libstdc++-v3/include/bits/streambuf.tcc

   1 // Stream buffer classes -*- C++ -*-
   2
   3 // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002
   4 // Free Software Foundation, Inc.
   5 //
   6 // This file is part of the GNU ISO C++ Library.  This library is free
   7 // software; you can redistribute it and/or modify it under the
   8 // terms of the GNU General Public License as published by the
   9 // Free Software Foundation; either version 2, or (at your option)
  10 // any later version.
  11
  12 // This library is distributed in the hope that it will be useful,
  13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 // GNU General Public License for more details.
  16
  17 // You should have received a copy of the GNU General Public License along
  18 // with this library; see the file COPYING.  If not, write to the Free
  19 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  20 // USA.
  21
  22 // As a special exception, you may use this file as part of a free software
  23 // library without restriction.  Specifically, if other files instantiate
  24 // templates or use macros or inline functions from this file, or you compile
  25 // this file and link it with other files to produce an executable, this
  26 // file does not by itself cause the resulting executable to be covered by
  27 // the GNU General Public License.  This exception does not however
  28 // invalidate any other reasons why the executable file might be covered by
  29 // the GNU General Public License.
  30
  31 //
  32 // ISO C++ 14882: 27.5  Stream buffers
  33 //
  34
  35 #ifndef _CPP_BITS_STREAMBUF_TCC
  36 #define _CPP_BITS_STREAMBUF_TCC 1
  37
  38 #pragma GCC system_header
  39
  40 namespace std
  41 {
  42   template<typename _CharT, typename _Traits>
  43     const size_t
  44     basic_streambuf<_CharT, _Traits>::_S_pback_size;
  45
  46   template<typename _CharT, typename _Traits>
  47     typename basic_streambuf<_CharT, _Traits>::int_type
  48     basic_streambuf<_CharT, _Traits>::
  49     sbumpc()
  50     {
  51       int_type __ret;
  52       if (_M_in_cur && _M_in_cur < _M_in_end)
  53         {
  54           char_type __c = *(this->gptr());
  55           _M_in_cur_move(1);
  56           __ret = traits_type::to_int_type(__c);
  57         }
  58       else
  59         __ret = this->uflow();
  60       return __ret;
  61     }
  62
  63   template<typename _CharT, typename _Traits>
  64     typename basic_streambuf<_CharT, _Traits>::int_type
  65     basic_streambuf<_CharT, _Traits>::
  66     sputbackc(char_type __c)
  67     {
  68       int_type __ret;
  69       bool __testpos = _M_in_cur && _M_in_beg < _M_in_cur;
  70       bool __testne = _M_in_cur && !traits_type::eq(__c, this->gptr()[-1]);
  71       if (!__testpos || __testne)
  72         __ret = pbackfail(traits_type::to_int_type(__c));
  73       else
  74         {
  75           _M_in_cur_move(-1);
  76           __ret = traits_type::to_int_type(*this->gptr());
  77         }
  78       return __ret;
  79     }
  80
  81   template<typename _CharT, typename _Traits>
  82     typename basic_streambuf<_CharT, _Traits>::int_type
  83     basic_streambuf<_CharT, _Traits>::
  84     sungetc()
  85     {
  86       int_type __ret;
  87       if (_M_in_cur && _M_in_beg < _M_in_cur)
  88         {
  89           _M_in_cur_move(-1);
  90           __ret = traits_type::to_int_type(*_M_in_cur);
  91         }
  92       else
  93         __ret = this->pbackfail();
  94       return __ret;
  95     }
  96
  97   // Don't test against _M_buf + _M_buf_size, because _M_buf reflects
  98   // allocated space, and on certain (rare but entirely legal)
  99   // situations, there will be no allocated space yet the internal
 100   // buffers will still be valid. (This happens if setp is used to set
 101   // the internal buffer to say some externally-allocated sequence.)
 102   template<typename _CharT, typename _Traits>
 103     typename basic_streambuf<_CharT, _Traits>::int_type
 104     basic_streambuf<_CharT, _Traits>::
 105     sputc(char_type __c)
 106     {
 107       int_type __ret;
 108       if (_M_out_buf_size())
 109         {
 110           *_M_out_cur = __c;
 111           _M_out_cur_move(1);
 112           __ret = traits_type::to_int_type(__c);
 113         }
 114       else
 115         __ret = this->overflow(traits_type::to_int_type(__c));
 116       return __ret;
 117     }
 118
 119   template<typename _CharT, typename _Traits>
 120     streamsize
 121     basic_streambuf<_CharT, _Traits>::
 122     xsgetn(char_type* __s, streamsize __n)
 123     {
 124       streamsize __ret = 0;
 125       while (__ret < __n)
 126         {
 127           size_t __buf_len = _M_in_end - _M_in_cur;
 128           if (__buf_len > 0)
 129             {
 130               size_t __remaining = __n - __ret;
 131               size_t __len = min(__buf_len, __remaining);
 132               traits_type::copy(__s, _M_in_cur, __len);
 133               __ret += __len;
 134               __s += __len;
 135               _M_in_cur_move(__len);
 136             }
 137
 138           if (__ret < __n)
 139             {
 140               int_type __c = this->uflow();
 141               if (!traits_type::eq_int_type(__c, traits_type::eof()))
 142                 {
 143                   traits_type::assign(*__s++, traits_type::to_char_type(__c));
 144                   ++__ret;
 145                 }
 146               else
 147                 break;
 148             }
 149         }
 150       return __ret;
 151     }
 152
 153   // Don't test against _M_buf + _M_buf_size, because _M_buf reflects
 154   // allocated space, and on certain (rare but entirely legal)
 155   // situations, there will be no allocated space yet the internal
 156   // buffers will still be valid. (This happens if setp is used to set
 157   // the internal buffer to say some externally-allocated sequence.)
