Hash24.h

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/*

             *
            ***
           *****
   *********************       Mercenaries Engineering SARL
     *****************              Copyright (C) 2018
       *************
         *********        http://www.mercenaries-engineering.com
        ***********
       ****     ****
      **           **

*/
#pragma once

  namespace maquina
  {

// This is the 32 bits Jenkins hash masked to 24 bits
inline int hash_24(const uint8_t *key, size_t length)
{
  uint32_t hash = 0;
  size_t i;
  for (i = 0; i < length; ++i) {
    hash += key[i];
    hash += hash << 10;
    hash ^= hash >> 6;
  }
  hash += (hash << 3);
  hash ^= (hash >> 11);
  hash += (hash << 15);
  return int(hash & 0xffffff);
}

inline int hash_24(const std::string& str)
{
  return str.empty()
      ? 0
      : hash_24( reinterpret_cast<const uint8_t*>( str.data() ), str.size() );
}

  }