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 "FastAllocBase.h"
  25 #include "HashTable.h"
  26
  27 namespace WTF {
  28
  29     template<typename Value, typename HashFunctions, typename Traits> class HashSet;
  30     template<typename Value, typename HashFunctions, typename Traits>
  31     void deleteAllValues(const HashSet<Value, HashFunctions, Traits>&);
  32     template<typename Value, typename HashFunctions, typename Traits>
  33     void fastDeleteAllValues(const HashSet<Value, HashFunctions, Traits>&);
  34
  35     template<typename T> struct IdentityExtractor;
  36
  37     template<typename ValueArg, typename HashArg = typename DefaultHash<ValueArg>::Hash,
  38         typename TraitsArg = HashTraits<ValueArg> > class HashSet {
  39         WTF_MAKE_FAST_ALLOCATED;
  40     private:
  41         typedef HashArg HashFunctions;
  42         typedef TraitsArg ValueTraits;
  43
  44     public:
  45         typedef typename ValueTraits::TraitType ValueType;
  46
  47     private:
  48         typedef HashTable<ValueType, ValueType, IdentityExtractor<ValueType>,
  49             HashFunctions, ValueTraits, ValueTraits> HashTableType;
  50
  51     public:
  52         typedef HashTableConstIteratorAdapter<HashTableType, ValueType> iterator;
  53         typedef HashTableConstIteratorAdapter<HashTableType, ValueType> const_iterator;
  54
  55         void swap(HashSet&);
  56
  57         int size() const;
  58         int capacity() const;
  59         bool isEmpty() const;
  60
  61         iterator begin() const;
  62         iterator end() const;
  63
  64         iterator find(const ValueType&) const;
  65         bool contains(const ValueType&) const;
  66
  67         // An alternate version of find() that finds the object by hashing and comparing
  68         // with some other type, to avoid the cost of type conversion. HashTranslator
  69         // must have the following function members:
  70         //   static unsigned hash(const T&);
  71         //   static bool equal(const ValueType&, const T&);
  72         template<typename T, typename HashTranslator> 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 function members:
  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         friend void fastDeleteAllValues<>(const HashSet&);
  94
  95         HashTableType m_impl;
  96     };
  97
  98     template<typename T> struct IdentityExtractor {
  99         static const T& extract(const T& t) { return t; }
 100     };
 101
 102     template<typename ValueType, typename ValueTraits, typename T, typename Translator>
 103     struct HashSetTranslatorAdapter {
 104         static unsigned hash(const T& key) { return Translator::hash(key); }
 105         static bool equal(const ValueType& a, const T& b) { return Translator::equal(a, b); }
 106         static void translate(ValueType& location, const T& key, const T&, unsigned hashCode)
 107         {
 108             Translator::translate(location, key, hashCode);
 109         }
 110     };
 111
 112     template<typename T, typename U, typename V>
 113     inline void HashSet<T, U, V>::swap(HashSet& other)
 114     {
 115         m_impl.swap(other.m_impl);
 116     }
 117
 118     template<typename T, typename U, typename V>
 119     inline int HashSet<T, U, V>::size() const
 120     {
 121         return m_impl.size();
 122     }
 123
 124     template<typename T, typename U, typename V>
 125     inline int HashSet<T, U, V>::capacity() const
 126     {
 127         return m_impl.capacity();
 128     }
 129
 130     template<typename T, typename U, typename V>
 131     inline bool HashSet<T, U, V>::isEmpty() const
 132     {
 133         return m_impl.isEmpty();
 134     }
 135
 136     template<typename T, typename U, typename V>
 137     inline typename HashSet<T, U, V>::iterator HashSet<T, U, V>::begin() const
 138     {
 139         return m_impl.begin();
 140     }
 141
 142     template<typename T, typename U, typename V>
 143     inline typename HashSet<T, U, V>::iterator HashSet<T, U, V>::end() const
 144     {
 145         return m_impl.end();
 146     }
 147
 148     template<typename T, typename U, typename V>
 149     inline typename HashSet<T, U, V>::iterator HashSet<T, U, V>::find(const ValueType& value) const
 150     {
