aboutsummaryrefslogtreecommitdiff
path: root/paludis/util/pool-impl.hh
blob: aa02d222f1a222be2c616ed6ed34c7aea7e1b661 (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
131
132
133
134
135
136
137
138
139
140
141
142
143
/* vim: set sw=4 sts=4 et foldmethod=syntax : */

/*
 * Copyright (c) 2011 Ciaran McCreesh
 *
 * This file is part of the Paludis package manager. Paludis 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.
 *
 * Paludis 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., 59 Temple
 * Place, Suite 330, Boston, MA  02111-1307  USA
 */

#ifndef PALUDIS_GUARD_PALUDIS_UTIL_POOL_IMPL_HH
#define PALUDIS_GUARD_PALUDIS_UTIL_POOL_IMPL_HH 1

#include <paludis/util/pool.hh>
#include <paludis/util/mutex.hh>
#include <paludis/util/hashes.hh>
#include <paludis/util/stringify.hh>
#include <unordered_map>
#include <memory>

namespace paludis
{
    template <typename Arg_, typename... Args_>
    void
    PoolKeys::add(const Arg_ & arg, const Args_ & ... args)
    {
        add_one(std::make_shared<ConcretePoolKey<Arg_> >(arg));
        add(args...);
    }

    template <typename T_>
    struct PoolReuseScore
    {
        static const std::string message(const int size, const int reused)
        {
            return "Size " + stringify(size) + " reused " + stringify(reused) + " for " + __PRETTY_FUNCTION__;
        }
    };

    template <typename T_>
    struct Imp<Pool<T_> >
    {
        mutable Mutex mutex;
        mutable std::unordered_map<PoolKeys, std::shared_ptr<const T_>, PoolKeysHasher, PoolKeysComparator> store;
        mutable unsigned reused;

        Imp() :
            reused(0)
        {
        }
    };

    template <typename T_>
    Pool<T_>::Pool() :
        _imp()
    {
    }

    template <typename T_>
    Pool<T_>::~Pool()
    {
    }

    template <typename T_>
    struct PreventConversion
    {
        const T_ & ref;

        PreventConversion(const T_ & r) :
            ref(r)
        {
        }

        operator const T_ & ()
        {
            return ref;
        }
    };

    template <typename T_>
    template <typename... Args_>
    const std::shared_ptr<const T_>
    Pool<T_>::create(const Args_ & ... args) const
    {
        PoolKeys keys;
        keys.add(args...);

        Lock lock(_imp->mutex);
        auto i(_imp->store.find(keys));
        if (i == _imp->store.end())
        {
            /* std::make_shared<> doesn't play well with private ctors */
            i = _imp->store.insert(std::make_pair(keys, std::shared_ptr<const T_>(new T_(PreventConversion<Args_>(args)...)))).first;
        }
        else
            ++_imp->reused;

        return i->second;
    }

    template <typename T_>
    ConcretePoolKey<T_>::ConcretePoolKey(const T_ & t) :
        PoolKey(PoolKeyTypeCodes::get<T_>()),
        _value(t)
    {
    }

    template <typename T_>
    ConcretePoolKey<T_>::~ConcretePoolKey() = default;

    template <typename T_>
    std::size_t
    ConcretePoolKey<T_>::hash() const
    {
        return Hash<T_>()(_value);
    }

    template <typename T_>
    bool
    ConcretePoolKey<T_>::same_value(const PoolKey & other) const
    {
        return _value == static_cast<const ConcretePoolKey<T_> &>(other)._value;
    }

    template <typename T_>
    int
    PoolKeyTypeCodes::get()
    {
        static int result(next());
        return result;
    }
}

#endif