io.warp10.script

Class HyperLogLogPlus

java.lang.Object

io.warp10.script.HyperLogLogPlus

public class HyperLogLogPlus
extends java.lang.Object

This class implements an HyperLogLog+ cardinality estimator. It implements the HLL+ algorithm as described in the Google research paper http://research.google.com/pubs/pub40671.html

Constructor Summary

Constructors

Constructor and Description
HyperLogLogPlus(int p, int pprime)

Method Summary

Modifier and Type	Method and Description
void	aggregate(long x)
long	cardinality() Compute the estimated cardinality
static HyperLogLogPlus	fromBytes(byte[] bytes)
void	fuse(HyperLogLogPlus other) Merge estimates from another HLL+
long	getInitTime()
java.lang.String	getKey()
int	getP()
int	getPPrime()
byte	getRho(int idx)
boolean	hasExpired()
boolean	isNew(long x) Check if 'x' would modify the cardinality estimation
void	setInitTime(long instant)
void	setKey(java.lang.String key)
byte	setRho(int idx, byte rho)
byte[]	toBytes()
void	toNormal()

Methods inherited from class java.lang.Object

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

Constructor Detail

HyperLogLogPlus

public HyperLogLogPlus(int p,
                       int pprime)

Method Detail

getInitTime

public long getInitTime()

setInitTime

public void setInitTime(long instant)

hasExpired

public boolean hasExpired()

isNew

public boolean isNew(long x)

Check if 'x' would modify the cardinality estimation

aggregate

public void aggregate(long x)
               throws java.io.IOException

Throws:

java.io.IOException

cardinality

public long cardinality()
                 throws java.io.IOException

Compute the estimated cardinality

Throws:

java.io.IOException

setRho

public byte setRho(int idx,
                   byte rho)

getRho

public byte getRho(int idx)

toNormal

public void toNormal()
              throws java.io.IOException

Throws:

java.io.IOException

fuse

public void fuse(HyperLogLogPlus other)
          throws java.io.IOException

Merge estimates from another HLL+

Parameters:

other -

Throws:

java.io.IOException

toBytes

public byte[] toBytes()
               throws java.io.IOException

Throws:

java.io.IOException

fromBytes

public static HyperLogLogPlus fromBytes(byte[] bytes)
                                 throws java.io.IOException,
                                        java.lang.ClassNotFoundException

Throws:

java.io.IOException

java.lang.ClassNotFoundException

getP

public int getP()

getPPrime

public int getPPrime()

getKey

public java.lang.String getKey()

setKey

public void setKey(java.lang.String key)