wtf/HashSet.h

   1 /*
   2  * Copyright (C) 2005, 2006, 2007, 2008 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 "HashTable.h"
  25
  26 namespace WTF {
  27
  28     template<typename Value, typename HashFunctions, typename Traits> class HashSet;
  29     template<typename Value, typename HashFunctions, typename Traits>
  30     void deleteAllValues(const HashSet<Value, HashFunctions, Traits>&);
  31
  32     template<typename T> struct IdentityExtractor;
  33
  34     template<typename ValueArg, typename HashArg = typename DefaultHash<ValueArg>::Hash,
  35         typename TraitsArg = HashTraits<ValueArg> > class HashSet {
  36     private:
  37         typedef HashArg HashFunctions;
  38         typedef TraitsArg ValueTraits;
  39
  40     public:
  41         typedef typename ValueTraits::TraitType ValueType;
  42
  43     private:
  44         typedef HashTable<ValueType, ValueType, IdentityExtractor<ValueType>,
  45             HashFunctions, ValueTraits, ValueTraits> HashTableType;
  46
  47     public:
  48         typedef HashTableIteratorAdapter<HashTableType, ValueType> iterator;
  49         typedef HashTableConstIteratorAdapter<HashTableType, ValueType> const_iterator;
  50
  51         void swap(HashSet&);
  52
  53         int size() const;
  54         int capacity() const;
  55         bool isEmpty() const;
  56
  57         iterator begin();
  58         iterator end();
  59         const_iterator begin() const;
  60         const_iterator end() const;
  61
  62         iterator find(const ValueType&);
  63         const_iterator find(const ValueType&) const;
  64         bool contains(const ValueType&) const;
  65
  66         // An alternate version of find() that finds the object by hashing and comparing
  67         // with some other type, to avoid the cost of type conversion. HashTranslator
  68         // must have the following function members:
  69         //   static unsigned hash(const T&);
  70         //   static bool equal(const ValueType&, const T&);
  71         template<typename T, typename HashTranslator> iterator find(const T&);
  72         template<typename T, typename HashTranslator> const_iterator find(const T&) const;
  73         template<typename T, typename HashTranslator> bool contains(const T&) const;
  74
  75         // The return value is a pair of an interator to the new value's location,
  76         // and a bool that is true if an new entry was added.
  77         pair<iterator, bool> add(const ValueType&);
  78
  79         // An alternate version of add() that finds the object by hashing and comparing
  80         // with some other type, to avoid the cost of type conversion if the object is already
  81         // in the table. HashTranslator must have the following methods:
  82         //   static unsigned hash(const T&);
  83         //   static bool equal(const ValueType&, const T&);
  84         //   static translate(ValueType&, const T&, unsigned hashCode);
  85         template<typename T, typename HashTranslator> pair<iterator, bool> add(const T&);
  86
  87         void remove(const ValueType&);
  88         void remove(iterator);
  89         void clear();
  90
  91     private:
  92         friend void deleteAllValues<>(const HashSet&);
  93
  94         HashTableType m_impl;
  95     };
  96
  97     template<typename T> struct IdentityExtractor {
  98         static const T& extract(const T& t) { return t; }
  99     };
 100
 101     template<typename ValueType, typename ValueTraits, typename T, typename Translator>
 102     struct HashSetTranslatorAdapter {
 103         static unsigned hash(const T& key) { return Translator::hash(key); }
 104         static bool equal(const ValueType& a, const T& b) { return Translator::equal(a, b); }
 105         static void translate(ValueType& location, const T& key, const T&, unsigned hashCode)
 106         {
 107             Translator::translate(location, key, hashCode);
 108         }
 109     };
 110
 111     template<typename T, typename U, typename V>
 112     inline void HashSet<T, U, V>::swap(HashSet& other)
 113     {
 114         m_impl.swap(other.m_impl);
 115     }
 116
 117     template<typename T, typename U, typename V>
 118     inline int HashSet<T, U, V>::size() const
 119     {
 120         return m_impl.size();
 121     }
 122
 123     template<typename T, typename U, typename V>
 124     inline int HashSet<T, U, V>::capacity() const
 125     {
 126         return m_impl.capacity();
 127     }
 128
 129     template<typename T, typename U, typename V>
 130     inline bool HashSet<T, U, V>::isEmpty() const
 131     {
 132         return m_impl.isEmpty();
 133     }
 134
 135     template<typename T, typename U, typename V>
 136     inline typename HashSet<T, U, V>::iterator HashSet<T, U, V>::begin()
 137     {
 138         return m_impl.begin();
 139     }
 140
 141     template<typename T, typename U, typename V>
 142     inline typename HashSet<T, U, V>::iterator HashSet<T, U, V>::end()
