www.pudn.com > scanalyze-1.0.3_source_code.rar > stl_tempbuf.h, change:2003-09-15,size:3929b

/*
 *
 * Copyright (c) 1994
 * Hewlett-Packard Company
 *
 * 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.  Hewlett-Packard Company makes no
 * representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied warranty.
 *
 *
 * Copyright (c) 1996,1997
 * 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.
 */

/* NOTE: This is an internal header file, included by other STL headers.
 *   You should not attempt to use it directly.
 */

#ifndef __SGI_STL_INTERNAL_TEMPBUF_H
#define __SGI_STL_INTERNAL_TEMPBUF_H


__STL_BEGIN_NAMESPACE

template <class _T>
pair<_T*, ptrdiff_t> 
get_temporary_buffer(ptrdiff_t __len, _T*)
{
  if (__len > ptrdiff_t(INT_MAX / sizeof(_T)))
    __len = INT_MAX / sizeof(_T);

  while (__len > 0) {
    _T* __tmp = (_T*) malloc((size_t)__len * sizeof(_T));
    if (__tmp != 0)
      return pair<_T*, ptrdiff_t>(__tmp, __len);
    __len /= 2;
  }

  return pair<_T*, ptrdiff_t>((_T*)0, 0);
}

template <class _T>
void return_temporary_buffer(_T* __p) {
  free(__p);
}

template <class _ForwardIterator, class _T>
class _Temporary_buffer {
private:
  ptrdiff_t _M_original_len;
  ptrdiff_t _M_len;
  _T*       _M_buffer;

  void _M_allocate_buffer() {
    _M_original_len = _M_len;
    _M_buffer = 0;

    if (_M_len > (ptrdiff_t)(INT_MAX / sizeof(_T)))
      _M_len = INT_MAX / sizeof(_T);

    while (_M_len > 0) {
      _M_buffer = (_T*) malloc(_M_len * sizeof(_T));
      if (_M_buffer)
        break;
      _M_len /= 2;
    }
  }

  void _M_initialize_buffer(const _T&, __true_type) {}
  void _M_initialize_buffer(const _T& val, __false_type) {
    uninitialized_fill_n(_M_buffer, _M_len, val);
  }

public:
  ptrdiff_t size() const { return _M_len; }
  ptrdiff_t requested_size() const { return _M_original_len; }
  _T* begin() { return _M_buffer; }
  _T* end() { return _M_buffer + _M_len; }

  _Temporary_buffer(_ForwardIterator __first, _ForwardIterator __last) {
    __STL_TRY {
      _M_len = 0;
      distance(__first, __last, _M_len);
      _M_allocate_buffer();
      if (_M_len > 0)
        _M_initialize_buffer(
            *__first,
            __type_traits<_T>::has_trivial_default_constructor());
    }
    __STL_UNWIND(free(_M_buffer); _M_buffer = 0; _M_len = 0);
  }
 
  ~_Temporary_buffer() {  
    destroy(_M_buffer, _M_buffer + _M_len);
    free(_M_buffer);
  }

private:
  // Disable copy constructor and assignment operator.
  _Temporary_buffer(const _Temporary_buffer&) {}
  void operator=(const _Temporary_buffer&) {}
};

// Class temporary_buffer is not part of the standard.  It is an extension.

template <class _ForwardIterator, 
          class _T 
#ifdef __STL_CLASS_PARTIAL_SPECIALIZATION
                    = typename iterator_traits<_ForwardIterator>::value_type
#endif /* __STL_CLASS_PARTIAL_SPECIALIZATION */
         >
struct temporary_buffer : public _Temporary_buffer<_ForwardIterator, _T>
{
  temporary_buffer(_ForwardIterator __first, _ForwardIterator __last)
    : _Temporary_buffer<_ForwardIterator, _T>(__first, __last) {}
  ~temporary_buffer() {}
};
    
__STL_END_NAMESPACE

#endif /* __SGI_STL_INTERNAL_TEMPBUF_H */

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