com.stratio.decision.api.partitioner.HashPartitionerStrategy Maven / Gradle / Ivy

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Decision API

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/**
 * Copyright (C) 2014 Stratio (http://stratio.com)
 *
 * 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 com.stratio.decision.api.partitioner;

import java.util.List;

import com.stratio.decision.api.messaging.ColumnNameValue;

/**
 * Created by josepablofernandez on 7/03/16.
 */
public class HashPartitionerStrategy implements IPartitionerStrategy {

    public Integer getPartitionNumber(List keyValues, Integer numberOfNodes) {

        int  hash = 0;

        for (int i = 0; i < keyValues.size(); i++) {

           hash = JenkinsHash.hash32(keyValues.get(i).columnValue().toString().getBytes(), hash);

        }

        return  Math.abs(hash % numberOfNodes);

    }

}