com.hazelcast.jet.pipeline

Class GroupAggregateBuilder1<T0,K>

java.lang.Object

com.hazelcast.jet.pipeline.GroupAggregateBuilder1<T0,K>

Type Parameters:

T0 - type of the stream-0 item

K - type of the grouping key

public class GroupAggregateBuilder1<T0,K>
extends Object

Offers a step-by-step API to build a pipeline stage that co-groups and aggregates the data from several input stages. To obtain it, call BatchStageWithKey.aggregateBuilder() on one of the stages to co-group and refer to that method's Javadoc for further details.

Note: this is not a builder of AggregateOperation. If that' s what you are looking for, go here.

Method Summary

Modifier and Type	Method and Description
<T> Tag<T>	add(BatchStageWithKey<T,K> stage) Adds another stage that will contribute its data to the aggregate operation to be performed.
<R> BatchStage<Map.Entry<K,R>>	build(AggregateOperation<?,R> aggrOp) Convenience for build(aggrOp, mapToOutputFn) which emits Map.Entrys as output.
<R,OUT> BatchStage<OUT>	build(AggregateOperation<?,R> aggrOp, DistributedBiFunction<? super K,? super R,OUT> mapToOutputFn) Creates and returns a pipeline stage that performs the co-grouping and aggregation of pipeline stages registered with this builder object.
Tag<T0>	tag0() Returns the tag corresponding to the pipeline stage this builder was obtained from.

Methods inherited from class java.lang.Object

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

Method Detail

tag0

@Nonnull
public Tag<T0> tag0()

Returns the tag corresponding to the pipeline stage this builder was obtained from. Use this tag to refer to this stage when building the AggregateOperation that you'll pass to build(aggrOp).

add

@Nonnull
public <T> Tag<T> add(@Nonnull
                               BatchStageWithKey<T,K> stage)

Adds another stage that will contribute its data to the aggregate operation to be performed. Returns the tag you'll use to refer to this stage when building the AggregateOperation that you'll pass to build().

build

@Nonnull
public <R,OUT> BatchStage<OUT> build(@Nonnull
                                              AggregateOperation<?,R> aggrOp,
                                              @Nonnull
                                              DistributedBiFunction<? super K,? super R,OUT> mapToOutputFn)

Creates and returns a pipeline stage that performs the co-grouping and aggregation of pipeline stages registered with this builder object. The tags you register with the aggregate operation must match the tags you registered with this builder.

Type Parameters:

R - the type of the output item

Parameters:

aggrOp - the aggregate operation to perform

Returns:

a new stage representing the co-aggregation

build

@Nonnull
public <R> BatchStage<Map.Entry<K,R>> build(@Nonnull
                                                     AggregateOperation<?,R> aggrOp)

Convenience for build(aggrOp, mapToOutputFn) which emits Map.Entrys as output.

Type Parameters:

R - the type of the aggregation result

Parameters:

aggrOp - the aggregate operation to perform.

Returns:

a new stage representing the co-group-and-aggregate operation