net.agkn.hll.serialization

Class HLLMetadata

java.lang.Object

net.agkn.hll.serialization.HLLMetadata

All Implemented Interfaces:

IHLLMetadata

public class HLLMetadata
extends Object
implements IHLLMetadata

A concrete IHLLMetadata implemented as a simple struct.

Author:

timon

Constructor Summary

Constructors

Constructor and Description
HLLMetadata(int schemaVersion, HLLType type, int registerCountLog2, int registerWidth, int log2ExplicitCutoff, boolean explicitOff, boolean explicitAuto, boolean sparseEnabled)

Method Summary

Methods

Modifier and Type	Method and Description
boolean	explicitAuto()
boolean	explicitOff()
HLLType	HLLType()
int	log2ExplicitCutoff()
int	registerCountLog2()
int	registerWidth()
int	schemaVersion()
boolean	sparseEnabled()
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

HLLMetadata

public HLLMetadata(int schemaVersion,
           HLLType type,
           int registerCountLog2,
           int registerWidth,
           int log2ExplicitCutoff,
           boolean explicitOff,
           boolean explicitAuto,
           boolean sparseEnabled)

Parameters:

schemaVersion - the schema version number of the HLL. This must be greater than or equal to zero.

type - the type of the HLL. This cannot be null.

registerCountLog2 - the log-base-2 register count parameter for probabilistic HLLs. This must be greater than or equal to zero.

registerWidth - the register width parameter for probabilistic HLLs. This must be greater than or equal to zero.

log2ExplicitCutoff - the log-base-2 of the explicit cardinality cutoff, if it is explicitly defined. (If explicitOff or explicitAuto is true then this has no meaning.)

explicitOff - the flag for 'explicit off'-mode, where the HLLType.EXPLICIT representation is not used. Both this and explicitAuto cannot be true at the same time.

explicitAuto - the flag for 'explicit auto'-mode, where the HLLType.EXPLICIT representation's promotion cutoff is determined based on in-memory size automatically. Both this and explicitOff cannot be true at the same time.

sparseEnabled - the flag for 'sparse-enabled'-mode, where the HLLType.SPARSE representation is used.

Method Detail

schemaVersion

public int schemaVersion()

Specified by:

schemaVersion in interface IHLLMetadata

Returns:

the schema version of the HLL. This will never be null.

HLLType

public HLLType HLLType()

Specified by:

HLLType in interface IHLLMetadata

Returns:

the type of the HLL. This will never be null.

registerCountLog2

public int registerCountLog2()

Specified by:

registerCountLog2 in interface IHLLMetadata

Returns:

the log-base-2 of the register count parameter of the HLL. This will always be greater than or equal to 4 and less than or equal to 31.

registerWidth

public int registerWidth()

Specified by:

registerWidth in interface IHLLMetadata

Returns:

the register width parameter of the HLL. This will always be greater than or equal to 1 and less than or equal to 8.

log2ExplicitCutoff

public int log2ExplicitCutoff()

Specified by:

log2ExplicitCutoff in interface IHLLMetadata

Returns:

the log-base-2 of the explicit cutoff cardinality. This will always be greater than or equal to zero and less than 31, per the specification.

explicitOff

public boolean explicitOff()

Specified by:

explicitOff in interface IHLLMetadata

Returns:

true if the HLLType.EXPLICIT representation has been disabled. false otherwise.

explicitAuto

public boolean explicitAuto()

Specified by:

explicitAuto in interface IHLLMetadata

Returns:

true if the HLLType.EXPLICIT representation cutoff cardinality is set to be automatically chosen, false otherwise.

sparseEnabled

public boolean sparseEnabled()

Specified by:

sparseEnabled in interface IHLLMetadata

Returns:

true if the HLLType.SPARSE representation is enabled.

toString

public String toString()

Overrides:

toString in class Object