IdDatumPair.java

/**
 * Copyright [2011] [Datasalt Systems S.L.]
 *
 * 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.datasalt.utils.io;

import org.apache.hadoop.io.BytesWritable;
import org.apache.hadoop.io.WritableComparator;

/**
 * A class with a number, that can be used as an identifier of the types of the
 * data that the other two items, stored as byte arrays, belongs to. These
 * arrays can be objects serialized with the {@link Serialization}. <br/>
 * The advantages of this pair is that the comparison is done at the binary
 * level, without deserializing the items. That can be useful for using this
 * class as key on a Map Reduce job. <br/>
 * Both items must be present and cannot be null.
 * 
 * @author ivan,eric
 * 
 */
public class IdDatumPair extends IdDatumPairBase {

	static { // register this comparator
		WritableComparator.define(IdDatumPair.class, new Comparator());
	}

	@Override
  protected int getIdentifier() {
	  return super.getIdentifier();
  }

	@Override
  protected BytesWritable getItem1() {
	  return super.getItem1();
  }

	@Override
  protected BytesWritable getItem2() {
	  return super.getItem2();
  }

	@Override
  protected void setItem1(BytesWritable b) {
	  super.setItem1(b);
  }

	@Override
  protected void setItem2(BytesWritable b) {
	  super.setItem2(b);
  }

	@Override
  protected void setItem1(byte[] datum) {
	  super.setItem1(datum);
  }

	@Override
  protected void setItem1(byte[] datum, int offset, int length) {
	  super.setItem1(datum, offset, length);
  }

	@Override
  protected void setItem2(byte[] datum) {
	  super.setItem2(datum);
  }

	@Override
  protected void setItem2(byte[] datum, int offset, int length) {
	  super.setItem2(datum, offset, length);
  }

}