libstdc++-v3/src/strstream.cc

   1 // strstream definitions -*- C++ -*-
   2
   3 // Copyright (C) 2001, 2002 Free Software Foundation
   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  * Copyright (c) 1998
  32  * Silicon Graphics Computer Systems, Inc.
  33  *
  34  * Permission to use, copy, modify, distribute and sell this software
  35  * and its documentation for any purpose is hereby granted without fee,
  36  * provided that the above copyright notice appear in all copies and
  37  * that both that copyright notice and this permission notice appear
  38  * in supporting documentation.  Silicon Graphics makes no
  39  * representations about the suitability of this software for any
  40  * purpose.  It is provided "as is" without express or implied warranty.
  41  */
  42
  43 // Implementation of the classes in header <strstream>.
  44 // WARNING: The classes defined in <strstream> are DEPRECATED.  This
  45 // header is defined in section D.7.1 of the C++ standard, and it
  46 // MAY BE REMOVED in a future standard revision.  You should use the
  47 // header <sstream> instead.
  48
  49 #include <strstream>
  50 #include <algorithm>
  51 #include <new>
  52 #include <stdlib.h>
  53 #include <string.h>
  54 #include <limits.h>
  55
  56 namespace std
  57 {
  58   strstreambuf::strstreambuf(streamsize initial_capacity)
  59   : _Base(), _M_alloc_fun(0), _M_free_fun(0), _M_dynamic(true),
  60     _M_frozen(false), _M_constant(false)
  61   {
  62     streamsize n = std::max(initial_capacity, streamsize(16));
  63
  64     char* buf = _M_alloc(n);
  65     if (buf)
  66       {
  67         setp(buf, buf + n);
  68         setg(buf, buf, buf);
  69       }
  70   }
  71
  72   strstreambuf::strstreambuf(void* (*alloc_f)(size_t), void (*free_f)(void*))
  73   : _Base(), _M_alloc_fun(alloc_f), _M_free_fun(free_f), _M_dynamic(true),
  74     _M_frozen(false), _M_constant(false)
  75   {
  76     streamsize n = 16;
  77
  78     char* buf = _M_alloc(n);
  79     if (buf)
  80       {
  81         setp(buf, buf + n);
  82         setg(buf, buf, buf);
  83       }
  84   }
  85
  86   strstreambuf::strstreambuf(char* get, streamsize n, char* put)
  87   : _Base(), _M_alloc_fun(0), _M_free_fun(0), _M_dynamic(false),
  88     _M_frozen(false), _M_constant(false)
  89   { _M_setup(get, put, n); }
  90
  91   strstreambuf::strstreambuf(signed char* get, streamsize n, signed char* put)
  92   : _Base(), _M_alloc_fun(0), _M_free_fun(0), _M_dynamic(false),
  93   _M_frozen(false), _M_constant(false)
  94   { _M_setup(reinterpret_cast<char*>(get), reinterpret_cast<char*>(put), n); }
  95
  96   strstreambuf::strstreambuf(unsigned char* get, streamsize n,
  97                              unsigned char* put)
  98   : _Base(), _M_alloc_fun(0), _M_free_fun(0), _M_dynamic(false),
  99     _M_frozen(false), _M_constant(false)
 100   { _M_setup(reinterpret_cast<char*>(get), reinterpret_cast<char*>(put), n); }
 101
 102   strstreambuf::strstreambuf(const char* get, streamsize n)
 103   : _Base(), _M_alloc_fun(0), _M_free_fun(0), _M_dynamic(false),
 104     _M_frozen(false), _M_constant(true)
 105   { _M_setup(const_cast<char*>(get), 0, n); }
 106
 107   strstreambuf::strstreambuf(const signed char* get, streamsize n)
 108   : _Base(), _M_alloc_fun(0), _M_free_fun(0), _M_dynamic(false),
 109     _M_frozen(false), _M_constant(true)
 110   { _M_setup(reinterpret_cast<char*>(const_cast<signed char*>(get)), 0, n); }
 111
 112   strstreambuf::strstreambuf(const unsigned char* get, streamsize n)
 113   : _Base(), _M_alloc_fun(0), _M_free_fun(0), _M_dynamic(false),
 114     _M_frozen(false), _M_constant(true)
 115   { _M_setup(reinterpret_cast<char*>(const_cast<unsigned char*>(get)), 0, n); }
 116
 117   strstreambuf::~strstreambuf()
 118   {
 119     if (_M_dynamic && !_M_frozen)
 120       _M_free(eback());
 121   }
 122
 123   void
 124   strstreambuf::freeze(bool frozenflag)
 125   {
 126     if (_M_dynamic)
 127       _M_frozen = frozenflag;
 128   }
 129
 130   char*
 131   strstreambuf::str()
 132   {
 133     freeze(true);
 134     return eback();
 135   }
 136
 137   int
 138   strstreambuf::pcount() const
 139   { return pptr() ? pptr() - pbase() : 0; }
 140
 141   strstreambuf::int_type
 142   strstreambuf::overflow(int_type c)
 143   {
 144     if (c == traits_type::eof())
 145       return traits_type::not_eof(c);
 146
 147     // Try to expand the buffer.
