private String getWindowStoragePolicy(long now, long windowStartMillis) {
    if (windowStartMillis >= (now - comConf.getHotWindowAgeMillis())) {
      return comConf.getHotWindowStoragePolicy();
    } else if (windowStartMillis >= (now - comConf.getWarmWindowAgeMillis())) {
      return comConf.getWarmWindowStoragePolicy();
    }
    return comConf.getColdWindowStoragePolicy();
  }
Returns a list of boundaries for multiple compaction output from minTimestamp to maxTimestamp.
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/compactions/DateTieredCompactionPolicy.java