hashtable.h

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    typename HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::const_iterator HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::find(const T& key) const
    {
        if (!m_table)
            return end();

        ValueType* entry = const_cast<HashTable*>(this)->lookup<T, HashTranslator>(key);
        if (!entry)
            return end();

        return makeKnownGoodConstIterator(entry);
    }

    template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits>
    template <typename T, typename HashTranslator> 
    bool HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::contains(const T& key) const
    {
        if (!m_table)
            return false;

        return const_cast<HashTable*>(this)->lookup<T, HashTranslator>(key);
    }

    template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits>
    void HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::removeAndInvalidateWithoutEntryConsistencyCheck(ValueType* pos)
    {
        invalidateIterators();
        remove(pos);
    }

    template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits>
    void HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::removeAndInvalidate(ValueType* pos)
    {
        invalidateIterators();
        checkTableConsistency();
        remove(pos);
    }

    template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits>
    void HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::remove(ValueType* pos)
    {
#if DUMP_HASHTABLE_STATS
        atomicIncrement(&HashTableStats::numRemoves);
#endif

        deleteBucket(*pos);
        ++m_deletedCount;
        --m_keyCount;

        if (shouldShrink())
            shrink();

        checkTableConsistency();
    }

    template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits>
    inline void HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::remove(iterator it)
    {
        if (it == end())
            return;

        removeAndInvalidate(const_cast<ValueType*>(it.m_iterator.m_position));
    }

    template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits>
    inline void HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::removeWithoutEntryConsistencyCheck(iterator it)
    {
        if (it == end())
            return;

        removeAndInvalidateWithoutEntryConsistencyCheck(const_cast<ValueType*>(it.m_iterator.m_position));
    }

    template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits>
    inline void HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::remove(const KeyType& key)
    {
        remove(find(key));
    }

    template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits>
    Value* HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::allocateTable(int size)
    {
        // would use a template member function with explicit specializations here, but
        // gcc doesn't appear to support that
        if (Traits::emptyValueIsZero)
            return static_cast<ValueType*>(fastZeroedMalloc(size * sizeof(ValueType)));
        ValueType* result = static_cast<ValueType*>(fastMalloc(size * sizeof(ValueType)));
        for (int i = 0; i < size; i++)
            initializeBucket(result[i]);
        return result;
    }

    template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits>
    void HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::deallocateTable(ValueType* table, int size)
    {
        if (Traits::needsDestruction) {
            for (int i = 0; i < size; ++i) {
                if (!isDeletedBucket(table[i]))
                    table[i].~ValueType();
            }
        }
        fastFree(table);
    }

    template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits>
    void HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::expand()
    {
        int newSize;
        if (m_tableSize == 0)
            newSize = m_minTableSize;
        else if (mustRehashInPlace())
            newSize = m_tableSize;
        else
            newSize = m_tableSize * 2;

        rehash(newSize);
    }

    template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits>
    void HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::rehash(int newTableSize)
    {
        checkTableConsistencyExceptSize();

        int oldTableSize = m_tableSize;
        ValueType* oldTable = m_table;

#if DUMP_HASHTABLE_STATS
        if (oldTableSize != 0)
            atomicIncrement(&HashTableStats::numRehashes);
#endif

        m_tableSize = newTableSize;
        m_tableSizeMask = newTableSize - 1;
        m_table = allocateTable(newTableSize);

        for (int i = 0; i != oldTableSize; ++i)
            if (!isEmptyOrDeletedBucket(oldTable[i]))
                reinsert(oldTable[i]);

        m_deletedCount = 0;

        deallocateTable(oldTable, oldTableSize);

        checkTableConsistency();
    }

    template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits>
    void HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::clear()
    {
        invalidateIterators();
        deallocateTable(m_table, m_tableSize);
        m_table = 0;
        m_tableSize = 0;
        m_tableSizeMask = 0;
        m_keyCount = 0;
    }

    template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits>
    HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::HashTable(const HashTable& other)
        : m_table(0)
        , m_tableSize(0)
        , m_tableSizeMask(0)
        , m_keyCount(0)
        , m_deletedCount(0)
#if CHECK_HASHTABLE_ITERATORS
        , m_iterators(0)
#endif
    {
        // Copy the hash table the dumb way, by adding each element to the new table.
        // It might be more efficient to copy the table slots, but it's not clear that efficiency is needed.
        const_iterator end = other.end();
        for (const_iterator it = other.begin(); it != end; ++it)
            add(*it);
    }

    template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits>
    void HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::swap(HashTable& other)
    {
        invalidateIterators();
        other.invalidateIterators();

        ValueType* tmp_table = m_table;
        m_table = other.m_table;
        other.m_table = tmp_table;

        int tmp_tableSize = m_tableSize;
        m_tableSize = other.m_tableSize;
        other.m_tableSize = tmp_tableSize;

        int tmp_tableSizeMask = m_tableSizeMask;
        m_tableSizeMask = other.m_tableSizeMask;
        other.m_tableSizeMask = tmp_tableSizeMask;

        int tmp_keyCount = m_keyCount;
        m_keyCount = other.m_keyCount;
        other.m_keyCount = tmp_keyCount;

        int tmp_deletedCount = m_deletedCount;
        m_deletedCount = other.m_deletedCount;
        other.m_deletedCount = tmp_deletedCount;
    }

    template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits>
    HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>& HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::operator=(const HashTable& other)
    {
        HashTable tmp(other);
        swap(tmp);
        return *this;
    }

