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.util.compression;
  
  import static java.util.stream.Collectors.toList;
  
  import org.apache.commons.compress.archivers.tar.TarArchiveEntry;
  import org.apache.commons.compress.archivers.tar.TarArchiveInputStream;
  import org.apache.commons.compress.archivers.tar.TarArchiveOutputStream;
  import org.apache.commons.compress.compressors.gzip.GzipCompressorInputStream;
  import org.apache.commons.compress.compressors.gzip.GzipCompressorOutputStream;
  import org.apache.commons.compress.compressors.gzip.GzipParameters;
  import org.apache.commons.io.IOUtils;
  
  import java.io.BufferedInputStream;
  import java.io.BufferedOutputStream;
  import java.io.File;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.nio.file.Files;
  import java.nio.file.Path;
  import java.util.stream.Stream;
  
  /**
   * Utility methods for working with tar archives.
   */
  public final class TarUtils {
    /**
     * Creates a gzipped tar archive from the given path, streaming the data to the give output
     * stream.
     *
     * @param dirPath the path to archive
     * @param compressionLevel the compression level to use (0 for no compression, 9 for the most
     *                         compression, or -1 for system default)
     * @param output the output stream to write the data to
     * @return the number of bytes copied from the directory into the archive
     */
    public static long writeTarGz(Path dirPath, OutputStream output, int compressionLevel)
        throws IOException, InterruptedException {
      GzipParameters params = new GzipParameters();
      params.setCompressionLevel(compressionLevel);
      GzipCompressorOutputStream zipStream = new GzipCompressorOutputStream(output, params);
      TarArchiveOutputStream archiveStream = new TarArchiveOutputStream(zipStream);
      archiveStream.setLongFileMode(TarArchiveOutputStream.LONGFILE_POSIX);
      archiveStream.setBigNumberMode(TarArchiveOutputStream.BIGNUMBER_POSIX);
      long totalBytesCopied = 0;
      try (final Stream<Path> stream = Files.walk(dirPath)) {
        for (Path subPath : stream.collect(toList())) {
          if (Thread.interrupted()) {
            throw new InterruptedException();
          }
          File file = subPath.toFile();
          TarArchiveEntry entry = new TarArchiveEntry(file, dirPath.relativize(subPath).toString());
          archiveStream.putArchiveEntry(entry);
          if (file.isFile()) {
            try (InputStream fileIn = new BufferedInputStream(Files.newInputStream(subPath))) {
              totalBytesCopied += IOUtils.copyLarge(fileIn, archiveStream);
            }
          }
          archiveStream.closeArchiveEntry();
        }
      }
      archiveStream.finish();
      zipStream.finish();
      return totalBytesCopied;
    }
  
    /**
     * Reads a gzipped tar archive from a stream and writes it to the given path.
     *
     * @param dirPath the path to write the archive to
     * @param input the input stream
     * @return the number of bytes copied from the archive in the directory
     */
    public static long readTarGz(Path dirPath, InputStream input) throws IOException {
      InputStream zipStream = new GzipCompressorInputStream(input);
      TarArchiveInputStream archiveStream = new TarArchiveInputStream(zipStream);
      TarArchiveEntry entry;
      long totalBytesCopied = 0;
      while ((entry = (TarArchiveEntry) archiveStream.getNextEntry()) != null) {
        File outputFile = new File(dirPath.toFile(), entry.getName());
        if (entry.isDirectory()) {
          outputFile.mkdirs();
        } else {
          outputFile.getParentFile().mkdirs();
          try (OutputStream fileOut =
                   new BufferedOutputStream(Files.newOutputStream(outputFile.toPath()))) {
            totalBytesCopied += IOUtils.copyLarge(archiveStream, fileOut);
          }
        }
      }
      return totalBytesCopied;
    }
  
    private TarUtils() {} // Utils class
  }
  