/*

 * Copyright (C) 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Library General Public

 * License as published by the Free Software Foundation; either

 * version 2 of the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Library General Public License for more details.

 *

 * You should have received a copy of the GNU Library General Public License

 * along with this library; see the file COPYING.LIB.  If not, write to

 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,

 * Boston, MA 02110-1301, USA.

 *

 */

#ifndef WTF_HashMap_h

#define WTF_HashMap_h

#include "HashTable.h"

namespace WTF {

    template<typename PairType> struct PairFirstExtractor;

    template<typename KeyArg, typename MappedArg, typename HashArg = typename DefaultHash<KeyArg>::Hash,

        typename KeyTraitsArg = HashTraits<KeyArg>, typename MappedTraitsArg = HashTraits<MappedArg> >

    class HashMap : public FastAllocBase {

    private:

        typedef KeyTraitsArg KeyTraits;

        typedef MappedTraitsArg MappedTraits;

        typedef PairHashTraits<KeyTraits, MappedTraits> ValueTraits;

    public:

        typedef typename KeyTraits::TraitType KeyType;

        typedef typename MappedTraits::TraitType MappedType;

        typedef typename ValueTraits::TraitType ValueType;

    private:

        typedef HashArg HashFunctions;

        typedef HashTable<KeyType, ValueType, PairFirstExtractor<ValueType>,

            HashFunctions, ValueTraits, KeyTraits> HashTableType;

    public:

        typedef HashTableIteratorAdapter<HashTableType, ValueType> iterator;

        typedef HashTableConstIteratorAdapter<HashTableType, ValueType> const_iterator;

        void swap(HashMap&);

        int size() const;

        int capacity() const;

        bool isEmpty() const;

        // iterators iterate over pairs of keys and values

        iterator begin();

        iterator end();

        const_iterator begin() const;

        const_iterator end() const;

        iterator find(const KeyType&);

        const_iterator find(const KeyType&) const;

        bool contains(const KeyType&) const;

        MappedType get(const KeyType&) const;

        // replaces value but not key if key is already present

        // return value is a pair of the iterator to the key location, 

        // and a boolean that's true if a new value was actually added

        pair<iterator, bool> set(const KeyType&, const MappedType&); 

        // does nothing if key is already present

        // return value is a pair of the iterator to the key location, 

        // and a boolean that's true if a new value was actually added

        pair<iterator, bool> add(const KeyType&, const MappedType&); 

        void remove(const KeyType&);

        void remove(iterator);

        void clear();

        MappedType take(const KeyType&); // efficient combination of get with remove

        // An alternate version of find() that finds the object by hashing and comparing

        // with some other type, to avoid the cost of type conversion. HashTranslator

        // must have the following function members:

        //   static unsigned hash(const T&);

        //   static bool equal(const ValueType&, const T&);

        template<typename T, typename HashTranslator> iterator find(const T&);

        template<typename T, typename HashTranslator> const_iterator find(const T&) const;

        template<typename T, typename HashTranslator> bool contains(const T&) const;

        // An alternate version of add() that finds the object by hashing and comparing

        // with some other type, to avoid the cost of type conversion if the object is already

        // in the table. HashTranslator must have the following function members:

        //   static unsigned hash(const T&);

        //   static bool equal(const ValueType&, const T&);

        //   static translate(ValueType&, const T&, unsigned hashCode);

        template<typename T, typename HashTranslator> pair<iterator, bool> add(const T&, const MappedType&);

        void checkConsistency() const;

    private:

        pair<iterator, bool> inlineAdd(const KeyType&, const MappedType&);

        HashTableType m_impl;

    };

    template<typename PairType> struct PairFirstExtractor {

        static const typename PairType::first_type& extract(const PairType& p) { return p.first; }

    };

    template<typename ValueType, typename ValueTraits, typename HashFunctions>

    struct HashMapTranslator {

        typedef typename ValueType::first_type KeyType;

        typedef typename ValueType::second_type MappedType;

        static unsigned hash(const KeyType& key) { return HashFunctions::hash(key); }

        static bool equal(const KeyType& a, const KeyType& b) { return HashFunctions::equal(a, b); }

        static void translate(ValueType& location, const KeyType& key, const MappedType& mapped)

        {

            location.first = key;

            location.second = mapped;

        }

    };

    template<typename ValueType, typename ValueTraits, typename T, typename Translator>

    struct HashMapTranslatorAdapter {

        typedef typename ValueType::first_type KeyType;

        typedef typename ValueType::second_type MappedType;

        static unsigned hash(const T& key) { return Translator::hash(key); }

        static bool equal(const KeyType& a, const T& b) { return Translator::equal(a, b); }

        static void translate(ValueType& location, const T& key, const MappedType& mapped, unsigned hashCode)

        {

            Translator::translate(location.first, key, hashCode);

            location.second = mapped;

        }

    };

    template<typename T, typename U, typename V, typename W, typename X>

    inline void HashMap<T, U, V, W, X>::swap(HashMap& other)