 148     if (pptr() == epptr() && _M_dynamic && !_M_frozen && !_M_constant)
 149       {
 150         ptrdiff_t old_size = epptr() - pbase();
 151         ptrdiff_t new_size = std::max(2 * old_size, ptrdiff_t(1));
 152
 153         char* buf = _M_alloc(new_size);
 154         if (buf)
 155           {
 156             memcpy(buf, pbase(), old_size);
 157             char* old_buffer = pbase();
 158             bool reposition_get = false;
 159             ptrdiff_t old_get_offset;
 160             if (gptr() != 0)
 161               {
 162                 reposition_get = true;
 163                 old_get_offset = gptr() - eback();
 164               }
 165
 166             setp(buf, buf + new_size);
 167             pbump(old_size);
 168
 169             if (reposition_get)
 170               setg(buf, buf + old_get_offset, buf +
 171                    std::max(old_get_offset, old_size));
 172
 173             _M_free(old_buffer);
 174           }
 175       }
 176
 177     if (pptr() != epptr())
 178       {
 179         *pptr() = c;
 180         pbump(1);
 181         return c;
 182       }
 183     else
 184       return traits_type::eof();
 185   }
 186
 187   strstreambuf::int_type
 188   strstreambuf::pbackfail(int_type c)
 189   {
 190     if (gptr() != eback())
 191       {
 192       if (c == _Traits::eof())
 193         {
 194           gbump(-1);
 195           return _Traits::not_eof(c);
 196         }
 197       else if (c == static_cast<int_type>(gptr()[-1]))
 198         {  // KLUDGE
 199           gbump(-1);
 200           return c;
 201         }
 202       else if (!_M_constant)
 203         {
 204           gbump(-1);
 205           *gptr() = c;
 206           return c;
 207         }
 208     }
 209     return _Traits::eof();
 210   }
 211
 212   strstreambuf::int_type
 213   strstreambuf::underflow()
 214   {
 215     if (gptr() == egptr() && pptr() && pptr() > egptr())
 216       setg(eback(), gptr(), pptr());
 217
 218     if (gptr() != egptr())
 219       return (unsigned char) *gptr();
 220     else
 221       return _Traits::eof();
 222   }
 223
 224   basic_streambuf<char, char_traits<char> >*
 225   strstreambuf::setbuf(char*, streamsize)
 226   { return this; }
 227
 228   strstreambuf::pos_type
 229   strstreambuf::seekoff(off_type off, ios_base::seekdir dir,
 230                         ios_base::openmode mode)
 231   {
 232     bool do_get = false;
 233     bool do_put = false;
 234
 235     if ((mode & (ios_base::in | ios_base::out))
 236         == (ios_base::in | ios_base::out) &&
 237         (dir == ios_base::beg || dir == ios_base::end))
 238       do_get = do_put = true;
 239     else if (mode & ios_base::in)
 240       do_get = true;
 241     else if (mode & ios_base::out)
 242       do_put = true;
 243
 244     // !gptr() is here because, according to D.7.1 paragraph 4, the seekable
 245     // area is undefined if there is no get area.
