2 * Copyright (C) 2005, 2006, 2008 Apple Inc. All rights reserved.
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Library General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
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10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Library General Public License for more details.
14 * You should have received a copy of the GNU Library General Public License
15 * along with this library; see the file COPYING.LIB. If not, write to
16 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
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21 #ifndef WTF_HashCountedSet_h
22 #define WTF_HashCountedSet_h
24 #include "wtf/Assertions.h"
25 #include "wtf/HashMap.h"
26 #include "wtf/Vector.h"
30 // An unordered hash set that keeps track of how many times you added an
31 // item to the set. The iterators have fields ->key and ->value that return
32 // the set members and their counts, respectively.
35 typename HashFunctions = typename DefaultHash<Value>::Hash,
36 typename Traits = HashTraits<Value>,
37 typename Allocator = DefaultAllocator > class HashCountedSet {
38 WTF_USE_ALLOCATOR(HashCountedSet, Allocator);
40 typedef HashMap<Value, unsigned, HashFunctions, Traits, HashTraits<unsigned>, Allocator> ImplType;
42 typedef Value ValueType;
43 typedef typename ImplType::iterator iterator;
44 typedef typename ImplType::const_iterator const_iterator;
45 typedef typename ImplType::AddResult AddResult;
49 void swap(HashCountedSet& other) { m_impl.swap(other.m_impl); }
51 unsigned size() const { return m_impl.size(); }
52 unsigned capacity() const { return m_impl.capacity(); }
53 bool isEmpty() const { return m_impl.isEmpty(); }
55 // Iterators iterate over pairs of values (called key) and counts (called value).
56 iterator begin() { return m_impl.begin(); }
57 iterator end() { return m_impl.end(); }
58 const_iterator begin() const { return m_impl.begin(); }
59 const_iterator end() const { return m_impl.end(); }
61 iterator find(const ValueType& value) { return m_impl.find(value); }
62 const_iterator find(const ValueType& value) const { return m_impl.find(value); }
63 bool contains(const ValueType& value ) const { return m_impl.contains(value); }
64 unsigned count(const ValueType& value ) const { return m_impl.get(value); }
66 // Increases the count if an equal value is already present
67 // the return value is a pair of an iterator to the new value's
68 // location, and a bool that is true if an new entry was added.
69 AddResult add(const ValueType&);
71 // Reduces the count of the value, and removes it if count
72 // goes down to zero, returns true if the value is removed.
73 bool remove(const ValueType& value) { return remove(find(value)); }
74 bool remove(iterator);
76 // Removes the value, regardless of its count.
77 void removeAll(const ValueType& value) { removeAll(find(value)); }
78 void removeAll(iterator);
80 // Clears the whole set.
81 void clear() { m_impl.clear(); }
83 void trace(typename Allocator::Visitor* visitor) { m_impl.trace(visitor); }
89 template<typename T, typename U, typename V, typename W>
90 inline typename HashCountedSet<T, U, V, W>::AddResult HashCountedSet<T, U, V, W>::add(const ValueType& value)
92 AddResult result = m_impl.add(value, 0);
93 ++result.storedValue->value;
97 template<typename T, typename U, typename V, typename W>
98 inline bool HashCountedSet<T, U, V, W>::remove(iterator it)
103 unsigned oldVal = it->value;
105 unsigned newVal = oldVal - 1;
115 template<typename T, typename U, typename V, typename W>
116 inline void HashCountedSet<T, U, V, W>::removeAll(iterator it)
124 template<typename T, typename U, typename V, typename W, typename VectorType>
125 inline void copyToVector(const HashCountedSet<T, U, V, W>& collection, VectorType& vector)
127 typedef typename HashCountedSet<T, U, V, W>::const_iterator iterator;
129 vector.resize(collection.size());
131 iterator it = collection.begin();
132 iterator end = collection.end();
133 for (unsigned i = 0; it != end; ++it, ++i)
137 template<typename Value, typename HashFunctions, typename Traits, typename Allocator, size_t inlineCapacity, typename VectorAllocator>
138 inline void copyToVector(const HashCountedSet<Value, HashFunctions, Traits, Allocator>& collection, Vector<Value, inlineCapacity, VectorAllocator>& vector)
140 typedef typename HashCountedSet<Value, HashFunctions, Traits, Allocator>::const_iterator iterator;
142 vector.resize(collection.size());
144 iterator it = collection.begin();
145 iterator end = collection.end();
146 for (unsigned i = 0; it != end; ++it, ++i)
147 vector[i] = (*it).key;
153 using WTF::HashCountedSet;
155 #endif /* WTF_HashCountedSet_h */