com.codahale.metrics

Class UniformReservoir

java.lang.Object

com.codahale.metrics.UniformReservoir

All Implemented Interfaces:

Reservoir

public class UniformReservoir
extends Object
implements Reservoir

A random sampling reservoir of a stream of longs. Uses Vitter's Algorithm R to produce a statistically representative sample.

See Also:

Random Sampling with a Reservoir

Constructor Summary

Constructors

Constructor and Description
UniformReservoir() Creates a new UniformReservoir of 1028 elements, which offers a 99.9% confidence level with a 5% margin of error assuming a normal distribution.
UniformReservoir(int size) Creates a new UniformReservoir.

Method Summary

Modifier and Type	Method and Description
Snapshot	getSnapshot() Returns a snapshot of the reservoir's values.
int	size() Returns the number of values recorded.
void	update(long value) Adds a new recorded value to the reservoir.

Methods inherited from class java.lang.Object

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

Constructor Detail

UniformReservoir

public UniformReservoir()

Creates a new UniformReservoir of 1028 elements, which offers a 99.9% confidence level with a 5% margin of error assuming a normal distribution.

UniformReservoir

public UniformReservoir(int size)

Creates a new UniformReservoir.

Parameters:

size - the number of samples to keep in the sampling reservoir

Method Detail

size

public int size()

Description copied from interface: Reservoir

Returns the number of values recorded.

Specified by:

size in interface Reservoir

Returns:

the number of values recorded

update

public void update(long value)

Description copied from interface: Reservoir

Adds a new recorded value to the reservoir.

Specified by:

update in interface Reservoir

Parameters:

value - a new recorded value

getSnapshot

public Snapshot getSnapshot()

Description copied from interface: Reservoir

Returns a snapshot of the reservoir's values.

Specified by:

getSnapshot in interface Reservoir

Returns:

a snapshot of the reservoir's values