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
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
|
/*
* Copyright (C) 2003-2014 The Music Player Daemon Project
* http://www.musicpd.org
*
* This program 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 of the License, or
* (at your option) any later version.
*
* 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 Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef MPD_NFS_CANCELLABLE_HXX
#define MPD_NFS_CANCELLABLE_HXX
#include "Compiler.h"
#include <boost/intrusive/list.hpp>
#include <algorithm>
#include <assert.h>
template<typename T>
class CancellablePointer
: public boost::intrusive::list_base_hook<boost::intrusive::link_mode<boost::intrusive::normal_link>> {
public:
typedef T *pointer_type;
typedef T &reference_type;
typedef const T &const_reference_type;
private:
pointer_type p;
public:
explicit CancellablePointer(reference_type _p):p(&_p) {}
CancellablePointer(const CancellablePointer &) = delete;
constexpr bool IsCancelled() const {
return p == nullptr;
}
void Cancel() {
assert(!IsCancelled());
p = nullptr;
}
reference_type Get() {
assert(p != nullptr);
return *p;
}
constexpr bool Is(const_reference_type other) const {
return p == &other;
}
};
template<typename T, typename CT=CancellablePointer<T>>
class CancellableList {
public:
typedef typename CT::reference_type reference_type;
typedef typename CT::const_reference_type const_reference_type;
private:
typedef boost::intrusive::list<CT,
boost::intrusive::constant_time_size<false>> List;
typedef typename List::iterator iterator;
typedef typename List::const_iterator const_iterator;
List list;
class MatchPointer {
const_reference_type p;
public:
explicit constexpr MatchPointer(const_reference_type _p)
:p(_p) {}
constexpr bool operator()(const CT &a) const {
return a.Is(p);
}
};
gcc_pure
iterator Find(reference_type p) {
return std::find_if(list.begin(), list.end(), MatchPointer(p));
}
gcc_pure
const_iterator Find(const_reference_type p) const {
return std::find_if(list.begin(), list.end(), MatchPointer(p));
}
gcc_pure
iterator Find(CT &c) {
return list.iterator_to(c);
}
gcc_pure
const_iterator Find(const CT &c) const {
return list.iterator_to(c);
}
public:
#ifndef NDEBUG
gcc_pure
bool IsEmpty() const {
for (const auto &c : list)
if (!c.IsCancelled())
return false;
return true;
}
#endif
gcc_pure
bool Contains(const_reference_type p) const {
return Find(p) != list.end();
}
template<typename... Args>
CT &Add(reference_type p, Args&&... args) {
assert(Find(p) == list.end());
CT *c = new CT(p, std::forward<Args>(args)...);
list.push_back(*c);
return *c;
}
void Remove(CT &ct) {
auto i = Find(ct);
assert(i != list.end());
list.erase(i);
delete &ct;
}
void Cancel(reference_type p) {
auto i = Find(p);
assert(i != list.end());
i->Cancel();
}
CT &Get(reference_type p) {
auto i = Find(p);
assert(i != list.end());
return *i;
}
};
#endif
|
