/*
* Copyright (c) 1996,1997
* Silicon Graphics Computer Systems, Inc.
*
* Copyright (c) 1999
* Boris Fomitchev
*
* This material is provided "as is", with absolutely no warranty expressed
* or implied. Any use is at your own risk.
*
* Permission to use or copy this software for any purpose is hereby granted
* without fee, provided the above notices are retained on all copies.
* Permission to modify the code and to distribute modified code is granted,
* provided the above notices are retained, and a notice that the code was
* modified is included with the above copyright notice.
*
*/
#ifndef _STLP_FSTREAM_C
#define _STLP_FSTREAM_C
#ifndef _STLP_INTERNAL_FSTREAM_H
# include <stl/_fstream.h>
#endif
#ifndef _STLP_INTERNAL_LIMITS
# include <stl/_limits.h>
#endif
_STLP_BEGIN_NAMESPACE
# if defined ( _STLP_NESTED_TYPE_PARAM_BUG )
// no wchar_t is supported for this mode
# define __BF_int_type__ int
# define __BF_pos_type__ streampos
# define __BF_off_type__ streamoff
# else
# define __BF_int_type__ _STLP_TYPENAME_ON_RETURN_TYPE basic_filebuf<_CharT, _Traits>::int_type
# define __BF_pos_type__ _STLP_TYPENAME_ON_RETURN_TYPE basic_filebuf<_CharT, _Traits>::pos_type
# define __BF_off_type__ _STLP_TYPENAME_ON_RETURN_TYPE basic_filebuf<_CharT, _Traits>::off_type
# endif
//----------------------------------------------------------------------
// Public basic_filebuf<> member functions
template <class _CharT, class _Traits>
basic_filebuf<_CharT, _Traits>::basic_filebuf()
: basic_streambuf<_CharT, _Traits>(), _M_base(),
_M_constant_width(false), _M_always_noconv(false),
_M_int_buf_dynamic(false),
_M_in_input_mode(false), _M_in_output_mode(false),
_M_in_error_mode(false), _M_in_putback_mode(false),
_M_int_buf(0), _M_int_buf_EOS(0),
_M_ext_buf(0), _M_ext_buf_EOS(0),
_M_ext_buf_converted(0), _M_ext_buf_end(0),
_M_state(_STLP_DEFAULT_CONSTRUCTED(_State_type)),
_M_end_state(_STLP_DEFAULT_CONSTRUCTED(_State_type)),
_M_mmap_base(0), _M_mmap_len(0),
_M_saved_eback(0), _M_saved_gptr(0), _M_saved_egptr(0),
_M_codecvt(0),
_M_width(1), _M_max_width(1)
{
this->_M_setup_codecvt(locale(), false);
}
template <class _CharT, class _Traits>
basic_filebuf<_CharT, _Traits>::~basic_filebuf() {
this->close();
_M_deallocate_buffers();
}
template <class _CharT, class _Traits>
_STLP_TYPENAME_ON_RETURN_TYPE basic_filebuf<_CharT, _Traits>::int_type
basic_filebuf<_CharT, _Traits>::underflow() {
return _Underflow<_CharT, _Traits>::_M_doit(this);
}
template <class _CharT, class _Traits>
basic_filebuf<_CharT, _Traits>*
basic_filebuf<_CharT, _Traits>::close() {
bool __ok = this->is_open();
if (_M_in_output_mode) {
__ok = __ok && !_Traits::eq_int_type(this->overflow(traits_type::eof()),
traits_type::eof());
__ok == __ok && this->_M_unshift();
}
else if (_M_in_input_mode)
this->_M_exit_input_mode();
// Note order of arguments. We close the file even if __ok is false.
__ok = _M_base._M_close() && __ok;
// Restore the initial state, except that we don't deallocate the buffer
// or mess with the cached codecvt information.
