fstream.tcc

mingw32.rar

      streamsize __plen;
      if (__check_facet(_M_codecvt).always_noconv())
	{
	  __elen = _M_file.xsputn(reinterpret_cast<char*>(__ibuf), __ilen);
	  __plen = __ilen;
	}
      else
	{
	  // Worst-case number of external bytes needed.
	  // XXX Not done encoding() == -1.
	  streamsize __blen = __ilen * _M_codecvt->max_length();
	  char* __buf = static_cast<char*>(__builtin_alloca(__blen));

	  char* __bend;
	  const char_type* __iend;
	  codecvt_base::result __r;
	  __r = _M_codecvt->out(_M_state_cur, __ibuf, __ibuf + __ilen,
				__iend, __buf, __buf + __blen, __bend);

	  if (__r == codecvt_base::ok || __r == codecvt_base::partial)
	    __blen = __bend - __buf;
	  else if (__r == codecvt_base::noconv)
	    {
	      // Same as the always_noconv case above.
	      __buf = reinterpret_cast<char*>(__ibuf);
	      __blen = __ilen;
	    }
	  else
	    __throw_ios_failure(__N("basic_filebuf::_M_convert_to_external "
				    "conversion error"));
  
	  __elen = _M_file.xsputn(__buf, __blen);
	  __plen = __blen;

	  // Try once more for partial conversions.
	  if (__r == codecvt_base::partial && __elen == __plen)
	    {
	      const char_type* __iresume = __iend;
	      streamsize __rlen = this->pptr() - __iend;
	      __r = _M_codecvt->out(_M_state_cur, __iresume,
				    __iresume + __rlen, __iend, __buf,
				    __buf + __blen, __bend);
	      if (__r != codecvt_base::error)
		{
		  __rlen = __bend - __buf;
		  __elen = _M_file.xsputn(__buf, __rlen);
		  __plen = __rlen;
		}
	      else
		__throw_ios_failure(__N("basic_filebuf::_M_convert_to_external "
					"conversion error"));
	    }
	}
      return __elen == __plen;
    }

   template<typename _CharT, typename _Traits>
     streamsize
     basic_filebuf<_CharT, _Traits>::
     xsgetn(_CharT* __s, streamsize __n)
     {
       // Clear out pback buffer before going on to the real deal...
       streamsize __ret = 0;
       if (this->_M_pback_init)
	 {
	   if (__n > 0 && this->gptr() == this->eback())
	     {
	       *__s++ = *this->gptr();
	       this->gbump(1);
	       __ret = 1;
	       --__n;
	     }
	   _M_destroy_pback();
	 }
       
       // Optimization in the always_noconv() case, to be generalized in the
       // future: when __n > __buflen we read directly instead of using the
       // buffer repeatedly.
       const bool __testin = this->_M_mode & ios_base::in;
       const streamsize __buflen = this->_M_buf_size > 1 ? this->_M_buf_size - 1
	                                                 : 1;
       if (__n > __buflen && __check_facet(_M_codecvt).always_noconv()
	   && __testin && !_M_writing)
	 {
	   // First, copy the chars already present in the buffer.
	   const streamsize __avail = this->egptr() - this->gptr();
	   if (__avail != 0)
	     {
	       if (__avail == 1)
		 *__s = *this->gptr();
	       else if (__avail > 1)
		 traits_type::copy(__s, this->gptr(), __avail);
	       __s += __avail;
	       this->gbump(__avail);
	       __ret += __avail;
	       __n -= __avail;
	     }

	   const streamsize __len = _M_file.xsgetn(reinterpret_cast<char*>(__s),
						   __n);
	   if (__len == -1)
	     __throw_ios_failure(__N("basic_filebuf::xsgetn "
				     "error reading the file"));
	   __ret += __len;
	   if (__len == __n)
	     {
	       _M_set_buffer(0);
	       _M_reading = true;
	     }
	   else if (__len == 0)
	     {
	       // If end of file is reached, set 'uncommitted'
	       // mode, thus allowing an immediate write without
	       // an intervening seek.
	       _M_set_buffer(-1);
	       _M_reading = false;
	     }
	 }
       else
	 __ret += __streambuf_type::xsgetn(__s, __n);

       return __ret;
     }

   template<typename _CharT, typename _Traits>
     streamsize
     basic_filebuf<_CharT, _Traits>::
     xsputn(const _CharT* __s, streamsize __n)
     {
       // Optimization in the always_noconv() case, to be generalized in the
       // future: when __n is sufficiently large we write directly instead of
       // using the buffer.
       streamsize __ret = 0;
       const bool __testout = this->_M_mode & ios_base::out;
       if (__check_facet(_M_codecvt).always_noconv()
	   && __testout && !_M_reading)
	{
	  // Measurement would reveal the best choice.
	  const streamsize __chunk = 1ul << 10;
	  streamsize __bufavail = this->epptr() - this->pptr();

