gearman/libhashkit/one_at_a_time.cc

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 *  HashKit library
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/*
  This has is Jenkin's "One at A time Hash".
http://en.wikipedia.org/wiki/Jenkins_hash_function
*/

#include <libhashkit/common.h>

uint32_t hashkit_one_at_a_time(const char *key, size_t key_length, void *context)
{
  const char *ptr= key;
  uint32_t value= 0;
  (void)context;

  while (key_length--)
  {
    uint32_t val= (uint32_t) *ptr++;
    value += val;
    value += (value << 10);
    value ^= (value >> 6);
  }
  value += (value << 3);
  value ^= (value >> 11);
  value += (value << 15);

  return value;
}