/*
**************************************************************************
* *
* General Purpose Hash Function Algorithms Library *
* *
* Author: Arash Partow - 2002 *
* URL: http://www.partow.net *
* URL: http://www.partow.net/programming/hashfunctions/index.html *
* *
* Copyright notice: *
* Free use of the General Purpose Hash Function Algorithms Library is *
* permitted under the guidelines and in accordance with the most current *
* version of the Common Public License. *
* http://www.opensource.org/licenses/cpl1.0.php *
* *
**************************************************************************
*/
#ifndef INCLUDE_GENERALHASHFUNCTION_C_H
#define INCLUDE_GENERALHASHFUNCTION_C_H
#include <stdio.h>
typedef unsigned int (*hash_function)(char*, unsigned int len);
unsigned int RSHash (char* str, unsigned int len);
unsigned int JSHash (char* str, unsigned int len);
unsigned int PJWHash (char* str, unsigned int len);
unsigned int ELFHash (char* str, unsigned int len);
unsigned int BKDRHash(char* str, unsigned int len);
unsigned int SDBMHash(char* str, unsigned int len);
unsigned int DJBHash (char* str, unsigned int len);
unsigned int DEKHash (char* str, unsigned int len);
unsigned int BPHash (char* str, unsigned int len);
unsigned int FNVHash (char* str, unsigned int len);
unsigned int APHash (char* str, unsigned int len);
#endif
#include "GeneralHashFunctions.h"
unsigned int RSHash(char* str, unsigned int len)
{
unsigned int b = 378551;
unsigned int a = 63689;
unsigned int hash = 0;
unsigned int i = 0;
for(i = 0; i < len; str++, i++)
{
hash = hash * a + (*str);
a = a * b;
}
return hash;
}
/* End Of RS Hash Function */
unsigned int JSHash(char* str, unsigned int len)
{
unsigned int hash = 1315423911;
unsigned int i = 0;
for(i = 0; i < len; str++, i++)
{
hash ^= ((hash << 5) + (*str) + (hash >> 2));
}
return hash;
}
/* End Of JS Hash Function */
unsigned int PJWHash(char* str, unsigned int len)
{
const unsigned int BitsInUnsignedInt = (unsigned int)(sizeof(unsigned int) * 8);
const unsigned int ThreeQuarters = (unsigned int)((BitsInUnsignedInt * 3) / 4);
const unsigned int OneEighth = (unsigned int)(BitsInUnsignedInt / 8);
const unsigned int HighBits = (unsigned int)(0xFFFFFFFF) << (BitsInUnsignedInt - OneEighth);
unsigned int hash = 0;
unsigned int test = 0;
unsigned int i = 0;
for(i = 0; i < len; str++, i++)
{
hash = (hash << OneEighth) + (*str);
if((test = hash & HighBits) != 0)
{
hash = (( hash ^ (test >> ThreeQuarters)) & (~HighBits));
}
}
return hash;
}
/* End Of P. J. Weinberger Hash Function */
unsigned int ELFHash(char* str, unsigned int len)
{
unsigned int hash = 0;
unsigned int x = 0;
unsigned int i = 0;
for(i = 0; i < len; str++, i++)
{
hash = (hash << 4) + (*str);
if((x = hash & 0xF0000000L) != 0)
{
hash ^= (x >> 24);
}
hash &= ~x;
}
return hash;
}
/* End Of ELF Hash Function */
unsigned int BKDRHash(char* str, unsigned int len)
{
unsigned int seed = 131; /* 31 131 1313 13131 131313 etc.. */
unsigned int hash = 0;
unsigned int i = 0;
for(i = 0; i < len; str++, i++)
{
hash = (hash * seed) + (*str);
}
return hash;
}
/* End Of BKDR Hash Function */
unsigned int SDBMHash(char* str, unsigned int len)
{
unsigned int hash = 0;
unsigned int i = 0;
for(i = 0; i < len; str++, i++)
{
hash = (*str) + (hash << 6) + (hash << 16) - hash;
}
return hash;
}
/* End Of SDBM Hash Function */
unsigned int DJBHash(char* str, unsigned int len)
{
unsigned int hash = 5381;
unsigned int i = 0;
for(i = 0; i < len; str++, i++)
{
hash = ((hash << 5) + hash) + (*str);
}
return hash;
}
/* End Of DJB Hash Function */
unsigned int DEKHash(char* str, unsigned int len)
{
unsigned int hash = len;
unsigned int i = 0;
for(i = 0; i < len; str++, i++)
{
hash = ((hash << 5) ^ (hash >> 27)) ^ (*str);
}
return hash;
}
/* End Of DEK Hash Function */
unsigned int BPHash(char* str, unsigned int len)
{
unsigned int hash = 0;
unsigned int i = 0;
for(i = 0; i < len; str++, i++)
{
hash = hash << 7 ^ (*str);
}
return hash;
}
/* End Of BP Hash Function */
unsigned int FNVHash(char* str, unsigned int len)
{
const unsigned int fnv_prime = 0x811C9DC5;
unsigned int hash = 0;
unsigned int i = 0;
for(i = 0; i < len; str++, i++)
{
hash *= fnv_prime;
hash ^= (*str);
}
return hash;
}
/* End Of FNV Hash Function */
unsigned int APHash(char* str, unsigned int len)
{
unsigned int hash = 0xAAAAAAAA;
unsigned int i = 0;
for(i = 0; i < len; str++, i++)
{
hash ^= ((i & 1) == 0) ? ( (hash << 7) ^ (*str) * (hash >> 3)) :
(~((hash << 11) + ((*str) ^ (hash >> 5))));
}
return hash;
}
/* End Of AP Hash Function */
/*
**************************************************************************
* *
* General Purpose Hash Function Algorithms Test *
* *
* Author: Arash Partow - 2002 *
* URL: http://www.partow.net *
* URL: http://www.partow.net/programming/hashfunctions/index.html *
* *
* Copyright notice: *
* Free use of the General Purpose Hash Function Algorithms Library is *
* permitted under the guidelines and in accordance with the most current *
* version of the Common Public License. *
* http://www.opensource.org/licenses/cpl1.0.php *
* *
**************************************************************************
*/
#include <stdio.h>
#include <stdlib.h>
#include "GeneralHashFunctions.h"
int main(int argc, char* argv[])
{
char* key = "abcdefghijklmnopqrstuvwxyz1234567890";
printf("General Purpose Hash Function Algorithms Test\n");
printf("By Arash Partow - 2002 \n");
printf("Key: %s\n",key);
printf(" 1. RS-Hash Function Value: %u\n",RSHash(key,36));
printf(" 2. JS-Hash Function Value: %u\n",JSHash(key,36));
printf(" 3. PJW-Hash Function Value: %u\n",PJWHash(key,36));
printf(" 4. ELF-Hash Function Value: %u\n",ELFHash(key,36));
printf(" 5. BKDR-Hash Function Value: %u\n",BKDRHash(key,36));
printf(" 6. SDBM-Hash Function Value: %u\n",SDBMHash(key,36));
printf(" 7. DJB-Hash Function Value: %u\n",DJBHash(key,36));
printf(" 8. DEK-Hash Function Value: %u\n",DEKHash(key,36));
printf(" 9. BP-Hash Function Value: %u\n",BPHash(key,36));
printf("10. FNV-Hash Function Value: %u\n",FNVHash(key,36));
printf("11. AP-Hash Function Value: %u\n",APHash(key,36));
exit(EXIT_SUCCESS);
return 1;
}