 143     {
 144         return m_impl.end();
 145     }
 146
 147     template<typename T, typename U, typename V>
 148     inline typename HashSet<T, U, V>::const_iterator HashSet<T, U, V>::begin() const
 149     {
 150         return m_impl.begin();
 151     }
 152
 153     template<typename T, typename U, typename V>
 154     inline typename HashSet<T, U, V>::const_iterator HashSet<T, U, V>::end() const
 155     {
 156         return m_impl.end();
 157     }
 158
 159     template<typename T, typename U, typename V>
 160     inline typename HashSet<T, U, V>::iterator HashSet<T, U, V>::find(const ValueType& value)
 161     {
 162         return m_impl.find(value);
 163     }
 164
 165     template<typename T, typename U, typename V>
 166     inline typename HashSet<T, U, V>::const_iterator HashSet<T, U, V>::find(const ValueType& value) const
 167     {
 168         return m_impl.find(value);
 169     }
 170
 171     template<typename T, typename U, typename V>
 172     inline bool HashSet<T, U, V>::contains(const ValueType& value) const
 173     {
 174         return m_impl.contains(value);
 175     }
 176
 177     template<typename Value, typename HashFunctions, typename Traits>
 178     template<typename T, typename Translator>
 179     typename HashSet<Value, HashFunctions, Traits>::iterator
 180     inline HashSet<Value, HashFunctions, Traits>::find(const T& value)
 181     {
 182         typedef HashSetTranslatorAdapter<ValueType, ValueTraits, T, Translator> Adapter;
 183         return m_impl.template find<T, Adapter>(value);
 184     }
 185
 186     template<typename Value, typename HashFunctions, typename Traits>
 187     template<typename T, typename Translator>
 188     typename HashSet<Value, HashFunctions, Traits>::const_iterator
 189     inline HashSet<Value, HashFunctions, Traits>::find(const T& value) const
 190     {
 191         typedef HashSetTranslatorAdapter<ValueType, ValueTraits, T, Translator> Adapter;
 192         return m_impl.template find<T, Adapter>(value);
 193     }
 194
 195     template<typename Value, typename HashFunctions, typename Traits>
 196     template<typename T, typename Translator>
 197     inline bool HashSet<Value, HashFunctions, Traits>::contains(const T& value) const
 198     {
 199         typedef HashSetTranslatorAdapter<ValueType, ValueTraits, T, Translator> Adapter;
 200         return m_impl.template contains<T, Adapter>(value);
 201     }
 202
 203     template<typename T, typename U, typename V>
 204     pair<typename HashSet<T, U, V>::iterator, bool> HashSet<T, U, V>::add(const ValueType& value)
 205     {
 206         return m_impl.add(value);
 207     }
 208
 209     template<typename Value, typename HashFunctions, typename Traits>
 210     template<typename T, typename Translator>
 211     pair<typename HashSet<Value, HashFunctions, Traits>::iterator, bool>
 212     HashSet<Value, HashFunctions, Traits>::add(const T& value)
 213     {
 214         typedef HashSetTranslatorAdapter<ValueType, ValueTraits, T, Translator> Adapter;
 215         return m_impl.template addPassingHashCode<T, T, Adapter>(value, value);
 216     }
 217
 218     template<typename T, typename U, typename V>
 219     inline void HashSet<T, U, V>::remove(iterator it)
 220     {
 221         if (it.m_impl == m_impl.end())
 222             return;
 223         m_impl.checkTableConsistency();
 224         m_impl.removeWithoutEntryConsistencyCheck(it.m_impl);
 225     }
 226
 227     template<typename T, typename U, typename V>
 228     inline void HashSet<T, U, V>::remove(const ValueType& value)
 229     {
 230         remove(find(value));
 231     }
 232
 233     template<typename T, typename U, typename V>
 234     inline void HashSet<T, U, V>::clear()
 235     {
 236         m_impl.clear();
 237     }
 238
 239     template<typename ValueType, typename HashTableType>
 240     void deleteAllValues(HashTableType& collection)
 241     {
 242         typedef typename HashTableType::const_iterator iterator;
 243         iterator end = collection.end();
 244         for (iterator it = collection.begin(); it != end; ++it)
 245             delete *it;
 246     }
 247
 248     template<typename T, typename U, typename V>
 249     inline void deleteAllValues(const HashSet<T, U, V>& collection)
 250     {
 251         deleteAllValues<typename HashSet<T, U, V>::ValueType>(collection.m_impl);
 252     }
 253
 254     template<typename T, typename U, typename V, typename W>
 255     inline void copyToVector(const HashSet<T, U, V>& collection, W& vector)
 256     {
 257         typedef typename HashSet<T, U, V>::const_iterator iterator;
 258
 259         vector.resize(collection.size());
 260
 261         iterator it = collection.begin();
 262         iterator end = collection.end();
 263         for (unsigned i = 0; it != end; ++it, ++i)
 264             vector[i] = *it;
 265     }
 266
 267 } // namespace WTF
 268
 269 using WTF::HashSet;
 270
 271 #endif /* WTF_HashSet_h */