libstdc++-v3/src/c++98/strstream.cc

   1 // strstream definitions -*- C++ -*-
   2
   3 // Copyright (C) 2001-2017 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 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 namespace std _GLIBCXX_VISIBILITY(default)
  52 {
  53 _GLIBCXX_BEGIN_NAMESPACE_VERSION
  54
  55   strstreambuf::strstreambuf(streamsize initial_capacity)
  56   : _Base(), _M_alloc_fun(0), _M_free_fun(0), _M_dynamic(true),
  57     _M_frozen(false), _M_constant(false)
  58   {
  59     streamsize n = std::max(initial_capacity, streamsize(16));
  60
  61     char* buf = _M_alloc(n);
  62     if (buf)
  63       {
  64         setp(buf, buf + n);
  65         setg(buf, buf, buf);
  66       }
  67   }
  68
  69   strstreambuf::strstreambuf(void* (*alloc_f)(size_t), void (*free_f)(void*))
  70   : _Base(), _M_alloc_fun(alloc_f), _M_free_fun(free_f), _M_dynamic(true),
  71     _M_frozen(false), _M_constant(false)
  72   {
  73     streamsize n = 16;
  74
  75     char* buf = _M_alloc(n);
  76     if (buf)
  77       {
  78         setp(buf, buf + n);
  79         setg(buf, buf, buf);
  80       }
  81   }
  82
  83   strstreambuf::strstreambuf(char* get, streamsize n, char* put) throw ()
  84   : _Base(), _M_alloc_fun(0), _M_free_fun(0), _M_dynamic(false),
  85     _M_frozen(false), _M_constant(false)
  86   { _M_setup(get, put, n); }
  87
  88   strstreambuf::strstreambuf(signed char* get, streamsize n, signed char* put) throw ()
  89   : _Base(), _M_alloc_fun(0), _M_free_fun(0), _M_dynamic(false),
  90   _M_frozen(false), _M_constant(false)
  91   { _M_setup(reinterpret_cast<char*>(get), reinterpret_cast<char*>(put), n); }
  92
  93   strstreambuf::strstreambuf(unsigned char* get, streamsize n,
  94                              unsigned char* put) throw ()
  95   : _Base(), _M_alloc_fun(0), _M_free_fun(0), _M_dynamic(false),
  96     _M_frozen(false), _M_constant(false)
  97   { _M_setup(reinterpret_cast<char*>(get), reinterpret_cast<char*>(put), n); }
  98
  99   strstreambuf::strstreambuf(const char* get, streamsize n) throw ()
 100   : _Base(), _M_alloc_fun(0), _M_free_fun(0), _M_dynamic(false),
 101     _M_frozen(false), _M_constant(true)
 102   { _M_setup(const_cast<char*>(get), 0, n); }
 103
 104   strstreambuf::strstreambuf(const signed char* get, streamsize n) throw ()
 105   : _Base(), _M_alloc_fun(0), _M_free_fun(0), _M_dynamic(false),
 106     _M_frozen(false), _M_constant(true)
 107   { _M_setup(reinterpret_cast<char*>(const_cast<signed char*>(get)), 0, n); }
 108
 109   strstreambuf::strstreambuf(const unsigned char* get, streamsize n) throw ()
 110   : _Base(), _M_alloc_fun(0), _M_free_fun(0), _M_dynamic(false),
 111     _M_frozen(false), _M_constant(true)
 112   { _M_setup(reinterpret_cast<char*>(const_cast<unsigned char*>(get)), 0, n); }
 113
 114   strstreambuf::~strstreambuf()
 115   {
 116     if (_M_dynamic && !_M_frozen)
 117       _M_free(eback());
 118   }
 119
 120   void
 121   strstreambuf::freeze(bool frozenflag) throw ()
 122   {
 123     if (_M_dynamic)
 124       _M_frozen = frozenflag;
 125   }
 126
 127   char*
 128   strstreambuf::str() throw ()
 129   {
 130     freeze(true);
 131     return eback();
 132   }
 133
 134   int
 135   strstreambuf::pcount() const throw ()
 136   { return pptr() ? pptr() - pbase() : 0; }
 137
 138   strstreambuf::int_type
 139   strstreambuf::overflow(int_type c)
 140   {
 141     if (c == traits_type::eof())
 142       return traits_type::not_eof(c);
 143
 144     // Try to expand the buffer.
