src/java/org/apache/hadoop/io/file/tfile/RawComparable.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.hadoop.io.file.tfile;

import java.util.Collections;
import java.util.Comparator;

import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.io.RawComparator;

/**
 * Interface for objects that can be compared through {@link RawComparator}.
 * This is useful in places where we need a single object reference to specify a
 * range of bytes in a byte array, such as {@link Comparable} or
 * {@link Collections#binarySearch(java.util.List, Object, Comparator)}
 * 
 * The actual comparison among RawComparable's requires an external
 * RawComparator and it is applications' responsibility to ensure two
 * RawComparable are supposed to be semantically comparable with the same
 * RawComparator.
 */
@InterfaceAudience.Public
@InterfaceStability.Evolving
public interface RawComparable {
  /**
   * Get the underlying byte array.
   * 
   * @return The underlying byte array.
   */
  abstract byte[] buffer();

  /**
   * Get the offset of the first byte in the byte array.
   * 
   * @return The offset of the first byte in the byte array.
   */
  abstract int offset();

  /**
   * Get the size of the byte range in the byte array.
   * 
   * @return The size of the byte range in the byte array.
   */
  abstract int size();
}