@Override
  public int length() {
    // For ROW_COL blooms we use bytes
    // <RK length> (2 bytes) , <RK>, 0 (one byte CF length), <CQ>, <TS> (8 btes), <TYPE> ( 1 byte)
    return KeyValue.ROW_LENGTH_SIZE + this.t.getRowLength() + KeyValue.FAMILY_LENGTH_SIZE
      + this.t.getQualifierLength() + KeyValue.TIMESTAMP_TYPE_SIZE;
  }
An hash key for ROWCOL bloom. This assumes the cells to be serialized in the Keyvalue
serialization format with Empty column family. Note that the byte representing the family length
is considered to be 0
hbase-common/src/main/java/org/apache/hadoop/hbase/util/RowColBloomHashKey.java