org.hydracache.data.hashing.KetamaBasedHashFunction Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of data-partition Show documentation

Hydra Cache consistent hash based data partition library

The newest version!

/*
 * Copyright 2008 the original author or authors.
 *
 * 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.
 */
package org.hydracache.data.hashing;

/**
 * A hashing function based on last.fm's ketama project.
 * 
 * @see Ketama Hashing
 * @author Tan Quach
 * @since 1.0
 */
public class KetamaBasedHashFunction implements HashFunction {

    /*
     * (non-Javadoc)
     * 
     * @see org.hydracache.data.hashing.HashFunction#hash(java.lang.Object)
     */
    public long hash(Object key) {
        long rv = 0;

        byte[] bKey = HashingUtils.computeMd5(key);
        rv = ((long) (bKey[3] & 0xFF) << 24) | ((long) (bKey[2] & 0xFF) << 16)
                | ((long) (bKey[1] & 0xFF) << 8) | (bKey[0] & 0xFF);

        return rv;
    }

}