com.phantom.hadoop.examples.pi.TaskResult.java Source code

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Here is the source code for com.phantom.hadoop.examples.pi.TaskResult.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 com.phantom.hadoop.examples.pi;

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

import org.apache.hadoop.io.Writable;

import com.phantom.hadoop.examples.pi.math.Summation;

/** A class for map task results or reduce task results. */
public class TaskResult implements Container<Summation>, Combinable<TaskResult>, Writable {
    private Summation sigma;
    private long duration;

    public TaskResult() {
    }

    TaskResult(Summation sigma, long duration) {
        this.sigma = sigma;
        this.duration = duration;
    }

    /** {@inheritDoc} */
    @Override
    public Summation getElement() {
        return sigma;
    }

    /** @return The time duration used */
    long getDuration() {
        return duration;
    }

    /** {@inheritDoc} */
    @Override
    public int compareTo(TaskResult that) {
        return this.sigma.compareTo(that.sigma);
    }

    /** {@inheritDoc} */
    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        else if (obj != null && obj instanceof TaskResult) {
            final TaskResult that = (TaskResult) obj;
            return this.compareTo(that) == 0;
        }
        throw new IllegalArgumentException(obj == null ? "obj == null" : "obj.getClass()=" + obj.getClass());
    }

    /** Not supported */
    @Override
    public int hashCode() {
        throw new UnsupportedOperationException();
    }

    /** {@inheritDoc} */
    @Override
    public TaskResult combine(TaskResult that) {
        final Summation s = sigma.combine(that.sigma);
        return s == null ? null : new TaskResult(s, this.duration + that.duration);
    }

    /** {@inheritDoc} */
    @Override
    public void readFields(DataInput in) throws IOException {
        sigma = SummationWritable.read(in);
        duration = in.readLong();
    }

    /** {@inheritDoc} */
    @Override
    public void write(DataOutput out) throws IOException {
        SummationWritable.write(sigma, out);
        out.writeLong(duration);
    }

    /** {@inheritDoc} */
    @Override
    public String toString() {
        return "sigma=" + sigma + ", duration=" + duration + "(" + Util.millis2String(duration) + ")";
    }

    /** Covert a String to a TaskResult */
    public static TaskResult valueOf(String s) {
        int i = 0;
        int j = s.indexOf(", duration=");
        if (j < 0)
            throw new IllegalArgumentException("i=" + i + ", j=" + j + " < 0, s=" + s);
        final Summation sigma = Summation.valueOf(Util.parseStringVariable("sigma", s.substring(i, j)));

        i = j + 2;
        j = s.indexOf("(", i);
        if (j < 0)
            throw new IllegalArgumentException("i=" + i + ", j=" + j + " < 0, s=" + s);
        final long duration = Util.parseLongVariable("duration", s.substring(i, j));

        return new TaskResult(sigma, duration);
    }
}