fstream.tcc

mingw32.rar

// File based streams -*- C++ -*-

// Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004
// Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library.  This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 2, or (at your option)
// any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING.  If not, write to the Free
// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
// USA.

// As a special exception, you may use this file as part of a free software
// library without restriction.  Specifically, if other files instantiate
// templates or use macros or inline functions from this file, or you compile
// this file and link it with other files to produce an executable, this
// file does not by itself cause the resulting executable to be covered by
// the GNU General Public License.  This exception does not however
// invalidate any other reasons why the executable file might be covered by
// the GNU General Public License.

//
// ISO C++ 14882: 27.8  File-based streams
//

#ifndef _FSTREAM_TCC
#define _FSTREAM_TCC 1

#pragma GCC system_header

namespace std
{
  template<typename _CharT, typename _Traits>
    void
    basic_filebuf<_CharT, _Traits>::
    _M_allocate_internal_buffer()
    {
      // Allocate internal buffer only if one doesn't already exist
      // (either allocated or provided by the user via setbuf).
      if (!_M_buf_allocated && !this->_M_buf)
	{
	  this->_M_buf = new char_type[this->_M_buf_size];
	  _M_buf_allocated = true;
	}
    }

  template<typename _CharT, typename _Traits>
    void
    basic_filebuf<_CharT, _Traits>::
    _M_destroy_internal_buffer() throw()
    {
      if (_M_buf_allocated)
	{
	  delete [] this->_M_buf;
	  this->_M_buf = NULL;
	  _M_buf_allocated = false;
	}
      delete [] _M_ext_buf;
      _M_ext_buf = NULL;
      _M_ext_buf_size = 0;
      _M_ext_next = NULL;
      _M_ext_end = NULL;
    }

  template<typename _CharT, typename _Traits>
    basic_filebuf<_CharT, _Traits>::
    basic_filebuf() : __streambuf_type(), _M_lock(), _M_file(&_M_lock),
    _M_mode(ios_base::openmode(0)), _M_state_beg(), _M_state_cur(),
    _M_state_last(), _M_buf(NULL), _M_buf_size(BUFSIZ),
    _M_buf_allocated(false), _M_reading(false), _M_writing(false), _M_pback(), 
    _M_pback_cur_save(0), _M_pback_end_save(0), _M_pback_init(false),
    _M_codecvt(0), _M_ext_buf(0), _M_ext_buf_size(0), _M_ext_next(0),
    _M_ext_end(0)
    {
      if (has_facet<__codecvt_type>(this->_M_buf_locale))
	_M_codecvt = &use_facet<__codecvt_type>(this->_M_buf_locale);
    }

  template<typename _CharT, typename _Traits>
    typename basic_filebuf<_CharT, _Traits>::__filebuf_type*
    basic_filebuf<_CharT, _Traits>::
    open(const char* __s, ios_base::openmode __mode)
    {
      __filebuf_type *__ret = NULL;
      if (!this->is_open())
	{
	  _M_file.open(__s, __mode);
	  if (this->is_open())
	    {
	      _M_allocate_internal_buffer();
	      this->_M_mode = __mode;

	      // Setup initial buffer to 'uncommitted' mode.
	      _M_reading = false;
	      _M_writing = false;
	      _M_set_buffer(-1);

	      // Reset to initial state.
	      _M_state_last = _M_state_cur = _M_state_beg;

	      // 27.8.1.3,4
	      if ((__mode & ios_base::ate)
		  && this->seekoff(0, ios_base::end, __mode)
		  == pos_type(off_type(-1)))
		this->close();
	      else
		__ret = this;
	    }
	}
      return __ret;
    }

  template<typename _CharT, typename _Traits>
    typename basic_filebuf<_CharT, _Traits>::__filebuf_type*
    basic_filebuf<_CharT, _Traits>::
    close() throw()
    {
      __filebuf_type* __ret = NULL;
      if (this->is_open())
	{
	  bool __testfail = false;
	  try
	    {
	      if (!_M_terminate_output())
		__testfail = true;
	    }
	  catch(...)
	    { __testfail = true; }

