io.druid.query.groupby.orderby

Class TopNSorter<T>

java.lang.Object

io.druid.query.groupby.orderby.TopNSorter<T>

public class TopNSorter<T>
extends Object

A utility class that sorts a list of comparable items in the given order, and keeps only the top N sorted items.

Constructor Summary

Constructors

Constructor and Description
TopNSorter(com.google.common.collect.Ordering<T> ordering) Constructs a sorter that will sort items with given ordering.

Method Summary

Methods

Modifier and Type	Method and Description
Iterable<T>	toTopN(Iterable<T> items, int n) Sorts a list of rows and retain the top n items

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

TopNSorter

public TopNSorter(com.google.common.collect.Ordering<T> ordering)

Constructs a sorter that will sort items with given ordering.

Parameters:

ordering - the order that this sorter instance will use for sorting

Method Detail

toTopN

public Iterable<T> toTopN(Iterable<T> items,
                 int n)

Sorts a list of rows and retain the top n items

Parameters:

items - the collections of items to be sorted

n - the number of items to be retained

Returns:

Top n items that are sorted in the order specified when this instance is constructed.