1/*
2 * Copyright (C) 2011, 2014 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#pragma once
27
28#include <wtf/HashMap.h>
29#include <wtf/Vector.h>
30#include <algorithm>
31
32namespace WTF {
33
34template<typename T, typename CounterType = unsigned>
35class Spectrum {
36 WTF_MAKE_FAST_ALLOCATED;
37public:
38 typedef typename HashMap<T, CounterType>::iterator iterator;
39 typedef typename HashMap<T, CounterType>::const_iterator const_iterator;
40
41 Spectrum() { }
42
43 void add(const T& key, CounterType count = 1)
44 {
45 if (!count)
46 return;
47 typename HashMap<T, CounterType>::AddResult result = m_map.add(key, count);
48 if (!result.isNewEntry)
49 result.iterator->value += count;
50 }
51
52 template<typename U>
53 void addAll(const Spectrum<T, U>& otherSpectrum)
54 {
55 for (auto& entry : otherSpectrum)
56 add(entry.key, entry.count);
57 }
58
59 CounterType get(const T& key) const
60 {
61 const_iterator iter = m_map.find(key);
62 if (iter == m_map.end())
63 return 0;
64 return iter->value;
65 }
66
67 size_t size() const { return m_map.size(); }
68
69 iterator begin() { return m_map.begin(); }
70 iterator end() { return m_map.end(); }
71 const_iterator begin() const { return m_map.begin(); }
72 const_iterator end() const { return m_map.end(); }
73
74 struct KeyAndCount {
75 WTF_MAKE_STRUCT_FAST_ALLOCATED;
76 KeyAndCount() { }
77
78 KeyAndCount(const T& key, CounterType count)
79 : key(key)
80 , count(count)
81 {
82 }
83
84 bool operator<(const KeyAndCount& other) const
85 {
86 if (count != other.count)
87 return count < other.count;
88 // This causes lower-ordered keys being returned first; this is really just
89 // here to make sure that the order is somewhat deterministic rather than being
90 // determined by hashing.
91 return key > other.key;
92 }
93
94 T key;
95 CounterType count;
96 };
97
98 // Returns a list ordered from lowest-count to highest-count.
99 Vector<KeyAndCount> buildList() const
100 {
101 Vector<KeyAndCount> list;
102 for (const_iterator iter = begin(); iter != end(); ++iter)
103 list.append(KeyAndCount(iter->key, iter->value));
104
105 std::sort(list.begin(), list.end());
106 return list;
107 }
108
109 void clear() { m_map.clear(); }
110
111 template<typename Functor>
112 void removeIf(const Functor& functor)
113 {
114 m_map.removeIf([&functor] (typename HashMap<T, CounterType>::KeyValuePairType& pair) {
115 return functor(KeyAndCount(pair.key, pair.value));
116 });
117 }
118
119private:
120 HashMap<T, CounterType> m_map;
121};
122
123} // namespace WTF
124
125using WTF::Spectrum;
126