// -*- mode: C++; indent-tabs-mode: nil; c-basic-offset: 4 -*-

/*
 *     2010-2012 Bob Jenkins (code in public domain)
 * (c) 2013 Vladimír Štill <xstill@fi.muni.cz>
 *
 * Based on http://burtleburtle.net/bob/c/SpookyV2.cpp
 */

/* 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 THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 THE COPYRIGHT HOLDER 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. */

#include "brick-assert"
#include <spot/misc/common.hh>

#include <cstddef>
#include <utility> // pair
#include <tuple> // tie

#ifdef _MSC_VER
# define INLINE __forceinline
  typedef  unsigned __int64 uint64;
  typedef  unsigned __int32 uint32;
  typedef  unsigned __int16 uint16;
  typedef  unsigned __int8  uint8;
#else
# include <cstdint>
# define INLINE inline
  typedef  uint64_t  uint64;
  typedef  uint32_t  uint32;
  typedef  uint16_t  uint16;
  typedef  uint8_t   uint8;
#endif
#include <cstring>
#include <cinttypes>

#define ALLOW_UNALIGNED_READS 1

#ifndef BRICK_HASH_H
#define BRICK_HASH_H

namespace brick {
namespace hash {

typedef uint32_t hash32_t;
typedef uint64_t hash64_t;
typedef std::pair< hash64_t, hash64_t > hash128_t;

namespace jenkins {
//
// SpookyHash: a 128-bit noncryptographic hash function
// By Bob Jenkins, public domain
//   Oct 31 2010: alpha, framework + SpookyHash::Mix appears right
//   Oct 31 2011: alpha again, Mix only good to 2^^69 but rest appears right
//   Dec 31 2011: beta, improved Mix, tested it for 2-bit deltas
//   Feb  2 2012: production, same bits as beta
//   Feb  5 2012: adjusted definitions of uint* to be more portable
//   Mar 30 2012: 3 bytes/cycle, not 4.  Alpha was 4 but wasn't thorough enough.
//   August 5 2012: SpookyV2 (different results)
//
// Up to 3 bytes/cycle for long messages.  Reasonably fast for short messages.
// All 1 or 2 bit deltas achieve avalanche within 1% bias per output bit.
//
// This was developed for and tested on 64-bit x86-compatible processors.
// It assumes the processor is little-endian.  There is a macro
// controlling whether unaligned reads are allowed (by default they are).
// This should be an equally good hash on big-endian machines, but it will
// compute different results on them than on little-endian machines.
//
// Google's CityHash has similar specs to SpookyHash, and CityHash is faster
// on new Intel boxes.  MD4 and MD5 also have similar specs, but they are orders
// of magnitude slower.  CRCs are two or more times slower, but unlike
// SpookyHash, they have nice math for combining the CRCs of pieces to form
// the CRCs of wholes.  There are also cryptographic hashes, but those are even
// slower than MD5.
//

// Modifications for brick-hash.h:
// - merged into one file
// - pairs are used instead of output parameters
// - some functions were marked explicitly for inlining with gcc attribete
//   as they are considered too long otherwise

class SpookyHash
{
public:
    //
    // SpookyHash: hash a single message in one call, produce 128-bit output
    //
    static INLINE std::pair< uint64, uint64 > Hash128(
        const void *message,  // message to hash
        size_t length,        // length of message in bytes
        uint64 seed1,        // in/out: in seed 1, out hash value 1
        uint64 seed2)       // in/out: in seed 2, out hash value 2
    {
        if (length < sc_bufSize)
        {
            return Short(message, length, seed1, seed2);
        }

        uint64 h0,h1,h2,h3,h4,h5,h6,h7,h8,h9,h10,h11;
        uint64 buf[sc_numVars];
        uint64 *end;
        union
        {
            const uint8 *p8;
            uint64 *p64;
            size_t i;
        } u;
        size_t remainder;

        h0=h3=h6=h9  = seed1;
        h1=h4=h7=h10 = seed2;
        h2=h5=h8=h11 = sc_const;

        u.p8 = reinterpret_cast< const uint8 * >( message );
        end = u.p64 + (length/sc_blockSize)*sc_numVars;

        // handle all whole sc_blockSize blocks of bytes
        if (ALLOW_UNALIGNED_READS || ((u.i & 0x7) == 0))
        {
            while (u.p64 < end)
            {
                Mix(u.p64, h0,h1,h2,h3,h4,h5,h6,h7,h8,h9,h10,h11);
            u.p64 += sc_numVars;
            }
        }
        else
        {
            while (u.p64 < end)
            {
                memcpy(buf, u.p64, sc_blockSize);
                Mix(buf, h0,h1,h2,h3,h4,h5,h6,h7,h8,h9,h10,h11);
            u.p64 += sc_numVars;
            }
        }

        // handle the last partial block of sc_blockSize bytes
        remainder = (length - (reinterpret_cast< const uint8 *>(end)-reinterpret_cast< const uint8 * >(message)));
        memcpy(buf, end, remainder);
        memset( reinterpret_cast< uint8 * >( buf )+remainder, 0, sc_blockSize-remainder);
        reinterpret_cast< uint8 * >( buf )[sc_blockSize-1] = remainder;

        // do some final mixing
        End(buf, h0,h1,h2,h3,h4,h5,h6,h7,h8,h9,h10,h11);
        return std::make_pair( h0, h1 );
    }