_M_state = _M_end_state = _State_type();
_M_ext_buf_converted = _M_ext_buf_end = 0;
_M_mmap_base = 0;
_M_mmap_len = 0;
this->setg(0, 0, 0);
this->setp(0, 0);
_M_saved_eback = _M_saved_gptr = _M_saved_egptr = 0;
_M_in_input_mode = _M_in_output_mode = _M_in_error_mode = _M_in_putback_mode
= false;
return __ok ? this : 0;
}
// This member function is called whenever we exit input mode.
// It unmaps the memory-mapped file, if any, and sets
// _M_in_input_mode to false.
template <class _CharT, class _Traits>
void basic_filebuf<_CharT, _Traits>::_M_exit_input_mode() {
if (_M_mmap_base != 0)
_M_base._M_unmap(_M_mmap_base, _M_mmap_len);
_M_in_input_mode = false;
_M_mmap_base = 0;
}
//----------------------------------------------------------------------
// basic_filebuf<> overridden protected virtual member functions
template <class _CharT, class _Traits>
streamsize basic_filebuf<_CharT, _Traits>::showmanyc() {
// Is there any possibility that reads can succeed?
if (!this->is_open() || _M_in_output_mode || _M_in_error_mode)
return -1;
else if (_M_in_putback_mode)
return this->egptr() - this->gptr();
else if (_M_constant_width) {
streamoff __pos = _M_base._M_seek(0, ios_base::cur);
streamoff __size = _M_base._M_file_size();
return __pos >= 0 && __size > __pos ? __size - __pos : 0;
}
else
return 0;
}
// Make a putback position available, if necessary, by switching to a
// special internal buffer used only for putback. The buffer is
// [_M_pback_buf, _M_pback_buf + _S_pback_buf_size), but the base
// class only sees a piece of it at a time. (We want to make sure
// that we don't try to read a character that hasn't been initialized.)
// The end of the putback buffer is always _M_pback_buf + _S_pback_buf_size,
// but the beginning is usually not _M_pback_buf.
template <class _CharT, class _Traits>
__BF_int_type__
basic_filebuf<_CharT, _Traits>::pbackfail(int_type __c) {
const int_type __eof = traits_type::eof();
// If we aren't already in input mode, pushback is impossible.
if (!_M_in_input_mode)
return __eof;
// We can use the ordinary get buffer if there's enough space, and
// if it's a buffer that we're allowed to write to.
if (this->gptr() != this->eback() &&
(traits_type::eq_int_type(__c, __eof) ||
traits_type::eq(traits_type::to_char_type(__c), this->gptr()[-1]) ||
!_M_mmap_base)) {
this->gbump(-1);
if (traits_type::eq_int_type(__c, __eof) ||
traits_type::eq(traits_type::to_char_type(__c), *this->gptr()))
return traits_type::to_int_type(*this->gptr());
}
else if (!traits_type::eq_int_type(__c, __eof)) {
// Are we in the putback buffer already?
_CharT* __pback_end = _M_pback_buf + __STATIC_CAST(int,_S_pback_buf_size);
if (_M_in_putback_mode) {
// Do we have more room in the putback buffer?
if (this->eback() != _M_pback_buf)
this->setg(this->egptr() - 1, this->egptr() - 1, __pback_end);
else
return __eof; // No more room in the buffer, so fail.
}
else { // We're not yet in the putback buffer.
_M_saved_eback = this->eback();
_M_saved_gptr = this->gptr();
_M_saved_egptr = this->egptr();
this->setg(__pback_end - 1, __pback_end - 1, __pback_end);
_M_in_putback_mode = true;
}
}
else
return __eof;
// We have made a putback position available. Assign to it, and return.
