org.apache.hadoop.examples.pi.TaskResult Maven / Gradle / Ivy
/**
* 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.hadoop.examples.pi;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import org.apache.hadoop.examples.pi.math.Summation;
import org.apache.hadoop.io.Writable;
/** A class for map task results or reduce task results. */
public class TaskResult implements Container, Combinable, 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);
}
}