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// strstream definitions -*- C++ -*-

// Copyright (C) 2001, 2002, 2003 Free Software Foundation

//

// This file is part of the GNU ISO C++ Library.  This library is free

// software; you can redistribute it and/or modify it under the

// terms of the GNU General Public License as published by the

// Free Software Foundation; either version 2, or (at your option)

// any later version.

// This library is distributed in the hope that it will be useful,

// but WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License along

// with this library; see the file COPYING.  If not, write to the Free

// Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,

// USA.

// As a special exception, you may use this file as part of a free software

// library without restriction.  Specifically, if other files instantiate

// templates or use macros or inline functions from this file, or you compile

// this file and link it with other files to produce an executable, this

// file does not by itself cause the resulting executable to be covered by

// the GNU General Public License.  This exception does not however

// invalidate any other reasons why the executable file might be covered by

// the GNU General Public License.

/*

 * Copyright (c) 1998

 * Silicon Graphics Computer Systems, Inc.

 *

 * Permission to use, copy, modify, distribute and sell this software

 * and its documentation for any purpose is hereby granted without fee,

 * provided that the above copyright notice appear in all copies and

 * that both that copyright notice and this permission notice appear

 * in supporting documentation.  Silicon Graphics makes no

 * representations about the suitability of this software for any

 * purpose.  It is provided "as is" without express or implied warranty.

 */

// Implementation of the classes in header <strstream>.

// WARNING: The classes defined in <strstream> are DEPRECATED.  This

// header is defined in section D.7.1 of the C++ standard, and it

// MAY BE REMOVED in a future standard revision.  You should use the

// header <sstream> instead.

#include <strstream>

#include <algorithm>

#include <new>

#include <stdlib.h>

#include <string.h>

#include <limits.h>

namespace std

{

  strstreambuf::strstreambuf(streamsize initial_capacity)

  : _Base(), _M_alloc_fun(0), _M_free_fun(0), _M_dynamic(true),

    _M_frozen(false), _M_constant(false)

  {

    streamsize n = std::max(initial_capacity, streamsize(16));

    char* buf = _M_alloc(n);

    if (buf)

      {

        setp(buf, buf + n);

        setg(buf, buf, buf);

      }

  }

  strstreambuf::strstreambuf(void* (*alloc_f)(size_t), void (*free_f)(void*))

  : _Base(), _M_alloc_fun(alloc_f), _M_free_fun(free_f), _M_dynamic(true),

    _M_frozen(false), _M_constant(false)

  {

    streamsize n = 16;

    char* buf = _M_alloc(n);

    if (buf)

      {

        setp(buf, buf + n);

        setg(buf, buf, buf);

      }

  }

  strstreambuf::strstreambuf(char* get, streamsize n, char* put)

  : _Base(), _M_alloc_fun(0), _M_free_fun(0), _M_dynamic(false),

    _M_frozen(false), _M_constant(false)

  { _M_setup(get, put, n); }

  strstreambuf::strstreambuf(signed char* get, streamsize n, signed char* put)

  : _Base(), _M_alloc_fun(0), _M_free_fun(0), _M_dynamic(false),

  _M_frozen(false), _M_constant(false)

  { _M_setup(reinterpret_cast<char*>(get), reinterpret_cast<char*>(put), n); }

  strstreambuf::strstreambuf(unsigned char* get, streamsize n,

                             unsigned char* put)

  : _Base(), _M_alloc_fun(0), _M_free_fun(0), _M_dynamic(false),

    _M_frozen(false), _M_constant(false)

  { _M_setup(reinterpret_cast<char*>(get), reinterpret_cast<char*>(put), n); }

  strstreambuf::strstreambuf(const char* get, streamsize n)

  : _Base(), _M_alloc_fun(0), _M_free_fun(0), _M_dynamic(false),

    _M_frozen(false), _M_constant(true)

  { _M_setup(const_cast<char*>(get), 0, n); }

  strstreambuf::strstreambuf(const signed char* get, streamsize n)

  : _Base(), _M_alloc_fun(0), _M_free_fun(0), _M_dynamic(false),

    _M_frozen(false), _M_constant(true)

  { _M_setup(reinterpret_cast<char*>(const_cast<signed char*>(get)), 0, n); }

  strstreambuf::strstreambuf(const unsigned char* get, streamsize n)