	  // Don't mistake 'uncommitted' mode buffered with unbuffered.
	  if (!_M_writing && this->_M_buf_size > 1)
	    __bufavail = this->_M_buf_size - 1;

	  const streamsize __limit = std::min(__chunk, __bufavail);
	  if (__n >= __limit)
	    {
	      const streamsize __buffill = this->pptr() - this->pbase();
	      const char* __buf = reinterpret_cast<const char*>(this->pbase());
	      __ret = _M_file.xsputn_2(__buf, __buffill,
				       reinterpret_cast<const char*>(__s),
				       __n);
	      if (__ret == __buffill + __n)
		{
		  _M_set_buffer(0);
		  _M_writing = true;
		}
	      if (__ret > __buffill)
		__ret -= __buffill;
	      else
		__ret = 0;
	    }
	  else
	    __ret = __streambuf_type::xsputn(__s, __n);
	}
       else
	 __ret = __streambuf_type::xsputn(__s, __n);
       return __ret;
    }

  template<typename _CharT, typename _Traits>
    typename basic_filebuf<_CharT, _Traits>::__streambuf_type*
    basic_filebuf<_CharT, _Traits>::
    setbuf(char_type* __s, streamsize __n)
    {
      if (!this->is_open())
	if (__s == 0 && __n == 0)
	  this->_M_buf_size = 1;
	else if (__s && __n > 0)
	  {
	    // This is implementation-defined behavior, and assumes that
	    // an external char_type array of length __n exists and has
	    // been pre-allocated. If this is not the case, things will
	    // quickly blow up. When __n > 1, __n - 1 positions will be
	    // used for the get area, __n - 1 for the put area and 1
	    // position to host the overflow char of a full put area.
	    // When __n == 1, 1 position will be used for the get area
	    // and 0 for the put area, as in the unbuffered case above.
	    this->_M_buf = __s;
	    this->_M_buf_size = __n;
	  }
      return this;
    }


  // According to 27.8.1.4 p11 - 13, seekoff should ignore the last
  // argument (of type openmode).
  template<typename _CharT, typename _Traits>
    typename basic_filebuf<_CharT, _Traits>::pos_type
    basic_filebuf<_CharT, _Traits>::
    seekoff(off_type __off, ios_base::seekdir __way, ios_base::openmode)
    {
      int __width = 0;
      if (_M_codecvt)
	__width = _M_codecvt->encoding();
      if (__width < 0)
	__width = 0;

      pos_type __ret =  pos_type(off_type(-1));
      const bool __testfail = __off != 0 && __width <= 0;
      if (this->is_open() && !__testfail)
	{
	  // Ditch any pback buffers to avoid confusion.
	  _M_destroy_pback();

	  // Correct state at destination. Note that this is the correct
	  // state for the current position during output, because
	  // codecvt::unshift() returns the state to the initial state.
	  // This is also the correct state at the end of the file because
	  // an unshift sequence should have been written at the end.
	  __state_type __state = _M_state_beg;
	  off_type __computed_off = __off * __width;
	  if (_M_reading && __way == ios_base::cur)
	    {
	      if (_M_codecvt->always_noconv())
		__computed_off += this->gptr() - this->egptr();
	      else
		{
		  // Calculate offset from _M_ext_buf that corresponds
		  // to gptr(). Note: uses _M_state_last, which
		  // corresponds to eback().
		  const int __gptr_off =
		    _M_codecvt->length(_M_state_last, _M_ext_buf, _M_ext_next,
				       this->gptr() - this->eback());
		  __computed_off += _M_ext_buf + __gptr_off - _M_ext_end;

		  // _M_state_last is modified by codecvt::length() so
		  // it now corresponds to gptr().
		  __state = _M_state_last;
		}
	    }
	  __ret = _M_seek(__computed_off, __way, __state);
	}
      return __ret;
    }

  // _GLIBCXX_RESOLVE_LIB_DEFECTS
  // 171. Strange seekpos() semantics due to joint position
  // According to the resolution of DR 171, seekpos should ignore the last
  // argument (of type openmode).
  template<typename _CharT, typename _Traits>
    typename basic_filebuf<_CharT, _Traits>::pos_type
    basic_filebuf<_CharT, _Traits>::
    seekpos(pos_type __pos, ios_base::openmode)
    {
      pos_type __ret =  pos_type(off_type(-1));
      if (this->is_open())
	{
	  // Ditch any pback buffers to avoid confusion.
	  _M_destroy_pback();
	  __ret = _M_seek(off_type(__pos), ios_base::beg, __pos.state());
	}
      return __ret;
    }

  template<typename _CharT, typename _Traits>
    typename basic_filebuf<_CharT, _Traits>::pos_type
    basic_filebuf<_CharT, _Traits>::
    _M_seek(off_type __off, ios_base::seekdir __way, __state_type __state)
    {
      pos_type __ret = pos_type(off_type(-1));
      if (_M_terminate_output())
	{
	  // Returns pos_type(off_type(-1)) in case of failure.
	  __ret = pos_type(_M_file.seekoff(__off, __way));
	  _M_reading = false;
	  _M_writing = false;
	  _M_ext_next = _M_ext_end = _M_ext_buf;
	  _M_set_buffer(-1);
	  _M_state_cur = __state;
	  __ret.state(_M_state_cur);
	}
      return __ret;
    }

  template<typename _CharT, typename _Traits>
    bool
    basic_filebuf<_CharT, _Traits>::
    _M_terminate_output()
    {
      // Part one: update the output sequence.
      bool __testvalid = true;
      if (this->pbase() < this->pptr())
	{
	  const int_type __tmp = this->overflow();
	  if (traits_type::eq_int_type(__tmp, traits_type::eof()))
	    __testvalid = false;
	}