*this->gptr() = traits_type::to_char_type(__c);
return __c;
}
// This member function flushes the put area, and also outputs the
// character __c (unless __c is eof). Invariant: we always leave room
// in the internal buffer for one character more than the base class knows
// about. We see the internal buffer as [_M_int_buf, _M_int_buf_EOS), but
// the base class only sees [_M_int_buf, _M_int_buf_EOS - 1).
template <class _CharT, class _Traits>
__BF_int_type__
basic_filebuf<_CharT, _Traits>::overflow(int_type __c) {
// Switch to output mode, if necessary.
if (!_M_in_output_mode)
if (!_M_switch_to_output_mode())
return traits_type::eof();
_CharT* __ibegin = this->_M_int_buf;
_CharT* __iend = this->pptr();
this->setp(_M_int_buf, _M_int_buf_EOS - 1);
// Put __c at the end of the internal buffer.
if (!traits_type::eq_int_type(__c, traits_type::eof()))
*__iend++ = _Traits::to_char_type(__c);
// For variable-width encodings, output may take more than one pass.
while (__ibegin != __iend) {
const _CharT* __inext = __ibegin;
char* __enext = _M_ext_buf;
typename _Codecvt::result __status
= _M_codecvt->out(_M_state, __ibegin, __iend, __inext,
_M_ext_buf, _M_ext_buf_EOS, __enext);
if (__status == _Codecvt::noconv) {
return _Noconv_output<_Traits>::_M_doit(this, __ibegin, __iend)
? traits_type::not_eof(__c)
: _M_output_error();
}
// For a constant-width encoding we know that the external buffer
// is large enough, so failure to consume the entire internal buffer
// or to produce the correct number of external characters, is an error.
// For a variable-width encoding, however, we require only that we
// consume at least one internal character
else if (__status != _Codecvt::error &&
(((__inext == __iend) &&
(__enext - _M_ext_buf == _M_width * (__iend - __ibegin))) ||
(!_M_constant_width && __inext != __ibegin))) {
// We successfully converted part or all of the internal buffer.
ptrdiff_t __n = __enext - _M_ext_buf;
if (_M_write(_M_ext_buf, __n))
__ibegin += __inext - __ibegin;
else
return _M_output_error();
}
else
return _M_output_error();
}
return traits_type::not_eof(__c);
}
// This member function must be called before any I/O has been
// performed on the stream, otherwise it has no effect.
//
// __buf == 0 && __n == 0 means to make this stream unbuffered.
// __buf != 0 && __n > 0 means to use __buf as the stream's internal
// buffer, rather than the buffer that would otherwise be allocated
// automatically. __buf must be a pointer to an array of _CharT whose
// size is at least __n.
template <class _CharT, class _Traits>
basic_streambuf<_CharT, _Traits>*
basic_filebuf<_CharT, _Traits>::setbuf(_CharT* __buf, streamsize __n) {
if (!_M_in_input_mode &&! _M_in_output_mode && !_M_in_error_mode &&
_M_int_buf == 0) {
if (__buf == 0 && __n == 0)
_M_allocate_buffers(0, 1);
else if (__buf != 0 && __n > 0)
_M_allocate_buffers(__buf, __n);
}
return this;
}
template <class _CharT, class _Traits>
__BF_pos_type__
basic_filebuf<_CharT, _Traits>::seekoff(off_type __off,
ios_base::seekdir __whence,
ios_base::openmode /* dummy */) {
if (this->is_open() &&
(__off == 0 || (_M_constant_width && this->_M_base._M_in_binary_mode()))) {
if (!_M_seek_init(__off != 0 || __whence != ios_base::cur))
return pos_type(-1);
// Seek to beginning or end, regardless of whether we're in input mode.
if (__whence == ios_base::beg || __whence == ios_base::end)
return _M_seek_return(_M_base._M_seek(_M_width * __off, __whence),
_State_type());
// Seek relative to current position. Complicated if we're in input mode.
else if (__whence == ios_base::cur) {
if (!_M_in_input_mode)
return _M_seek_return(_M_base._M_seek(_M_width * __off, __whence),
_State_type());
else if (_M_mmap_base != 0) {
// __off is relative to gptr(). We need to do a bit of arithmetic
// to get an offset relative to the external file pointer.
streamoff __adjust = _M_mmap_len - (this->gptr() - (_CharT*) _M_mmap_base);
// if __off == 0, we do not need to exit input mode and to shift file pointer
return __off == 0 ? pos_type(_M_base._M_seek(0, ios_base::cur) - __adjust)
: _M_seek_return(_M_base._M_seek(__off - __adjust, ios_base::cur), _State_type());
}
else if (_M_constant_width) { // Get or set the position.
