tajo-core/src/main/java/org/apache/tajo/engine/planner/physical/TupleSet.java

/**
 * 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.tajo.engine.planner.physical;

import java.util.HashSet;

/**
 * TupleSet is a set which accepts only KeyTuple.
 * Input tuples are automatically cloned whenever the add() method is called.
 * This data structure is usually used in physical operators like hash join or hash aggregation.
 */
public class TupleSet extends HashSet<KeyTuple> {

  @Override
  public boolean add(KeyTuple tuple) {
    return super.add(new KeyTuple(tuple));
  }
}