  : _Base(), _M_alloc_fun(0), _M_free_fun(0), _M_dynamic(false),

    _M_frozen(false), _M_constant(true)

  { _M_setup(reinterpret_cast<char*>(const_cast<unsigned char*>(get)), 0, n); }

  strstreambuf::~strstreambuf()

  {

    if (_M_dynamic && !_M_frozen)

      _M_free(eback());

  }

  void

  strstreambuf::freeze(bool frozenflag)

  {

    if (_M_dynamic)

      _M_frozen = frozenflag;

  }

  char*

  strstreambuf::str()

  {

    freeze(true);

    return eback();

  }

  int

  strstreambuf::pcount() const

  { return pptr() ? pptr() - pbase() : 0; }

  strstreambuf::int_type

  strstreambuf::overflow(int_type c)

  {

    if (c == traits_type::eof())

      return traits_type::not_eof(c);

    // Try to expand the buffer.

    if (pptr() == epptr() && _M_dynamic && !_M_frozen && !_M_constant)

      {

        ptrdiff_t old_size = epptr() - pbase();

        ptrdiff_t new_size = std::max(ptrdiff_t(2 * old_size), ptrdiff_t(1));

        char* buf = _M_alloc(new_size);

        if (buf)

          {

            memcpy(buf, pbase(), old_size);

            char* old_buffer = pbase();

            bool reposition_get = false;

            ptrdiff_t old_get_offset;

            if (gptr() != 0)

              {

                reposition_get = true;

                old_get_offset = gptr() - eback();

              }

            setp(buf, buf + new_size);

            pbump(old_size);

            if (reposition_get)

              setg(buf, buf + old_get_offset, buf +

                   std::max(old_get_offset, old_size));

            _M_free(old_buffer);

          }

      }

    if (pptr() != epptr())

      {

        *pptr() = c;

        pbump(1);

        return c;

      }

    else

      return traits_type::eof();

  }

  strstreambuf::int_type

  strstreambuf::pbackfail(int_type c)

  {

    if (gptr() != eback())

      {

      if (c == _Traits::eof())

        {

          gbump(-1);

          return _Traits::not_eof(c);

        }

      else if (c == _Traits::to_int_type(gptr()[-1]))

        {  // KLUDGE

          gbump(-1);

          return c;

        }

      else if (!_M_constant)

        {

          gbump(-1);

          *gptr() = c;

          return c;

        }

    }

    return _Traits::eof();

  }

  strstreambuf::int_type

  strstreambuf::underflow()

  {

    if (gptr() == egptr() && pptr() && pptr() > egptr())

      setg(eback(), gptr(), pptr());

    if (gptr() != egptr())

      return (unsigned char) *gptr();

    else

      return _Traits::eof();

  }

  basic_streambuf<char, char_traits<char> >*

  strstreambuf::setbuf(char*, streamsize)

  { return this; }

  strstreambuf::pos_type

  strstreambuf::seekoff(off_type off, ios_base::seekdir dir,

                        ios_base::openmode mode)

  {

    bool do_get = false;

    bool do_put = false;

    if ((mode & (ios_base::in | ios_base::out))

        == (ios_base::in | ios_base::out) &&

        (dir == ios_base::beg || dir == ios_base::end))

      do_get = do_put = true;

    else if (mode & ios_base::in)

      do_get = true;

    else if (mode & ios_base::out)

      do_put = true;

    // !gptr() is here because, according to D.7.1 paragraph 4, the seekable

    // area is undefined if there is no get area.

    if ((!do_get && !do_put) || (do_put && !pptr()) || !gptr())

      return pos_type(off_type(-1));

    char* seeklow  = eback();

    char* seekhigh = epptr() ? epptr() : egptr();

    off_type newoff;

    switch (dir)

      {

      case ios_base::beg:

        newoff = 0;

        break;

      case ios_base::end:

        newoff = seekhigh - seeklow;

        break;

      case ios_base::cur:

        newoff = do_put ? pptr() - seeklow : gptr() - seeklow;

        break;

      default:

        return pos_type(off_type(-1));

      }

    off += newoff;

    if (off < 0 || off > seekhigh - seeklow)

      return pos_type(off_type(-1));

    if (do_put)