    //
    // Hash64: hash a single message in one call, return 64-bit output
    //
    static INLINE uint64 Hash64(
        const void *message,  // message to hash
        size_t length,        // length of message in bytes
        uint64 seed)          // seed
    {
        return Hash128(message, length, seed, seed).first;
    }

    //
    // Hash32: hash a single message in one call, produce 32-bit output
    //
    static INLINE uint32 Hash32(
        const void *message,  // message to hash
        size_t length,        // length of message in bytes
        uint32 seed)          // seed
    {
        return uint32( Hash128(message, length, seed, seed).first );
    }

    //
    // Init: initialize the context of a SpookyHash
    //
    INLINE void Init(
        uint64 seed1,       // any 64-bit value will do, including 0
        uint64 seed2)      // different seeds produce independent hashes
    {
        m_length = 0;
        m_remainder = 0;
        m_state[0] = seed1;
        m_state[1] = seed2;
    }

    //
    // Update: add a piece of a message to a SpookyHash state
    //
    INLINE void Update(
        const void *message,  // message fragment
        size_t length)       // length of message fragment in bytes
    {
        uint64 h0,h1,h2,h3,h4,h5,h6,h7,h8,h9,h10,h11;
        size_t newLength = length + m_remainder;
        uint8  remainder;
        union
        {
            const uint8 *p8;
            uint64 *p64;
            size_t i;
        } u;
        const uint64 *end;

        // Is this message fragment too short?  If it is, stuff it away.
        if (newLength < sc_bufSize)
        {
#ifndef NDEBUG
            if ( length > sc_bufSize ) abort();
#endif
            memcpy(&reinterpret_cast< uint8 * >( m_data )[m_remainder], message, length);
            m_length = length + m_length;
            m_remainder = uint8( newLength );
            return;
        }

        // init the variables
        if (m_length < sc_bufSize)
        {
            h0=h3=h6=h9  = m_state[0];
            h1=h4=h7=h10 = m_state[1];
            h2=h5=h8=h11 = sc_const;
        }
        else
        {
            h0 = m_state[0];
            h1 = m_state[1];
            h2 = m_state[2];
            h3 = m_state[3];
            h4 = m_state[4];
            h5 = m_state[5];
            h6 = m_state[6];
            h7 = m_state[7];
            h8 = m_state[8];
            h9 = m_state[9];
            h10 = m_state[10];
            h11 = m_state[11];
        }
        m_length = length + m_length;

        // if we've got anything stuffed away, use it now
        if (m_remainder)
        {
            uint8 prefix = sc_bufSize-m_remainder;
            memcpy(&(reinterpret_cast< uint8 * >( m_data )[m_remainder]), message, prefix);
            u.p64 = m_data;
            Mix(u.p64, h0,h1,h2,h3,h4,h5,h6,h7,h8,h9,h10,h11);
            Mix(&u.p64[sc_numVars], h0,h1,h2,h3,h4,h5,h6,h7,h8,h9,h10,h11);
            u.p8 = reinterpret_cast< const uint8 * >( message ) + prefix;
            length -= prefix;
        }
        else
        {
            u.p8 = reinterpret_cast< const uint8 * >( message );
        }

        // handle all whole blocks of sc_blockSize bytes
        end = u.p64 + (length/sc_blockSize)*sc_numVars;
        remainder = uint8(length-(reinterpret_cast< const uint8 * >( end ) - u.p8));
        if (ALLOW_UNALIGNED_READS || (u.i & 0x7) == 0)
        {
            while (u.p64 < end)
            {
                Mix(u.p64, h0,h1,h2,h3,h4,h5,h6,h7,h8,h9,h10,h11);
            u.p64 += sc_numVars;
            }
        }
        else
        {
            while (u.p64 < end)
            {
                memcpy(m_data, u.p8, sc_blockSize);
                Mix(m_data, h0,h1,h2,h3,h4,h5,h6,h7,h8,h9,h10,h11);
            u.p64 += sc_numVars;
            }
        }

        // stuff away the last few bytes
        m_remainder = remainder;
        memcpy(m_data, end, remainder);

        // stuff away the variables
        m_state[0] = h0;
        m_state[1] = h1;
        m_state[2] = h2;
        m_state[3] = h3;
        m_state[4] = h4;
        m_state[5] = h5;
        m_state[6] = h6;
        m_state[7] = h7;
        m_state[8] = h8;
        m_state[9] = h9;
        m_state[10] = h10;
        m_state[11] = h11;
    }


    //
    // Final: compute the hash for the current SpookyHash state
    //
    // This does not modify the state; you can keep updating it afterward
    //
    // The result is the same as if SpookyHash() had been called with
    // all the pieces concatenated into one message.
    //
    INLINE std::pair< uint64, uint64 > Final()
    {
        // init the variables
        if (m_length < sc_bufSize)
        {
            return Short( m_data, m_length, m_state[0], m_state[1]);
        }

        uint64 *data = reinterpret_cast< uint64 * >( m_data );
        uint8 remainder = m_remainder;

        uint64 h0 = m_state[0];
        uint64 h1 = m_state[1];
        uint64 h2 = m_state[2];
        uint64 h3 = m_state[3];
        uint64 h4 = m_state[4];
        uint64 h5 = m_state[5];
        uint64 h6 = m_state[6];
        uint64 h7 = m_state[7];
        uint64 h8 = m_state[8];
        uint64 h9 = m_state[9];
        uint64 h10 = m_state[10];
        uint64 h11 = m_state[11];

        if (remainder >= sc_blockSize)
        {
            // m_data can contain two blocks; handle any whole first block
            Mix(data, h0,h1,h2,h3,h4,h5,h6,h7,h8,h9,h10,h11);
            data += sc_numVars;
            remainder -= sc_blockSize;
        }

