HashFunction.java

/*
 * Licensed to Elasticsearch under one or more contributor
 * license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright
 * ownership. Elasticsearch licenses this file to you 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.elasticsearch.cluster.routing;

/**
 * Simple hash function interface used for shard routing.
 */
public interface HashFunction {

    /**
     * Calculate a hash value for routing 
     * @param routing String to calculate the hash value from 
     * @return hash value of the given routing string
     */
    int hash(String routing);

    /**
     * Calculate a hash value for routing and its type
     * @param type types name
     * @param id String to calculate the hash value from 
     * @return hash value of the given type and routing string
     */
    @Deprecated
    int hash(String type, String id);
}