libstdc++-v3/src/strstream.cc

   1 // strstream definitions -*- C++ -*-
   2
   3 // Copyright (C) 2001, 2002, 2003, 2005, 2009 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 3, 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 // Under Section 7 of GPL version 3, you are granted additional
  17 // permissions described in the GCC Runtime Library Exception, version
  18 // 3.1, as published by the Free Software Foundation.
  19
  20 // You should have received a copy of the GNU General Public License and
  21 // a copy of the GCC Runtime Library Exception along with this program;
  22 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  23 // <http://www.gnu.org/licenses/>.
  24
  25 /*
  26  * Copyright (c) 1998
  27  * Silicon Graphics Computer Systems, Inc.
  28  *
  29  * Permission to use, copy, modify, distribute and sell this software
  30  * and its documentation for any purpose is hereby granted without fee,
  31  * provided that the above copyright notice appear in all copies and
  32  * that both that copyright notice and this permission notice appear
  33  * in supporting documentation.  Silicon Graphics makes no
  34  * representations about the suitability of this software for any
  35  * purpose.  It is provided "as is" without express or implied warranty.
  36  */
  37
  38 // Implementation of the classes in header <strstream>.
  39 // WARNING: The classes defined in <strstream> are DEPRECATED.  This
  40 // header is defined in section D.7.1 of the C++ standard, and it
  41 // MAY BE REMOVED in a future standard revision.  You should use the
  42 // header <sstream> instead.
  43
  44 #include <strstream>
  45 #include <algorithm>
  46 #include <new>
  47 #include <stdlib.h>
  48 #include <string.h>
  49 #include <limits.h>
  50
  51 _GLIBCXX_BEGIN_NAMESPACE(std)
  52
  53   strstreambuf::strstreambuf(streamsize initial_capacity)
  54   : _Base(), _M_alloc_fun(0), _M_free_fun(0), _M_dynamic(true),
  55     _M_frozen(false), _M_constant(false)
  56   {
  57     streamsize n = std::max(initial_capacity, streamsize(16));
  58
  59     char* buf = _M_alloc(n);
  60     if (buf)
  61       {
  62         setp(buf, buf + n);
  63         setg(buf, buf, buf);
  64       }
  65   }
  66
  67   strstreambuf::strstreambuf(void* (*alloc_f)(size_t), void (*free_f)(void*))
  68   : _Base(), _M_alloc_fun(alloc_f), _M_free_fun(free_f), _M_dynamic(true),
  69     _M_frozen(false), _M_constant(false)
  70   {
  71     streamsize n = 16;
  72
  73     char* buf = _M_alloc(n);
  74     if (buf)
  75       {
  76         setp(buf, buf + n);
  77         setg(buf, buf, buf);
  78       }
  79   }
  80
  81   strstreambuf::strstreambuf(char* get, streamsize n, char* put) throw ()
  82   : _Base(), _M_alloc_fun(0), _M_free_fun(0), _M_dynamic(false),
  83     _M_frozen(false), _M_constant(false)
  84   { _M_setup(get, put, n); }
  85
  86   strstreambuf::strstreambuf(signed char* get, streamsize n, signed char* put) throw ()
  87   : _Base(), _M_alloc_fun(0), _M_free_fun(0), _M_dynamic(false),
  88   _M_frozen(false), _M_constant(false)
  89   { _M_setup(reinterpret_cast<char*>(get), reinterpret_cast<char*>(put), n); }
  90
  91   strstreambuf::strstreambuf(unsigned char* get, streamsize n,
  92                              unsigned char* put) throw ()
  93   : _Base(), _M_alloc_fun(0), _M_free_fun(0), _M_dynamic(false),
  94     _M_frozen(false), _M_constant(false)
  95   { _M_setup(reinterpret_cast<char*>(get), reinterpret_cast<char*>(put), n); }
  96
  97   strstreambuf::strstreambuf(const char* get, streamsize n) throw ()
  98   : _Base(), _M_alloc_fun(0), _M_free_fun(0), _M_dynamic(false),
  99     _M_frozen(false), _M_constant(true)
 100   { _M_setup(const_cast<char*>(get), 0, n); }
 101
 102   strstreambuf::strstreambuf(const signed char* get, streamsize n) throw ()
 103   : _Base(), _M_alloc_fun(0), _M_free_fun(0), _M_dynamic(false),
 104     _M_frozen(false), _M_constant(true)
 105   { _M_setup(reinterpret_cast<char*>(const_cast<signed char*>(get)), 0, n); }
 106
 107   strstreambuf::strstreambuf(const unsigned char* get, streamsize n) throw ()
 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<unsigned char*>(get)), 0, n); }
 111
 112   strstreambuf::~strstreambuf()
 113   {
 114     if (_M_dynamic && !_M_frozen)
 115       _M_free(eback());
 116   }
 117
 118   void
 119   strstreambuf::freeze(bool frozenflag) throw ()
 120   {
 121     if (_M_dynamic)
 122       _M_frozen = frozenflag;
 123   }
 124
 125   char*
 126   strstreambuf::str() throw ()
 127   {
 128     freeze(true);
 129     return eback();
 130   }
 131
 132   int
 133   strstreambuf::pcount() const throw ()
 134   { return pptr() ? pptr() - pbase() : 0; }
 135
 136   strstreambuf::int_type
 137   strstreambuf::overflow(int_type c)
 138   {
 139     if (c == traits_type::eof())
 140       return traits_type::not_eof(c);
 141
 142     // Try to expand the buffer.
