libstdc++-v3/src/strstream.cc

   1 // strstream definitions -*- C++ -*-
   2
   3 // Copyright (C) 2001, 2002, 2003, 2005, 2009, 2010, 2011
   4 // Free Software Foundation
   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 3, 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 // Under Section 7 of GPL version 3, you are granted additional
  18 // permissions described in the GCC Runtime Library Exception, version
  19 // 3.1, as published by the Free Software Foundation.
  20
  21 // You should have received a copy of the GNU General Public License and
  22 // a copy of the GCC Runtime Library Exception along with this program;
  23 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  24 // <http://www.gnu.org/licenses/>.
  25
  26 /*
  27  * Copyright (c) 1998
  28  * Silicon Graphics Computer Systems, Inc.
  29  *
  30  * Permission to use, copy, modify, distribute and sell this software
  31  * and its documentation for any purpose is hereby granted without fee,
  32  * provided that the above copyright notice appear in all copies and
  33  * that both that copyright notice and this permission notice appear
  34  * in supporting documentation.  Silicon Graphics makes no
  35  * representations about the suitability of this software for any
  36  * purpose.  It is provided "as is" without express or implied warranty.
  37  */
  38
  39 // Implementation of the classes in header <strstream>.
  40 // WARNING: The classes defined in <strstream> are DEPRECATED.  This
  41 // header is defined in section D.7.1 of the C++ standard, and it
  42 // MAY BE REMOVED in a future standard revision.  You should use the
  43 // header <sstream> instead.
  44
  45 #include <strstream>
  46 #include <algorithm>
  47 #include <new>
  48 #include <stdlib.h>
  49 #include <string.h>
  50 #include <limits.h>
  51
  52 namespace std _GLIBCXX_VISIBILITY(default)
  53 {
  54 _GLIBCXX_BEGIN_NAMESPACE_VERSION
  55
  56   strstreambuf::strstreambuf(streamsize initial_capacity)
  57   : _Base(), _M_alloc_fun(0), _M_free_fun(0), _M_dynamic(true),
  58     _M_frozen(false), _M_constant(false)
  59   {
  60     streamsize n = std::max(initial_capacity, streamsize(16));
  61
  62     char* buf = _M_alloc(n);
  63     if (buf)
  64       {
  65         setp(buf, buf + n);
  66         setg(buf, buf, buf);
  67       }
  68   }
  69
  70   strstreambuf::strstreambuf(void* (*alloc_f)(size_t), void (*free_f)(void*))
  71   : _Base(), _M_alloc_fun(alloc_f), _M_free_fun(free_f), _M_dynamic(true),
  72     _M_frozen(false), _M_constant(false)
  73   {
  74     streamsize n = 16;
  75
  76     char* buf = _M_alloc(n);
  77     if (buf)
  78       {
  79         setp(buf, buf + n);
  80         setg(buf, buf, buf);
  81       }
  82   }
  83
  84   strstreambuf::strstreambuf(char* get, streamsize n, char* put) throw ()
  85   : _Base(), _M_alloc_fun(0), _M_free_fun(0), _M_dynamic(false),
  86     _M_frozen(false), _M_constant(false)
  87   { _M_setup(get, put, n); }
  88
  89   strstreambuf::strstreambuf(signed char* get, streamsize n, signed char* put) throw ()
  90   : _Base(), _M_alloc_fun(0), _M_free_fun(0), _M_dynamic(false),
  91   _M_frozen(false), _M_constant(false)
  92   { _M_setup(reinterpret_cast<char*>(get), reinterpret_cast<char*>(put), n); }
  93
  94   strstreambuf::strstreambuf(unsigned char* get, streamsize n,
  95                              unsigned char* put) throw ()
  96   : _Base(), _M_alloc_fun(0), _M_free_fun(0), _M_dynamic(false),
  97     _M_frozen(false), _M_constant(false)
  98   { _M_setup(reinterpret_cast<char*>(get), reinterpret_cast<char*>(put), n); }
  99
 100   strstreambuf::strstreambuf(const char* get, streamsize n) throw ()
 101   : _Base(), _M_alloc_fun(0), _M_free_fun(0), _M_dynamic(false),
 102     _M_frozen(false), _M_constant(true)
 103   { _M_setup(const_cast<char*>(get), 0, n); }
 104
 105   strstreambuf::strstreambuf(const signed char* get, streamsize n) throw ()
 106   : _Base(), _M_alloc_fun(0), _M_free_fun(0), _M_dynamic(false),
 107     _M_frozen(false), _M_constant(true)
