1/*
2 * Copyright (C) 2005, 2006, 2007, 2008, 2011 Apple Inc. All rights reserved.
3 *
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.
8 *
9 * This library is distributed in the hope that it will be useful,
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.
13 *
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,
17 * Boston, MA 02110-1301, USA.
18 *
19 */
20
21#ifndef WTF_HashSet_h
22#define WTF_HashSet_h
23
24#include "wtf/DefaultAllocator.h"
25#include "wtf/HashTable.h"
26
27namespace WTF {
28
29    struct IdentityExtractor;
30
31    // Note: empty or deleted values are not allowed, using them may lead to undefined behavior.
32    // For pointer valuess this means that null pointers are not allowed unless you supply custom traits.
33    template<
34        typename ValueArg,
35        typename HashArg = typename DefaultHash<ValueArg>::Hash,
36        typename TraitsArg = HashTraits<ValueArg>,
37        typename Allocator = DefaultAllocator> class HashSet {
38        WTF_USE_ALLOCATOR(HashSet, Allocator);
39    private:
40        typedef HashArg HashFunctions;
41        typedef TraitsArg ValueTraits;
42        typedef typename ValueTraits::PeekInType ValuePeekInType;
43        typedef typename ValueTraits::PassInType ValuePassInType;
44        typedef typename ValueTraits::PassOutType ValuePassOutType;
45
46    public:
47        typedef typename ValueTraits::TraitType ValueType;
48
49    private:
50        typedef HashTable<ValueType, ValueType, IdentityExtractor,
51            HashFunctions, ValueTraits, ValueTraits, Allocator> HashTableType;
52
53    public:
54        typedef HashTableConstIteratorAdapter<HashTableType, ValueTraits> iterator;
55        typedef HashTableConstIteratorAdapter<HashTableType, ValueTraits> const_iterator;
56        typedef typename HashTableType::AddResult AddResult;
57
58        void swap(HashSet& ref)
59        {
60            m_impl.swap(ref.m_impl);
61        }
62
63        void swap(typename Allocator::template OtherType<HashSet>::Type other)
64        {
65            HashSet& ref = Allocator::getOther(other);
66            m_impl.swap(ref.m_impl);
67        }
68
69        unsigned size() const;
70        unsigned capacity() const;
71        bool isEmpty() const;
72
73        iterator begin() const;
74        iterator end() const;
75
76        iterator find(ValuePeekInType) const;
77        bool contains(ValuePeekInType) const;
78
79        // An alternate version of find() that finds the object by hashing and comparing
80        // with some other type, to avoid the cost of type conversion. HashTranslator
81        // must have the following function members:
82        //   static unsigned hash(const T&);
83        //   static bool equal(const ValueType&, const T&);
84        template<typename HashTranslator, typename T> iterator find(const T&) const;
85        template<typename HashTranslator, typename T> bool contains(const T&) const;
86
87        // The return value is a pair of an iterator to the new value's location,
88        // and a bool that is true if an new entry was added.
89        AddResult add(ValuePassInType);
90
91        // An alternate version of add() that finds the object by hashing and comparing
92        // with some other type, to avoid the cost of type conversion if the object is already
93        // in the table. HashTranslator must have the following function members:
94        //   static unsigned hash(const T&);
95        //   static bool equal(const ValueType&, const T&);
96        //   static translate(ValueType&, const T&, unsigned hashCode);
97        template<typename HashTranslator, typename T> AddResult add(const T&);
98
99        void remove(ValuePeekInType);
100        void remove(iterator);
101        void clear();
102        template<typename Collection>
103        void removeAll(const Collection& toBeRemoved) { WTF::removeAll(*this, toBeRemoved); }
104
105        static bool isValidValue(ValuePeekInType);
106
107        ValuePassOutType take(iterator);
108        ValuePassOutType take(ValuePeekInType);
109        ValuePassOutType takeAny();
110
111        void trace(typename Allocator::Visitor* visitor) { m_impl.trace(visitor); }
112
113    private:
114        HashTableType m_impl;
115    };
116
117    struct IdentityExtractor {
118        template<typename T>
119        static const T& extract(const T& t) { return t; }
120    };
121
122    template<typename Translator>
123    struct HashSetTranslatorAdapter {
124        template<typename T> static unsigned hash(const T& key) { return Translator::hash(key); }
125        template<typename T, typename U> static bool equal(const T& a, const U& b) { return Translator::equal(a, b); }
126        template<typename T, typename U> static void translate(T& location, const U& key, const U&, unsigned hashCode)
127        {
128            Translator::translate(location, key, hashCode);
129        }
130    };
131
132    template<typename T, typename U, typename V, typename W>
133    inline unsigned HashSet<T, U, V, W>::size() const
134    {
135        return m_impl.size();
136    }
137
138    template<typename T, typename U, typename V, typename W>
139    inline unsigned HashSet<T, U, V, W>::capacity() const
