Question

There was a hash algorithm that I came across some time ago that was quite useful for small files. From memory the algorithm itself was very simple. It involved adding the hash with the next byte and multiplying by some fixed number (33 maybe?) then there was a bit shift at the end.

The pseudocode looked something like the following:

for each byte:
    x = nextbyte * 33
    hash += x
    hash <<= 4

Does anyone know the name of this hash algorithm?

Answer 1

It looks like the java hash code algorithm:

public static int calculateHash(String input) {
    int h = 0;
    int len = input.length();
    for (int i = 0; i < len; i++) {
        h = 31 * h + input.charAt(i);
    }
    return h;
}

But it in case this is not true try scrolling through the list of hash functions