        // mix in the last partial block, and the length mod sc_blockSize
        memset(&reinterpret_cast< uint8 * >( data )[remainder], 0, (sc_blockSize-remainder));

        reinterpret_cast< uint8 * >( data )[sc_blockSize-1] = remainder;

        // do some final mixing
        End(data, h0,h1,h2,h3,h4,h5,h6,h7,h8,h9,h10,h11);

        return std::make_pair( h0, h1 );
    }

    //
    // left rotate a 64-bit value by k bytes
    //
    static INLINE constexpr uint64 Rot64(uint64 x, int k) __attribute__((always_inline))
    {
        return (x << k) | (x >> (64 - k));
    }

    //
    // This is used if the input is 96 bytes long or longer.
    //
    // The internal state is fully overwritten every 96 bytes.
    // Every input bit appears to cause at least 128 bits of entropy
    // before 96 other bytes are combined, when run forward or backward
    //   For every input bit,
    //   Two inputs differing in just that input bit
    //   Where "differ" means xor or subtraction
    //   And the base value is random
    //   When run forward or backwards one Mix
    // I tried 3 pairs of each; they all differed by at least 212 bits.
    //
    static INLINE void Mix(
        const uint64 *data,
        uint64 &s0, uint64 &s1, uint64 &s2, uint64 &s3,
        uint64 &s4, uint64 &s5, uint64 &s6, uint64 &s7,
        uint64 &s8, uint64 &s9, uint64 &s10,uint64 &s11) __attribute__((always_inline))
    {
      s0 += data[0];    s2 ^= s10;    s11 ^= s0;    s0 = Rot64(s0,11);    s11 += s1;
      s1 += data[1];    s3 ^= s11;    s0 ^= s1;    s1 = Rot64(s1,32);    s0 += s2;
      s2 += data[2];    s4 ^= s0;    s1 ^= s2;    s2 = Rot64(s2,43);    s1 += s3;
      s3 += data[3];    s5 ^= s1;    s2 ^= s3;    s3 = Rot64(s3,31);    s2 += s4;
      s4 += data[4];    s6 ^= s2;    s3 ^= s4;    s4 = Rot64(s4,17);    s3 += s5;
      s5 += data[5];    s7 ^= s3;    s4 ^= s5;    s5 = Rot64(s5,28);    s4 += s6;
      s6 += data[6];    s8 ^= s4;    s5 ^= s6;    s6 = Rot64(s6,39);    s5 += s7;
      s7 += data[7];    s9 ^= s5;    s6 ^= s7;    s7 = Rot64(s7,57);    s6 += s8;
      s8 += data[8];    s10 ^= s6;    s7 ^= s8;    s8 = Rot64(s8,55);    s7 += s9;
      s9 += data[9];    s11 ^= s7;    s8 ^= s9;    s9 = Rot64(s9,54);    s8 += s10;
      s10 += data[10];    s0 ^= s8;    s9 ^= s10;    s10 = Rot64(s10,22);    s9 += s11;
      s11 += data[11];    s1 ^= s9;    s10 ^= s11;    s11 = Rot64(s11,46);    s10 += s0;
    }

    //
    // Mix all 12 inputs together so that h0, h1 are a hash of them all.
    //
    // For two inputs differing in just the input bits
    // Where "differ" means xor or subtraction
    // And the base value is random, or a counting value starting at that bit
    // The final result will have each bit of h0, h1 flip
    // For every input bit,
    // with probability 50 +- .3%
    // For every pair of input bits,
    // with probability 50 +- 3%
    //
    // This does not rely on the last Mix() call having already mixed some.
    // Two iterations was almost good enough for a 64-bit result, but a
    // 128-bit result is reported, so End() does three iterations.
    //
    static INLINE void EndPartial(
        uint64 &h0, uint64 &h1, uint64 &h2, uint64 &h3,
        uint64 &h4, uint64 &h5, uint64 &h6, uint64 &h7,
        uint64 &h8, uint64 &h9, uint64 &h10,uint64 &h11) __attribute__((always_inline))
    {
        h11+= h1;    h2 ^= h11;   h1 = Rot64(h1,44);
        h0 += h2;    h3 ^= h0;    h2 = Rot64(h2,15);
        h1 += h3;    h4 ^= h1;    h3 = Rot64(h3,34);
        h2 += h4;    h5 ^= h2;    h4 = Rot64(h4,21);
        h3 += h5;    h6 ^= h3;    h5 = Rot64(h5,38);
        h4 += h6;    h7 ^= h4;    h6 = Rot64(h6,33);
        h5 += h7;    h8 ^= h5;    h7 = Rot64(h7,10);
        h6 += h8;    h9 ^= h6;    h8 = Rot64(h8,13);
        h7 += h9;    h10^= h7;    h9 = Rot64(h9,38);
        h8 += h10;   h11^= h8;    h10= Rot64(h10,53);
        h9 += h11;   h0 ^= h9;    h11= Rot64(h11,42);
        h10+= h0;    h1 ^= h10;   h0 = Rot64(h0,54);
    }

