com.yahoo.sketches.theta

Class UpdateSketchBuilder

java.lang.Object

com.yahoo.sketches.theta.UpdateSketchBuilder

public class UpdateSketchBuilder
extends Object

For building a new UpdateSketch.

Author:

Lee Rhodes

Constructor Summary

Constructors

Constructor and Description
UpdateSketchBuilder() Constructor for building a new UpdateSketch.

Method Summary

Modifier and Type	Method and Description
UpdateSketch	build() Returns an UpdateSketch with the current configuration of this Builder.
UpdateSketch	build(int nomEntries) Returns an UpdateSketch with the current configuration of this Builder and the given Nominal Entres.
Family	getFamily() Returns the Family
int	getLgNominalEntries() Returns Log-base 2 Nominal Entries
Memory	getMemory() Returns the Destination Memory See Destination Memory.
float	getP() Returns the pre-sampling probability p
ResizeFactor	getResizeFactor() Returns the Resize Factor
long	getSeed() Returns the seed
UpdateSketchBuilder	initMemory(Memory dstMem) Initialize the specified backing destination Memory store.
UpdateSketchBuilder	setFamily(Family family) Set the Family.
UpdateSketchBuilder	setNominalEntries(int nomEntries) Sets the Nominal Entries for this sketch.
UpdateSketchBuilder	setP(float p) Sets the upfront uniform sampling probability, p
UpdateSketchBuilder	setResizeFactor(ResizeFactor rf) Sets the cache Resize Factor.
UpdateSketchBuilder	setSeed(long seed) Sets the long seed value that is required by the hashing function.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

UpdateSketchBuilder

public UpdateSketchBuilder()

Constructor for building a new UpdateSketch. The default configuration is

• Nominal Entries: 4096
• Seed: 9001L
• Resize Factor: The default for sketches on the Java heap is ResizeFactor.X8. For direct sketches, which are targeted for native memory off the Java heap, this value will be fixed at either ResizeFactor.X1 or ResizeFactor.X2.
• Family.QUICKSELECT
• Input Sampling Probability: 1.0
• Memory: null

Method Detail

setNominalEntries

public UpdateSketchBuilder setNominalEntries(int nomEntries)

Sets the Nominal Entries for this sketch. The minimum value is 16 and the maximum value is 67,108,864, which is 2^26. Be aware that sketches as large as this maximum value have not been thoroughly tested or characterized for performance.

Parameters:

nomEntries - Nominal Entres This will become the ceiling power of 2 if it is not.

Returns:

this UpdateSketchBuilder

getLgNominalEntries

public int getLgNominalEntries()

Returns Log-base 2 Nominal Entries

Returns:

Log-base 2 Nominal Entries

setSeed

public UpdateSketchBuilder setSeed(long seed)

Sets the long seed value that is required by the hashing function.

Parameters:

seed - See seed

Returns:

this UpdateSketchBuilder

getSeed

public long getSeed()

Returns the seed

Returns:

the seed

setP

public UpdateSketchBuilder setP(float p)

Sets the upfront uniform sampling probability, p

Parameters:

p - See Sampling Probability, p

Returns:

this UpdateSketchBuilder

getP

public float getP()

Returns the pre-sampling probability p

Returns:

the pre-sampling probability p

setResizeFactor

public UpdateSketchBuilder setResizeFactor(ResizeFactor rf)

Sets the cache Resize Factor.

Parameters:

rf - See Resize Factor

Returns:

this UpdateSketchBuilder

getResizeFactor

public ResizeFactor getResizeFactor()

Returns the Resize Factor

Returns:

the Resize Factor

setFamily

public UpdateSketchBuilder setFamily(Family family)

Set the Family.

Parameters:

family - the family for this builder

Returns:

this UpdateSketchBuilder

getFamily

public Family getFamily()

Returns the Family

Returns:

the Family

initMemory

public UpdateSketchBuilder initMemory(Memory dstMem)

Initialize the specified backing destination Memory store. Note: this cannot be used with the Alpha Family of sketches.

Parameters:

dstMem - The destination Memory. See Destination Memory.

Returns:

this UpdateSketchBuilder

getMemory

public Memory getMemory()

Returns the Destination Memory See Destination Memory.

Returns:

the Destination Memory

build

public UpdateSketch build()

Returns an UpdateSketch with the current configuration of this Builder.

Returns:

an UpdateSketch

build

public UpdateSketch build(int nomEntries)

Returns an UpdateSketch with the current configuration of this Builder and the given Nominal Entres.

Parameters:

nomEntries - Nominal Entres This will become the ceiling power of 2 if it is not.

Returns:

an UpdateSketch

toString

public String toString()

Overrides:

toString in class Object