common/src/main/java/org/apache/nemo/common/KeyRange.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.nemo.common;

import java.io.Serializable;

/**
 * Represents the key range of data partitions within a block.
 *
 * @param <K> the type of key to assign for each partition.
 */
public interface KeyRange<K extends Serializable> extends Serializable {

  /**
   * @return whether this instance represents the entire range or not.
   */
  boolean isAll();

  /**
   * @return the beginning of this range (inclusive).
   */
  K rangeBeginInclusive();

  /**
   * @return the end of this range (exclusive).
   */
  K rangeEndExclusive();

  /**
   * @param key the value to check
   * @return {@code true} if this key range includes the specified value, {@code false} otherwise
   */
  boolean includes(final K key);

  /**
   * {@inheritDoc}
   * This method should be overridden for a readable representation of KeyRange.
   * The generic type K should override {@link Object}'s toString() as well.
   */
  @Override
  String toString();

  /**
   * {@inheritDoc}
   * This method should be overridden for KeyRange comparisons.
   */
  @Override
  boolean equals(final Object o);

  /**
   * {@inheritDoc}
   * This method should be overridden for KeyRange comparisons.
   */
  @Override
  int hashCode();
}