    static INLINE void End(
        const uint64 *data,
        uint64 &h0, uint64 &h1, uint64 &h2, uint64 &h3,
        uint64 &h4, uint64 &h5, uint64 &h6, uint64 &h7,
        uint64 &h8, uint64 &h9, uint64 &h10,uint64 &h11) __attribute__((always_inline))
    {
        h0 += data[0];   h1 += data[1];   h2 += data[2];   h3 += data[3];
        h4 += data[4];   h5 += data[5];   h6 += data[6];   h7 += data[7];
        h8 += data[8];   h9 += data[9];   h10 += data[10]; h11 += data[11];
        EndPartial(h0,h1,h2,h3,h4,h5,h6,h7,h8,h9,h10,h11);
        EndPartial(h0,h1,h2,h3,h4,h5,h6,h7,h8,h9,h10,h11);
        EndPartial(h0,h1,h2,h3,h4,h5,h6,h7,h8,h9,h10,h11);
    }

    //
    // The goal is for each bit of the input to expand into 128 bits of
    //   apparent entropy before it is fully overwritten.
    // n trials both set and cleared at least m bits of h0 h1 h2 h3
    //   n: 2   m: 29
    //   n: 3   m: 46
    //   n: 4   m: 57
    //   n: 5   m: 107
    //   n: 6   m: 146
    //   n: 7   m: 152
    // when run forwards or backwards
    // for all 1-bit and 2-bit diffs
    // with diffs defined by either xor or subtraction
    // with a base of all zeros plus a counter, or plus another bit, or random
    //
    static INLINE void ShortMix(uint64 &h0, uint64 &h1, uint64 &h2, uint64 &h3) __attribute__((always_inline))
    {
        h2 = Rot64(h2,50);  h2 += h3;  h0 ^= h2;
        h3 = Rot64(h3,52);  h3 += h0;  h1 ^= h3;
        h0 = Rot64(h0,30);  h0 += h1;  h2 ^= h0;
        h1 = Rot64(h1,41);  h1 += h2;  h3 ^= h1;
        h2 = Rot64(h2,54);  h2 += h3;  h0 ^= h2;
        h3 = Rot64(h3,48);  h3 += h0;  h1 ^= h3;
        h0 = Rot64(h0,38);  h0 += h1;  h2 ^= h0;
        h1 = Rot64(h1,37);  h1 += h2;  h3 ^= h1;
        h2 = Rot64(h2,62);  h2 += h3;  h0 ^= h2;
        h3 = Rot64(h3,34);  h3 += h0;  h1 ^= h3;
        h0 = Rot64(h0,5);   h0 += h1;  h2 ^= h0;
        h1 = Rot64(h1,36);  h1 += h2;  h3 ^= h1;
    }

    //
    // Mix all 4 inputs together so that h0, h1 are a hash of them all.
    //
    // For two inputs differing in just the input bits
    // Where "differ" means xor or subtraction
    // And the base value is random, or a counting value starting at that bit
    // The final result will have each bit of h0, h1 flip
    // For every input bit,
    // with probability 50 +- .3% (it is probably better than that)
    // For every pair of input bits,
    // with probability 50 +- .75% (the worst case is approximately that)
    //
    static INLINE void ShortEnd(uint64 &h0, uint64 &h1, uint64 &h2, uint64 &h3) __attribute__((always_inline))
    {
        h3 ^= h2;  h2 = Rot64(h2,15);  h3 += h2;
        h0 ^= h3;  h3 = Rot64(h3,52);  h0 += h3;
        h1 ^= h0;  h0 = Rot64(h0,26);  h1 += h0;
        h2 ^= h1;  h1 = Rot64(h1,51);  h2 += h1;
        h3 ^= h2;  h2 = Rot64(h2,28);  h3 += h2;
        h0 ^= h3;  h3 = Rot64(h3,9);   h0 += h3;
        h1 ^= h0;  h0 = Rot64(h0,47);  h1 += h0;
        h2 ^= h1;  h1 = Rot64(h1,54);  h2 += h1;
        h3 ^= h2;  h2 = Rot64(h2,32);  h3 += h2;
        h0 ^= h3;  h3 = Rot64(h3,25);  h0 += h3;
        h1 ^= h0;  h0 = Rot64(h0,63);  h1 += h0;
    }

private:

    //
    // Short is used for messages under 192 bytes in length
    // Short has a low startup cost, the normal mode is good for long
    // keys, the cost crossover is at about 192 bytes.  The two modes were
    // held to the same quality bar.
    //
    static INLINE std::pair< uint64, uint64 > Short(
        const void *message,  // message (array of bytes, not necessarily aligned)
        size_t length,        // length of message (in bytes)
        uint64 seed1,        // in/out: in the seed, out the hash value
        uint64 seed2)       // in/out: in the seed, out the hash value
        __attribute__((always_inline))
    {
        uint64 buf[2*sc_numVars];
        union
        {
            const uint8 *p8;
            uint32 *p32;
            uint64 *p64;
            size_t i;
        } u;

        u.p8 = reinterpret_cast< const uint8 *>( message );

        if (!ALLOW_UNALIGNED_READS && (u.i & 0x7))
        {
            memcpy(buf, message, length);
            u.p64 = buf;
        }

        size_t remainder = length%32;
        uint64 a= seed1;
        uint64 b= seed2;
        uint64 c=sc_const;
        uint64 d=sc_const;

        if (length > 15)
        {
            const uint64 *end = u.p64 + (length/32)*4;