streamoff __iadj = _M_width * (this->gptr() - this->eback());
// Compensate for offset relative to gptr versus offset relative
// to external pointer. For a text-oriented stream, where the
// compensation is more than just pointer arithmetic, we may get
// but not set the current position.
if (__iadj <= _M_ext_buf_end - _M_ext_buf) {
streamoff __eadj = _M_base._M_get_offset(_M_ext_buf + __STATIC_CAST(ptrdiff_t, __iadj), _M_ext_buf_end);
return __off == 0 ? pos_type(_M_base._M_seek(0, ios_base::cur) - __eadj)
: _M_seek_return(_M_base._M_seek(__off - __eadj, ios_base::cur), _State_type());
}
} else { // Get the position. Encoding is var width.
// Get position in internal buffer.
ptrdiff_t __ipos = this->gptr() - this->eback();
// Get corresponding position in external buffer.
_State_type __state = _M_state;
int __epos = _M_codecvt->length(__state, _M_ext_buf, _M_ext_buf_end,
__ipos);
if (__epos >= 0) {
// Sanity check (expensive): make sure __epos is the right answer.
_State_type __tmp_state = _M_state;
_Filebuf_Tmp_Buf<_CharT> __buf(__ipos);
_CharT* __ibegin = __buf._M_ptr;
_CharT* __inext = __ibegin;
const char* __dummy;
typename _Codecvt::result __status
= _M_codecvt->in(__tmp_state,
_M_ext_buf, _M_ext_buf + __epos, __dummy,
__ibegin, __ibegin + __ipos, __inext);
if (__status != _Codecvt::error &&
(__status == _Codecvt::noconv ||
(__inext == __ibegin + __ipos &&
equal(this->eback(), this->gptr(), __ibegin, _STLP_PRIV _Eq_traits<traits_type>())))) {
// Get the current position (at the end of the external buffer),
// then adjust it. Again, it might be a text-oriented stream.
streamoff __cur = _M_base._M_seek(0, ios_base::cur);
streamoff __adj =
_M_base._M_get_offset(_M_ext_buf, _M_ext_buf + __epos) -
_M_base._M_get_offset(_M_ext_buf, _M_ext_buf_end);
if (__cur != -1 && __cur + __adj >= 0)
return __off == 0 ? pos_type(__cur + __adj)
: _M_seek_return(__cur + __adj, __state);
//return _M_seek_return(__cur + __adj, __state);
}
// We failed the sanity check here.
}
}
}
// Unrecognized value for __whence here.
}
return pos_type(-1);
}
template <class _CharT, class _Traits>
__BF_pos_type__
basic_filebuf<_CharT, _Traits>::seekpos(pos_type __pos,
ios_base::openmode /* dummy */) {
if (this->is_open()) {
if (!_M_seek_init(true))
return pos_type(-1);
streamoff __off = off_type(__pos);
if (__off != -1 && _M_base._M_seek(__off, ios_base::beg) != -1) {
_M_state = __pos.state();
return _M_seek_return(__off, __pos.state());
}
}
return pos_type(-1);
}
template <class _CharT, class _Traits>
int basic_filebuf<_CharT, _Traits>::sync() {
if (_M_in_output_mode)
return traits_type::eq_int_type(this->overflow(traits_type::eof()),
traits_type::eof()) ? -1 : 0;
return 0;
}
// Change the filebuf's locale. This member function has no effect
// unless it is called before any I/O is performed on the stream.
template <class _CharT, class _Traits>
void basic_filebuf<_CharT, _Traits>::imbue(const locale& __loc) {
if (!_M_in_input_mode && !_M_in_output_mode && !_M_in_error_mode) {
this->_M_setup_codecvt(__loc);
}
}
//----------------------------------------------------------------------
// basic_filebuf<> helper functions.
//----------------------------------------
// Helper functions for switching between modes.