    {

        m_impl.swap(other.m_impl); 

    }

    template<typename T, typename U, typename V, typename W, typename X>

    inline int HashMap<T, U, V, W, X>::size() const

    {

        return m_impl.size(); 

    }

    template<typename T, typename U, typename V, typename W, typename X>

    inline int HashMap<T, U, V, W, X>::capacity() const

    { 

        return m_impl.capacity(); 

    }

    template<typename T, typename U, typename V, typename W, typename X>

    inline bool HashMap<T, U, V, W, X>::isEmpty() const

    {

        return m_impl.isEmpty();

    }

    template<typename T, typename U, typename V, typename W, typename X>

    inline typename HashMap<T, U, V, W, X>::iterator HashMap<T, U, V, W, X>::begin()

    {

        return m_impl.begin();

    }

    template<typename T, typename U, typename V, typename W, typename X>

    inline typename HashMap<T, U, V, W, X>::iterator HashMap<T, U, V, W, X>::end()

    {

        return m_impl.end();

    }

    template<typename T, typename U, typename V, typename W, typename X>

    inline typename HashMap<T, U, V, W, X>::const_iterator HashMap<T, U, V, W, X>::begin() const

    {

        return m_impl.begin();

    }

    template<typename T, typename U, typename V, typename W, typename X>

    inline typename HashMap<T, U, V, W, X>::const_iterator HashMap<T, U, V, W, X>::end() const

    {

        return m_impl.end();

    }

    template<typename T, typename U, typename V, typename W, typename X>

    inline typename HashMap<T, U, V, W, X>::iterator HashMap<T, U, V, W, X>::find(const KeyType& key)

    {

        return m_impl.find(key);

    }

    template<typename T, typename U, typename V, typename W, typename X>

    inline typename HashMap<T, U, V, W, X>::const_iterator HashMap<T, U, V, W, X>::find(const KeyType& key) const

    {

        return m_impl.find(key);

    }

    template<typename T, typename U, typename V, typename W, typename X>

    inline bool HashMap<T, U, V, W, X>::contains(const KeyType& key) const

    {

        return m_impl.contains(key);

    }

    template<typename T, typename U, typename V, typename W, typename X>

    template<typename TYPE, typename HashTranslator>

    inline typename HashMap<T, U, V, W, X>::iterator

    HashMap<T, U, V, W, X>::find(const TYPE& value)

    {

        typedef HashMapTranslatorAdapter<ValueType, ValueTraits, TYPE, HashTranslator> Adapter;

        return m_impl.template find<TYPE, Adapter>(value);

    }

    template<typename T, typename U, typename V, typename W, typename X>

    template<typename TYPE, typename HashTranslator>

    inline typename HashMap<T, U, V, W, X>::const_iterator 

    HashMap<T, U, V, W, X>::find(const TYPE& value) const

    {

        typedef HashMapTranslatorAdapter<ValueType, ValueTraits, TYPE, HashTranslator> Adapter;

        return m_impl.template find<TYPE, Adapter>(value);

    }

    template<typename T, typename U, typename V, typename W, typename X>

    template<typename TYPE, typename HashTranslator>

    inline bool

    HashMap<T, U, V, W, X>::contains(const TYPE& value) const

    {

        typedef HashMapTranslatorAdapter<ValueType, ValueTraits, TYPE, HashTranslator> Adapter;

        return m_impl.template contains<TYPE, Adapter>(value);

    }

    template<typename T, typename U, typename V, typename W, typename X>

    inline pair<typename HashMap<T, U, V, W, X>::iterator, bool>

    HashMap<T, U, V, W, X>::inlineAdd(const KeyType& key, const MappedType& mapped) 

    {

        typedef HashMapTranslator<ValueType, ValueTraits, HashFunctions> TranslatorType;

        return m_impl.template add<KeyType, MappedType, TranslatorType>(key, mapped);

    }

    template<typename T, typename U, typename V, typename W, typename X>

    pair<typename HashMap<T, U, V, W, X>::iterator, bool>

    HashMap<T, U, V, W, X>::set(const KeyType& key, const MappedType& mapped) 

    {

        pair<iterator, bool> result = inlineAdd(key, mapped);

        if (!result.second) {

            // add call above didn't change anything, so set the mapped value

            result.first->second = mapped;

        }

        return result;

    }

    template<typename T, typename U, typename V, typename W, typename X>

    template<typename TYPE, typename HashTranslator>

    pair<typename HashMap<T, U, V, W, X>::iterator, bool>

    HashMap<T, U, V, W, X>::add(const TYPE& key, const MappedType& value)

    {

        typedef HashMapTranslatorAdapter<ValueType, ValueTraits, TYPE, HashTranslator> Adapter;

        return m_impl.template addPassingHashCode<TYPE, MappedType, Adapter>(key, value);

    }

    template<typename T, typename U, typename V, typename W, typename X>

    pair<typename HashMap<T, U, V, W, X>::iterator, bool>

    HashMap<T, U, V, W, X>::add(const KeyType& key, const MappedType& mapped)