            // handle all complete sets of 32 bytes
            for (; u.p64 < end; u.p64 += 4)
            {
                c += u.p64[0];
                d += u.p64[1];
                ShortMix(a,b,c,d);
                a += u.p64[2];
                b += u.p64[3];
            }

            //Handle the case of 16+ remaining bytes.
            if (remainder >= 16)
            {
                c += u.p64[0];
                d += u.p64[1];
                ShortMix(a,b,c,d);
                u.p64 += 2;
                remainder -= 16;
            }
        }

        // Handle the last 0..15 bytes, and its length
        d += uint64( length ) << 56;
        switch (remainder)
        {
        case 15:
            d += uint64( u.p8[14] ) << 48;
            SPOT_FALLTHROUGH;
        case 14:
            d += uint64( u.p8[13] ) << 40;
            SPOT_FALLTHROUGH;
        case 13:
            d += uint64( u.p8[12] ) << 32;
            SPOT_FALLTHROUGH;
        case 12:
            d += u.p32[2];
            c += u.p64[0];
            break;
        case 11:
            d += uint64( u.p8[10] ) << 16;
            SPOT_FALLTHROUGH;
        case 10:
            d += uint64( u.p8[9] ) << 8;
            SPOT_FALLTHROUGH;
        case 9:
            d += uint64( u.p8[8] );
            SPOT_FALLTHROUGH;
        case 8:
            c += u.p64[0];
            break;
        case 7:
            c += uint64(u.p8[6] ) << 48;
            SPOT_FALLTHROUGH;
        case 6:
            c += uint64( u.p8[5] ) << 40;
            SPOT_FALLTHROUGH;
        case 5:
            c += uint64( u.p8[4] ) << 32;
            SPOT_FALLTHROUGH;
        case 4:
            c += u.p32[0];
            break;
        case 3:
            c += uint64( u.p8[2] ) << 16;
            SPOT_FALLTHROUGH;
        case 2:
            c += uint64( u.p8[1] ) << 8;
            SPOT_FALLTHROUGH;
        case 1:
            c += uint64( u.p8[0] );
            break;
        case 0:
            c += sc_const;
            d += sc_const;
        }
        ShortEnd(a,b,c,d);

        return std::make_pair( a, b );
    }

    // number of uint64's in internal state
    static const size_t sc_numVars = 12;

    // size of the internal state
    static const size_t sc_blockSize = sc_numVars*8;

    // size of buffer of unhashed data, in bytes
    static const size_t sc_bufSize = 2*sc_blockSize;

    //
    // sc_const: a constant which:
    //  * is not zero
    //  * is odd
    //  * is a not-very-regular mix of 1's and 0's
    //  * does not need any other special mathematical properties
    //
    static const uint64 sc_const = 0xdeadbeefdeadbeefLL;

    uint64 m_data[2*sc_numVars];   // unhashed data, for partial messages
    uint64 m_state[sc_numVars];  // internal state of the hash
    size_t m_length;             // total length of the input so far
    uint8  m_remainder;          // length of unhashed data stashed in m_data
};

struct SpookyState {

    SpookyState( uint64_t seed1, uint64_t seed2 ) : state() {
        state.Init( seed1, seed2 );
    }
    SpookyState() = delete;
    SpookyState( const SpookyState & ) = delete;
    SpookyState &operator=( const SpookyState & ) = delete;

    void update( const void *message, size_t length ) {
        state.Update( message, length );
    }

    hash128_t finalize() {
        return state.Final();
    }

  private:
    SpookyHash state;
};

}

namespace {

inline hash128_t spooky( const void *message, size_t length, uint64_t seed1 = 0, uint64_t seed2 = 0 ) {
    return jenkins::SpookyHash::Hash128( message, length, seed1, seed2 );
}

}

}

namespace t_hash {

using namespace hash;

class Random
{
public:
    inline uint64 Value()
    {
        uint64 e = m_a - Rot64(m_b, 23);
        m_a = m_b ^ Rot64(m_c, 16);
        m_b = m_c + Rot64(m_d, 11);
        m_c = m_d + e;
        m_d = e + m_a;
        return m_d;
    }

    inline void Init( uint64 seed)
    {
        m_a = 0xdeadbeef;
        m_b = m_c = m_d = seed;
        for (int i=0; i<20; ++i)
            static_cast< void >( Value() );
    }

private:
    static inline uint64 Rot64(uint64 x, int k)
    {
        return (x << k) | (x >> (64-(k)));
    }

    uint64 m_a;
    uint64 m_b;
    uint64 m_c;
    uint64 m_d;
};