 108   { _M_setup(reinterpret_cast<char*>(const_cast<signed char*>(get)), 0, n); }
 109
 110   strstreambuf::strstreambuf(const unsigned char* get, streamsize n) throw ()
 111   : _Base(), _M_alloc_fun(0), _M_free_fun(0), _M_dynamic(false),
 112     _M_frozen(false), _M_constant(true)
 113   { _M_setup(reinterpret_cast<char*>(const_cast<unsigned char*>(get)), 0, n); }
 114
 115   strstreambuf::~strstreambuf()
 116   {
 117     if (_M_dynamic && !_M_frozen)
 118       _M_free(eback());
 119   }
 120
 121   void
 122   strstreambuf::freeze(bool frozenflag) throw ()
 123   {
 124     if (_M_dynamic)
 125       _M_frozen = frozenflag;
 126   }
 127
 128   char*
 129   strstreambuf::str() throw ()
 130   {
 131     freeze(true);
 132     return eback();
 133   }
 134
 135   int
 136   strstreambuf::pcount() const throw ()
 137   { return pptr() ? pptr() - pbase() : 0; }
 138
 139   strstreambuf::int_type
 140   strstreambuf::overflow(int_type c)
 141   {
 142     if (c == traits_type::eof())
 143       return traits_type::not_eof(c);
 144
 145     // Try to expand the buffer.
 146     if (pptr() == epptr() && _M_dynamic && !_M_frozen && !_M_constant)
 147       {
 148         ptrdiff_t old_size = epptr() - pbase();
 149         ptrdiff_t new_size = std::max(ptrdiff_t(2 * old_size), ptrdiff_t(1));
 150
 151         char* buf = _M_alloc(new_size);
 152         if (buf)
 153           {
 154             memcpy(buf, pbase(), old_size);
 155             char* old_buffer = pbase();
 156             bool reposition_get = false;
 157             ptrdiff_t old_get_offset;
 158             if (gptr() != 0)
 159               {
 160                 reposition_get = true;
 161                 old_get_offset = gptr() - eback();
 162               }
 163
 164             setp(buf, buf + new_size);
 165             __safe_pbump(old_size);
 166
 167             if (reposition_get)
 168               setg(buf, buf + old_get_offset, buf +
 169                    std::max(old_get_offset, old_size));
 170
 171             _M_free(old_buffer);
 172           }
 173       }
 174
 175     if (pptr() != epptr())
 176       {
 177         *pptr() = c;
 178         pbump(1);
 179         return c;
 180       }
 181     else
 182       return traits_type::eof();
 183   }
 184
 185   strstreambuf::int_type
 186   strstreambuf::pbackfail(int_type c)
 187   {
 188     if (gptr() != eback())
 189       {
 190       if (c == _Traits::eof())
 191         {
 192           gbump(-1);
 193           return _Traits::not_eof(c);
 194         }
 195       else if (c == _Traits::to_int_type(gptr()[-1]))
 196         {  // KLUDGE
 197           gbump(-1);
 198           return c;
 199         }
 200       else if (!_M_constant)
 201         {
 202           gbump(-1);
 203           *gptr() = c;
 204           return c;
 205         }
 206     }
 207     return _Traits::eof();
 208   }
 209
 210   strstreambuf::int_type
 211   strstreambuf::underflow()
 212   {
 213     if (gptr() == egptr() && pptr() && pptr() > egptr())
 214       setg(eback(), gptr(), pptr());
 215
 216     if (gptr() != egptr())
 217       return (unsigned char) *gptr();
 218     else
 219       return _Traits::eof();
 220   }
 221
 222   basic_streambuf<char, char_traits<char> >*
 223   strstreambuf::setbuf(char*, streamsize)
 224   { return this; }
 225
 226   strstreambuf::pos_type
 227   strstreambuf::seekoff(off_type off, ios_base::seekdir dir,
 228                         ios_base::openmode mode)
 229   {
 230     bool do_get = false;
 231     bool do_put = false;
 232
 233     if ((mode & (ios_base::in | ios_base::out))
 234         == (ios_base::in | ios_base::out) &&
 235         (dir == ios_base::beg || dir == ios_base::end))
 236       do_get = do_put = true;
 237     else if (mode & ios_base::in)
 238       do_get = true;
 239     else if (mode & ios_base::out)
 240       do_put = true;
 241
 242     // !gptr() is here because, according to D.7.1 paragraph 4, the seekable
 243     // area is undefined if there is no get area.