    {

        return inlineAdd(key, mapped);

    }

    template<typename T, typename U, typename V, typename W, typename MappedTraits>

    typename HashMap<T, U, V, W, MappedTraits>::MappedType

    HashMap<T, U, V, W, MappedTraits>::get(const KeyType& key) const

    {

        ValueType* entry = const_cast<HashTableType&>(m_impl).lookup(key);

        if (!entry)

            return MappedTraits::emptyValue();

        return entry->second;

    }

    template<typename T, typename U, typename V, typename W, typename X>

    inline void HashMap<T, U, V, W, X>::remove(iterator it)

    {

        if (it.m_impl == m_impl.end())

            return;

        m_impl.internalCheckTableConsistency();

        m_impl.removeWithoutEntryConsistencyCheck(it.m_impl);

    }

    template<typename T, typename U, typename V, typename W, typename X>

    inline void HashMap<T, U, V, W, X>::remove(const KeyType& key)

    {

        remove(find(key));

    }

    template<typename T, typename U, typename V, typename W, typename X>

    inline void HashMap<T, U, V, W, X>::clear()

    {

        m_impl.clear();

    }

    template<typename T, typename U, typename V, typename W, typename MappedTraits>

    typename HashMap<T, U, V, W, MappedTraits>::MappedType

    HashMap<T, U, V, W, MappedTraits>::take(const KeyType& key)

    {

        // This can probably be made more efficient to avoid ref/deref churn.

        iterator it = find(key);

        if (it == end())

            return MappedTraits::emptyValue();

        typename HashMap<T, U, V, W, MappedTraits>::MappedType result = it->second;

        remove(it);

        return result;

    }

    template<typename T, typename U, typename V, typename W, typename X>

    inline void HashMap<T, U, V, W, X>::checkConsistency() const

    {

        m_impl.checkTableConsistency();

    }

    template<typename T, typename U, typename V, typename W, typename X>

    bool operator==(const HashMap<T, U, V, W, X>& a, const HashMap<T, U, V, W, X>& b)

    {

        if (a.size() != b.size())

            return false;

        typedef typename HashMap<T, U, V, W, X>::const_iterator const_iterator;

        const_iterator end = a.end();

        const_iterator notFound = b.end();

        for (const_iterator it = a.begin(); it != end; ++it) {

            const_iterator bPos = b.find(it->first);

            if (bPos == notFound || it->second != bPos->second)

                return false;

        }

        return true;

    }

    template<typename T, typename U, typename V, typename W, typename X>

    inline bool operator!=(const HashMap<T, U, V, W, X>& a, const HashMap<T, U, V, W, X>& b)

    {

        return !(a == b);

    }

    template<typename MappedType, typename HashTableType>

    void deleteAllPairSeconds(HashTableType& collection)

    {

        typedef typename HashTableType::const_iterator iterator;

        iterator end = collection.end();

        for (iterator it = collection.begin(); it != end; ++it)

            delete it->second;

    }

    template<typename T, typename U, typename V, typename W, typename X>

    inline void deleteAllValues(const HashMap<T, U, V, W, X>& collection)

    {

        deleteAllPairSeconds<typename HashMap<T, U, V, W, X>::MappedType>(collection);

    }

    template<typename KeyType, typename HashTableType>

    void deleteAllPairFirsts(HashTableType& collection)

    {

        typedef typename HashTableType::const_iterator iterator;

        iterator end = collection.end();

        for (iterator it = collection.begin(); it != end; ++it)

            delete it->first;

    }

    template<typename T, typename U, typename V, typename W, typename X>

    inline void deleteAllKeys(const HashMap<T, U, V, W, X>& collection)

    {

        deleteAllPairFirsts<typename HashMap<T, U, V, W, X>::KeyType>(collection);

    }

    template<typename T, typename U, typename V, typename W, typename X, typename Y>

    inline void copyKeysToVector(const HashMap<T, U, V, W, X>& collection, Y& vector)

    {

        typedef typename HashMap<T, U, V, W, X>::const_iterator::Keys iterator;

        vector.resize(collection.size());

        iterator it = collection.begin().keys();

        iterator end = collection.end().keys();

        for (unsigned i = 0; it != end; ++it, ++i)

            vector[i] = *it;

    }  

    template<typename T, typename U, typename V, typename W, typename X, typename Y>

    inline void copyValuesToVector(const HashMap<T, U, V, W, X>& collection, Y& vector)

    {

        typedef typename HashMap<T, U, V, W, X>::const_iterator::Values iterator;

        vector.resize(collection.size());

        iterator it = collection.begin().values();

        iterator end = collection.end().values();

        for (unsigned i = 0; it != end; ++it, ++i)

            vector[i] = *it;

    }   

} // namespace WTF

using WTF::HashMap;

#include "RefPtrHashMap.h"

#endif /* WTF_HashMap_h */