Package org.apache.flink.api.common.operators

Class Ordering

java.lang.Object

org.apache.flink.api.common.operators.Ordering

All Implemented Interfaces:

Cloneable

@Internal
public class Ordering
extends Object
implements Cloneable

This class represents an ordering on a set of fields. It specifies the fields and order direction (ascending, descending).

Field Summary

Fields

Modifier and Type	Field	Description
protected FieldList	indexes
protected ArrayList<Order>	orders
protected ArrayList<Class<? extends Comparable<?>>>	types

Constructor Summary

Constructors

Constructor	Description
Ordering()	Creates an empty ordering.
Ordering(int index, Class<? extends Comparable<?>> type, Order order)

Method Summary

Modifier and Type	Method	Description
Ordering	appendOrdering(Integer index, Class<? extends Comparable<?>> type, Order order)	Extends this ordering by appending an additional order requirement.
Ordering	clone()
Ordering	createNewOrderingUpToIndex(int exclusiveIndex)	Creates a new ordering the represents an ordering on a prefix of the fields.
boolean	equals(Object obj)
Integer	getFieldNumber(int index)
Order[]	getFieldOrders()
int[]	getFieldPositions()
boolean[]	getFieldSortDirections()
FieldList	getInvolvedIndexes()
int	getNumberOfFields()
Order	getOrder(int index)
Class<? extends Comparable<?>>	getType(int index)
Class<? extends Comparable<?>>[]	getTypes()
boolean	groupsFields(FieldSet fields)
int	hashCode()
boolean	isMetBy(Ordering otherOrdering)
boolean	isOrderEqualOnFirstNFields(Ordering other, int n)
String	toString()

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

indexes

protected FieldList indexes

types

protected final ArrayList<Class<? extends Comparable<?>>> types

orders

protected final ArrayList<Order> orders

Constructor Detail

Ordering

public Ordering()

Creates an empty ordering.

Ordering

public Ordering(int index,
                Class<? extends Comparable<?>> type,
                Order order)

Parameters:

index -

type -

order -

Method Detail

appendOrdering

public Ordering appendOrdering(Integer index,
                               Class<? extends Comparable<?>> type,
                               Order order)

Extends this ordering by appending an additional order requirement. If the index has been previously appended then the unmodified Ordering is returned.

Parameters:

index - Field index of the appended order requirement.

type - Type of the appended order requirement.

order - Order of the appended order requirement.

Returns:

This ordering with an additional appended order requirement.

getNumberOfFields

public int getNumberOfFields()

getInvolvedIndexes

public FieldList getInvolvedIndexes()

getFieldNumber

public Integer getFieldNumber(int index)

getType

public Class<? extends Comparable<?>> getType(int index)

getOrder

public Order getOrder(int index)

getTypes

public Class<? extends Comparable<?>>[] getTypes()

getFieldPositions

public int[] getFieldPositions()

getFieldOrders

public Order[] getFieldOrders()

getFieldSortDirections

public boolean[] getFieldSortDirections()

isMetBy

public boolean isMetBy(Ordering otherOrdering)

isOrderEqualOnFirstNFields

public boolean isOrderEqualOnFirstNFields(Ordering other,
                                          int n)

createNewOrderingUpToIndex

public Ordering createNewOrderingUpToIndex(int exclusiveIndex)

Creates a new ordering the represents an ordering on a prefix of the fields. If the exclusive index up to which to create the ordering is 0, then there is no resulting ordering and this method return null.

Parameters:

exclusiveIndex - The index (exclusive) up to which to create the ordering.

Returns:

The new ordering on the prefix of the fields, or null, if the prefix is empty.

groupsFields

public boolean groupsFields(FieldSet fields)

clone

public Ordering clone()

Overrides:

clone in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

toString

public String toString()

Overrides:

toString in class Object