// This member function is called if we're performing the first I/O
// operation on a filebuf, or if we're performing an input operation
// immediately after a seek.
template <class _CharT, class _Traits>
bool basic_filebuf<_CharT, _Traits>::_M_switch_to_input_mode() {
if (this->is_open() && (((int)_M_base.__o_mode() & (int)ios_base::in) != 0)
&& (_M_in_output_mode == 0) && (_M_in_error_mode == 0)) {
if (!_M_int_buf && !_M_allocate_buffers())
return false;
_M_ext_buf_converted = _M_ext_buf;
_M_ext_buf_end = _M_ext_buf;
_M_end_state = _M_state;
_M_in_input_mode = true;
return true;
}
return false;
}
// This member function is called if we're performing the first I/O
// operation on a filebuf, or if we're performing an output operation
// immediately after a seek.
template <class _CharT, class _Traits>
bool basic_filebuf<_CharT, _Traits>::_M_switch_to_output_mode() {
if (this->is_open() && (_M_base.__o_mode() & (int)ios_base::out) &&
_M_in_input_mode == 0 && _M_in_error_mode == 0) {
if (!_M_int_buf && !_M_allocate_buffers())
return false;
// In append mode, every write does an implicit seek to the end
// of the file. Whenever leaving output mode, the end of file
// get put in the initial shift state.
if (_M_base.__o_mode() & ios_base::app)
_M_state = _State_type();
this->setp(_M_int_buf, _M_int_buf_EOS - 1);
_M_in_output_mode = true;
return true;
}
return false;
}
//----------------------------------------
// Helper functions for input
// This member function is called if there is an error during input.
// It puts the filebuf in error mode, clear the get area buffer, and
// returns eof.
// returns eof. Error mode is sticky; it is cleared only by close or
// seek.
template <class _CharT, class _Traits>
__BF_int_type__
basic_filebuf<_CharT, _Traits>::_M_input_error() {
this->_M_exit_input_mode();
_M_in_output_mode = false;
_M_in_error_mode = true;
this->setg(0, 0, 0);
return traits_type::eof();
}
template <class _CharT, class _Traits>
__BF_int_type__
basic_filebuf<_CharT, _Traits>::_M_underflow_aux() {
// We have the state and file position from the end of the internal
// buffer. This round, they become the beginning of the internal buffer.
_M_state = _M_end_state;
// Fill the external buffer. Start with any leftover characters that
// didn't get converted last time.
if (_M_ext_buf_end > _M_ext_buf_converted)
_M_ext_buf_end = copy(_M_ext_buf_converted, _M_ext_buf_end, _M_ext_buf);
// boris : copy_backward did not work
//_M_ext_buf_end = copy_backward(_M_ext_buf_converted, _M_ext_buf_end,
//_M_ext_buf+ (_M_ext_buf_end - _M_ext_buf_converted));
else
_M_ext_buf_end = _M_ext_buf;
// Now fill the external buffer with characters from the file. This is
// a loop because occasionally we don't get enough external characters
// to make progress.
for (;;) {
ptrdiff_t __n = _M_base._M_read(_M_ext_buf_end, _M_ext_buf_EOS - _M_ext_buf_end);
// Don't enter error mode for a failed read. Error mode is sticky,
// and we might succeed if we try again.
if (__n <= 0)
return traits_type::eof();
// Convert the external buffer to internal characters.
_M_ext_buf_end += __n;
const char* __enext;
_CharT* __inext;
typename _Codecvt::result __status
= _M_codecvt->in(_M_end_state,
_M_ext_buf, _M_ext_buf_end, __enext,
_M_int_buf, _M_int_buf_EOS, __inext);
// Error conditions: (1) Return value of error. (2) Producing internal
// characters without consuming external characters. (3) In fixed-width
// encodings, producing an internal sequence whose length is inconsistent
// with that of the internal sequence. (4) Failure to produce any
// characters if we have enough characters in the external buffer, where
// "enough" means the largest possible width of a single character.