      {

        if (seeklow + off < pbase())

          {

            setp(seeklow, epptr());

            pbump(off);

          }

        else

          {

            setp(pbase(), epptr());

            pbump(off - (pbase() - seeklow));

          }

      }

    if (do_get)

      {

        if (off <= egptr() - seeklow)

          setg(seeklow, seeklow + off, egptr());

        else if (off <= pptr() - seeklow)

          setg(seeklow, seeklow + off, pptr());

        else

          setg(seeklow, seeklow + off, epptr());

      }

    return pos_type(newoff);

  }

  strstreambuf::pos_type

  strstreambuf::seekpos(pos_type pos, ios_base::openmode mode)

  { return seekoff(pos - pos_type(off_type(0)), ios_base::beg, mode); }

  char*

  strstreambuf::_M_alloc(size_t n)

  {

    if (_M_alloc_fun)

      return static_cast<char*>(_M_alloc_fun(n));

    else

      return new char[n];

  }

  void

  strstreambuf::_M_free(char* p)

  {

    if (p)

      if (_M_free_fun)

        _M_free_fun(p);

      else

        delete[] p;

  }

  void

  strstreambuf::_M_setup(char* get, char* put, streamsize n)

  {

    if (get)

      {

        size_t N = n > 0 ? size_t(n) : n == 0 ? strlen(get) : size_t(INT_MAX);

        if (put)

          {

            setg(get, get, put);

            setp(put, put + N);

          }

        else

          setg(get, get, get + N);

      }

  }

  istrstream::istrstream(char* s)

  : basic_ios<char>(), basic_istream<char>(0), _M_buf(s, 0)

  { basic_ios<char>::init(&_M_buf); }

  istrstream::istrstream(const char* s)

  : basic_ios<char>(), basic_istream<char>(0), _M_buf(s, 0)

  { basic_ios<char>::init(&_M_buf); }

  istrstream::istrstream(char* s, streamsize n)

  : basic_ios<char>(), basic_istream<char>(0), _M_buf(s, n)

  { basic_ios<char>::init(&_M_buf); }

  istrstream::istrstream(const char* s, streamsize n)

  : basic_ios<char>(), basic_istream<char>(0), _M_buf(s, n)

  { basic_ios<char>::init(&_M_buf); }

  istrstream::~istrstream() { }

  strstreambuf*

  istrstream::rdbuf() const

  { return const_cast<strstreambuf*>(&_M_buf); }

  char*

  istrstream::str()

  { return _M_buf.str(); }

  ostrstream::ostrstream()

  : basic_ios<char>(), basic_ostream<char>(0), _M_buf()

  { basic_ios<char>::init(&_M_buf); }

  ostrstream::ostrstream(char* s, int n, ios_base::openmode mode)

  : basic_ios<char>(), basic_ostream<char>(0),

    _M_buf(s, n, mode & ios_base::app ? s + strlen(s) : s)

  { basic_ios<char>::init(&_M_buf); }

  ostrstream::~ostrstream() {}

  strstreambuf*

  ostrstream::rdbuf() const

  { return const_cast<strstreambuf*>(&_M_buf); }

  void

  ostrstream::freeze(bool freezeflag)

  { _M_buf.freeze(freezeflag); }

  char*

  ostrstream::str()

  { return _M_buf.str(); }

  int

  ostrstream::pcount() const

  { return _M_buf.pcount(); }

  strstream::strstream()

  : basic_ios<char>(), basic_iostream<char>(0), _M_buf()

  { basic_ios<char>::init(&_M_buf); }

  strstream::strstream(char* s, int n, ios_base::openmode mode)

  : basic_ios<char>(), basic_iostream<char>(0),

    _M_buf(s, n, mode & ios_base::app ? s + strlen(s) : s)

  { basic_ios<char>::init(&_M_buf); }

  strstream::~strstream() { }

  strstreambuf*

  strstream::rdbuf() const

  { return const_cast<strstreambuf*>(&_M_buf); }

  void

  strstream::freeze(bool freezeflag)

  { _M_buf.freeze(freezeflag); }

  int

  strstream::pcount() const

  { return _M_buf.pcount(); }

  char*

  strstream::str()

  { return _M_buf.str(); }

} // namespace std