1/*
2 * Copyright (C) 2005, 2006, 2007, 2008, 2011, 2013 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 <initializer_list>
25#include <wtf/FastMalloc.h>
26#include <wtf/GetPtr.h>
27#include <wtf/HashTable.h>
28
29namespace WTF {
30
31 struct IdentityExtractor;
32
33 template<typename Value, typename HashFunctions, typename Traits> class HashSet;
34
35 template<typename ValueArg, typename HashArg = typename DefaultHash<ValueArg>::Hash,
36 typename TraitsArg = HashTraits<ValueArg>> class HashSet final {
37 WTF_MAKE_FAST_ALLOCATED;
38 private:
39 typedef HashArg HashFunctions;
40 typedef TraitsArg ValueTraits;
41
42 public:
43 typedef typename ValueTraits::TraitType ValueType;
44
45 private:
46 typedef HashTable<ValueType, ValueType, IdentityExtractor,
47 HashFunctions, ValueTraits, ValueTraits> HashTableType;
48
49 public:
50 typedef HashTableConstIteratorAdapter<HashTableType, ValueType> iterator;
51 typedef HashTableConstIteratorAdapter<HashTableType, ValueType> const_iterator;
52 typedef typename HashTableType::AddResult AddResult;
53
54 HashSet()
55 {
56 }
57
58 HashSet(std::initializer_list<ValueArg> initializerList)
59 {
60 for (const auto& value : initializerList)
61 add(value);
62 }
63
64 void swap(HashSet&);
65
66 unsigned size() const;
67 unsigned capacity() const;
68 bool isEmpty() const;
69
70 iterator begin() const;
71 iterator end() const;
72
73 iterator find(const ValueType&) const;
74 bool contains(const ValueType&) const;
75
76 // An alternate version of find() that finds the object by hashing and comparing
77 // with some other type, to avoid the cost of type conversion. HashTranslator
78 // must have the following function members:
79 // static unsigned hash(const T&);
80 // static bool equal(const ValueType&, const T&);
81 template<typename HashTranslator, typename T> iterator find(const T&) const;
82 template<typename HashTranslator, typename T> bool contains(const T&) const;
83
84 // The return value includes both an iterator to the added value's location,
85 // and an isNewEntry bool that indicates if it is a new or existing entry in the set.
86 AddResult add(const ValueType&);
87 AddResult add(ValueType&&);
88
89 // An alternate version of add() that finds the object by hashing and comparing
90 // with some other type, to avoid the cost of type conversion if the object is already
91 // in the table. HashTranslator must have the following function members:
92 // static unsigned hash(const T&);
93 // static bool equal(const ValueType&, const T&);
94 // static translate(ValueType&, const T&, unsigned hashCode);
95 template<typename HashTranslator, typename T> AddResult add(const T&);
96
97 // Attempts to add a list of things to the set. Returns true if any of
98 // them are new to the set. Returns false if the set is unchanged.
99 template<typename IteratorType>
100 bool add(IteratorType begin, IteratorType end);
101
102 bool remove(const ValueType&);
103 bool remove(iterator);
104 void clear();
105
106 ValueType take(const ValueType&);
107 ValueType take(iterator);
108 ValueType takeAny();
109
110 // Overloads for smart pointer values that take the raw pointer type as the parameter.
