@Override
  protected TsFileSequenceReader getReader(String filePath) throws IOException {
    if (filePath.contains(IoTDBConstant.UNSEQUENCE_FOLDER_NAME)) {
      return new CompactionTsFileReader(filePath, CompactionType.INNER_UNSEQ_COMPACTION);
    } else {
      return new CompactionTsFileReader(filePath, CompactionType.INNER_SEQ_COMPACTION);
    }
  }
Estimate the memory cost of one inner space compaction task with specific source files based on
its corresponding implementation.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/storageengine/dataregion/compaction/selector/estimator/AbstractInnerSpaceEstimator.java