/*
    Copyright (c) 2005-2019 Intel Corporation

    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at

        http://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
*/

// must be included outside namespaces.
#ifndef __TBB_tbb_hash_compare_impl_H
#define __TBB_tbb_hash_compare_impl_H

#include <string>

namespace tbb {
namespace interface5 {
namespace internal {

// Template class for hash compare
template<typename Key, typename Hasher, typename Key_equality>
class hash_compare
{
public:
    typedef Hasher hasher;
    typedef Key_equality key_equal;

    hash_compare() {}

    hash_compare(Hasher a_hasher) : my_hash_object(a_hasher) {}

    hash_compare(Hasher a_hasher, Key_equality a_keyeq) : my_hash_object(a_hasher), my_key_compare_object(a_keyeq) {}

    size_t operator()(const Key& key) const {
        return ((size_t)my_hash_object(key));
    }

    bool operator()(const Key& key1, const Key& key2) const {
        // TODO: get rid of the result invertion
        return (!my_key_compare_object(key1, key2));
    }

    Hasher       my_hash_object;        // The hash object
    Key_equality my_key_compare_object; // The equality comparator object
};

//! Hash multiplier
static const size_t hash_multiplier = tbb::internal::select_size_t_constant<2654435769U, 11400714819323198485ULL>::value;

} // namespace internal

//! Hasher functions
template<typename T>
inline size_t tbb_hasher( const T& t ) {
    return static_cast<size_t>( t ) * internal::hash_multiplier;
}
template<typename P>
inline size_t tbb_hasher( P* ptr ) {
    size_t const h = reinterpret_cast<size_t>( ptr );
    return (h >> 3) ^ h;
}
template<typename E, typename S, typename A>
inline size_t tbb_hasher( const std::basic_string<E,S,A>& s ) {
    size_t h = 0;
    for( const E* c = s.c_str(); *c; ++c )
        h = static_cast<size_t>(*c) ^ (h * internal::hash_multiplier);
    return h;
}
template<typename F, typename S>
inline size_t tbb_hasher( const std::pair<F,S>& p ) {
    return tbb_hasher(p.first) ^ tbb_hasher(p.second);
}

} // namespace interface5
using interface5::tbb_hasher;

// Template class for hash compare
template<typename Key>
class tbb_hash
{
public:
    tbb_hash() {}

    size_t operator()(const Key& key) const
    {
        return tbb_hasher(key);
    }
};

//! hash_compare that is default argument for concurrent_hash_map
template<typename Key>
struct tbb_hash_compare {
    static size_t hash( const Key& a ) { return tbb_hasher(a); }
    static bool equal( const Key& a, const Key& b ) { return a == b; }
};

}  // namespace tbb
#endif  /*  __TBB_tbb_hash_compare_impl_H */
