com.ibm.bi.dml.runtime.matrix.sort.IndexSortComparable.java Source code

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Here is the source code for com.ibm.bi.dml.runtime.matrix.sort.IndexSortComparable.java

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/**
 * (C) Copyright IBM Corp. 2010, 2015
 *
 * 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.ibm.bi.dml.runtime.matrix.sort;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;

import org.apache.hadoop.io.DoubleWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.WritableComparable;

@SuppressWarnings("rawtypes")
public class IndexSortComparable implements WritableComparable {

    protected DoubleWritable _dval = null;
    protected LongWritable _lval = null;

    public IndexSortComparable() {
        _dval = new DoubleWritable();
        _lval = new LongWritable();
    }

    public void set(double dval, long lval) {
        _dval.set(dval);
        _lval.set(lval);
    }

    @Override
    public void readFields(DataInput arg0) throws IOException {
        _dval.readFields(arg0);
        _lval.readFields(arg0);
    }

    @Override
    public void write(DataOutput arg0) throws IOException {
        _dval.write(arg0);
        _lval.write(arg0);
    }

    @Override
    public int compareTo(Object o) {
        //compare only double value (e.g., for partitioner)
        if (o instanceof DoubleWritable) {
            return _dval.compareTo((DoubleWritable) o);
        }
        //compare double value and index (e.g., for stable sort)
        else if (o instanceof IndexSortComparable) {
            IndexSortComparable that = (IndexSortComparable) o;
            int tmp = _dval.compareTo(that._dval);
            if (tmp == 0) //secondary sort
                tmp = _lval.compareTo(that._lval);
            return tmp;
        } else {
            throw new RuntimeException("Unsupported comparison involving class: " + o.getClass().getName());
        }
    }
}