#if CHECK_HASHTABLE_CONSISTENCY

    template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits>
    void HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::checkTableConsistency() const
    {
        checkTableConsistencyExceptSize();
        ASSERT(!shouldExpand());
        ASSERT(!shouldShrink());
    }

    template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits>
    void HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::checkTableConsistencyExceptSize() const
    {
        if (!m_table)
            return;

        int count = 0;
        int deletedCount = 0;
        for (int j = 0; j < m_tableSize; ++j) {
            ValueType* entry = m_table + j;
            if (isEmptyBucket(*entry))
                continue;

            if (isDeletedBucket(*entry)) {
                ++deletedCount;
                continue;
            }

            const_iterator it = find(Extractor::extract(*entry));
            ASSERT(entry == it.m_position);
            ++count;
        }

        ASSERT(count == m_keyCount);
        ASSERT(deletedCount == m_deletedCount);
        ASSERT(m_tableSize >= m_minTableSize);
        ASSERT(m_tableSizeMask);
        ASSERT(m_tableSize == m_tableSizeMask + 1);
    }

#endif // CHECK_HASHTABLE_CONSISTENCY

#if CHECK_HASHTABLE_ITERATORS

    template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits>
    void HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>::invalidateIterators()
    {
        MutexLocker lock(m_mutex);
        const_iterator* next;
        for (const_iterator* p = m_iterators; p; p = next) {
            next = p->m_next;
            p->m_table = 0;
            p->m_next = 0;
            p->m_previous = 0;
        }
        m_iterators = 0;
    }

    template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits>
    void addIterator(const HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>* table,
        HashTableConstIterator<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>* it)
    {
        it->m_table = table;
        it->m_previous = 0;

        // Insert iterator at head of doubly-linked list of iterators.
        if (!table) {
            it->m_next = 0;
        } else {
            MutexLocker lock(table->m_mutex);
            ASSERT(table->m_iterators != it);
            it->m_next = table->m_iterators;
            table->m_iterators = it;
            if (it->m_next) {
                ASSERT(!it->m_next->m_previous);
                it->m_next->m_previous = it;
            }
        }
    }

    template<typename Key, typename Value, typename Extractor, typename HashFunctions, typename Traits, typename KeyTraits>
    void removeIterator(HashTableConstIterator<Key, Value, Extractor, HashFunctions, Traits, KeyTraits>* it)
    {
        typedef HashTable<Key, Value, Extractor, HashFunctions, Traits, KeyTraits> HashTableType;
        typedef HashTableConstIterator<Key, Value, Extractor, HashFunctions, Traits, KeyTraits> const_iterator;

        // Delete iterator from doubly-linked list of iterators.
        if (!it->m_table) {
            ASSERT(!it->m_next);
            ASSERT(!it->m_previous);
        } else {
            MutexLocker lock(it->m_table->m_mutex);
            if (it->m_next) {
                ASSERT(it->m_next->m_previous == it);
                it->m_next->m_previous = it->m_previous;
            }
            if (it->m_previous) {
                ASSERT(it->m_table->m_iterators != it);
                ASSERT(it->m_previous->m_next == it);
                it->m_previous->m_next = it->m_next;
            } else {
                ASSERT(it->m_table->m_iterators == it);
                it->m_table->m_iterators = it->m_next;
            }
        }

        it->m_table = 0;
        it->m_next = 0;
        it->m_previous = 0;
    }

#endif // CHECK_HASHTABLE_ITERATORS

    // iterator adapters

    template<typename HashTableType, typename ValueType> struct HashTableConstIteratorAdapter {
        HashTableConstIteratorAdapter(const typename HashTableType::const_iterator& impl) : m_impl(impl) {}

        const ValueType* get() const { return (const ValueType*)m_impl.get(); }
        const ValueType& operator*() const { return *get(); }
        const ValueType* operator->() const { return get(); }

        HashTableConstIteratorAdapter& operator++() { ++m_impl; return *this; }
        // postfix ++ intentionally omitted

        typename HashTableType::const_iterator m_impl;
    };

    template<typename HashTableType, typename ValueType> struct HashTableIteratorAdapter {
        HashTableIteratorAdapter(const typename HashTableType::iterator& impl) : m_impl(impl) {}

        ValueType* get() const { return (ValueType*)m_impl.get(); }
        ValueType& operator*() const { return *get(); }
        ValueType* operator->() const { return get(); }

        HashTableIteratorAdapter& operator++() { ++m_impl; return *this; }
        // postfix ++ intentionally omitted

        operator HashTableConstIteratorAdapter<HashTableType, ValueType>() {
            typename HashTableType::const_iterator i = m_impl;
            return i;
        }

        typename HashTableType::iterator m_impl;
    };

    template<typename T, typename U>
    inline bool operator==(const HashTableConstIteratorAdapter<T, U>& a, const HashTableConstIteratorAdapter<T, U>& b)
    {
        return a.m_impl == b.m_impl;
    }

    template<typename T, typename U>
    inline bool operator!=(const HashTableConstIteratorAdapter<T, U>& a, const HashTableConstIteratorAdapter<T, U>& b)
    {
        return a.m_impl != b.m_impl;
    }

    template<typename T, typename U>
    inline bool operator==(const HashTableIteratorAdapter<T, U>& a, const HashTableIteratorAdapter<T, U>& b)
    {
        return a.m_impl == b.m_impl;
    }

    template<typename T, typename U>
    inline bool operator!=(const HashTableIteratorAdapter<T, U>& a, const HashTableIteratorAdapter<T, U>& b)
    {
        return a.m_impl != b.m_impl;
    }

} // namespace WTF

#include "HashIterators.h"

#endif // WTF_HashTable_h