 244     if ((!do_get && !do_put) || (do_put && !pptr()) || !gptr())
 245       return pos_type(off_type(-1));
 246
 247     char* seeklow  = eback();
 248     char* seekhigh = epptr() ? epptr() : egptr();
 249
 250     off_type newoff;
 251     switch (dir)
 252       {
 253       case ios_base::beg:
 254         newoff = 0;
 255         break;
 256       case ios_base::end:
 257         newoff = seekhigh - seeklow;
 258         break;
 259       case ios_base::cur:
 260         newoff = do_put ? pptr() - seeklow : gptr() - seeklow;
 261         break;
 262       default:
 263         return pos_type(off_type(-1));
 264       }
 265
 266     off += newoff;
 267     if (off < 0 || off > seekhigh - seeklow)
 268       return pos_type(off_type(-1));
 269
 270     if (do_put)
 271       {
 272         if (seeklow + off < pbase())
 273           {
 274             setp(seeklow, epptr());
 275             __safe_pbump(off);
 276           }
 277         else
 278           {
 279             setp(pbase(), epptr());
 280             __safe_pbump(off - (pbase() - seeklow));
 281           }
 282       }
 283     if (do_get)
 284       {
 285         if (off <= egptr() - seeklow)
 286           setg(seeklow, seeklow + off, egptr());
 287         else if (off <= pptr() - seeklow)
 288           setg(seeklow, seeklow + off, pptr());
 289         else
 290           setg(seeklow, seeklow + off, epptr());
 291       }
 292     return pos_type(newoff);
 293   }
 294
 295   strstreambuf::pos_type
 296   strstreambuf::seekpos(pos_type pos, ios_base::openmode mode)
 297   { return seekoff(pos - pos_type(off_type(0)), ios_base::beg, mode); }
 298
 299   char*
 300   strstreambuf::_M_alloc(size_t n)
 301   {
 302     if (_M_alloc_fun)
 303       return static_cast<char*>(_M_alloc_fun(n));
 304     else
 305       return new char[n];
 306   }
 307
 308   void
 309   strstreambuf::_M_free(char* p)
 310   {
 311     if (p)
 312       {
 313         if (_M_free_fun)
 314           _M_free_fun(p);
 315         else
 316           delete[] p;
 317       }
 318   }
 319
 320   void
 321   strstreambuf::_M_setup(char* get, char* put, streamsize n) throw ()
 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 throw ()
 357   { return const_cast<strstreambuf*>(&_M_buf); }
 358
 359   char*
 360   istrstream::str() throw ()
 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 throw ()
 376   { return const_cast<strstreambuf*>(&_M_buf); }
 377
 378   void
 379   ostrstream::freeze(bool freezeflag) throw ()
 380   { _M_buf.freeze(freezeflag); }
 381
 382   char*
 383   ostrstream::str() throw ()
 384   { return _M_buf.str(); }
 385
 386   int
 387   ostrstream::pcount() const throw ()
 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 throw ()
 403   { return const_cast<strstreambuf*>(&_M_buf); }
 404
 405   void
 406   strstream::freeze(bool freezeflag) throw ()
 407   { _M_buf.freeze(freezeflag); }
 408
 409   int
 410   strstream::pcount() const throw ()
 411   { return _M_buf.pcount(); }
 412
 413   char*
 414   strstream::str() throw ()
 415   { return _M_buf.str(); }
 416
 417 _GLIBCXX_END_NAMESPACE_VERSION
 418 } // namespace