Package org.apache.druid.segment

Class IdMapping.Builder

java.lang.Object

org.apache.druid.segment.IdMapping.Builder

Enclosing class:

IdMapping

public static class IdMapping.Builder
extends Object

Method Summary

Modifier and Type	Method	Description
void	addForwardMapping(int forwardId)	Adds a lookup for the 'forwarded' index to the current highest index value.
void	addMapping(int forwardId)	Adds a lookup for the 'forwarded' index to the current highest index value, and a reverse lookup from this substitute index back to the original.
IdMapping	build()
static IdMapping.Builder	ofCardinality(int cardinality)	Create a IdMapping where the cardinality is known, to use with addMapping(int) to simultaneously populate both forwardMapping and reverseMapping.
static IdMapping.Builder	ofUnknownCardinality()	Create an IdMapping where the cardinality is not known up front.

Methods inherited from class java.lang.Object

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

Method Detail

ofCardinality

public static IdMapping.Builder ofCardinality(int cardinality)

Create a IdMapping where the cardinality is known, to use with addMapping(int) to simultaneously populate both forwardMapping and reverseMapping.

ofUnknownCardinality

public static IdMapping.Builder ofUnknownCardinality()

Create an IdMapping where the cardinality is not known up front. Since cardinality is unknown, reverseMapping is initialized to an empty array, and addForwardMapping(int) should be used to build the forwardMapping, when build() is called reverseMapping will be computed to produce the completed IdMapping. This is less efficient than ofCardinality(int), so it should be preferred if the value cardinality is in fact known

addMapping

public void addMapping(int forwardId)

Adds a lookup for the 'forwarded' index to the current highest index value, and a reverse lookup from this substitute index back to the original. This method can only be called when cardinality is known, to ensure that reverseMapping is initialized correctly.

addForwardMapping

public void addForwardMapping(int forwardId)

Adds a lookup for the 'forwarded' index to the current highest index value. This method can only be used when the cardinality is unknown, otherwise addMapping(int) should be used instead since the reverseMapping is only computed if knownCardinality is false

build

public IdMapping build()