if (__status == _Codecvt::noconv)
return _Noconv_input<_Traits>::_M_doit(this);
else if (__status == _Codecvt::error ||
(__inext != _M_int_buf && __enext == _M_ext_buf) ||
(_M_constant_width &&
// __inext - _M_int_buf != _M_width * (__enext - _M_ext_buf)) ||
(__inext - _M_int_buf) * _M_width != (__enext - _M_ext_buf)) ||
(__inext == _M_int_buf && __enext - _M_ext_buf >= _M_max_width))
return _M_input_error();
else if (__inext != _M_int_buf) {
_M_ext_buf_converted = _M_ext_buf + (__enext - _M_ext_buf);
this->setg(_M_int_buf, _M_int_buf, __inext);
return traits_type::to_int_type(*_M_int_buf);
}
// We need to go around the loop again to get more external characters.
}
}
//----------------------------------------
// Helper functions for output
// This member function is called if there is an error during output.
// It puts the filebuf in error mode, clear the put area buffer, and
// returns eof. Error mode is sticky; it is cleared only by close or
// seek.
template <class _CharT, class _Traits>
__BF_int_type__
basic_filebuf<_CharT, _Traits>::_M_output_error() {
_M_in_output_mode = false;
_M_in_input_mode = false;
_M_in_error_mode = true;
this->setp(0, 0);
return traits_type::eof();
}
// Write whatever sequence of characters is necessary to get back to
// the initial shift state. This function overwrites the external
// buffer, changes the external file position, and changes the state.
// Precondition: the internal buffer is empty.
template <class _CharT, class _Traits>
bool basic_filebuf<_CharT, _Traits>::_M_unshift() {
if (_M_in_output_mode && !_M_constant_width) {
typename _Codecvt::result __status;
do {
char* __enext = _M_ext_buf;
__status = _M_codecvt->unshift(_M_state,
_M_ext_buf, _M_ext_buf_EOS, __enext);
if (__status == _Codecvt::noconv ||
(__enext == _M_ext_buf && __status == _Codecvt::ok))
return true;
else if (__status == _Codecvt::error)
return false;
else if (!_M_write(_M_ext_buf, __enext - _M_ext_buf))
return false;
} while (__status == _Codecvt::partial);
}
return true;
}
//----------------------------------------
// Helper functions for buffer allocation and deallocation
// This member function is called when we're initializing a filebuf's
// internal and external buffers. The argument is the size of the
// internal buffer; the external buffer is sized using the character
// width in the current encoding. Preconditions: the buffers are currently
// null. __n >= 1. __buf is either a null pointer or a pointer to an
// array show size is at least __n.
// We need __n >= 1 for two different reasons. For input, the base
// class always needs a buffer because of the semantics of underflow().
// For output, we want to have an internal buffer that's larger by one
// element than the buffer that the base class knows about. (See
// basic_filebuf<>::overflow() for the reason.)
template <class _CharT, class _Traits>
bool basic_filebuf<_CharT, _Traits>::_M_allocate_buffers(_CharT* __buf, streamsize __n) {
//The major hypothesis in the following implementation is that size_t is unsigned.
//We also need streamsize byte representation to be larger or equal to the int
//representation to correctly store the encoding information.
_STLP_STATIC_ASSERT(!numeric_limits<size_t>::is_signed &&
sizeof(streamsize) >= sizeof(int))
if (__buf == 0) {
streamsize __bufsize = __n * sizeof(_CharT);
//We first check that the streamsize representation can't overflow a size_t one.
