org.apache.flink.runtime.state

Class KeyGroupRange

java.lang.Object

org.apache.flink.runtime.state.KeyGroupRange

All Implemented Interfaces:

Serializable, Iterable<Integer>, KeyGroupsList

public class KeyGroupRange
extends Object
implements KeyGroupsList, Serializable

This class defines a range of key-group indexes. Key-groups are the granularity into which the keyspace of a job is partitioned for keyed state-handling in state backends. The boundaries of the range are inclusive.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static KeyGroupRange	EMPTY_KEY_GROUP_RANGE The empty key-group

Constructor Summary

Constructors

Constructor and Description
KeyGroupRange(int startKeyGroup, int endKeyGroup) Defines the range [startKeyGroup, endKeyGroup]

Method Summary

Methods

Modifier and Type	Method and Description
boolean	contains(int keyGroup) Checks whether or not a single key-group is contained in the range.
boolean	equals(Object o)
int	getEndKeyGroup()
KeyGroupRange	getIntersection(KeyGroupRange other) Create a range that represent the intersection between this range and the given range.
int	getKeyGroupId(int idx) Returns the id of the keygroup at the given index, where index in interval [0, KeyGroupsList.getNumberOfKeyGroups()[.
int	getNumberOfKeyGroups() Returns the number of key group ids in the list.
int	getStartKeyGroup()
int	hashCode()
Iterator<Integer>	iterator()
static KeyGroupRange	of(int startKeyGroup, int endKeyGroup) Factory method that also handles creation of empty key-groups.
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

EMPTY_KEY_GROUP_RANGE

public static final KeyGroupRange EMPTY_KEY_GROUP_RANGE

The empty key-group

Constructor Detail

KeyGroupRange

public KeyGroupRange(int startKeyGroup,
             int endKeyGroup)

Defines the range [startKeyGroup, endKeyGroup]

Parameters:

startKeyGroup - start of the range (inclusive)

endKeyGroup - end of the range (inclusive)

Method Detail

contains

public boolean contains(int keyGroup)

Checks whether or not a single key-group is contained in the range.

Specified by:

contains in interface KeyGroupsList

Parameters:

keyGroup - Key-group to check for inclusion.

Returns:

True, only if the key-group is in the range.

getIntersection

public KeyGroupRange getIntersection(KeyGroupRange other)

Create a range that represent the intersection between this range and the given range.

Parameters:

other - A KeyGroupRange to intersect.

Returns:

Key-group range that is the intersection between this and the given key-group range.

getNumberOfKeyGroups

public int getNumberOfKeyGroups()

Description copied from interface: KeyGroupsList

Returns the number of key group ids in the list.

Specified by:

getNumberOfKeyGroups in interface KeyGroupsList

Returns:

The number of key-groups in the range

getStartKeyGroup

public int getStartKeyGroup()

Returns:

The first key-group in the range.

getEndKeyGroup

public int getEndKeyGroup()

Returns:

The last key-group in the range.

getKeyGroupId

public int getKeyGroupId(int idx)

Description copied from interface: KeyGroupsList

Returns the id of the keygroup at the given index, where index in interval [0, KeyGroupsList.getNumberOfKeyGroups()[.

Specified by:

getKeyGroupId in interface KeyGroupsList

Parameters:

idx - the index into the list

Returns:

key group id at the given index

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object

iterator

public Iterator<Integer> iterator()

Specified by:

iterator in interface Iterable<Integer>

of

public static KeyGroupRange of(int startKeyGroup,
               int endKeyGroup)

Factory method that also handles creation of empty key-groups.

Parameters:

startKeyGroup - start of the range (inclusive)

endKeyGroup - end of the range (inclusive)

Returns:

the key-group from start to end or an empty key-group range.