 143     if (pptr() == epptr() && _M_dynamic && !_M_frozen && !_M_constant)
 144       {
 145         ptrdiff_t old_size = epptr() - pbase();
 146         ptrdiff_t new_size = std::max(ptrdiff_t(2 * old_size), ptrdiff_t(1));
 147
 148         char* buf = _M_alloc(new_size);
 149         if (buf)
 150           {
 151             memcpy(buf, pbase(), old_size);
 152             char* old_buffer = pbase();
 153             bool reposition_get = false;
 154             ptrdiff_t old_get_offset;
 155             if (gptr() != 0)
 156               {
 157                 reposition_get = true;
 158                 old_get_offset = gptr() - eback();
 159               }
 160
 161             setp(buf, buf + new_size);
 162             pbump(old_size);
 163
 164             if (reposition_get)
 165               setg(buf, buf + old_get_offset, buf +
 166                    std::max(old_get_offset, old_size));
 167
 168             _M_free(old_buffer);
 169           }
 170       }
 171
 172     if (pptr() != epptr())
 173       {
 174         *pptr() = c;
 175         pbump(1);
 176         return c;
 177       }
 178     else
 179       return traits_type::eof();
 180   }
 181
 182   strstreambuf::int_type
 183   strstreambuf::pbackfail(int_type c)
 184   {
 185     if (gptr() != eback())
 186       {
 187       if (c == _Traits::eof())
 188         {
 189           gbump(-1);
 190           return _Traits::not_eof(c);
 191         }
 192       else if (c == _Traits::to_int_type(gptr()[-1]))
 193         {  // KLUDGE
 194           gbump(-1);
 195           return c;
 196         }
 197       else if (!_M_constant)
 198         {
 199           gbump(-1);
 200           *gptr() = c;
 201           return c;
 202         }
 203     }
 204     return _Traits::eof();
 205   }
 206
 207   strstreambuf::int_type
 208   strstreambuf::underflow()
 209   {
 210     if (gptr() == egptr() && pptr() && pptr() > egptr())
 211       setg(eback(), gptr(), pptr());
 212
 213     if (gptr() != egptr())
 214       return (unsigned char) *gptr();
 215     else
 216       return _Traits::eof();
 217   }
 218
 219   basic_streambuf<char, char_traits<char> >*
 220   strstreambuf::setbuf(char*, streamsize)
 221   { return this; }
 222
 223   strstreambuf::pos_type
 224   strstreambuf::seekoff(off_type off, ios_base::seekdir dir,
 225                         ios_base::openmode mode)
 226   {
 227     bool do_get = false;
 228     bool do_put = false;
 229
 230     if ((mode & (ios_base::in | ios_base::out))
 231         == (ios_base::in | ios_base::out) &&
 232         (dir == ios_base::beg || dir == ios_base::end))
 233       do_get = do_put = true;
 234     else if (mode & ios_base::in)
 235       do_get = true;
 236     else if (mode & ios_base::out)
 237       do_put = true;
 238
 239     // !gptr() is here because, according to D.7.1 paragraph 4, the seekable
 240     // area is undefined if there is no get area.