//If it can, we check that __bufsize is not higher than the size_t max value.
if ((sizeof(streamsize) > sizeof(size_t)) &&
(__bufsize > __STATIC_CAST(streamsize, (numeric_limits<size_t>::max)())))
return false;
_M_int_buf = __STATIC_CAST(_CharT*, malloc(__STATIC_CAST(size_t, __bufsize)));
if (!_M_int_buf)
return false;
_M_int_buf_dynamic = true;
}
else {
_M_int_buf = __buf;
_M_int_buf_dynamic = false;
}
streamsize __ebufsiz = (max)(__n * __STATIC_CAST(streamsize, _M_width),
__STATIC_CAST(streamsize, _M_codecvt->max_length()));
_M_ext_buf = 0;
if ((sizeof(streamsize) < sizeof(size_t)) ||
((sizeof(streamsize) == sizeof(size_t)) && numeric_limits<streamsize>::is_signed) ||
(__ebufsiz <= __STATIC_CAST(streamsize, (numeric_limits<size_t>::max)()))) {
_M_ext_buf = __STATIC_CAST(char*, malloc(__STATIC_CAST(size_t, __ebufsiz)));
}
if (!_M_ext_buf) {
_M_deallocate_buffers();
return false;
}
_M_int_buf_EOS = _M_int_buf + __STATIC_CAST(ptrdiff_t, __n);
_M_ext_buf_EOS = _M_ext_buf + __STATIC_CAST(ptrdiff_t, __ebufsiz);
return true;
}
// Abbreviation for the most common case.
template <class _CharT, class _Traits>
bool basic_filebuf<_CharT, _Traits>::_M_allocate_buffers() {
// Choose a buffer that's at least 4096 characters long and that's a
// multiple of the page size.
streamsize __default_bufsiz =
((_M_base.__page_size() + 4095UL) / _M_base.__page_size()) * _M_base.__page_size();
return _M_allocate_buffers(0, __default_bufsiz);
}
template <class _CharT, class _Traits>
void basic_filebuf<_CharT, _Traits>::_M_deallocate_buffers() {
if (_M_int_buf_dynamic)
free(_M_int_buf);
free(_M_ext_buf);
_M_int_buf = 0;
_M_int_buf_EOS = 0;
_M_ext_buf = 0;
_M_ext_buf_EOS = 0;
}
//----------------------------------------
// Helper functiosn for seek and imbue
template <class _CharT, class _Traits>
bool basic_filebuf<_CharT, _Traits>::_M_seek_init(bool __do_unshift) {
// If we're in error mode, leave it.
_M_in_error_mode = false;
// Flush the output buffer if we're in output mode, and (conditionally)
// emit an unshift sequence.
if (_M_in_output_mode) {
bool __ok = !traits_type::eq_int_type(this->overflow(traits_type::eof()),
traits_type::eof());
if (__do_unshift)
__ok = __ok && this->_M_unshift();
if (!__ok) {
_M_in_output_mode = false;
_M_in_error_mode = true;
this->setp(0, 0);
return false;
}
}
// Discard putback characters, if any.
if (_M_in_input_mode && _M_in_putback_mode)
_M_exit_putback_mode();
return true;
}
/* Change the filebuf's locale. This member function has no effect
* unless it is called before any I/O is performed on the stream.
* This function is called on construction and on an imbue call. In the
* case of the construction the codecvt facet might be a custom one if
* the basic_filebuf user has instanciate it with a custom char_traits.
* The user will have to call imbue before any I/O operation.
*/
template <class _CharT, class _Traits>
void basic_filebuf<_CharT, _Traits>::_M_setup_codecvt(const locale& __loc, bool __on_imbue) {
if (has_facet<_Codecvt>(__loc)) {
_M_codecvt = &use_facet<_Codecvt>(__loc) ;
int __encoding = _M_codecvt->encoding();
_M_width = (max)(__encoding, 1);
_M_max_width = _M_codecvt->max_length();
_M_constant_width = __encoding > 0;
_M_always_noconv = _M_codecvt->always_noconv();
}
else {
_M_codecvt = 0;
_M_width = _M_max_width = 1;
_M_constant_width = _M_always_noconv = false;
if (__on_imbue) {
//This call will generate an exception reporting the problem.
use_facet<_Codecvt>(__loc);
}
}
}
_STLP_END_NAMESPACE
# undef __BF_int_type__
# undef __BF_pos_type__
# undef __BF_off_type__
#endif /* _STLP_FSTREAM_C */
// Local Variables:
// mode:C++
// End: