MapFileOutputFormat.java 文件源码

/** Open the output generated by this format. */
public static MapFile.Reader[] getReaders(Path dir,
    Configuration conf) throws IOException {
  FileSystem fs = dir.getFileSystem(conf);
  PathFilter filter = new PathFilter() {
    @Override
    public boolean accept(Path path) {
      String name = path.getName();
      if (name.startsWith("_") || name.startsWith("."))
        return false;
      return true;
    }
  };
  Path[] names = FileUtil.stat2Paths(fs.listStatus(dir, filter));

  // sort names, so that hash partitioning works
  Arrays.sort(names);

  MapFile.Reader[] parts = new MapFile.Reader[names.length];
  for (int i = 0; i < names.length; i++) {
    parts[i] = new MapFile.Reader(fs, names[i].toString(), conf);
  }
  return parts;
}