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 {
36public:
37 typedef typename HashMap<T, CounterType>::iterator iterator;
38 typedef typename HashMap<T, CounterType>::const_iterator const_iterator;
39
40 Spectrum() { }
41
42 void add(const T& key, CounterType count = 1)
43 {
44 if (!count)
45 return;
46 typename HashMap<T, CounterType>::AddResult result = m_map.add(key, count);
47 if (!result.isNewEntry)
48 result.iterator->value += count;
49 }
50
51 template<typename U>
52 void addAll(const Spectrum<T, U>& otherSpectrum)
53 {
54 for (auto& entry : otherSpectrum)
55 add(entry.key, entry.count);
56 }
57
58 CounterType get(const T& key) const
59 {
60 const_iterator iter = m_map.find(key);
61 if (iter == m_map.end())
62 return 0;
63 return iter->value;
64 }
65
66 size_t size() const { return m_map.size(); }
67
68 iterator begin() { return m_map.begin(); }
69 iterator end() { return m_map.end(); }
70 const_iterator begin() const { return m_map.begin(); }
71 const_iterator end() const { return m_map.end(); }
72
73 struct KeyAndCount {
74 KeyAndCount() { }
75
76 KeyAndCount(const T& key, CounterType count)
77 : key(key)
78 , count(count)
79 {
80 }
81
82 bool operator<(const KeyAndCount& other) const
83 {
84 if (count != other.count)
85 return count < other.count;
86 // This causes lower-ordered keys being returned first; this is really just
87 // here to make sure that the order is somewhat deterministic rather than being
88 // determined by hashing.
89 return key > other.key;
90 }
91
92 T key;
93 CounterType count;
94 };
95
96 // Returns a list ordered from lowest-count to highest-count.
97 Vector<KeyAndCount> buildList() const
98 {
99 Vector<KeyAndCount> list;
100 for (const_iterator iter = begin(); iter != end(); ++iter)
101 list.append(KeyAndCount(iter->key, iter->value));
102
103 std::sort(list.begin(), list.end());
104 return list;
105 }
106
107 void clear() { m_map.clear(); }
108
109 template<typename Functor>
110 void removeIf(const Functor& functor)
111 {
112 m_map.removeIf([&functor] (typename HashMap<T, CounterType>::KeyValuePairType& pair) {
113 return functor(KeyAndCount(pair.key, pair.value));
114 });
115 }
116
117private:
118 HashMap<T, CounterType> m_map;
119};
120
121} // namespace WTF
122
123using WTF::Spectrum;
124