com.clearspring.analytics.stream

Class StochasticTopper<T>

java.lang.Object

com.clearspring.analytics.stream.StochasticTopper<T>

All Implemented Interfaces:

ITopK<T>

public class StochasticTopper<T>
extends Object
implements ITopK<T>

Estimates most frequently occurring items in a data stream using a bounded amount of memory.

Warning: this class is not thread safe.

Constructor Summary

Constructors

Constructor and Description
StochasticTopper(int sampleSize)
StochasticTopper(int sampleSize, Long seed)

Method Summary

Modifier and Type	Method and Description
boolean	offer(T item) offer a single element to the top.
boolean	offer(T item, int incrementCount) offer a single element to the top and increment the count for that element by incrementCount.
List<T>	peek(int k) Retrieve top k items

Methods inherited from class java.lang.Object

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

Constructor Detail

StochasticTopper

public StochasticTopper(int sampleSize)

StochasticTopper

public StochasticTopper(int sampleSize,
                        Long seed)

Method Detail

offer

public boolean offer(T item,
                     int incrementCount)

Description copied from interface: ITopK

offer a single element to the top and increment the count for that element by incrementCount.

Specified by:

offer in interface ITopK<T>

Parameters:

item - - the element to add to the top

incrementCount - - the increment count for the given count

Returns:

false if the element was already in the top

offer

public boolean offer(T item)

Description copied from interface: ITopK

offer a single element to the top.

Specified by:

offer in interface ITopK<T>

Parameters:

item - - the element to add to the top

Returns:

false if the element was already in the top

peek

public List<T> peek(int k)

Retrieve top k items

Specified by:

peek in interface ITopK<T>

Returns:

top k elements offered (may be an approximation)