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 */
018
019package org.apache.hadoop.io.compress;
020
021import java.io.IOException;
022import java.io.OutputStream;
023
024import org.apache.hadoop.classification.InterfaceAudience;
025import org.apache.hadoop.classification.InterfaceStability;
026import org.apache.hadoop.io.compress.CompressionOutputStream;
027import org.apache.hadoop.io.compress.Compressor;
028
029@InterfaceAudience.Public
030@InterfaceStability.Evolving
031public class CompressorStream extends CompressionOutputStream {
032  protected Compressor compressor;
033  protected byte[] buffer;
034  protected boolean closed = false;
035  
036  public CompressorStream(OutputStream out, Compressor compressor, int bufferSize) {
037    super(out);
038
039    if (out == null || compressor == null) {
040      throw new NullPointerException();
041    } else if (bufferSize <= 0) {
042      throw new IllegalArgumentException("Illegal bufferSize");
043    }
044
045    this.compressor = compressor;
046    buffer = new byte[bufferSize];
047  }
048
049  public CompressorStream(OutputStream out, Compressor compressor) {
050    this(out, compressor, 512);
051  }
052  
053  /**
054   * Allow derived classes to directly set the underlying stream.
055   * 
056   * @param out Underlying output stream.
057   */
058  protected CompressorStream(OutputStream out) {
059    super(out);
060  }
061
062  @Override
063  public void write(byte[] b, int off, int len) throws IOException {
064    // Sanity checks
065    if (compressor.finished()) {
066      throw new IOException("write beyond end of stream");
067    }
068    if ((off | len | (off + len) | (b.length - (off + len))) < 0) {
069      throw new IndexOutOfBoundsException();
070    } else if (len == 0) {
071      return;
072    }
073
074    compressor.setInput(b, off, len);
075    while (!compressor.needsInput()) {
076      compress();
077    }
078  }
079
080  protected void compress() throws IOException {
081    int len = compressor.compress(buffer, 0, buffer.length);
082    if (len > 0) {
083      out.write(buffer, 0, len);
084    }
085  }
086
087  @Override
088  public void finish() throws IOException {
089    if (!compressor.finished()) {
090      compressor.finish();
091      while (!compressor.finished()) {
092        compress();
093      }
094    }
095  }
096
097  @Override
098  public void resetState() throws IOException {
099    compressor.reset();
100  }
101  
102  @Override
103  public void close() throws IOException {
104    if (!closed) {
105      try {
106        finish();
107      }
108      finally {
109        out.close();
110        closed = true;
111      }
112    }
113  }
114
115  private byte[] oneByte = new byte[1];
116  @Override
117  public void write(int b) throws IOException {
118    oneByte[0] = (byte)(b & 0xff);
119    write(oneByte, 0, oneByte.length);
120  }
121
122}