summaryrefslogtreecommitdiffstats
path: root/parser/rxx_allocator.h
blob: e4a3875543d4eb6933e93d60198a3c8b90e10bac (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
/*
 * This file is part of the API Extractor project.
 *
 * Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
 * Copyright (C) 2002-2005 Roberto Raggi <roberto@kdevelop.org>
 *
 * Contact: PySide team <contact@pyside.org>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 * This program 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 program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 *
 */


#ifndef RXX_ALLOCATOR_H
#define RXX_ALLOCATOR_H

#include <cstddef>
#include <cstdlib>
#include <cstring>
#include <memory>

template <class _Tp> class rxx_allocator
{
public:
    typedef _Tp value_type;
    typedef _Tp* pointer;
    typedef const _Tp* const_pointer;
    typedef _Tp& reference;
    typedef const _Tp& const_reference;
    typedef std::size_t size_type;
    typedef std::ptrdiff_t difference_type;

    static const size_type max_block_count = size_type(-1);
    static const size_type _S_block_size = 1 << 16; // 64K

    rxx_allocator()
    {
        _M_block_index = max_block_count;
        _M_current_index = 0;
        _M_storage = 0;
        _M_current_block = 0;
    }

    ~rxx_allocator()
    {
        for (size_type index = 0; index < _M_block_index + 1; ++index)
            delete[] _M_storage[index];

        ::free(_M_storage);
    }

    pointer address(reference __val) { return &__val; }
    const_pointer address(const_reference __val) const { return &__val; }

    pointer allocate(size_type __n, const void* = 0)
    {
        const size_type bytes = __n * sizeof(_Tp);

        if (_M_current_block == 0
            || _S_block_size < _M_current_index + bytes) {
            ++_M_block_index;

            _M_storage = reinterpret_cast<char**>
                         (::realloc(_M_storage, sizeof(char*) * (1 + _M_block_index)));

            _M_current_block = _M_storage[_M_block_index] = reinterpret_cast<char*>
                                                            (new char[_S_block_size]);

#if defined(RXX_ALLOCATOR_INIT_0) // ### make it a policy
            ::memset(_M_current_block, 0, _S_block_size);
#endif
            _M_current_index = 0;
        }

        pointer p = reinterpret_cast<pointer>
                    (_M_current_block + _M_current_index);

        _M_current_index += bytes;

        return p;
    }

    void deallocate(pointer __p, size_type __n) {}

    size_type max_size() const
    {
        return size_type(-1) / sizeof(_Tp);
    }

    void contruct(pointer __p, const_reference __val)
    {
        new(__p) _Tp(__val);
    }
    void destruct(pointer __p)
    {
        __p->~_Tp();
    }

private:
    template <class _Tp1>
    struct rebind
    {
        typedef rxx_allocator<_Tp1> other;
    };

    template <class _Tp1> rxx_allocator(const rxx_allocator<_Tp1> &__o) {}

private:
    size_type _M_block_index;
    size_type _M_current_index;
    char *_M_current_block;
    char **_M_storage;
};

#endif // RXX_ALLOCATOR_H

// kate: space-indent on; indent-width 2; replace-tabs on;