public Set<Long> getTimePartitions() {
    readLock();
    try {
      Set<Long> timePartitions = new HashSet<>(sequenceFiles.keySet());
      timePartitions.addAll(unsequenceFiles.keySet());
      return timePartitions;
    } finally {
      readUnlock();
    }
  }
This method is called after compaction to update memory.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/storageengine/dataregion/tsfile/TsFileManager.java