com.yahoo.bullet.querying.aggregations.sketches

Class FrequentItemsSketch

java.lang.Object

com.yahoo.bullet.querying.aggregations.sketches.Sketch

com.yahoo.bullet.querying.aggregations.sketches.FrequentItemsSketch

public class FrequentItemsSketch
extends Sketch

Wraps a ItemsSketch of String.

Field Summary

Fields

Modifier and Type	Field and Description
static String	COUNT_FIELD
static String	ITEM_FIELD

Fields inherited from class com.yahoo.bullet.querying.aggregations.sketches.Sketch

provider

Constructor Summary

Constructors

Constructor and Description
FrequentItemsSketch(com.yahoo.sketches.frequencies.ErrorType type, int maxMapCapacity, int maxSize, com.yahoo.bullet.record.BulletRecordProvider provider) Creates a FrequentItemsSketch with the given ErrorType and the maximum map entries.
FrequentItemsSketch(com.yahoo.sketches.frequencies.ErrorType type, int maxMapCapacity, long threshold, int maxSize, com.yahoo.bullet.record.BulletRecordProvider provider) Creates a FrequentItemsSketch with the given ErrorType, the maximum map entries, and threshold.

Method Summary

Modifier and Type	Method and Description
protected Map<String,Object>	addMetadata(Map<String,String> conceptKeys) Adds the common metadata for this Sketch to Map.
protected String	getFamily() Returns a String representing the family of this sketch.
List<com.yahoo.bullet.record.BulletRecord>	getRecords() Collects the data presented to the sketch so far and returns the List of BulletRecord representation of the resulting data in the sketch.
Clip	getResult(String metaKey, Map<String,String> conceptKeys) Gets the result from the data presented to the sketch as a Clip.
protected Integer	getSize() Returns the size of the Sketch in bytes.
protected Boolean	isEstimationMode() Returns whether this sketch was in estimation mode or not.
void	reset() Resets the Sketch to the original state.
byte[]	serialize() Serializes the sketch.
void	union(byte[] serialized) Union a sketch serialized using Sketch.serialize() into this.
void	update(String item) Inserts an item into the Sketch.

Methods inherited from class com.yahoo.bullet.querying.aggregations.sketches.Sketch

getMetadata

Methods inherited from class java.lang.Object

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

Field Detail

ITEM_FIELD

public static final String ITEM_FIELD

See Also:

Constant Field Values

COUNT_FIELD

public static final String COUNT_FIELD

See Also:

Constant Field Values

Constructor Detail

FrequentItemsSketch

public FrequentItemsSketch(com.yahoo.sketches.frequencies.ErrorType type,
                           int maxMapCapacity,
                           long threshold,
                           int maxSize,
                           com.yahoo.bullet.record.BulletRecordProvider provider)

Creates a FrequentItemsSketch with the given ErrorType, the maximum map entries, and threshold.

Parameters:

type - The ErrorType for the Sketch.

maxMapCapacity - The maximum power of 2 entries for the Sketch used as the internal map size.

threshold - The threshold that will be used for selecting items if the Sketch error is less than it.

maxSize - The maximum size of the number of frequent items.

provider - A BulletRecordProvider to generate BulletRecords.

FrequentItemsSketch

public FrequentItemsSketch(com.yahoo.sketches.frequencies.ErrorType type,
                           int maxMapCapacity,
                           int maxSize,
                           com.yahoo.bullet.record.BulletRecordProvider provider)

Creates a FrequentItemsSketch with the given ErrorType and the maximum map entries.

Parameters:

type - The ErrorType for the Sketch.

maxMapCapacity - The maximum power of 2 entries for the Sketch used as the internal map size.

maxSize - The maximum size of the number of frequent items.

provider - A BulletRecordProvider to generate BulletRecords.

Method Detail

update

public void update(String item)

Inserts an item into the Sketch.

Parameters:

item - The String item to add to the Sketch.

union

public void union(byte[] serialized)

Description copied from class: Sketch

Union a sketch serialized using Sketch.serialize() into this.

Specified by:

union in class Sketch

Parameters:

serialized - A sketch serialized using the serialize method.

getRecords

public List<com.yahoo.bullet.record.BulletRecord> getRecords()

Description copied from class: Sketch

Collects the data presented to the sketch so far and returns the List of BulletRecord representation of the resulting data in the sketch. See Sketch.getResult(String, Map) for getting the result including the metadata and see Sketch.getMetadata(String, Map) for getting only the metadata.

Specified by:

getRecords in class Sketch

Returns:

A list of resulting records representing the result in the sketch.

serialize

public byte[] serialize()

Description copied from class: Sketch

Serializes the sketch.

Specified by:

serialize in class Sketch

Returns:

A byte[] representing the serialized sketch.

getResult

public Clip getResult(String metaKey,
                      Map<String,String> conceptKeys)

Description copied from class: Sketch

Gets the result from the data presented to the sketch as a Clip. Also adds Meta if asked for.

Overrides:

getResult in class Sketch

Parameters:

metaKey - If set to a non-null value, Sketch metadata will be added to the result.

conceptKeys - If provided, these Meta.Concept names will be added to the metadata.

Returns:

A Clip of the results.

addMetadata

protected Map<String,Object> addMetadata(Map<String,String> conceptKeys)

Description copied from class: Sketch

Adds the common metadata for this Sketch to Map.

Overrides:

addMetadata in class Sketch

Parameters:

conceptKeys - The Map of Meta.Concept names to their keys.

Returns:

The created Map of sketch metadata.

reset

public void reset()

Description copied from class: Sketch

Resets the Sketch to the original state. The old results are lost. You should call this after you call Sketch.serialize() or Sketch.getResult(String, Map) if you want to add more data to the sketch.

Specified by:

reset in class Sketch

getFamily

protected String getFamily()

Description copied from class: Sketch

Returns a String representing the family of this sketch.

Specified by:

getFamily in class Sketch

Returns:

The String family of this sketch.

isEstimationMode

protected Boolean isEstimationMode()

Description copied from class: Sketch

Returns whether this sketch was in estimation mode or not.

Specified by:

isEstimationMode in class Sketch

Returns:

A Boolean denoting whether this sketch was estimating.

getSize

protected Integer getSize()

Description copied from class: Sketch

Returns the size of the Sketch in bytes.

Specified by:

getSize in class Sketch

Returns:

An Integer representing the size of the sketch.