package org.infinispan.distribution;

/**
 * Use the objects built in hash to obtain an initial value, then
 * use a second four byte hash to obtain a more uniform distribution
 * of hash values. This uses a <a href
 * = "http://burtleburtle.net/bob/hash/integer.html">4-byte (integer)
 * hash</a>, which produces well distributed values even when the original
 * hash produces thghtly clustered values.
 *
 * It is important that the object impliment its own hashcode,
 * and not use the Object hashcode.
 *
 * @version $Rev: $, $Date: $
 * @author akluge
 */
public class ReHash implements  Hasher
{
    public int hash(Object object)
    {
        int hash = object.hashCode();

        hash = (hash + 0x7ED55D16) + (hash<<12);
        hash = (hash ^ 0xc761c23c) ^ (hash>>19);
        hash = (hash + 0x165667b1) + (hash<<5);
        hash = (hash + 0xd3a2646c) ^ (hash<<9);
        hash = (hash + 0xfd7046c5) + (hash<<3);
        hash = (hash ^ 0xb55a4f09) ^ (hash>>16);

        return hash;
    }
}