#define BUFSIZE (512)

using brick::hash::jenkins::SpookyHash;

struct Jenkins {

    TEST(results) {
        static const uint64 expected[BUFSIZE] = {
            0x6bf50919,0x70de1d26,0xa2b37298,0x35bc5fbf,0x8223b279,0x5bcb315e,0x53fe88a1,0xf9f1a233,
            0xee193982,0x54f86f29,0xc8772d36,0x9ed60886,0x5f23d1da,0x1ed9f474,0xf2ef0c89,0x83ec01f9,
            0xf274736c,0x7e9ac0df,0xc7aed250,0xb1015811,0xe23470f5,0x48ac20c4,0xe2ab3cd5,0x608f8363,
            0xd0639e68,0xc4e8e7ab,0x863c7c5b,0x4ea63579,0x99ae8622,0x170c658b,0x149ba493,0x027bca7c,
            0xe5cfc8b6,0xce01d9d7,0x11103330,0x5d1f5ed4,0xca720ecb,0xef408aec,0x733b90ec,0x855737a6,
            0x9856c65f,0x647411f7,0x50777c74,0xf0f1a8b7,0x9d7e55a5,0xc68dd371,0xfc1af2cc,0x75728d0a,
            0x390e5fdc,0xf389b84c,0xfb0ccf23,0xc95bad0e,0x5b1cb85a,0x6bdae14f,0x6deb4626,0x93047034,
            0x6f3266c6,0xf529c3bd,0x396322e7,0x3777d042,0x1cd6a5a2,0x197b402e,0xc28d0d2b,0x09c1afb4,

            0x069c8bb7,0x6f9d4e1e,0xd2621b5c,0xea68108d,0x8660cb8f,0xd61e6de6,0x7fba15c7,0xaacfaa97,
            0xdb381902,0x4ea22649,0x5d414a1e,0xc3fc5984,0xa0fc9e10,0x347dc51c,0x37545fb6,0x8c84b26b,
            0xf57efa5d,0x56afaf16,0xb6e1eb94,0x9218536a,0xe3cc4967,0xd3275ef4,0xea63536e,0x6086e499,
            0xaccadce7,0xb0290d82,0x4ebfd0d6,0x46ccc185,0x2eeb10d3,0x474e3c8c,0x23c84aee,0x3abae1cb,
            0x1499b81a,0xa2993951,0xeed176ad,0xdfcfe84c,0xde4a961f,0x4af13fe6,0xe0069c42,0xc14de8f5,
            0x6e02ce8f,0x90d19f7f,0xbca4a484,0xd4efdd63,0x780fd504,0xe80310e3,0x03abbc12,0x90023849,
            0xd6f6fb84,0xd6b354c5,0x5b8575f0,0x758f14e4,0x450de862,0x90704afb,0x47209a33,0xf226b726,
            0xf858dab8,0x7c0d6de9,0xb05ce777,0xee5ff2d4,0x7acb6d5c,0x2d663f85,0x41c72a91,0x82356bf2,

            0x94e948ec,0xd358d448,0xeca7814d,0x78cd7950,0xd6097277,0x97782a5d,0xf43fc6f4,0x105f0a38,
            0x9e170082,0x4bfe566b,0x4371d25f,0xef25a364,0x698eb672,0x74f850e4,0x4678ff99,0x4a290dc6,
            0x3918f07c,0x32c7d9cd,0x9f28e0af,0x0d3c5a86,0x7bfc8a45,0xddf0c7e1,0xdeacb86b,0x970b3c5c,
            0x5e29e199,0xea28346d,0x6b59e71b,0xf8a8a46a,0x862f6ce4,0x3ccb740b,0x08761e9e,0xbfa01e5f,
            0xf17cfa14,0x2dbf99fb,0x7a0be420,0x06137517,0xe020b266,0xd25bfc61,0xff10ed00,0x42e6be8b,
            0x029ef587,0x683b26e0,0xb08afc70,0x7c1fd59e,0xbaae9a70,0x98c8c801,0xb6e35a26,0x57083971,
            0x90a6a680,0x1b44169e,0x1dce237c,0x518e0a59,0xccb11358,0x7b8175fb,0xb8fe701a,0x10d259bb,
            0xe806ce10,0x9212be79,0x4604ae7b,0x7fa22a84,0xe715b13a,0x0394c3b2,0x11efbbae,0xe13d9e19,

            0x77e012bd,0x2d05114c,0xaecf2ddd,0xb2a2b4aa,0xb9429546,0x55dce815,0xc89138f8,0x46dcae20,
            0x1f6f7162,0x0c557ebc,0x5b996932,0xafbbe7e2,0xd2bd5f62,0xff475b9f,0x9cec7108,0xeaddcffb,
            0x5d751aef,0xf68f7bdf,0xf3f4e246,0x00983fcd,0x00bc82bb,0xbf5fd3e7,0xe80c7e2c,0x187d8b1f,
            0xefafb9a7,0x8f27a148,0x5c9606a9,0xf2d2be3e,0xe992d13a,0xe4bcd152,0xce40b436,0x63d6a1fc,
            0xdc1455c4,0x64641e39,0xd83010c9,0x2d535ae0,0x5b748f3e,0xf9a9146b,0x80f10294,0x2859acd4,
            0x5fc846da,0x56d190e9,0x82167225,0x98e4daba,0xbf7865f3,0x00da7ae4,0x9b7cd126,0x644172f8,
            0xde40c78f,0xe8803efc,0xdd331a2b,0x48485c3c,0x4ed01ddc,0x9c0b2d9e,0xb1c6e9d7,0xd797d43c,
            0x274101ff,0x3bf7e127,0x91ebbc56,0x7ffeb321,0x4d42096f,0xd6e9456a,0x0bade318,0x2f40ee0b,

