001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.io.compress;
019
020import java.io.IOException;
021import java.io.InputStream;
022
023import org.apache.hadoop.classification.InterfaceAudience;
024import org.apache.hadoop.classification.InterfaceStability;
025
026/**
027 * An InputStream covering a range of compressed data. The start and end
028 * offsets requested by a client may be modified by the codec to fit block
029 * boundaries or other algorithm-dependent requirements.
030 */
031@InterfaceAudience.Public
032@InterfaceStability.Evolving
033public abstract class SplitCompressionInputStream
034    extends CompressionInputStream {
035
036  private long start;
037  private long end;
038
039  public SplitCompressionInputStream(InputStream in, long start, long end)
040      throws IOException {
041    super(in);
042    this.start = start;
043    this.end = end;
044  }
045
046  protected void setStart(long start) {
047    this.start = start;
048  }
049
050  protected void setEnd(long end) {
051    this.end = end;
052  }
053
054  /**
055   * After calling createInputStream, the values of start or end
056   * might change.  So this method can be used to get the new value of start.
057   * @return The changed value of start
058   */
059  public long getAdjustedStart() {
060    return start;
061  }
062
063  /**
064   * After calling createInputStream, the values of start or end
065   * might change.  So this method can be used to get the new value of end.
066   * @return The changed value of end
067   */
068  public long getAdjustedEnd() {
069    return end;
070  }
071}