      // Part two: output unshift sequence.
      if (_M_writing && !__check_facet(_M_codecvt).always_noconv()
	  && __testvalid)
	{
	  // Note: this value is arbitrary, since there is no way to
	  // get the length of the unshift sequence from codecvt,
	  // without calling unshift.
	  const size_t __blen = 128;
	  char __buf[__blen];
	  codecvt_base::result __r;
	  streamsize __ilen = 0;

	  do
	    {
	      char* __next;
	      __r = _M_codecvt->unshift(_M_state_cur, __buf,
					__buf + __blen, __next);
	      if (__r == codecvt_base::error)
		__testvalid = false;
	      else if (__r == codecvt_base::ok ||
		       __r == codecvt_base::partial)
		{
		  __ilen = __next - __buf;
		  if (__ilen > 0)
		    {
		      const streamsize __elen = _M_file.xsputn(__buf, __ilen);
		      if (__elen != __ilen)
			__testvalid = false;
		    }
		}
	    }
	  while (__r == codecvt_base::partial && __ilen > 0 && __testvalid);

	  if (__testvalid)
	    {
	      // This second call to overflow() is required by the standard,
	      // but it's not clear why it's needed, since the output buffer
	      // should be empty by this point (it should have been emptied
	      // in the first call to overflow()).
	      const int_type __tmp = this->overflow();
	      if (traits_type::eq_int_type(__tmp, traits_type::eof()))
		__testvalid = false;
	    }
	}
      return __testvalid;
    }

  template<typename _CharT, typename _Traits>
    int
    basic_filebuf<_CharT, _Traits>::
    sync()
    {
      // Make sure that the internal buffer resyncs its idea of
      // the file position with the external file.
      // NB: _M_file.sync() will be called within.
      int __ret = 0;
      if (this->pbase() < this->pptr())
	{
	  const int_type __tmp = this->overflow();
	  if (traits_type::eq_int_type(__tmp, traits_type::eof()))
	    __ret = -1;
	}
      return __ret;
    }

  template<typename _CharT, typename _Traits>
    void
    basic_filebuf<_CharT, _Traits>::
    imbue(const locale& __loc)
    {
      bool __testvalid = true;

      const __codecvt_type* _M_codecvt_tmp = 0;
      if (__builtin_expect(has_facet<__codecvt_type>(__loc), true))
	_M_codecvt_tmp = &use_facet<__codecvt_type>(__loc);

      if (this->is_open())
	{
	  // encoding() == -1 is ok only at the beginning.
	  if ((_M_reading || _M_writing)
	      && __check_facet(_M_codecvt).encoding() == -1)
	    __testvalid = false;
	  else
	    {
	      if (_M_reading)
		{
		  if (__check_facet(_M_codecvt).always_noconv())
		    {
		      if (_M_codecvt_tmp
			  && !__check_facet(_M_codecvt_tmp).always_noconv())
			__testvalid = this->seekoff(0, ios_base::cur, this->_M_mode)
			              != pos_type(off_type(-1));
		    }
		  else
		    {
		      // External position corresponding to gptr().
		      _M_ext_next = _M_ext_buf
			+ _M_codecvt->length(_M_state_last, _M_ext_buf, _M_ext_next,
					     this->gptr() - this->eback());
		      const streamsize __remainder = _M_ext_end - _M_ext_next;
		      if (__remainder)
			std::memmove(_M_ext_buf, _M_ext_next, __remainder);

		      _M_ext_next = _M_ext_buf;
		      _M_ext_end = _M_ext_buf + __remainder;
		      _M_set_buffer(-1);
		      _M_state_last = _M_state_cur = _M_state_beg;
		    }
		}
	      else if (_M_writing && (__testvalid = _M_terminate_output()))
		_M_set_buffer(-1);
	    }
	}

      if (__testvalid)
	_M_codecvt = _M_codecvt_tmp;
      else
	_M_codecvt = 0;
    }

  // Inhibit implicit instantiations for required instantiations,
  // which are defined via explicit instantiations elsewhere.
  // NB:  This syntax is a GNU extension.
#if _GLIBCXX_EXTERN_TEMPLATE
  extern template class basic_filebuf<char>;
  extern template class basic_ifstream<char>;
  extern template class basic_ofstream<char>;
  extern template class basic_fstream<char>;

#ifdef _GLIBCXX_USE_WCHAR_T
  extern template class basic_filebuf<wchar_t>;
  extern template class basic_ifstream<wchar_t>;
  extern template class basic_ofstream<wchar_t>;
  extern template class basic_fstream<wchar_t>;
#endif
#endif
} // namespace std

#endif