Saf/Algo/Hash.h

Go to the documentation of this file.

/*
    This file is part of Simple Application Framework (Saf) library.
    Copyright (C) 2010 - 2012 Ondrej Danek <ondrej.danek@gmail.com>

    This library is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published 
    by the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    Saf 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 General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with Simple Application Framework library. If not, 
    see <http://www.gnu.org/licenses/>.
*/

#ifndef SAF_ALGO_HASH_H
#define SAF_ALGO_HASH_H

#include "../Core.h"
#include "../Type.h"
#include "Function.h"

namespace Saf
{
    namespace Algo
    {
        template <class T>
        struct Hash
            : public UnaryFunction<T,Size>
        {
            Size operator()(const T& val) const;
        };

        SAF_DLL_EXPORT Size HashBytes(const Uint8 *data, Size sz);

        // Explicit Hash instantiations
        template <> inline Size Hash<Uint8>::operator()(const Uint8 &val) const
        {
            return (Size)val;
        }

        template <> inline Size Hash<Uint16>::operator()(const Uint16 &val) const
        {
            return (Size)val;
        }

        template <> inline Size Hash<Uint32>::operator()(const Uint32 &val) const
        {
            return (Size)val;
        }

        template <> inline Size Hash<Uint64>::operator()(const Uint64 &val) const
        {
            return sizeof(Uint64) > sizeof(Size) ? Size((val & 0xffffffff) ^ (val >> 32)) : (Size)val;
        }

        template <> inline Size Hash<Int8>::operator()(const Int8 &val) const
        {
            return (Size)val;
        }

        template <> inline Size Hash<Int16>::operator()(const Int16 &val) const
        {
            return (Size)val;
        }

        template <> inline Size Hash<Int32>::operator()(const Int32 &val) const
        {
            return (Size)val;
        }

        template <> inline Size Hash<Int64>::operator()(const Int64 &val) const
        {
            return Hash<Uint64>()(Uint64(val));
        }

        template <> inline Size Hash<Float32>::operator()(const Float32 &val) const
        {
            return (val == -0.0f || val == 0.0f) ? Size(0) : Hash<Uint32>()(*((Uint32*)&val));
        }

        template <> inline Size Hash<Float64>::operator()(const Float64 &val) const
        {
            return (val == -0.0 || val == 0.0) ? Size(0) : Hash<Uint64>()(*((Uint64*)&val));
        }
    }
}

#endif