MurmurHash2.hpp

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/*
    Copyright (c) 2009-2010 Christopher A. Taylor.  All rights reserved.

    Redistribution and use in source and binary forms, with or without
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      to endorse or promote products derived from this software without
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/*
    MurmurHash2 is a very fast noncryptographic 32/64-bit hash

    Algorithm by Austin Appleby <aappleby@gmail.com>
    http://murmurhash.googlepages.com/
*/

#ifndef CAT_MURMUR_HASH_2_HPP
#define CAT_MURMUR_HASH_2_HPP

#include <cat/Platform.hpp>

namespace cat {


// NOTE: Result is NOT endian-neutral.  Use getLE().
u32 MurmurHash32(const void *key, int bytes, u32 seed);
u64 MurmurHash64(const void *key, int bytes, u64 seed);


class IncrementalMurmurHash32
{
    u32 _hash, _tail, _count, _size;

    static const u32 M = 0x5bd1e995;
    static const u32 R = 24;

public:
    void Begin(u32 seed = 0);
    void Add(const void *data, int bytes);
    u32 End();
};


class IncrementalMurmurHash64
{
    u32 _count;
    u64 _hash, _tail, _size;

    static const u64 M = 0xc6a4a7935bd1e995ULL;
    static const u64 R = 47;

public:
    void Begin(u64 seed = 0);
    void Add(const void *data, int bytes);
    u64 End();
};


} // namespace cat

#endif // CAT_MURMUR_HASH_2_HPP