 158   template<typename _CharT, typename _Traits>
 159     streamsize
 160     basic_streambuf<_CharT, _Traits>::
 161     xsputn(const char_type* __s, streamsize __n)
 162     {
 163       streamsize __ret = 0;
 164       while (__ret < __n)
 165         {
 166           off_type __buf_len = _M_out_buf_size();
 167           if (__buf_len > 0)
 168             {
 169               off_type __remaining = __n - __ret;
 170               off_type __len = min(__buf_len, __remaining);
 171               traits_type::copy(_M_out_cur, __s, __len);
 172               __ret += __len;
 173               __s += __len;
 174               _M_out_cur_move(__len);
 175             }
 176
 177           if (__ret < __n)
 178             {
 179               int_type __c = this->overflow(traits_type::to_int_type(*__s));
 180               if (!traits_type::eq_int_type(__c, traits_type::eof()))
 181                 {
 182                   ++__ret;
 183                   ++__s;
 184                 }
 185               else
 186                 break;
 187             }
 188         }
 189       return __ret;
 190     }
 191
 192   // Conceivably, this could be used to implement buffer-to-buffer
 193   // copies, if this was ever desired in an un-ambiguous way by the
 194   // standard. If so, then checks for __ios being zero would be
 195   // necessary.
 196   template<typename _CharT, typename _Traits>
 197     streamsize
 198     __copy_streambufs(basic_ios<_CharT, _Traits>& __ios,
 199                       basic_streambuf<_CharT, _Traits>* __sbin,
 200                       basic_streambuf<_CharT, _Traits>* __sbout)
 201   {
 202       typedef typename _Traits::int_type        int_type;
 203
 204       streamsize __ret = 0;
 205       streamsize __bufsize = __sbin->in_avail();
 206       streamsize __xtrct;
 207       bool __testput = __sbout->_M_mode & ios_base::out;
 208       try
 209         {
 210           while (__testput && __bufsize != -1)
 211             {
 212               if (__bufsize != 0 && __sbin->gptr() != NULL)
 213                 {
 214                   __xtrct = __sbout->sputn(__sbin->gptr(), __bufsize);
 215                   __ret += __xtrct;
 216                   __sbin->_M_in_cur_move(__xtrct);
 217                   if (__xtrct != __bufsize)
 218                     break;
 219                 }
 220               else
 221                 {
 222                   _CharT __buf[256];
 223                   streamsize __charsread = __sbin->sgetn(__buf, sizeof(__buf));
 224                   __xtrct = __sbout->sputn(__buf, __charsread);
 225                   __ret += __xtrct;
 226                   if (__xtrct != __charsread)
 227                     break;
 228                 }
 229               if (_Traits::eq_int_type(__sbin->sgetc(), _Traits::eof()))
 230                 break;
 231               __bufsize = __sbin->in_avail();
 232             }
 233         }
 234       catch(exception& __fail)
 235         {
 236           __ios.setstate(ios_base::failbit);
 237           if ((__ios.exceptions() & ios_base::failbit) != 0)
 238             __throw_exception_again;
 239         }
 240       return __ret;
 241     }
 242
 243   // Inhibit implicit instantiations for required instantiations,
 244   // which are defined via explicit instantiations elsewhere.
 245   // NB:  This syntax is a GNU extension.
 246   extern template class basic_streambuf<char>;
 247   extern template
 248     streamsize
 249     __copy_streambufs(basic_ios<char>&, basic_streambuf<char>*,
 250                       basic_streambuf<char>*);
 251
 252 #ifdef _GLIBCPP_USE_WCHAR_T
 253   extern template class basic_streambuf<wchar_t>;
 254   extern template
 255     streamsize
 256     __copy_streambufs(basic_ios<wchar_t>&, basic_streambuf<wchar_t>*,
 257                       basic_streambuf<wchar_t>*);
 258 #endif
 259 } // namespace std
 260
 261 #endif