// Copyright (c) 2010, Paul Hsieh
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice, this
//   list of conditions and the following disclaimer.
// * 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.
// * Neither my name, Paul Hsieh, nor the names of any other contributors to the
//   code use may not be used to endorse or promote products derived from this
//   software without specific prior written permission.
//
// 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 OWNER 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 <stdint.h>
#include <stdlib.h>
#undef get16bits
#if (defined(__GNUC__) && defined(__i386__)) || defined(__WATCOMC__) \
  || defined(_MSC_VER) || defined (__BORLANDC__) || defined (__TURBOC__)
#define get16bits(d) (*((const uint16_t *) (d)))
#endif
#if !defined (get16bits)
#define get16bits(d) ((((uint32_t)(((const uint8_t *)(d))[1])) << 8)\
                       +(uint32_t)(((const uint8_t *)(d))[0]) )
#endif
uint32_t SuperFastHash(const char * data, int len) {
    uint32_t hash = len, tmp;
    int rem;
    if (len <= 0 || data == NULL) return 0;
    rem = len & 3;
    len >>= 2;
    /* Main loop */
    for (; len > 0; len--) {
        hash += get16bits(data);
        tmp = (get16bits(data + 2) << 11) ^ hash;
        hash = (hash << 16) ^ tmp;
        data += 2 * sizeof(uint16_t);
        hash += hash >> 11;
    }
    /* Handle end cases */
    switch (rem) {
    case 3: hash += get16bits(data);
        hash ^= hash << 16;
        hash ^= ((signed char)data[sizeof(uint16_t)]) << 18;
        hash += hash >> 11;
        break;
    case 2: hash += get16bits(data);
        hash ^= hash << 11;
        hash += hash >> 17;
        break;
    case 1: hash += (signed char)*data;
        hash ^= hash << 10;
        hash += hash >> 1;
    }
    /* Force "avalanching" of final 127 bits */
    hash ^= hash << 3;
    hash += hash >> 5;
    hash ^= hash << 4;
    hash += hash >> 17;
    hash ^= hash << 25;
    hash += hash >> 6;
    return hash;
}