Java Hash Calculate hash(Object a, Object b)

Description

hash

License

Apache License

Declaration

public static int hash(Object a, Object b) 

Method Source Code

//package com.java2s;
/* Copyright 2009 - 2010 The Stajistics Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.//from w  ww  .  ja  v  a  2 s  . c o m
 */

public class Main {
    public static int hash(Object a, Object b) {
        return hashCombine(a.hashCode(), b.hashCode());
    }

    public static int hash(Object a, Object b, Object c) {
        return hashCombine(a.hashCode(), b.hashCode(), c.hashCode());
    }

    public static int hash(float f, int discretness) {
        return (int) (f * discretness);
    }

    /** from clojure.Util */
    public static int hashCombine(int seed, int hash) {
        return seed ^ (hash + 0x9e3779b9 + (seed << 6) + (seed >> 2));

        //return seed * 31 + hash;
    }

    public static int hashCombine(int a, int b, int c) {
        //TODO decide if this is efficient and hashes well
        return hashCombine(hashCombine(a, b), c);
    }
}

Related

1. hash(int val)
2. hash(int value)
3. hash(int x, int y)
4. hash(long key)
5. hash(long mover, long enemy)
6. hash(Object key, int limit)
7. hash(Object o)
8. hash(Object obj)
9. hash(Object obj)