libstdc++-v3/bits/streambuf.tcc

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