140    {
141        return m_impl.capacity();
142    }
143
144    template<typename T, typename U, typename V, typename W>
145    inline bool HashSet<T, U, V, W>::isEmpty() const
146    {
147        return m_impl.isEmpty();
148    }
149
150    template<typename T, typename U, typename V, typename W>
151    inline typename HashSet<T, U, V, W>::iterator HashSet<T, U, V, W>::begin() const
152    {
153        return m_impl.begin();
154    }
155
156    template<typename T, typename U, typename V, typename W>
157    inline typename HashSet<T, U, V, W>::iterator HashSet<T, U, V, W>::end() const
158    {
159        return m_impl.end();
160    }
161
162    template<typename T, typename U, typename V, typename W>
163    inline typename HashSet<T, U, V, W>::iterator HashSet<T, U, V, W>::find(ValuePeekInType value) const
164    {
165        return m_impl.find(value);
166    }
167
168    template<typename Value, typename HashFunctions, typename Traits, typename Allocator>
169    inline bool HashSet<Value, HashFunctions, Traits, Allocator>::contains(ValuePeekInType value) const
170    {
171        return m_impl.contains(value);
172    }
173
174    template<typename Value, typename HashFunctions, typename Traits, typename Allocator>
175    template<typename HashTranslator, typename T>
176    typename HashSet<Value, HashFunctions, Traits, Allocator>::iterator
177    inline HashSet<Value, HashFunctions, Traits, Allocator>::find(const T& value) const
178    {
179        return m_impl.template find<HashSetTranslatorAdapter<HashTranslator> >(value);
180    }
181
182    template<typename Value, typename HashFunctions, typename Traits, typename Allocator>
183    template<typename HashTranslator, typename T>
184    inline bool HashSet<Value, HashFunctions, Traits, Allocator>::contains(const T& value) const
185    {
186        return m_impl.template contains<HashSetTranslatorAdapter<HashTranslator> >(value);
187    }
188
189    template<typename T, typename U, typename V, typename W>
190    inline typename HashSet<T, U, V, W>::AddResult HashSet<T, U, V, W>::add(ValuePassInType value)
191    {
192        return m_impl.add(value);
193    }
194
195    template<typename Value, typename HashFunctions, typename Traits, typename Allocator>
196    template<typename HashTranslator, typename T>
197    inline typename HashSet<Value, HashFunctions, Traits, Allocator>::AddResult
198    HashSet<Value, HashFunctions, Traits, Allocator>::add(const T& value)
199    {
200        return m_impl.template addPassingHashCode<HashSetTranslatorAdapter<HashTranslator> >(value, value);
201    }
202
203    template<typename T, typename U, typename V, typename W>
204    inline void HashSet<T, U, V, W>::remove(iterator it)
205    {
206        m_impl.remove(it.m_impl);
207    }
208
209    template<typename T, typename U, typename V, typename W>
210    inline void HashSet<T, U, V, W>::remove(ValuePeekInType value)
211    {
212        remove(find(value));
213    }
214
215    template<typename T, typename U, typename V, typename W>
216    inline void HashSet<T, U, V, W>::clear()
217    {
218        m_impl.clear();
219    }
220
221    template<typename T, typename U, typename V, typename W>
222    inline bool HashSet<T, U, V, W>::isValidValue(ValuePeekInType value)
223    {
224        if (ValueTraits::isDeletedValue(value))
225            return false;
226
227        if (HashFunctions::safeToCompareToEmptyOrDeleted) {
228            if (value == ValueTraits::emptyValue())
229                return false;
230        } else {
231            if (isHashTraitsEmptyValue<ValueTraits>(value))
232                return false;
233        }
234
235        return true;
236    }
237
238    template<typename T, typename U, typename V, typename W>
239    inline typename HashSet<T, U, V, W>::ValuePassOutType HashSet<T, U, V, W>::take(iterator it)
240    {
241        if (it == end())
242            return ValueTraits::emptyValue();
243
244        ValuePassOutType result = ValueTraits::passOut(const_cast<ValueType&>(*it));
245        remove(it);
246
247        return result;
248    }
249
250    template<typename T, typename U, typename V, typename W>
251    inline typename HashSet<T, U, V, W>::ValuePassOutType HashSet<T, U, V, W>::take(ValuePeekInType value)
252    {
253        return take(find(value));
254    }
255
256    template<typename T, typename U, typename V, typename W>
257    inline typename HashSet<T, U, V, W>::ValuePassOutType HashSet<T, U, V, W>::takeAny()
258    {
259        return take(begin());
260    }
261
262    template<typename C, typename W>
263    inline void copyToVector(const C& collection, W& vector)
264    {
265        typedef typename C::const_iterator iterator;
266
267        vector.resize(collection.size());
268
269        iterator it = collection.begin();
270        iterator end = collection.end();
271        for (unsigned i = 0; it != end; ++it, ++i)
272            vector[i] = *it;
273    }
274
275#if !ENABLE(OILPAN)
276    template<typename T, typename U, typename V>
277    struct NeedsTracing<HashSet<T, U, V> > {
278        static const bool value = false;
279    };
280#endif
281
282} // namespace WTF
283
284using WTF::HashSet;
285
286#endif /* WTF_HashSet_h */
287