public static long getKeyValueDataStructureSize(int rlength, int flength, int qlength,
    int vlength) {
    return KeyValue.KEYVALUE_INFRASTRUCTURE_SIZE
      + getKeyDataStructureSize(rlength, flength, qlength) + vlength;
  }
Computes the number of bytes that a <code>KeyValue</code> instance with the provided
characteristics would take up for its underlying data structure.
@param rlength row length
@param flength family length
@param qlength qualifier length
@param vlength value length
@return the <code>KeyValue</code> data structure length
hbase-common/src/main/java/org/apache/hadoop/hbase/KeyValue.java