Package org.openrefine.runners.local.pll.partitioning

Class RangePartitioner<T>

java.lang.Object

org.openrefine.runners.local.pll.partitioning.RangePartitioner<T>

All Implemented Interfaces:

Partitioner<T>

Direct Known Subclasses:

LongRangePartitioner

public class RangePartitioner<T>
extends Object
implements Partitioner<T>

A partitioner which assumes that the keys are sorted in increasing order.

Author:

Antonin Delpeuch

Field Summary

Fields

Modifier and Type	Field	Description
protected Comparator<T>	comparator
protected List<T>	firstKeys
protected int	numPartitions

Constructor Summary

Constructors

Constructor	Description
RangePartitioner(int nbPartitions, List<T> firstKeys, Comparator<T> comparator)	Constructs a partitioner by supplying the first key value in each partition but the first one.

Method Summary

Modifier and Type	Method	Description
Comparator<T>	getComparator()
List<Optional<T>>	getFirstKeys()	List of (n-1) values, where n is the number of partitions.
int	getPartition(T key)	Retrieves the partition id given a key.
int	numPartitions()	Returns the number of partitions assumed by this partitioner.

Methods inherited from class java.lang.Object

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

Field Detail

numPartitions

protected final int numPartitions

firstKeys

protected final List<T> firstKeys

comparator

protected final Comparator<T> comparator

Constructor Detail

RangePartitioner

public RangePartitioner(int nbPartitions,
                        List<T> firstKeys,
                        Comparator<T> comparator)

Constructs a partitioner by supplying the first key value in each partition but the first one.

Parameters:

nbPartitions - the number of partitions of the PLL this partitioner is built for

firstKeys - list of (n-1) values, where n is the number of partitions. The first element of the list is the first key value in the second partition. If a partition is empty, null is used.

comparator - the comparator used to compare the keys

Method Detail

getPartition

public int getPartition(T key)

Description copied from interface: Partitioner

Retrieves the partition id given a key.

Specified by:

getPartition in interface Partitioner<T>

Returns:

numPartitions

public int numPartitions()

Description copied from interface: Partitioner

Returns the number of partitions assumed by this partitioner.

Specified by:

numPartitions in interface Partitioner<T>

getFirstKeys

public List<Optional<T>> getFirstKeys()

List of (n-1) values, where n is the number of partitions. The first element of the list is the first key value in the second partition. If a partition is empty, no value is returned.

getComparator

public Comparator<T> getComparator()