cpptoxml/parser/rxx_allocator.h

   1 /****************************************************************************
   2 **
   3 ** Copyright (C) 1992-2008 Trolltech ASA. All rights reserved.
   4 ** Copyright (C) 2002-2005 Roberto Raggi <roberto@kdevelop.org>
   5 **
   6 ** This file is part of the Qt Script Generator project on Trolltech Labs.
   7 **
   8 ** This file may be used under the terms of the GNU General Public
   9 ** License version 2.0 as published by the Free Software Foundation
  10 ** and appearing in the file LICENSE.GPL included in the packaging of
  11 ** this file.  Please review the following information to ensure GNU
  12 ** General Public Licensing requirements will be met:
  13 ** http://www.trolltech.com/products/qt/opensource.html
  14 **
  15 ** If you are unsure which license is appropriate for your use, please
  16 ** review the following information:
  17 ** http://www.trolltech.com/products/qt/licensing.html or contact the
  18 ** sales department at sales@trolltech.com.
  19 **
  20 ** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
  21 ** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  22 **
  23 ****************************************************************************/
  24
  25
  26 #ifndef RXX_ALLOCATOR_H
  27 #define RXX_ALLOCATOR_H
  28
  29 #include <cstddef>
  30 #include <cstdlib>
  31 #include <cstring>
  32 #include <memory>
  33
  34 template <class _Tp> class rxx_allocator {
  35 public:
  36   typedef _Tp value_type;
  37   typedef _Tp* pointer;
  38   typedef const _Tp* const_pointer;
  39   typedef _Tp& reference;
  40   typedef const _Tp& const_reference;
  41   typedef std::size_t size_type;
  42   typedef std::ptrdiff_t difference_type;
  43
  44   static const size_type max_block_count = size_type(-1);
  45   static const size_type _S_block_size = 1 << 16; // 64K
  46
  47   rxx_allocator() {
  48     _M_block_index = max_block_count;
  49     _M_current_index = 0;
  50     _M_storage = 0;
  51     _M_current_block = 0;
  52   }
  53
  54   ~rxx_allocator() {
  55     for (size_type index = 0; index < _M_block_index + 1; ++index)
  56       delete[] _M_storage[index];
  57
  58     ::free(_M_storage);
  59   }
  60
  61   pointer address(reference __val) { return &__val; }
  62   const_pointer address(const_reference __val) const { return &__val; }
  63
  64   pointer allocate(size_type __n, const void* = 0) {
  65     const size_type bytes = __n * sizeof(_Tp);
  66
  67     if (_M_current_block == 0
  68         || _S_block_size < _M_current_index + bytes)
  69       {
  70         ++_M_block_index;
  71
  72         _M_storage = reinterpret_cast<char**>
  73           (std::realloc(_M_storage, sizeof(char*) * (1 + _M_block_index)));
  74
  75         _M_current_block = _M_storage[_M_block_index] = reinterpret_cast<char*>
  76           (new char[_S_block_size]);
  77
  78 #if defined(RXX_ALLOCATOR_INIT_0) // ### make it a policy
  79         ::memset(_M_current_block, 0, _S_block_size);
  80 #endif
  81         _M_current_index = 0;
  82       }
  83
  84     pointer p = reinterpret_cast<pointer>
  85       (_M_current_block + _M_current_index);
  86
  87     _M_current_index += bytes;
  88
  89     return p;
  90   }
  91
  92   void deallocate(pointer __p, size_type __n) {}
  93
  94   size_type max_size() const { return size_type(-1) / sizeof(_Tp); }
  95
  96   void contruct(pointer __p, const_reference __val) { new (__p) _Tp(__val); }
  97   void destruct(pointer __p) { __p->~_Tp(); }
  98
  99 private:
 100   template <class _Tp1> struct rebind {
 101     typedef rxx_allocator<_Tp1> other;
 102   };
 103
 104   template <class _Tp1> rxx_allocator(const rxx_allocator<_Tp1> &__o) {}
 105
 106 private:
 107   size_type _M_block_index;
 108   size_type _M_current_index;
 109   char *_M_current_block;
 110   char **_M_storage;
 111 };
 112
 113 #endif // RXX_ALLOCATOR_H
 114
 115 // kate: space-indent on; indent-width 2; replace-tabs on;