	  // NB: Do this here so that re-opened filebufs will be cool...
	  this->_M_mode = ios_base::openmode(0);
	  this->_M_pback_init = false;
	  _M_destroy_internal_buffer();
	  _M_reading = false;
	  _M_writing = false;
	  _M_set_buffer(-1);
	  _M_state_last = _M_state_cur = _M_state_beg;

	  if (!_M_file.close())
	    __testfail = true;

	  if (!__testfail)
	    __ret = this;
	}
      return __ret;
    }

  template<typename _CharT, typename _Traits>
    streamsize
    basic_filebuf<_CharT, _Traits>::
    showmanyc()
    {
      streamsize __ret = -1;
      const bool __testin = this->_M_mode & ios_base::in;
      if (__testin && this->is_open())
	{
	  // For a stateful encoding (-1) the pending sequence might be just
	  // shift and unshift prefixes with no actual character.
	  __ret = this->egptr() - this->gptr();
	  if (__check_facet(_M_codecvt).encoding() >= 0)
	    __ret += _M_file.showmanyc() / _M_codecvt->max_length();
	}
      return __ret;
    }

  template<typename _CharT, typename _Traits>
    typename basic_filebuf<_CharT, _Traits>::int_type
    basic_filebuf<_CharT, _Traits>::
    underflow()
    {
      int_type __ret = traits_type::eof();
      const bool __testin = this->_M_mode & ios_base::in;
      if (__testin && !_M_writing)
	{
	  // Check for pback madness, and if so swich back to the
	  // normal buffers and jet outta here before expensive
	  // fileops happen...
	  _M_destroy_pback();

	  if (this->gptr() < this->egptr())
	    return traits_type::to_int_type(*this->gptr());

	  // Get and convert input sequence.
	  const size_t __buflen = this->_M_buf_size > 1
	                          ? this->_M_buf_size - 1 : 1;

	  // Will be set to true if ::read() returns 0 indicating EOF.
	  bool __got_eof = false;
	  // Number of internal characters produced.
	  streamsize __ilen = 0;
	  codecvt_base::result __r = codecvt_base::ok;
	  if (__check_facet(_M_codecvt).always_noconv())
	    {
	      __ilen = _M_file.xsgetn(reinterpret_cast<char*>(this->eback()),
				      __buflen);
	      if (__ilen == 0)
		__got_eof = true;
	    }
	  else
	    {
              // Worst-case number of external bytes.
	      // XXX Not done encoding() == -1.
	      const int __enc = _M_codecvt->encoding();
	      streamsize __blen; // Minimum buffer size.
	      streamsize __rlen; // Number of chars to read.
	      if (__enc > 0)
		__blen = __rlen = __buflen * __enc;
	      else
		{
		  __blen = __buflen + _M_codecvt->max_length() - 1;
		  __rlen = __buflen;
		}
	      const streamsize __remainder = _M_ext_end - _M_ext_next;
	      __rlen = __rlen > __remainder ? __rlen - __remainder : 0;

	      // An imbue in 'read' mode implies first converting the external
	      // chars already present.
	      if (_M_reading && this->egptr() == this->eback() && __remainder)
		__rlen = 0;

	      // Allocate buffer if necessary and move unconverted
	      // bytes to front.
	      if (_M_ext_buf_size < __blen)
		{
		  char* __buf = new char[__blen];
		  if (__remainder)
		    std::memcpy(__buf, _M_ext_next, __remainder);

		  delete [] _M_ext_buf;
		  _M_ext_buf = __buf;
		  _M_ext_buf_size = __blen;
		}
	      else 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_state_last = _M_state_cur;

	      do
		{
		  if (__rlen > 0)
		    {
		      // Sanity check!
		      // This may fail if the return value of
		      // codecvt::max_length() is bogus.
		      if (_M_ext_end - _M_ext_buf + __rlen > _M_ext_buf_size)
			{
			  __throw_ios_failure(__N("basic_filebuf::underflow "
					      "codecvt::max_length() "
					      "is not valid"));
			}
		      streamsize __elen = _M_file.xsgetn(_M_ext_end, __rlen);
		      if (__elen == 0)
			__got_eof = true;
		      else if (__elen == -1)
			break;
		      _M_ext_end += __elen;
		    }

		  char_type* __iend;
		  __r = _M_codecvt->in(_M_state_cur, _M_ext_next,
				       _M_ext_end, _M_ext_next, this->eback(),
				       this->eback() + __buflen, __iend);
		  if (__r == codecvt_base::noconv)
		    {
		      size_t __avail = _M_ext_end - _M_ext_buf;
		      __ilen = std::min(__avail, __buflen);
		      traits_type::copy(this->eback(),
					reinterpret_cast<char_type*>(_M_ext_buf), __ilen);
		      _M_ext_next = _M_ext_buf + __ilen;
		    }
		  else
		    __ilen = __iend - this->eback();

		  // _M_codecvt->in may return error while __ilen > 0: this is
		  // ok, and actually occurs in case of mixed encodings (e.g.,
		  // XML files).
		  if (__r == codecvt_base::error)
		    break;