            0x38cebf03,0x0cbc2e72,0xbf03e704,0x7b3e7a9a,0x8e985acd,0x90917617,0x413895f8,0xf11dde04,
            0xc66f8244,0xe5648174,0x6c420271,0x2469d463,0x2540b033,0xdc788e7b,0xe4140ded,0x0990630a,
            0xa54abed4,0x6e124829,0xd940155a,0x1c8836f6,0x38fda06c,0x5207ab69,0xf8be9342,0x774882a8,
            0x56fc0d7e,0x53a99d6e,0x8241f634,0x9490954d,0x447130aa,0x8cc4a81f,0x0868ec83,0xc22c642d,
            0x47880140,0xfbff3bec,0x0f531f41,0xf845a667,0x08c15fb7,0x1996cd81,0x86579103,0xe21dd863,
            0x513d7f97,0x3984a1f1,0xdfcdc5f4,0x97766a5e,0x37e2b1da,0x41441f3f,0xabd9ddba,0x23b755a9,
            0xda937945,0x103e650e,0x3eef7c8f,0x2760ff8d,0x2493a4cd,0x1d671225,0x3bf4bd4c,0xed6e1728,
            0xc70e9e30,0x4e05e529,0x928d5aa6,0x164d0220,0xb5184306,0x4bd7efb3,0x63830f11,0xf3a1526c,

            0xf1545450,0xd41d5df5,0x25a5060d,0x77b368da,0x4fe33c7e,0xeae09021,0xfdb053c4,0x2930f18d,
            0xd37109ff,0x8511a781,0xc7e7cdd7,0x6aeabc45,0xebbeaeaa,0x9a0c4f11,0xda252cbb,0x5b248f41,
            0x5223b5eb,0xe32ab782,0x8e6a1c97,0x11d3f454,0x3e05bd16,0x0059001d,0xce13ac97,0xf83b2b4c,
            0x71db5c9a,0xdc8655a6,0x9e98597b,0x3fcae0a2,0x75e63ccd,0x076c72df,0x4754c6ad,0x26b5627b,
            0xd818c697,0x998d5f3d,0xe94fc7b2,0x1f49ad1a,0xca7ff4ea,0x9fe72c05,0xfbd0cbbf,0xb0388ceb,
            0xb76031e3,0xd0f53973,0xfb17907c,0xa4c4c10f,0x9f2d8af9,0xca0e56b0,0xb0d9b689,0xfcbf37a3,
            0xfede8f7d,0xf836511c,0x744003fc,0x89eba576,0xcfdcf6a6,0xc2007f52,0xaaaf683f,0x62d2f9ca,
            0xc996f77f,0x77a7b5b3,0x8ba7d0a4,0xef6a0819,0xa0d903c0,0x01b27431,0x58fffd4c,0x4827f45c,

            0x44eb5634,0xae70edfc,0x591c740b,0x478bf338,0x2f3b513b,0x67bf518e,0x6fef4a0c,0x1e0b6917,
            0x5ac0edc5,0x2e328498,0x077de7d5,0x5726020b,0x2aeda888,0x45b637ca,0xcf60858d,0x3dc91ae2,
            0x3e6d5294,0xe6900d39,0x0f634c71,0x827a5fa4,0xc713994b,0x1c363494,0x3d43b615,0xe5fe7d15,
            0xf6ada4f2,0x472099d5,0x04360d39,0x7f2a71d0,0x88a4f5ff,0x2c28fac5,0x4cd64801,0xfd78dd33,
            0xc9bdd233,0x21e266cc,0x9bbf419d,0xcbf7d81d,0x80f15f96,0x04242657,0x53fb0f66,0xded11e46,
            0xf2fdba97,0x8d45c9f1,0x4eeae802,0x17003659,0xb9db81a7,0xe734b1b2,0x9503c54e,0xb7c77c3e,
            0x271dd0ab,0xd8b906b5,0x0d540ec6,0xf03b86e0,0x0fdb7d18,0x95e261af,0xad9ec04e,0x381f4a64,
            0xfec798d7,0x09ea20be,0x0ef4ca57,0x1e6195bb,0xfd0da78b,0xcea1653b,0x157d9777,0xf04af50f,

            0xad7baa23,0xd181714a,0x9bbdab78,0x6c7d1577,0x645eb1e7,0xa0648264,0x35839ca6,0x2287ef45,
            0x32a64ca3,0x26111f6f,0x64814946,0xb0cddaf1,0x4351c59e,0x1b30471c,0xb970788a,0x30e9f597,
            0xd7e58df1,0xc6d2b953,0xf5f37cf4,0x3d7c419e,0xf91ecb2d,0x9c87fd5d,0xb22384ce,0x8c7ac51c,
            0x62c96801,0x57e54091,0x964536fe,0x13d3b189,0x4afd1580,0xeba62239,0xb82ea667,0xae18d43a,
            0xbef04402,0x1942534f,0xc54bf260,0x3c8267f5,0xa1020ddd,0x112fcc8a,0xde596266,0xe91d0856,
            0xf300c914,0xed84478e,0x5b65009e,0x4764da16,0xaf8e07a2,0x4088dc2c,0x9a0cad41,0x2c3f179b,
            0xa67b83f7,0xf27eab09,0xdbe10e28,0xf04c911f,0xd1169f87,0x8e1e4976,0x17f57744,0xe4f5a33f,
            0x27c2e04b,0x0b7523bd,0x07305776,0xc6be7503,0x918fa7c9,0xaf2e2cd9,0x82046f8e,0xcc1c8250
        };

        uint8 buf[BUFSIZE];
        uint32 saw[BUFSIZE];
        for (int i=0; i<BUFSIZE; ++i)
        {
            buf[i] = i+128;
            saw[i] = SpookyHash::Hash32(buf, i, 0);
            if (saw[i] != expected[i])
            {
                printf("%3d: saw 0x%.8x, expected 0x%.8" PRIx64 "\n", i, saw[i], expected[i]);
                ASSERT( false );
            }
        }
    }
#undef BUFSIZE