 145     if (pptr() == epptr() && _M_dynamic && !_M_frozen && !_M_constant)
 146       {
 147         ptrdiff_t old_size = epptr() - pbase();
 148         ptrdiff_t new_size = std::max(ptrdiff_t(2 * old_size), ptrdiff_t(1));
 149
 150         char* buf = _M_alloc(new_size);
 151         if (buf)
 152           {
 153             memcpy(buf, pbase(), old_size);
 154             char* old_buffer = pbase();
 155             bool reposition_get = false;
 156             ptrdiff_t old_get_offset;
 157             if (gptr() != 0)
 158               {
 159                 reposition_get = true;
 160                 old_get_offset = gptr() - eback();
 161               }
 162
 163             setp(buf, buf + new_size);
 164             __safe_pbump(old_size);
 165
 166             if (reposition_get)
 167               setg(buf, buf + old_get_offset, buf +
 168                    std::max(old_get_offset, old_size));
 169
 170             _M_free(old_buffer);
 171           }
 172       }
 173
 174     if (pptr() != epptr())
 175       {
 176         *pptr() = c;
 177         pbump(1);
 178         return c;
 179       }
 180     else
 181       return traits_type::eof();
 182   }
 183
 184   strstreambuf::int_type
 185   strstreambuf::pbackfail(int_type c)
 186   {
 187     if (gptr() != eback())
 188       {
 189       if (c == _Traits::eof())
 190         {
 191           gbump(-1);
 192           return _Traits::not_eof(c);
 193         }
 194       else if (c == _Traits::to_int_type(gptr()[-1]))
 195         {  // KLUDGE
 196           gbump(-1);
 197           return c;
 198         }
 199       else if (!_M_constant)
 200         {
 201           gbump(-1);
 202           *gptr() = c;
 203           return c;
 204         }
 205     }
 206     return _Traits::eof();
 207   }
 208
 209   strstreambuf::int_type
 210   strstreambuf::underflow()
 211   {
 212     if (gptr() == egptr() && pptr() && pptr() > egptr())
 213       setg(eback(), gptr(), pptr());
 214
 215     if (gptr() != egptr())
 216       return (unsigned char) *gptr();
 217     else
 218       return _Traits::eof();
 219   }
 220
 221   basic_streambuf<char, char_traits<char> >*
 222   strstreambuf::setbuf(char*, streamsize)
 223   { return this; }
 224
 225   strstreambuf::pos_type
 226   strstreambuf::seekoff(off_type off, ios_base::seekdir dir,
 227                         ios_base::openmode mode)
 228   {
 229     bool do_get = false;
 230     bool do_put = false;
 231
 232     if ((mode & (ios_base::in | ios_base::out))
 233         == (ios_base::in | ios_base::out) &&
 234         (dir == ios_base::beg || dir == ios_base::end))
 235       do_get = do_put = true;
 236     else if (mode & ios_base::in)
 237       do_get = true;
 238     else if (mode & ios_base::out)
 239       do_put = true;
 240
 241     // !gptr() is here because, according to D.7.1 paragraph 4, the seekable
 242     // area is undefined if there is no get area.
 243     if ((!do_get && !do_put) || (do_put && !pptr()) || !gptr())
 244       return pos_type(off_type(-1));
 245
 246     char* seeklow  = eback();
 247     char* seekhigh = epptr() ? epptr() : egptr();
 248
 249     off_type newoff;
 250     switch (dir)
 251       {
 252       case ios_base::beg:
 253         newoff = 0;
 254         break;
 255       case ios_base::end:
 256         newoff = seekhigh - seeklow;
 257         break;
 258       case ios_base::cur:
 259         newoff = do_put ? pptr() - seeklow : gptr() - seeklow;
 260         break;
 261       default:
 262         return pos_type(off_type(-1));
 263       }
 264
 265     off += newoff;
 266     if (off < 0 || off > seekhigh - seeklow)
 267       return pos_type(off_type(-1));
 268
 269     if (do_put)
 270       {
 271         if (seeklow + off < pbase())
 272           {
 273             setp(seeklow, epptr());
 274             __safe_pbump(off);
 275           }
 276         else
 277           {
 278             setp(pbase(), epptr());
 279             __safe_pbump(off - (pbase() - seeklow));
