boolean isUdfBlocked(String functionName, Set<String> whiteList, Set<String> blackList) {
    functionName = functionName.toLowerCase();
    return blackList.contains(functionName) ||
        (!whiteList.isEmpty() && !whiteList.contains(functionName));
  }
Check if the function belongs to whitelist or blacklist
@param functionName
@param whiteList
@param blackList
@return true if the given udf is to be blocked
ql/src/java/org/apache/hadoop/hive/ql/exec/Registry.java