#define BUFSIZE 1024
    TEST(alignment) {
        char buf[BUFSIZE];
        uint64 hash[8];
        for (int i=0; i<BUFSIZE-16; ++i)
        {
            for (int j=0; j<8; ++j)
            {
                buf[j] = char(i+j);
                for (int k=1; k<=i; ++k)
                {
                    buf[j+k] = k;
                }
                buf[j+i+1] = char(i+j);
                hash[j] = SpookyHash::Hash64(reinterpret_cast< const void * >(buf+j+1), i, 0);
            }
            for (int j=1; j<8; ++j)
            {
                if (hash[0] != hash[j])
                {
                    printf("alignment problems: %d %d\n", i, j);
                    ASSERT( false );
                }
            }
        }
    }
#undef BUFSIZE

// test that all deltas of one or two input bits affect all output bits
#define BUFSIZE 256
#define TRIES 50
#define MEASURES 6

    // this takes hours, not doing that in tests...
    void deltas(int seed)
    {
        printf("\nall 1 or 2 bit input deltas get %d tries to flip every output bit ...\n", TRIES);

        Random random;
        random.Init(uint64(seed));

        // for messages 0..BUFSIZE-1 bytes
        for (int h=0; h<BUFSIZE; ++h)
        {
            int maxk = 0;
            // first bit to set
            for (int i=0; i<h*8; ++i)
            {
                // second bit to set, or don't have a second bit
                for (int j=0; j<=i; ++j)
                {
                    uint64 measure[MEASURES][2];
                    uint64 counter[MEASURES][2];
                    for (int l=0; l<2; ++l)
                    {
                        for (int m=0; m<MEASURES; ++m)
                        {
                            measure[m][l] = 0;
                            counter[m][l] = 0;
                        }
                    }

                    // try to hit every output bit TRIES times
                    int k;
                    for (k=0; k<TRIES; ++k)
                    {
                        uint8 buf1[BUFSIZE];
                        uint8 buf2[BUFSIZE];
                        int done = 1;
                        for (int l=0; l<h; ++l)
                        {
                            buf1[l] = buf2[l] = random.Value();
                        }
                        buf1[i/8] ^= (1 << (i%8));
                        if (j != i)
                        {
                            buf1[j/8] ^= (1 << (j%8));
                        }
                        std::tie( measure[0][0], measure[0][1] ) = SpookyHash::Hash128(buf1, h, measure[0][0], measure[0][1]);
                        std::tie( measure[1][0], measure[1][1] ) = SpookyHash::Hash128(buf2, h, measure[1][0], measure[1][1]);
                        for (int l=0; l<2; ++l) {
                            measure[2][l] = measure[0][l] ^ measure[1][l];
                            measure[3][l] = ~(measure[0][l] ^ measure[1][l]);
                            measure[4][l] = measure[0][l] - measure[1][l];
                            measure[4][l] ^= (measure[4][l]>>1);
                            measure[5][l] = measure[0][l] + measure[1][l];
                            measure[5][l] ^= (measure[4][l]>>1);
                        }
                        for (int l=0; l<2; ++l)
                        {
                            for (int m=0; m<MEASURES; ++m)
                            {
                                counter[m][l] |= measure[m][l];
                                if (~counter[m][l]) done = 0;
                            }
                        }
                        if (done) break;
                    }
                    if (k == TRIES)
                    {
                        printf("failed %d %d %d\n", h, i, j);
                        ASSERT( false );
                    }
                    else if (k > maxk)
                    {
                        maxk = k;
                    }
                }
            }
            printf("passed for buffer size %d  max %d\n", h, maxk);
        }
    }
#undef BUFSIZE
#undef TRIES
#undef MEASURES


// test that hashing pieces has the same behavior as hashing the whole
#define BUFSIZE 1024
    TEST(pieces)
    {
        char buf[BUFSIZE];
        for (int i=0; i<BUFSIZE; ++i)
        {
            buf[i] = i;
        }
        for (int i=0; i<BUFSIZE; ++i)
        {
            uint64 a,b,c,d,seed1=1,seed2=2;
            SpookyHash state;

            // all as one call
            a = seed1;
            b = seed2;
            std::tie( a, b ) = SpookyHash::Hash128(buf, i, a, b);

            // all as one piece
            c = 0xdeadbeefdeadbeef;
            d = 0xbaceba11baceba11;
            state.Init(seed1, seed2);
            state.Update(buf, i);
            std::tie( c, d ) = state.Final();

            ASSERT_EQ( a, c );
            ASSERT_EQ( b, d );

            // all possible two consecutive pieces
            for (int j=0; j<i; ++j)
            {
                c = seed1;
                d = seed2;
                state.Init(c, d);
                state.Update(&buf[0], j);
                state.Update(&buf[j], i-j);
                std::tie( c, d ) = state.Final();
                ASSERT_EQ( a, c );
                ASSERT_EQ( b, d );
            }
        }
    }
#undef BUFSIZE
};

}
}

#endif
// vim: syntax=cpp tabstop=4 shiftwidth=4 expandtab
