What is the fastest way to count the number of records in HBase using Java/Scala Program

I have a multiple HBase tables. Each table is having Millions of records. What is the best or fastest way to count the number of records. Through below program i will get the count but i want some some fastest way to count the records.

def getTotalRecords(connection: Connection, tableName: String): Long = {
    val startTime = System.currentTimeMillis();
    val table = connection.getTable(TableName.valueOf(Bytes.toBytes(tableName)))
    var resultScanner: ResultScanner = table.getScanner(new Scan());
    var count: Long = 0;
    while (resultScanner.next() != null) {
      count = count + 1;
    val endTime = System.currentTimeMillis();
    val timeDiff = endTime - startTime
    println(s"$tableName - Time taken $timeDiff")