		  __rlen = 1;
		}
	      while (__ilen == 0 && !__got_eof);
	    }

	  if (__ilen > 0)
	    {
	      _M_set_buffer(__ilen);
	      _M_reading = true;
	      __ret = traits_type::to_int_type(*this->gptr());
	    }
	  else if (__got_eof)
	    {
	      // If the actual end of file is reached, set 'uncommitted'
	      // mode, thus allowing an immediate write without an
	      // intervening seek.
	      _M_set_buffer(-1);
	      _M_reading = false;
	      // However, reaching it while looping on partial means that
	      // the file has got an incomplete character.
	      if (__r == codecvt_base::partial)
		__throw_ios_failure(__N("basic_filebuf::underflow "
				    "incomplete character in file"));
	    }
	  else if (__r == codecvt_base::error)
	    __throw_ios_failure(__N("basic_filebuf::underflow "
				"invalid byte sequence in file"));
	  else
	    __throw_ios_failure(__N("basic_filebuf::underflow "
				"error reading the file"));
	}
      return __ret;
    }

  template<typename _CharT, typename _Traits>
    typename basic_filebuf<_CharT, _Traits>::int_type
    basic_filebuf<_CharT, _Traits>::
    pbackfail(int_type __i)
    {
      int_type __ret = traits_type::eof();
      const bool __testin = this->_M_mode & ios_base::in;
      if (__testin && !_M_writing)
	{
	  // Remember whether the pback buffer is active, otherwise below
	  // we may try to store in it a second char (libstdc++/9761).
	  const bool __testpb = this->_M_pback_init;
	  const bool __testeof = traits_type::eq_int_type(__i, __ret);
	  int_type __tmp;
	  if (this->eback() < this->gptr())
	    {
	      this->gbump(-1);
	      __tmp = traits_type::to_int_type(*this->gptr());
	    }
	  else if (this->seekoff(-1, ios_base::cur) != pos_type(off_type(-1)))
	    {
	      __tmp = this->underflow();
	      if (traits_type::eq_int_type(__tmp, __ret))
		return __ret;
	    }
	  else
	    {
	      // At the beginning of the buffer, need to make a
	      // putback position available.  But the seek may fail
	      // (f.i., at the beginning of a file, see
	      // libstdc++/9439) and in that case we return
	      // traits_type::eof().
	      return __ret;
	    }

	  // Try to put back __i into input sequence in one of three ways.
	  // Order these tests done in is unspecified by the standard.
	  if (!__testeof && traits_type::eq_int_type(__i, __tmp))
	    __ret = __i;
	  else if (__testeof)
	    __ret = traits_type::not_eof(__i);
	  else if (!__testpb)
	    {
	      _M_create_pback();
	      _M_reading = true;
	      *this->gptr() = traits_type::to_char_type(__i);
	      __ret = __i;
	    }
	}
      return __ret;
    }

  template<typename _CharT, typename _Traits>
    typename basic_filebuf<_CharT, _Traits>::int_type
    basic_filebuf<_CharT, _Traits>::
    overflow(int_type __c)
    {
      int_type __ret = traits_type::eof();
      const bool __testeof = traits_type::eq_int_type(__c, __ret);
      const bool __testout = this->_M_mode & ios_base::out;
      if (__testout && !_M_reading)
	{
	  if (this->pbase() < this->pptr())
	    {
	      // If appropriate, append the overflow char.
	      if (!__testeof)
		{
		  *this->pptr() = traits_type::to_char_type(__c);
		  this->pbump(1);
		}

	      // Convert pending sequence to external representation,
	      // and output.
	      if (_M_convert_to_external(this->pbase(),
					 this->pptr() - this->pbase())
		  && (!__testeof || !_M_file.sync()))
		{
		  _M_set_buffer(0);
		  __ret = traits_type::not_eof(__c);
		}
	    }
	  else if (this->_M_buf_size > 1)
	    {
	      // Overflow in 'uncommitted' mode: set _M_writing, set
	      // the buffer to the initial 'write' mode, and put __c
	      // into the buffer.
	      _M_set_buffer(0);
	      _M_writing = true;
	      if (!__testeof)
		{
		  *this->pptr() = traits_type::to_char_type(__c);
		  this->pbump(1);
		}
	      __ret = traits_type::not_eof(__c);
	    }
	  else
	    {
	      // Unbuffered.
	      char_type __conv = traits_type::to_char_type(__c);
	      if (__testeof || _M_convert_to_external(&__conv, 1))
		{
		  _M_writing = true;
		  __ret = traits_type::not_eof(__c);
		}
	    }
	}
      return __ret;
    }

  template<typename _CharT, typename _Traits>
    bool
    basic_filebuf<_CharT, _Traits>::
    _M_convert_to_external(_CharT* __ibuf, streamsize __ilen)
    {
      // Sizes of external and pending output.
      streamsize __elen;