com.yahoo.sketches.tuple

Class CompactSketch<S extends Summary>

java.lang.Object

com.yahoo.sketches.tuple.Sketch<S>

com.yahoo.sketches.tuple.CompactSketch<S>

Type Parameters:

S - type of Summary

public class CompactSketch<S extends Summary>
extends Sketch<S>

CompactSketches are never created directly. They are created as a result of the compact() method of an UpdatableSketch or as a result of the getResult() method of a set operation like Union, Intersection or AnotB. CompactSketch consists of a compact list (i.e. no intervening spaces) of hash values, corresponding list of Summaries, and a value for theta. The lists may or may not be ordered. CompactSketch is read-only.

Field Summary

Fields inherited from class com.yahoo.sketches.tuple.Sketch

PREAMBLE_LONGS

Method Summary

Modifier and Type	Method and Description
int	getRetainedEntries()
S[]	getSummaries()
byte[]	toByteArray() This is to serialize an instance to a byte array.

Methods inherited from class com.yahoo.sketches.tuple.Sketch

getEstimate, getLowerBound, getTheta, getUpperBound, isEmpty, isEstimationMode, iterator

Methods inherited from class java.lang.Object

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

Method Detail

getSummaries

public S[] getSummaries()

Specified by:

getSummaries in class Sketch<S extends Summary>

Returns:

an array of Summary objects from the sketch

getRetainedEntries

public int getRetainedEntries()

Specified by:

getRetainedEntries in class Sketch<S extends Summary>

Returns:

number of retained entries

toByteArray

public byte[] toByteArray()

Description copied from class: Sketch

This is to serialize an instance to a byte array. For deserialization there must be a constructor, which takes a Memory object

Specified by:

toByteArray in class Sketch<S extends Summary>

Returns:

serialized representation of the sketch