ptrdiff_t, __ebufsiz);
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return true;
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}
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|
354 |
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355 |
// Abbreviation for the most common case.
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|
356 |
template <class _CharT, class _Traits>
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|
357 |
bool basic_filebuf<_CharT, _Traits>::_M_allocate_buffers() {
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|
358 |
// Choose a buffer that's at least 4096 characters long and that's a
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|
359 |
// multiple of the page size.
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|
360 |
streamsize __default_bufsiz =
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361 |
((_M_base.__page_size() + 4095UL) / _M_base.__page_size()) * _M_base.__page_size();
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|
362 |
return _M_allocate_buffers(0, __default_bufsiz);
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|
363 |
}
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|
364 |
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|
365 |
template <class _CharT, class _Traits>
|
|
366 |
void basic_filebuf<_CharT, _Traits>::_M_deallocate_buffers() {
|
|
367 |
if (_M_int_buf_dynamic)
|
|
368 |
free(_M_int_buf);
|
|
369 |
free(_M_ext_buf);
|
|
370 |
_M_int_buf = 0;
|
|
371 |
_M_int_buf_EOS = 0;
|
|
372 |
_M_ext_buf = 0;
|
|
373 |
_M_ext_buf_EOS = 0;
|
|
374 |
}
|
|
375 |
|
|
376 |
|
|
377 |
//----------------------------------------
|
|
378 |
// Helper functiosn for seek and imbue
|
|
379 |
|
|
380 |
template <class _CharT, class _Traits>
|
|
381 |
bool basic_filebuf<_CharT, _Traits>::_M_seek_init(bool __do_unshift) {
|
|
382 |
// If we're in error mode, leave it.
|
|
383 |
_M_in_error_mode = false;
|
|
384 |
|
|
385 |
// Flush the output buffer if we're in output mode, and (conditionally)
|
|
386 |
// emit an unshift sequence.
|
|
387 |
if (_M_in_output_mode) {
|
|
388 |
bool __ok = !traits_type::eq_int_type(this->overflow(traits_type::eof()),
|
|
389 |
traits_type::eof());
|
|
390 |
if (__do_unshift)
|
|
391 |
__ok = __ok && this->_M_unshift();
|
|
392 |
if (!__ok) {
|
|
393 |
_M_in_output_mode = false;
|
|
394 |
_M_in_error_mode = true;
|
|
395 |
this->setp(0, 0);
|
|
396 |
return false;
|
|
397 |
}
|
|
398 |
}
|
|
399 |
|
|
400 |
// Discard putback characters, if any.
|
|
401 |
if (_M_in_input_mode && _M_in_putback_mode)
|
|
402 |
_M_exit_putback_mode();
|
|
403 |
|
|
404 |
return true;
|
|
405 |
}
|
|
406 |
|
|
407 |
|
|
408 |
/* Change the filebuf's locale. This member function has no effect
|
|
409 |
* unless it is called before any I/O is performed on the stream.
|
|
410 |
* This function is called on construction and on an imbue call. In the
|
|
411 |
* case of the construction the codecvt facet might be a custom one if
|
|
412 |
* the basic_filebuf user has instanciate it with a custom char_traits.
|
|
413 |
* The user will have to call imbue before any I/O operation.
|
|
414 |
*/
|
|
415 |
template <class _CharT, class _Traits>
|
|
416 |
void basic_filebuf<_CharT, _Traits>::_M_setup_codecvt(const locale& __loc, bool __on_imbue) {
|
|
417 |
if (has_facet<_Codecvt>(__loc)) {
|
|
418 |
_M_codecvt = &use_facet<_Codecvt>(__loc) ;
|
|
419 |
int __encoding = _M_codecvt->encoding();
|
|
420 |
|
|
421 |
_M_width = (max)(__encoding, 1);
|
|
422 |
_M_max_width = _M_codecvt->max_length();
|
|
423 |
_M_constant_width = __encoding > 0;
|
|
424 |
_M_always_noconv = _M_codecvt->always_noconv();
|
|
425 |
}
|
|
426 |
else {
|
|
427 |
_M_codecvt = 0;
|
|
428 |
_M_width = _M_max_width = 1;
|
|
429 |
_M_constant_width = _M_always_noconv = false;
|
|
430 |
if (__on_imbue) {
|
|
431 |
//This call will generate an exception reporting the problem.
|
|
432 |
use_facet<_Codecvt>(__loc);
|
|
433 |
}
|
|
434 |
}
|
|
435 |
}
|
|
436 |
|
|
437 |
_STLP_END_NAMESPACE
|
|
438 |
|
|
439 |
# undef __BF_int_type__
|
|
440 |
# undef __BF_pos_type__
|
|
441 |
# undef __BF_off_type__
|
|
442 |
|
|
443 |
#endif /* _STLP_FSTREAM_C */
|
|
444 |
|
|
445 |
// Local Variables:
|
|
446 |
// mode:C++
|
|
447 |
// End:
|