third_party/WebKit/Source/wtf/HashIterators.h

/*
 * Copyright (C) 2007 Apple Inc.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef WTF_HashIterators_h
#define WTF_HashIterators_h

#include "wtf/Allocator.h"

namespace WTF {

template <typename HashTableType, typename KeyType, typename MappedType> struct HashTableConstKeysIterator;
template <typename HashTableType, typename KeyType, typename MappedType> struct HashTableConstValuesIterator;
template <typename HashTableType, typename KeyType, typename MappedType> struct HashTableKeysIterator;
template <typename HashTableType, typename KeyType, typename MappedType> struct HashTableValuesIterator;

template <typename HashTableType, typename KeyType, typename MappedType>
struct HashTableConstIteratorAdapter<HashTableType, KeyValuePair<KeyType, MappedType>> {
    STACK_ALLOCATED();
private:
    typedef KeyValuePair<KeyType, MappedType> ValueType;
public:
    typedef HashTableConstKeysIterator<HashTableType, KeyType, MappedType> KeysIterator;
    typedef HashTableConstValuesIterator<HashTableType, KeyType, MappedType> ValuesIterator;

    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

    KeysIterator keys() { return KeysIterator(*this); }
    ValuesIterator values() { return ValuesIterator(*this); }

    typename HashTableType::const_iterator m_impl;
};

template <typename HashTableType, typename KeyType, typename MappedType>
struct HashTableIteratorAdapter<HashTableType, KeyValuePair<KeyType, MappedType>> {
    STACK_ALLOCATED();
private:
    typedef KeyValuePair<KeyType, MappedType> ValueType;
public:
    typedef HashTableKeysIterator<HashTableType, KeyType, MappedType> KeysIterator;
    typedef HashTableValuesIterator<HashTableType, KeyType, MappedType> ValuesIterator;

    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;
    }

    KeysIterator keys() { return KeysIterator(*this); }
    ValuesIterator values() { return ValuesIterator(*this); }

    typename HashTableType::iterator m_impl;
};

template <typename HashTableType, typename KeyType, typename MappedType>
struct HashTableConstKeysIterator {
    STACK_ALLOCATED();
private:
    typedef HashTableConstIteratorAdapter<HashTableType, KeyValuePair<KeyType, MappedType>> ConstIterator;

public:
    HashTableConstKeysIterator(const ConstIterator& impl) : m_impl(impl) {}

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

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

    ConstIterator m_impl;
};

template <typename HashTableType, typename KeyType, typename MappedType>
struct HashTableConstValuesIterator {
    STACK_ALLOCATED();
private:
    typedef HashTableConstIteratorAdapter<HashTableType, KeyValuePair<KeyType, MappedType>> ConstIterator;

public:
    HashTableConstValuesIterator(const ConstIterator& impl) : m_impl(impl) {}

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

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

    ConstIterator m_impl;
};

template <typename HashTableType, typename KeyType, typename MappedType>
struct HashTableKeysIterator {
    STACK_ALLOCATED();
private:
    typedef HashTableIteratorAdapter<HashTableType, KeyValuePair<KeyType, MappedType>> Iterator;
    typedef HashTableConstIteratorAdapter<HashTableType, KeyValuePair<KeyType, MappedType>> ConstIterator;

public:
    HashTableKeysIterator(const Iterator& impl) : m_impl(impl) {}

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

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

    operator HashTableConstKeysIterator<HashTableType, KeyType, MappedType>()
    {
        ConstIterator i = m_impl;
        return i;
    }

    Iterator m_impl;
};

template <typename HashTableType, typename KeyType, typename MappedType>
struct HashTableValuesIterator {
    STACK_ALLOCATED();
private:
    typedef HashTableIteratorAdapter<HashTableType, KeyValuePair<KeyType, MappedType>> Iterator;
    typedef HashTableConstIteratorAdapter<HashTableType, KeyValuePair<KeyType, MappedType>> ConstIterator;

public:
    HashTableValuesIterator(const Iterator& impl) : m_impl(impl) {}

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

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

    operator HashTableConstValuesIterator<HashTableType, KeyType, MappedType>()
    {
        ConstIterator i = m_impl;
        return i;
    }

    Iterator m_impl;
};

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

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

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

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

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

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

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

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

} // namespace WTF

#endif // WTF_HashIterators_h