com.hazelcast.jet.datamodel

Class BagsByTag

java.lang.Object

com.hazelcast.jet.datamodel.BagsByTag

public class BagsByTag
extends Object

A heterogeneous map from Tag<E> to Collection<E>, where E can be different for each tag. Useful as a container of co-grouped items, where each tag corresponds to one contributing pipeline pipeline.

This is a less type-safe, but more flexible alternative to the TwoBags and ThreeBags containers, which have a fixed (and limited) number of integer-indexed, statically-typed fields. BagsByTag has a variable number of tag-indexed fields whose whose static type is encoded in the tags.

Constructor Summary

Constructors

Constructor and Description
BagsByTag()

Method Summary

Modifier and Type	Method and Description
<E> Collection<E>	bag(Tag<E> tag) Retrieves the bag associated with the supplied tag.
static BagsByTag	bagsByTag(Object... tagsAndBags) Accepts an argument list of alternating tags and collections, interprets them as a list of tag-bag pairs, and returns a BagsByTag populated with these pairs.
void	combineWith(BagsByTag that) Merges the contents of the supplied bag container into this one.
<E> Collection<E>	ensureBag(Tag<E> tag) Ensures that there is a mapping from the supplied tag to a bag, creating an empty one if necessary.
boolean	equals(Object o)
BagsByTag	finish() Returns a safe copy of this container.
int	hashCode()
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

BagsByTag

public BagsByTag()

Method Detail

bagsByTag

@Nonnull
public static BagsByTag bagsByTag(@Nonnull
                                           Object... tagsAndBags)

Accepts an argument list of alternating tags and collections, interprets them as a list of tag-bag pairs, and returns a BagsByTag populated with these pairs. Doesn't retain the supplied collections, but copies them into newly created ones.

bag

@Nonnull
public <E> Collection<E> bag(@Nonnull
                                      Tag<E> tag)

Retrieves the bag associated with the supplied tag. Throws IllegalArgumentException if there is none.

Type Parameters:

E - the type of items in the returned bag

Parameters:

tag - the lookup tag

Returns:

the associated bag

Throws:

IllegalArgumentException - if there is no bag associated with the tag

ensureBag

@Nonnull
public <E> Collection<E> ensureBag(@Nonnull
                                            Tag<E> tag)

Ensures that there is a mapping from the supplied tag to a bag, creating an empty one if necessary. Returns the bag.

Type Parameters:

E - the type of items in the returned bag

Parameters:

tag - the lookup tag

combineWith

public void combineWith(@Nonnull
                        BagsByTag that)

Merges the contents of the supplied bag container into this one. If both containers have a mapping for a given tag, appends the supplied container's items to the bag in this container; otherwise establishes a new mapping in this container to a copy of the supplied container's bag.

Does not modify the supplied container.

Parameters:

that - the container to combine with this one.

finish

public BagsByTag finish()

Returns a safe copy of this container.

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