/*

author: Christian Bender

This is the implementation unit of the hash-functions.

Overview about hash-functions:

- sdbm

- djb2

- xor8 (8 bits)

- adler_32 (32 bits)

*/

long long sdbm(char s[])

{

long long hash = 0;

int i = 0;

while (s[i] != '\0')

{

hash = s[i] + (hash << 6) + (hash << 16) - hash;

i++;

}

return hash;

}

long long djb2(char s[])

{

long long hash = 5381; /* init value */

int i = 0;

while (s[i] != '\0')

{

hash = ((hash << 5) + hash) + s[i];

i++;

}

return hash;

}

char xor8(char s[])

{

int hash = 0;

int i = 0;

while (s[i] != '\0')

{

hash = (hash + s[i]) & 0xff;

i++;

}

return (((hash ^ 0xff) + 1) & 0xff);

}

int adler_32(char s[])

{

int a = 1;

int b = 0;

const int MODADLER = 65521;

int i = 0;

while (s[i] != '\0')

{

a = (a + s[i]) % MODADLER;

b = (b + a) % MODADLER;

i++;

}

return (b << 16) | a;

}