org.apache.mahout.classifier.KnnMR.mapreduce.partial.StrataID.java Source code

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Here is the source code for org.apache.mahout.classifier.KnnMR.mapreduce.partial.StrataID.java

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/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF 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.apache.mahout.classifier.KnnMR.mapreduce.partial;

import com.google.common.base.Preconditions;
import org.apache.hadoop.io.LongWritable;

/**
 * Indicates both the strata and the data partition used to grow the strata
 */
public class StrataID extends LongWritable implements Cloneable {

    public static final int MAX_TREEID = 100000;

    public StrataID() {
    }

    public StrataID(int partition, int strataId) {
        Preconditions.checkArgument(partition >= 0, "partition < 0");
        Preconditions.checkArgument(strataId >= 0, "strataId < 0");
        set(partition, strataId);
    }

    public void set(int partition, int strataId) {
        set((long) partition * MAX_TREEID + strataId);
    }

    /**
     * Data partition (InputSplit's index) that was used as the strata
     */
    public int partition() {
        return (int) (get() / MAX_TREEID);
    }

    public int strataId() {
        return (int) (get() % MAX_TREEID);
    }

    @Override
    public StrataID clone() {
        return new StrataID(partition(), strataId());
    }
}