Package org.apache.datasketches.tuple.strings

Class ArrayOfStringsSketch

java.lang.Object

org.apache.datasketches.tuple.Sketch<S>

org.apache.datasketches.tuple.UpdatableSketch<String[],ArrayOfStringsSummary>

org.apache.datasketches.tuple.strings.ArrayOfStringsSketch

Direct Known Subclasses:

FdtSketch

public class ArrayOfStringsSketch
extends UpdatableSketch<String[],ArrayOfStringsSummary>

Author:

Lee Rhodes

Field Summary

Fields inherited from class org.apache.datasketches.tuple.Sketch

PREAMBLE_LONGS, summaryFactory_

Constructor Summary

Constructors

Constructor	Description
ArrayOfStringsSketch()	Constructs new sketch with default K = 4096 (lgK = 12), default ResizeFactor=X8, and default p = 1.0.
ArrayOfStringsSketch(int lgK)	Constructs new sketch with default ResizeFactor=X8, default p = 1.0 and given lgK.
ArrayOfStringsSketch(int lgK, ResizeFactor rf, float p)	Constructs new sketch with given ResizeFactor, p and lgK.
ArrayOfStringsSketch(org.apache.datasketches.memory.Memory mem)	Deprecated. As of 3.0.0, heapifying an UpdatableSketch is deprecated.
ArrayOfStringsSketch(ArrayOfStringsSketch sketch)	Copy Constructor

Method Summary

Modifier and Type	Method	Description
CompactSketch<S>	compact()	Converts the current state of the sketch into a compact sketch
ArrayOfStringsSketch	copy()
int	getCountLessThanThetaLong(long thetaLong)	Gets the number of hash values less than the given theta expressed as a long.
int	getCurrentCapacity()	Get current capacity
int	getLgK()	Get log_base2 of Nominal Entries
int	getNominalEntries()	Get configured nominal number of entries
ResizeFactor	getResizeFactor()	Get configured resize factor
int	getRetainedEntries()
float	getSamplingProbability()	Get configured sampling probability
protected void	insertSummary(int index, S summary)
TupleSketchIterator<S>	iterator()	Returns a SketchIterator
void	reset()	Resets this sketch an empty state.
byte[]	toByteArray()	Deprecated. As of 3.0.0, serializing an UpdatableSketch is deprecated.
void	trim()	Rebuilds reducing the actual number of entries to the nominal number of entries if needed
void	update(String[] strArrKey, String[] strArr)	Updates the sketch with String arrays for both key and value.

Methods inherited from class org.apache.datasketches.tuple.UpdatableSketch

update, update, update, update, update, update

Methods inherited from class org.apache.datasketches.tuple.Sketch

getEstimate, getEstimate, getLowerBound, getLowerBound, getSummaryFactory, getTheta, getThetaLong, getUpperBound, getUpperBound, isEmpty, isEstimationMode, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

ArrayOfStringsSketch

public ArrayOfStringsSketch()

Constructs new sketch with default K = 4096 (lgK = 12), default ResizeFactor=X8, and default p = 1.0.

ArrayOfStringsSketch

public ArrayOfStringsSketch(int lgK)

Constructs new sketch with default ResizeFactor=X8, default p = 1.0 and given lgK.

Parameters:

lgK - Log_base2 of Nominal Entries. See Nominal Entries

ArrayOfStringsSketch

public ArrayOfStringsSketch(int lgK,
                            ResizeFactor rf,
                            float p)

Constructs new sketch with given ResizeFactor, p and lgK.

Parameters:

lgK - Log_base2 of Nominal Entries. See Nominal Entries

rf - ResizeFactor See Resize Factor

p - sampling probability See Sampling Probability

ArrayOfStringsSketch

@Deprecated
public ArrayOfStringsSketch(org.apache.datasketches.memory.Memory mem)

Deprecated.

As of 3.0.0, heapifying an UpdatableSketch is deprecated. This capability will be removed in a future release. Heapifying a CompactSketch is not deprecated.

Constructs this sketch from a Memory image, which must be from an ArrayOfStringsSketch, and usually with data.

Parameters:

mem - the given Memory

ArrayOfStringsSketch

public ArrayOfStringsSketch(ArrayOfStringsSketch sketch)

Copy Constructor

Parameters:

sketch - the sketch to copy

Method Detail

copy

public ArrayOfStringsSketch copy()

Overrides:

copy in class UpdatableSketch<String[],ArrayOfStringsSummary>

Returns:

a deep copy of this sketch

update

public void update(String[] strArrKey,
                   String[] strArr)

Updates the sketch with String arrays for both key and value.

Parameters:

strArrKey - the given String array key

strArr - the given String array value

getRetainedEntries

public int getRetainedEntries()

Specified by:

getRetainedEntries in class Sketch<S extends Summary>

Returns:

number of retained entries

getCountLessThanThetaLong

public int getCountLessThanThetaLong(long thetaLong)

Description copied from class: Sketch

Gets the number of hash values less than the given theta expressed as a long.

Specified by:

getCountLessThanThetaLong in class Sketch<S extends Summary>

Parameters:

thetaLong - the given theta as a long between zero and Long.MAX_VALUE.

Returns:

the number of hash values less than the given thetaLong.

getNominalEntries

public int getNominalEntries()

Get configured nominal number of entries

Returns:

nominal number of entries

getLgK

public int getLgK()

Get log_base2 of Nominal Entries

Returns:

log_base2 of Nominal Entries

getSamplingProbability

public float getSamplingProbability()

Get configured sampling probability

Returns:

sampling probability

getCurrentCapacity

public int getCurrentCapacity()

Get current capacity

Returns:

current capacity

getResizeFactor

public ResizeFactor getResizeFactor()

Get configured resize factor

Returns:

resize factor

trim

public void trim()

Rebuilds reducing the actual number of entries to the nominal number of entries if needed

reset

public void reset()

Resets this sketch an empty state.

compact

public CompactSketch<S> compact()

Converts the current state of the sketch into a compact sketch

Specified by:

compact in class Sketch<S extends Summary>

Returns:

compact sketch

toByteArray

@Deprecated
public byte[] toByteArray()

Deprecated.

As of 3.0.0, serializing an UpdatableSketch is deprecated. This capability will be removed in a future release. Serializing a CompactSketch is not deprecated.

This serializes an UpdatableSketch (QuickSelectSketch).

Specified by:

toByteArray in class Sketch<S extends Summary>

Returns:

serialized representation of an UpdatableSketch (QuickSelectSketch).

insertSummary

protected void insertSummary(int index,
                             S summary)

iterator

public TupleSketchIterator<S> iterator()

Description copied from class: Sketch

Returns a SketchIterator

Specified by:

iterator in class Sketch<S extends Summary>

Returns:

a SketchIterator