essentials.hpp

/* Copyright (c) 2014-2015, The Nuria Project
 * The NuriaProject Framework is free software: you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 3 of the License,
 * or (at your option) any later version.
 * 
 * The NuriaProject Framework 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 Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with The NuriaProject Framework.
 * If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef NURIA_ESSENTIALS_HPP
#define NURIA_ESSENTIALS_HPP

#include "core_global.hpp"
#include <cstdint>

namespace Nuria {

constexpr uint32_t jenkinsOne (uint32_t hash, const char *key, int len) {
        return (len < 1)
                ? hash
                : jenkinsOne ((hash + *key + ((hash + *key) << 10)) ^
                              ((hash + *key + ((hash + *key) << 10)) >> 6),
                              key + 1, len - 1);
}

constexpr uint32_t jenkinsHash (const char *key, size_t len) {
        return ((jenkinsOne (0, key, len) + (jenkinsOne (0, key, len) << 3)) ^
                ((jenkinsOne (0, key, len) + (jenkinsOne (0, key, len) << 3)) >> 11)) +
               (((jenkinsOne (0, key, len) + (jenkinsOne (0, key, len) << 3)) ^
                ((jenkinsOne (0, key, len) + (jenkinsOne (0, key, len) << 3)) >> 11)) << 15);
}

}

#define NURIA_DECLARE_METATYPE(...)                                            \
    QT_BEGIN_NAMESPACE                                                         \
    template <>                                                                \
    struct QMetaTypeId< __VA_ARGS__ >                                          \
    {                                                                          \
        enum { Defined = 1 };                                                  \
        static int qt_metatype_id()                                            \
            {                                                                  \
                static QBasicAtomicInt metatype_id = Q_BASIC_ATOMIC_INITIALIZER(0); \
                if (const int id = metatype_id.loadAcquire())                  \
                    return id;                                                 \
                const int newId = qRegisterMetaType< __VA_ARGS__ >(#__VA_ARGS__, \
                              reinterpret_cast< __VA_ARGS__ *>(quintptr(-1))); \
                metatype_id.storeRelease(newId);                               \
                return newId;                                                  \
            }                                                                  \
    };                                                                         \
    QT_END_NAMESPACE

#endif // NURIA_ESSENTIALS_HPP