public HDFSBlocksDistribution getHDFSBlockDistribution() {
    if (initialReaderBlockDistribution != null) {
      return initialReaderBlockDistribution.getHDFSBlockDistribution();
    } else {
      return this.fileInfo.getHDFSBlockDistribution();
    }
  }
@return the cached value of HDFS blocks distribution. The cached value is calculated when store
        file is opened.
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HStoreFile.java