111 template<typename V = ValueType> typename std::enable_if<IsSmartPtr<V>::value, iterator>::type find(typename GetPtrHelper<V>::PtrType) const;
112 template<typename V = ValueType> typename std::enable_if<IsSmartPtr<V>::value, bool>::type contains(typename GetPtrHelper<V>::PtrType) const;
113 template<typename V = ValueType> typename std::enable_if<IsSmartPtr<V>::value, bool>::type remove(typename GetPtrHelper<V>::PtrType);
114 template<typename V = ValueType> typename std::enable_if<IsSmartPtr<V>::value, ValueType>::type take(typename GetPtrHelper<V>::PtrType);
115
116 static bool isValidValue(const ValueType&);
117
118 template<typename OtherCollection>
119 bool operator==(const OtherCollection&) const;
120
121 private:
122 HashTableType m_impl;
123 };
124
125 struct IdentityExtractor {
126 template<typename T> static const T& extract(const T& t) { return t; }
127 };
128
129 template<typename HashFunctions>
130 struct HashSetTranslator {
131 template<typename T> static unsigned hash(const T& key) { return HashFunctions::hash(key); }
132 template<typename T, typename U> static bool equal(const T& a, const U& b) { return HashFunctions::equal(a, b); }
133 template<typename T, typename U, typename V> static void translate(T& location, U&&, V&& value) { location = std::forward<V>(value); }
134 };
135
136 template<typename Translator>
137 struct HashSetTranslatorAdapter {
138 template<typename T> static unsigned hash(const T& key) { return Translator::hash(key); }
139 template<typename T, typename U> static bool equal(const T& a, const U& b) { return Translator::equal(a, b); }
140 template<typename T, typename U> static void translate(T& location, const U& key, const U&, unsigned hashCode)
141 {
142 Translator::translate(location, key, hashCode);
143 }
144 };
145
146 template<typename T, typename U, typename V>
147 inline void HashSet<T, U, V>::swap(HashSet& other)
148 {
149 m_impl.swap(other.m_impl);
150 }
151
152 template<typename T, typename U, typename V>
153 inline unsigned HashSet<T, U, V>::size() const
154 {
155 return m_impl.size();
156 }
157
158 template<typename T, typename U, typename V>
159 inline unsigned HashSet<T, U, V>::capacity() const
160 {
161 return m_impl.capacity();
162 }
163
164 template<typename T, typename U, typename V>
165 inline bool HashSet<T, U, V>::isEmpty() const
166 {
167 return m_impl.isEmpty();
168 }
169
170 template<typename T, typename U, typename V>
171 inline auto HashSet<T, U, V>::begin() const -> iterator
172 {
173 return m_impl.begin();
174 }
175
176 template<typename T, typename U, typename V>
177 inline auto HashSet<T, U, V>::end() const -> iterator
178 {
179 return m_impl.end();
180 }
181
182 template<typename T, typename U, typename V>
183 inline auto HashSet<T, U, V>::find(const ValueType& value) const -> iterator
184 {
185 return m_impl.find(value);
186 }
187
188 template<typename T, typename U, typename V>
189 inline bool HashSet<T, U, V>::contains(const ValueType& value) const
190 {
191 return m_impl.contains(value);
192 }
193
194 template<typename Value, typename HashFunctions, typename Traits>
195 template<typename HashTranslator, typename T>
196 inline auto HashSet<Value, HashFunctions, Traits>::find(const T& value) const -> iterator
197 {
198 return m_impl.template find<HashSetTranslatorAdapter<HashTranslator>>(value);
199 }
200
201 template<typename Value, typename HashFunctions, typename Traits>
202 template<typename HashTranslator, typename T>
203 inline bool HashSet<Value, HashFunctions, Traits>::contains(const T& value) const
204 {
205 return m_impl.template contains<HashSetTranslatorAdapter<HashTranslator>>(value);
206 }
207
208 template<typename T, typename U, typename V>
209 inline auto HashSet<T, U, V>::add(const ValueType& value) -> AddResult
210 {
211 return m_impl.add(value);
212 }
213
214 template<typename T, typename U, typename V>
215 inline auto HashSet<T, U, V>::add(ValueType&& value) -> AddResult
216 {
217 return m_impl.add(WTFMove(value));
218 }
219
220 template<typename Value, typename HashFunctions, typename Traits>
221 template<typename HashTranslator, typename T>
222 inline auto HashSet<Value, HashFunctions, Traits>::add(const T& value) -> AddResult
