gearman/libhashkit/fnv_32.cc

/*  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
 * 
 *  HashKit library
 *
 *  Copyright (C) 2011-2012 Data Differential, http://datadifferential.com/
 *  Copyright (C) 2009 Brian Aker All rights reserved.
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#include <libhashkit/common.h>

/* FNV hash'es lifted from Dustin Sallings work */
static uint32_t FNV_32_INIT= 2166136261UL;
static uint32_t FNV_32_PRIME= 16777619;

uint32_t hashkit_fnv1_32(const char *key, size_t key_length, void *context)
{
  uint32_t hash= FNV_32_INIT;
  (void)context;

  for (size_t x= 0; x < key_length; x++)
  {
    uint32_t val= (uint32_t)key[x];
    hash *= FNV_32_PRIME;
    hash ^= val;
  }

  return hash;
}

uint32_t hashkit_fnv1a_32(const char *key, size_t key_length, void *context)
{
  uint32_t hash= FNV_32_INIT;
  (void)context;

  for (size_t x= 0; x < key_length; x++)
  {
    uint32_t val= (uint32_t)key[x];
    hash ^= val;
    hash *= FNV_32_PRIME;
  }

  return hash;
}