public int compareTo(BigramWritable bw) {
   int cmp = leftBigram.compareTo(bw.leftBigram);
   if (cmp != 0) return cmp;
   else return rightBigram.compareTo(bw.rightBigram);
 }
예제 #2
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  /** Delete the dst files/dirs which do not exist in src */
  private static void deleteNonexisting(
      FileSystem dstfs,
      FileStatus dstroot,
      Path dstsorted,
      FileSystem jobfs,
      Path jobdir,
      JobConf jobconf,
      Configuration conf)
      throws IOException {
    if (!dstroot.isDir()) {
      throw new IOException(
          "dst must be a directory when option "
              + Options.DELETE.cmd
              + " is set, but dst (= "
              + dstroot.getPath()
              + ") is not a directory.");
    }

    // write dst lsr results
    final Path dstlsr = new Path(jobdir, "_distcp_dst_lsr");
    final SequenceFile.Writer writer =
        SequenceFile.createWriter(
            jobfs,
            jobconf,
            dstlsr,
            Text.class,
            FileStatus.class,
            SequenceFile.CompressionType.NONE);
    try {
      // do lsr to get all file statuses in dstroot
      final Stack<FileStatus> lsrstack = new Stack<FileStatus>();
      for (lsrstack.push(dstroot); !lsrstack.isEmpty(); ) {
        final FileStatus status = lsrstack.pop();
        if (status.isDir()) {
          for (FileStatus child : dstfs.listStatus(status.getPath())) {
            String relative = makeRelative(dstroot.getPath(), child.getPath());
            writer.append(new Text(relative), child);
            lsrstack.push(child);
          }
        }
      }
    } finally {
      checkAndClose(writer);
    }

    // sort lsr results
    final Path sortedlsr = new Path(jobdir, "_distcp_dst_lsr_sorted");
    SequenceFile.Sorter sorter =
        new SequenceFile.Sorter(
            jobfs, new Text.Comparator(), Text.class, FileStatus.class, jobconf);
    sorter.sort(dstlsr, sortedlsr);

    // compare lsr list and dst list
    SequenceFile.Reader lsrin = null;
    SequenceFile.Reader dstin = null;
    try {
      lsrin = new SequenceFile.Reader(jobfs, sortedlsr, jobconf);
      dstin = new SequenceFile.Reader(jobfs, dstsorted, jobconf);

      // compare sorted lsr list and sorted dst list
      final Text lsrpath = new Text();
      final FileStatus lsrstatus = new FileStatus();
      final Text dstpath = new Text();
      final Text dstfrom = new Text();
      final FsShell shell = new FsShell(conf);
      final String[] shellargs = {"-rmr", null};

      boolean hasnext = dstin.next(dstpath, dstfrom);
      for (; lsrin.next(lsrpath, lsrstatus); ) {
        int dst_cmp_lsr = dstpath.compareTo(lsrpath);
        for (; hasnext && dst_cmp_lsr < 0; ) {
          hasnext = dstin.next(dstpath, dstfrom);
          dst_cmp_lsr = dstpath.compareTo(lsrpath);
        }

        if (dst_cmp_lsr == 0) {
          // lsrpath exists in dst, skip it
          hasnext = dstin.next(dstpath, dstfrom);
        } else {
          // lsrpath does not exist, delete it
          String s = new Path(dstroot.getPath(), lsrpath.toString()).toString();
          if (shellargs[1] == null || !isAncestorPath(shellargs[1], s)) {
            shellargs[1] = s;
            int r = 0;
            try {
              r = shell.run(shellargs);
            } catch (Exception e) {
              throw new IOException("Exception from shell.", e);
            }
            if (r != 0) {
              throw new IOException(
                  "\"" + shellargs[0] + " " + shellargs[1] + "\" returns non-zero value " + r);
            }
          }
        }
      }
    } finally {
      checkAndClose(lsrin);
      checkAndClose(dstin);
    }
  }