223 {
224 return m_impl.template addPassingHashCode<HashSetTranslatorAdapter<HashTranslator>>(value, value);
225 }
226
227 template<typename T, typename U, typename V>
228 template<typename IteratorType>
229 inline bool HashSet<T, U, V>::add(IteratorType begin, IteratorType end)
230 {
231 bool changed = false;
232 for (IteratorType iter = begin; iter != end; ++iter)
233 changed |= add(*iter).isNewEntry;
234 return changed;
235 }
236
237 template<typename T, typename U, typename V>
238 inline bool HashSet<T, U, V>::remove(iterator it)
239 {
240 if (it.m_impl == m_impl.end())
241 return false;
242 m_impl.internalCheckTableConsistency();
243 m_impl.removeWithoutEntryConsistencyCheck(it.m_impl);
244 return true;
245 }
246
247 template<typename T, typename U, typename V>
248 inline bool HashSet<T, U, V>::remove(const ValueType& value)
249 {
250 return remove(find(value));
251 }
252
253 template<typename T, typename U, typename V>
254 inline void HashSet<T, U, V>::clear()
255 {
256 m_impl.clear();
257 }
258
259 template<typename T, typename U, typename V>
260 inline auto HashSet<T, U, V>::take(iterator it) -> ValueType
261 {
262 if (it == end())
263 return ValueTraits::emptyValue();
264
265 ValueType result = WTFMove(const_cast<ValueType&>(*it));
266 remove(it);
267 return result;
268 }
269
270 template<typename T, typename U, typename V>
271 inline auto HashSet<T, U, V>::take(const ValueType& value) -> ValueType
272 {
273 return take(find(value));
274 }
275
276 template<typename T, typename U, typename V>
277 inline auto HashSet<T, U, V>::takeAny() -> ValueType
278 {
279 return take(begin());
280 }
281
282 template<typename Value, typename HashFunctions, typename Traits>
283 template<typename V>
284 inline auto HashSet<Value, HashFunctions, Traits>::find(typename GetPtrHelper<V>::PtrType value) const -> typename std::enable_if<IsSmartPtr<V>::value, iterator>::type
285 {
286 return m_impl.template find<HashSetTranslator<HashFunctions>>(value);
287 }
288
289 template<typename Value, typename HashFunctions, typename Traits>
290 template<typename V>
291 inline auto HashSet<Value, HashFunctions, Traits>::contains(typename GetPtrHelper<V>::PtrType value) const -> typename std::enable_if<IsSmartPtr<V>::value, bool>::type
292 {
293 return m_impl.template contains<HashSetTranslator<HashFunctions>>(value);
294 }
295
296 template<typename Value, typename HashFunctions, typename Traits>
297 template<typename V>
298 inline auto HashSet<Value, HashFunctions, Traits>::remove(typename GetPtrHelper<V>::PtrType value) -> typename std::enable_if<IsSmartPtr<V>::value, bool>::type
299 {
300 return remove(find(value));
301 }
302
303 template<typename Value, typename HashFunctions, typename Traits>
304 template<typename V>
305 inline auto HashSet<Value, HashFunctions, Traits>::take(typename GetPtrHelper<V>::PtrType value) -> typename std::enable_if<IsSmartPtr<V>::value, ValueType>::type
306 {
307 return take(find(value));
308 }
309
310 template<typename T, typename U, typename V>
311 inline bool HashSet<T, U, V>::isValidValue(const ValueType& value)
312 {
313 if (ValueTraits::isDeletedValue(value))
314 return false;
315
316 if (HashFunctions::safeToCompareToEmptyOrDeleted) {
317 if (value == ValueTraits::emptyValue())
318 return false;
319 } else {
320 if (isHashTraitsEmptyValue<ValueTraits>(value))
321 return false;
322 }
323
324 return true;
325 }
326
327 template<typename C, typename W>
328 inline void copyToVector(const C& collection, W& vector)
329 {
330 typedef typename C::const_iterator iterator;
331
332 vector.resize(collection.size());
333
334 iterator it = collection.begin();
335 iterator end = collection.end();
336 for (unsigned i = 0; it != end; ++it, ++i)
337 vector[i] = *it;
338 }
339
340 template<typename T, typename U, typename V>
341 template<typename OtherCollection>
342 inline bool HashSet<T, U, V>::operator==(const OtherCollection& otherCollection) const
343 {
344 if (size() != otherCollection.size())
345 return false;
346 for (const auto& other : otherCollection) {
347 if (!contains(other))
348 return false;
349 }
350 return true;
351 }
352
353} // namespace WTF
354
355using WTF::HashSet;
356
357#endif /* WTF_HashSet_h */
358