 241     if ((!do_get && !do_put) || (do_put && !pptr()) || !gptr())
 242       return pos_type(off_type(-1));
 243
 244     char* seeklow  = eback();
 245     char* seekhigh = epptr() ? epptr() : egptr();
 246
 247     off_type newoff;
 248     switch (dir)
 249       {
 250       case ios_base::beg:
 251         newoff = 0;
 252         break;
 253       case ios_base::end:
 254         newoff = seekhigh - seeklow;
 255         break;
 256       case ios_base::cur:
 257         newoff = do_put ? pptr() - seeklow : gptr() - seeklow;
 258         break;
 259       default:
 260         return pos_type(off_type(-1));
 261       }
 262
 263     off += newoff;
 264     if (off < 0 || off > seekhigh - seeklow)
 265       return pos_type(off_type(-1));
 266
 267     if (do_put)
 268       {
 269         if (seeklow + off < pbase())
 270           {
 271             setp(seeklow, epptr());
 272             pbump(off);
 273           }
 274         else
 275           {
 276             setp(pbase(), epptr());
 277             pbump(off - (pbase() - seeklow));
 278           }
 279       }
 280     if (do_get)
 281       {
 282         if (off <= egptr() - seeklow)
 283           setg(seeklow, seeklow + off, egptr());
 284         else if (off <= pptr() - seeklow)
 285           setg(seeklow, seeklow + off, pptr());
 286         else
 287           setg(seeklow, seeklow + off, epptr());
 288       }
 289     return pos_type(newoff);
 290   }
 291
 292   strstreambuf::pos_type
 293   strstreambuf::seekpos(pos_type pos, ios_base::openmode mode)
 294   { return seekoff(pos - pos_type(off_type(0)), ios_base::beg, mode); }
 295
 296   char*
 297   strstreambuf::_M_alloc(size_t n)
 298   {
 299     if (_M_alloc_fun)
 300       return static_cast<char*>(_M_alloc_fun(n));
 301     else
 302       return new char[n];
 303   }
 304
 305   void
 306   strstreambuf::_M_free(char* p)
 307   {
 308     if (p)
 309       {
 310         if (_M_free_fun)
 311           _M_free_fun(p);
 312         else
 313           delete[] p;
 314       }
 315   }
 316
 317   void
 318   strstreambuf::_M_setup(char* get, char* put, streamsize n) throw ()
 319   {
 320     if (get)
 321       {
 322         size_t N = n > 0 ? size_t(n) : n == 0 ? strlen(get) : size_t(INT_MAX);
 323
 324         if (put)
 325           {
 326             setg(get, get, put);
 327             setp(put, put + N);
 328           }
 329         else
 330           setg(get, get, get + N);
 331       }
 332   }
 333
 334   istrstream::istrstream(char* s)
 335   : basic_ios<char>(), basic_istream<char>(0), _M_buf(s, 0)
 336   { basic_ios<char>::init(&_M_buf); }
 337
 338   istrstream::istrstream(const char* s)
 339   : basic_ios<char>(), basic_istream<char>(0), _M_buf(s, 0)
 340   { basic_ios<char>::init(&_M_buf); }
 341
 342   istrstream::istrstream(char* s, streamsize n)
 343   : basic_ios<char>(), basic_istream<char>(0), _M_buf(s, n)
 344   { basic_ios<char>::init(&_M_buf); }
 345
 346   istrstream::istrstream(const char* s, streamsize n)
 347   : basic_ios<char>(), basic_istream<char>(0), _M_buf(s, n)
 348   { basic_ios<char>::init(&_M_buf); }
 349
 350   istrstream::~istrstream() { }
 351
 352   strstreambuf*
 353   istrstream::rdbuf() const throw ()
 354   { return const_cast<strstreambuf*>(&_M_buf); }
 355
 356   char*
 357   istrstream::str() throw ()
 358   { return _M_buf.str(); }
 359
 360   ostrstream::ostrstream()
 361   : basic_ios<char>(), basic_ostream<char>(0), _M_buf()
 362   { basic_ios<char>::init(&_M_buf); }
 363
 364   ostrstream::ostrstream(char* s, int n, ios_base::openmode mode)
 365   : basic_ios<char>(), basic_ostream<char>(0),
 366     _M_buf(s, n, mode & ios_base::app ? s + strlen(s) : s)
 367   { basic_ios<char>::init(&_M_buf); }
 368
 369   ostrstream::~ostrstream() {}
 370
 371   strstreambuf*
 372   ostrstream::rdbuf() const throw ()
 373   { return const_cast<strstreambuf*>(&_M_buf); }
 374
 375   void
 376   ostrstream::freeze(bool freezeflag) throw ()
 377   { _M_buf.freeze(freezeflag); }
 378
 379   char*
 380   ostrstream::str() throw ()
 381   { return _M_buf.str(); }
 382
 383   int
 384   ostrstream::pcount() const throw ()
 385   { return _M_buf.pcount(); }
 386
 387   strstream::strstream()
 388   : basic_ios<char>(), basic_iostream<char>(0), _M_buf()
 389   { basic_ios<char>::init(&_M_buf); }
 390
 391   strstream::strstream(char* s, int n, ios_base::openmode mode)
 392   : basic_ios<char>(), basic_iostream<char>(0),
 393     _M_buf(s, n, mode & ios_base::app ? s + strlen(s) : s)
 394   { basic_ios<char>::init(&_M_buf); }
 395
 396   strstream::~strstream() { }
 397
 398   strstreambuf*
 399   strstream::rdbuf() const throw ()
 400   { return const_cast<strstreambuf*>(&_M_buf); }
 401
 402   void
 403   strstream::freeze(bool freezeflag) throw ()
 404   { _M_buf.freeze(freezeflag); }
 405
 406   int
 407   strstream::pcount() const throw ()
 408   { return _M_buf.pcount(); }
 409
 410   char*
 411   strstream::str() throw ()
 412   { return _M_buf.str(); }
 413
 414 _GLIBCXX_END_NAMESPACE