 151         return m_impl.find(value);
 152     }
 153
 154     template<typename T, typename U, typename V>
 155     inline bool HashSet<T, U, V>::contains(const ValueType& value) const
 156     {
 157         return m_impl.contains(value);
 158     }
 159
 160     template<typename Value, typename HashFunctions, typename Traits>
 161     template<typename T, typename HashTranslator>
 162     typename HashSet<Value, HashFunctions, Traits>::iterator
 163     inline HashSet<Value, HashFunctions, Traits>::find(const T& value) const
 164     {
 165         typedef HashSetTranslatorAdapter<ValueType, ValueTraits, T, HashTranslator> Adapter;
 166         return m_impl.template find<T, Adapter>(value);
 167     }
 168
 169     template<typename Value, typename HashFunctions, typename Traits>
 170     template<typename T, typename HashTranslator>
 171     inline bool HashSet<Value, HashFunctions, Traits>::contains(const T& value) const
 172     {
 173         typedef HashSetTranslatorAdapter<ValueType, ValueTraits, T, HashTranslator> Adapter;
 174         return m_impl.template contains<T, Adapter>(value);
 175     }
 176
 177     template<typename T, typename U, typename V>
 178     inline pair<typename HashSet<T, U, V>::iterator, bool> HashSet<T, U, V>::add(const ValueType& value)
 179     {
 180         return m_impl.add(value);
 181     }
 182
 183     template<typename Value, typename HashFunctions, typename Traits>
 184     template<typename T, typename HashTranslator>
 185     inline pair<typename HashSet<Value, HashFunctions, Traits>::iterator, bool>
 186     HashSet<Value, HashFunctions, Traits>::add(const T& value)
 187     {
 188         typedef HashSetTranslatorAdapter<ValueType, ValueTraits, T, HashTranslator> Adapter;
 189         return m_impl.template addPassingHashCode<T, T, Adapter>(value, value);
 190     }
 191
 192     template<typename T, typename U, typename V>
 193     inline void HashSet<T, U, V>::remove(iterator it)
 194     {
 195         if (it.m_impl == m_impl.end())
 196             return;
 197         m_impl.internalCheckTableConsistency();
 198         m_impl.removeWithoutEntryConsistencyCheck(it.m_impl);
 199     }
 200
 201     template<typename T, typename U, typename V>
 202     inline void HashSet<T, U, V>::remove(const ValueType& value)
 203     {
 204         remove(find(value));
 205     }
 206
 207     template<typename T, typename U, typename V>
 208     inline void HashSet<T, U, V>::clear()
 209     {
 210         m_impl.clear();
 211     }
 212
 213     template<typename ValueType, typename HashTableType>
 214     void deleteAllValues(HashTableType& collection)
 215     {
 216         typedef typename HashTableType::const_iterator iterator;
 217         iterator end = collection.end();
 218         for (iterator it = collection.begin(); it != end; ++it)
 219             delete *it;
 220     }
 221
 222     template<typename T, typename U, typename V>
 223     inline void deleteAllValues(const HashSet<T, U, V>& collection)
 224     {
 225         deleteAllValues<typename HashSet<T, U, V>::ValueType>(collection.m_impl);
 226     }
 227
 228     template<typename ValueType, typename HashTableType>
 229     void fastDeleteAllValues(HashTableType& collection)
 230     {
 231         typedef typename HashTableType::const_iterator iterator;
 232         iterator end = collection.end();
 233         for (iterator it = collection.begin(); it != end; ++it)
 234             fastDelete(*it);
 235     }
 236
 237     template<typename T, typename U, typename V>
 238     inline void fastDeleteAllValues(const HashSet<T, U, V>& collection)
 239     {
 240         fastDeleteAllValues<typename HashSet<T, U, V>::ValueType>(collection.m_impl);
 241     }
 242
 243     template<typename T, typename U, typename V, typename W>
 244     inline void copyToVector(const HashSet<T, U, V>& collection, W& vector)
 245     {
 246         typedef typename HashSet<T, U, V>::const_iterator iterator;
 247
 248         vector.resize(collection.size());
 249
 250         iterator it = collection.begin();
 251         iterator end = collection.end();
 252         for (unsigned i = 0; it != end; ++it, ++i)
 253             vector[i] = *it;
 254     }
 255
 256 } // namespace WTF
 257
 258 using WTF::HashSet;
 259
 260 #endif /* WTF_HashSet_h */