 280           }
 281       }
 282     if (do_get)
 283       {
 284         if (off <= egptr() - seeklow)
 285           setg(seeklow, seeklow + off, egptr());
 286         else if (off <= pptr() - seeklow)
 287           setg(seeklow, seeklow + off, pptr());
 288         else
 289           setg(seeklow, seeklow + off, epptr());
 290       }
 291     return pos_type(newoff);
 292   }
 293
 294   strstreambuf::pos_type
 295   strstreambuf::seekpos(pos_type pos, ios_base::openmode mode)
 296   { return seekoff(pos - pos_type(off_type(0)), ios_base::beg, mode); }
 297
 298   char*
 299   strstreambuf::_M_alloc(size_t n)
 300   {
 301     if (_M_alloc_fun)
 302       return static_cast<char*>(_M_alloc_fun(n));
 303     else
 304       return new char[n];
 305   }
 306
 307   void
 308   strstreambuf::_M_free(char* p)
 309   {
 310     if (p)
 311       {
 312         if (_M_free_fun)
 313           _M_free_fun(p);
 314         else
 315           delete[] p;
 316       }
 317   }
 318
 319   void
 320   strstreambuf::_M_setup(char* get, char* put, streamsize n) throw ()
 321   {
 322     if (get)
 323       {
 324         size_t N = n > 0 ? size_t(n) : n == 0 ? strlen(get) : size_t(INT_MAX);
 325
 326         if (put)
 327           {
 328             setg(get, get, put);
 329             setp(put, put + N);
 330           }
 331         else
 332           setg(get, get, get + N);
 333       }
 334   }
 335
 336   istrstream::istrstream(char* s)
 337   : basic_ios<char>(), basic_istream<char>(0), _M_buf(s, 0)
 338   { basic_ios<char>::init(&_M_buf); }
 339
 340   istrstream::istrstream(const char* s)
 341   : basic_ios<char>(), basic_istream<char>(0), _M_buf(s, 0)
 342   { basic_ios<char>::init(&_M_buf); }
 343
 344   istrstream::istrstream(char* s, streamsize n)
 345   : basic_ios<char>(), basic_istream<char>(0), _M_buf(s, n)
 346   { basic_ios<char>::init(&_M_buf); }
 347
 348   istrstream::istrstream(const char* s, streamsize n)
 349   : basic_ios<char>(), basic_istream<char>(0), _M_buf(s, n)
 350   { basic_ios<char>::init(&_M_buf); }
 351
 352   istrstream::~istrstream() { }
 353
 354   strstreambuf*
 355   istrstream::rdbuf() const throw ()
 356   { return const_cast<strstreambuf*>(&_M_buf); }
 357
 358   char*
 359   istrstream::str() throw ()
 360   { return _M_buf.str(); }
 361
 362   ostrstream::ostrstream()
 363   : basic_ios<char>(), basic_ostream<char>(0), _M_buf()
 364   { basic_ios<char>::init(&_M_buf); }
 365
 366   ostrstream::ostrstream(char* s, int n, ios_base::openmode mode)
 367   : basic_ios<char>(), basic_ostream<char>(0),
 368     _M_buf(s, n, mode & ios_base::app ? s + strlen(s) : s)
 369   { basic_ios<char>::init(&_M_buf); }
 370
 371   ostrstream::~ostrstream() {}
 372
 373   strstreambuf*
 374   ostrstream::rdbuf() const throw ()
 375   { return const_cast<strstreambuf*>(&_M_buf); }
 376
 377   void
 378   ostrstream::freeze(bool freezeflag) throw ()
 379   { _M_buf.freeze(freezeflag); }
 380
 381   char*
 382   ostrstream::str() throw ()
 383   { return _M_buf.str(); }
 384
 385   int
 386   ostrstream::pcount() const throw ()
 387   { return _M_buf.pcount(); }
 388
 389   strstream::strstream()
 390   : basic_ios<char>(), basic_iostream<char>(0), _M_buf()
 391   { basic_ios<char>::init(&_M_buf); }
 392
 393   strstream::strstream(char* s, int n, ios_base::openmode mode)
 394   : basic_ios<char>(), basic_iostream<char>(0),
 395     _M_buf(s, n, mode & ios_base::app ? s + strlen(s) : s)
 396   { basic_ios<char>::init(&_M_buf); }
 397
 398   strstream::~strstream() { }
 399
 400   strstreambuf*
 401   strstream::rdbuf() const throw ()
 402   { return const_cast<strstreambuf*>(&_M_buf); }
 403
 404   void
 405   strstream::freeze(bool freezeflag) throw ()
 406   { _M_buf.freeze(freezeflag); }
 407
 408   int
 409   strstream::pcount() const throw ()
 410   { return _M_buf.pcount(); }
 411
 412   char*
 413   strstream::str() throw ()
 414   { return _M_buf.str(); }
 415
 416 _GLIBCXX_END_NAMESPACE_VERSION
 417 } // namespace