 246     if ((!do_get && !do_put) || (do_put && !pptr()) || !gptr())
 247       return pos_type(off_type(-1));
 248
 249     char* seeklow  = eback();
 250     char* seekhigh = epptr() ? epptr() : egptr();
 251
 252     off_type newoff;
 253     switch (dir)
 254       {
 255       case ios_base::beg:
 256         newoff = 0;
 257         break;
 258       case ios_base::end:
 259         newoff = seekhigh - seeklow;
 260         break;
 261       case ios_base::cur:
 262         newoff = do_put ? pptr() - seeklow : gptr() - seeklow;
 263         break;
 264       default:
 265         return pos_type(off_type(-1));
 266       }
 267
 268     off += newoff;
 269     if (off < 0 || off > seekhigh - seeklow)
 270       return pos_type(off_type(-1));
 271
 272     if (do_put)
 273       {
 274         if (seeklow + off < pbase())
 275           {
 276             setp(seeklow, epptr());
 277             pbump(off);
 278           }
 279         else
 280           {
 281             setp(pbase(), epptr());
 282             pbump(off - (pbase() - seeklow));
 283           }
 284       }
 285     if (do_get)
 286       {
 287         if (off <= egptr() - seeklow)
 288           setg(seeklow, seeklow + off, egptr());
 289         else if (off <= pptr() - seeklow)
 290           setg(seeklow, seeklow + off, pptr());
 291         else
 292           setg(seeklow, seeklow + off, epptr());
 293       }
 294     return pos_type(newoff);
 295   }
 296
 297   strstreambuf::pos_type
 298   strstreambuf::seekpos(pos_type pos, ios_base::openmode mode)
 299   { return seekoff(pos - pos_type(off_type(0)), ios_base::beg, mode); }
 300
 301   char*
 302   strstreambuf::_M_alloc(size_t n)
 303   {
 304     if (_M_alloc_fun)
 305       return static_cast<char*>(_M_alloc_fun(n));
 306     else
 307       return new char[n];
 308   }
 309
 310   void
 311   strstreambuf::_M_free(char* p)
 312   {
 313     if (p)
 314       if (_M_free_fun)
 315         _M_free_fun(p);
 316       else
 317         delete[] p;
 318   }
 319
 320   void
 321   strstreambuf::_M_setup(char* get, char* put, streamsize n)
 322   {
 323     if (get)
 324       {
 325         size_t N = n > 0 ? size_t(n) : n == 0 ? strlen(get) : size_t(INT_MAX);
 326
 327         if (put)
 328           {
 329             setg(get, get, put);
 330             setp(put, put + N);
 331           }
 332         else
 333           setg(get, get, get + N);
 334       }
 335   }
 336
 337   istrstream::istrstream(char* s)
 338   : basic_ios<char>(), basic_istream<char>(0), _M_buf(s, 0)
 339   { basic_ios<char>::init(&_M_buf); }
 340
 341   istrstream::istrstream(const char* s)
 342   : basic_ios<char>(), basic_istream<char>(0), _M_buf(s, 0)
 343   { basic_ios<char>::init(&_M_buf); }
 344
 345   istrstream::istrstream(char* s, streamsize n)
 346   : basic_ios<char>(), basic_istream<char>(0), _M_buf(s, n)
 347   { basic_ios<char>::init(&_M_buf); }
 348
 349   istrstream::istrstream(const char* s, streamsize n)
 350   : basic_ios<char>(), basic_istream<char>(0), _M_buf(s, n)
 351   { basic_ios<char>::init(&_M_buf); }
 352
 353   istrstream::~istrstream() { }
 354
 355   strstreambuf*
 356   istrstream::rdbuf() const
 357   { return const_cast<strstreambuf*>(&_M_buf); }
 358
 359   char*
 360   istrstream::str()
 361   { return _M_buf.str(); }
 362
 363   ostrstream::ostrstream()
 364   : basic_ios<char>(), basic_ostream<char>(0), _M_buf()
 365   { basic_ios<char>::init(&_M_buf); }
 366
 367   ostrstream::ostrstream(char* s, int n, ios_base::openmode mode)
 368   : basic_ios<char>(), basic_ostream<char>(0),
 369     _M_buf(s, n, mode & ios_base::app ? s + strlen(s) : s)
 370   { basic_ios<char>::init(&_M_buf); }
 371
 372   ostrstream::~ostrstream() {}
 373
 374   strstreambuf*
 375   ostrstream::rdbuf() const
 376   { return const_cast<strstreambuf*>(&_M_buf); }
 377
 378   void
 379   ostrstream::freeze(bool freezeflag)
 380   { _M_buf.freeze(freezeflag); }
 381
 382   char*
 383   ostrstream::str()
 384   { return _M_buf.str(); }
 385
 386   int
 387   ostrstream::pcount() const
 388   { return _M_buf.pcount(); }
 389
 390   strstream::strstream()
 391   : basic_ios<char>(), basic_iostream<char>(0), _M_buf()
 392   { basic_ios<char>::init(&_M_buf); }
 393
 394   strstream::strstream(char* s, int n, ios_base::openmode mode)
 395   : basic_ios<char>(), basic_iostream<char>(0),
 396     _M_buf(s, n, mode & ios_base::app ? s + strlen(s) : s)
 397   { basic_ios<char>::init(&_M_buf); }
 398
 399   strstream::~strstream() { }
 400
 401   strstreambuf*
 402   strstream::rdbuf() const
 403   { return const_cast<strstreambuf*>(&_M_buf); }
 404
 405   void
 406   strstream::freeze(bool freezeflag)
 407   { _M_buf.freeze(freezeflag); }
 408
 409   int
 410   strstream::pcount() const
 411   { return _M_buf.pcount(); }
 412
 413   char*
 414   strstream::str()
 415   { return _M_buf.str(); }
 416 } // namespace std