Experiments of TsFile index area

        String path =
            "/home/fit/szs/data/data/sequence/root.sg/0/"
                + chunkNum
                + "/test"
                + fileIndex
                + ".tsfile";
        File f = FSFactoryProducer.getFSFactory().getFile(path);
        if (f.exists()) {
          f.delete();
        }

        try (TsFileWriter tsFileWriter = new TsFileWriter(f)) {
          // only one timeseries
          tsFileWriter.registerTimeseries(
              new Path(Constant.DEVICE_PREFIX, Constant.SENSOR_1),
              new UnaryMeasurementSchema(Constant.SENSOR_1, TSDataType.INT64, TSEncoding.RLE));

          // construct TSRecord
          for (int i = 1; i <= chunkNum * 100; i++) {
            TSRecord tsRecord = new TSRecord(i, Constant.DEVICE_PREFIX);
            DataPoint dPoint1 = new LongDataPoint(Constant.SENSOR_1, i);
            tsRecord.addTuple(dPoint1);
            // write TSRecord
            tsFileWriter.write(tsRecord);
            if (i % 100 == 0) {
              tsFileWriter.flushAllChunkGroups();
            }
          }
        }

for (int fileIndex = 0; fileIndex < fileNum; fileIndex++) {
      // file path
      String path =
          "/home/fit/szs/data/data/sequence/root.sg/0/"
              + chunkNum
              + "/test"
              + fileIndex
              + ".tsfile";

      // raw data query
      try (TsFileSequenceReader reader = new TsFileSequenceReader(path);
          ReadOnlyTsFile readTsFile = new ReadOnlyTsFile(reader)) {

        ArrayList<Path> paths = new ArrayList<>();
        paths.add(new Path(DEVICE1, "sensor_1"));

        QueryExpression queryExpression = QueryExpression.create(paths, null);

        long startTime = System.nanoTime();
        QueryDataSet queryDataSet = readTsFile.query(queryExpression);
        while (queryDataSet.hasNext()) {
          queryDataSet.next();
        }

        costTime += (System.nanoTime() - startTime);
      }
    }

long totalStartTime = System.nanoTime();
    for (int fileIndex = 0; fileIndex < fileNum; fileIndex++) {
      // file path
      String path =
          "/home/fit/szs/data/data/sequence/root.sg/0/"
              + chunkNum
              + "/test"
              + fileIndex
              + ".tsfile";

      // aggregation query
      try (TsFileSequenceReader reader = new TsFileSequenceReader(path)) {
        Path seriesPath = new Path(DEVICE1, "sensor_1");
        long startTime = System.nanoTime();
        TimeseriesMetadata timeseriesMetadata = reader.readTimeseriesMetadata(seriesPath, false);
        long count = timeseriesMetadata.getStatistics().getCount();
        costTime += (System.nanoTime() - startTime);
      }
    }
    System.out.println(
        "Total raw read cost time: " + (System.nanoTime() - totalStartTime) / 1000_000 + "ms");
    System.out.println("Index area cost time: " + costTime / 1000_000 + "ms");