code: private void gcFileIfStale(UfsJournalFile file, long checkpointSequenceNumber) {
      if (file.getEnd() > checkpointSequenceNumber && !file.isTmpCheckpoint()) {
        return;
      }
  
      long lastModifiedTimeMs;
      try {
        lastModifiedTimeMs = mUfs.getFileStatus(file.getLocation().toString()).getLastModifiedTime();
      } catch (IOException e) {
        LOG.warn("Failed to get the last modified time for {}.", file.getLocation());
        return;
      }
  
      long thresholdMs = file.isTmpCheckpoint()
          ? ServerConfiguration.getMs(PropertyKey.MASTER_JOURNAL_TEMPORARY_FILE_GC_THRESHOLD_MS)
          : ServerConfiguration.getMs(PropertyKey.MASTER_JOURNAL_GC_THRESHOLD_MS);
  
      if (System.currentTimeMillis() - lastModifiedTimeMs > thresholdMs) {
        deleteNoException(file.getLocation());
      }
    }
docs: Garbage collects a file if necessary.
  
  @param file the file
  @param checkpointSequenceNumber the first sequence number that has not been checkpointed