content: /*
   * The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
   * (the "License"). You may not use this work except in compliance with the License, which is
   * available at www.apache.org/licenses/LICENSE-2.0
   *
   * This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
   * either express or implied, as more fully set forth in the License.
   *
   * See the NOTICE file distributed with this work for information regarding copyright ownership.
   */
  
  package alluxio.master.journal.checkpoint;
  
  import alluxio.util.FormatUtils;
  
  import net.jpountz.lz4.LZ4FrameOutputStream;
  
  import java.io.BufferedOutputStream;
  import java.io.File;
  import java.io.IOException;
  import java.io.OutputStream;
  import java.nio.file.Files;
  import java.security.DigestOutputStream;
  import java.security.MessageDigest;
  
  /**
   * OutputStream to write checkpoint files efficiently.
   */
  public class OptimizedCheckpointOutputStream extends OutputStream {
    public static final int BUFFER_SIZE = (int) FormatUtils.parseSpaceSize("4MB");
  
    private final OutputStream mOutputStream;
  
    /**
     * @param file where the checkpoint will be written
     * @param digest to ensure uncorrupted data
     * @throws IOException propagates wrapped output stream exceptions
     */
    public OptimizedCheckpointOutputStream(File file, MessageDigest digest) throws IOException {
      this(file, digest, BUFFER_SIZE);
    }
  
    /**
     * Constructor used for benchmarking.
     * @param file where the checkpoint will be written
     * @param digest to ensure uncorrupted data
     * @param bufferSize the buffer size that the output stream should use
     */
    public OptimizedCheckpointOutputStream(File file, MessageDigest digest, int bufferSize)
        throws IOException {
      mOutputStream = new DigestOutputStream(new LZ4FrameOutputStream(
          new BufferedOutputStream(Files.newOutputStream(file.toPath()), bufferSize)),
          digest);
    }
  
    @Override
    public void write(int b) throws IOException {
      mOutputStream.write(b);
    }
  
    @Override
    public void close() throws IOException {
      mOutputStream.close();
    }
  }
  