com.hazelcast.jet.pipeline

Class WindowGroupAggregateBuilder<K,R0>

java.lang.Object

com.hazelcast.jet.pipeline.WindowGroupAggregateBuilder<K,R0>

Type Parameters:

K - type of the key

R0 - type of the aggregation result for stream-0

public class WindowGroupAggregateBuilder<K,R0>
extends Object

Offers a step-by-step API to build a pipeline stage that performs a windowed co-grouping and aggregation of the data from several input stages. To obtain it, call StageWithKeyAndWindow.aggregateBuilder() on one of the stages to co-aggregate 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.

Since:

Jet 3.0

Method Summary

Modifier and Type	Method and Description
<T,R> Tag<R>	add(StreamStageWithKey<T,K> stage, AggregateOperation1<? super T,?,? extends R> aggrOp) Adds another stage that will contribute its data to the windowed group-and-aggregate stage being constructed.
StreamStage<KeyedWindowResult<K,ItemsByTag>>	build() Creates and returns a pipeline stage that performs a windowed cogroup-and-aggregate operation on the stages registered with this builder object.
Tag<R0>	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<R0> tag0()

Returns the tag corresponding to the pipeline stage this builder was obtained from. Use this tag to refer to this stage when extracting the results from the aggregated stage.

add

@Nonnull
public <T,R> Tag<R> add(@Nonnull
                                 StreamStageWithKey<T,K> stage,
                                 @Nonnull
                                 AggregateOperation1<? super T,?,? extends R> aggrOp)

Adds another stage that will contribute its data to the windowed group-and-aggregate stage being constructed. Returns the tag you'll use to refer to this stage when building the AggregateOperation that you'll pass to build().

build

@Nonnull
public StreamStage<KeyedWindowResult<K,ItemsByTag>> build()

Creates and returns a pipeline stage that performs a windowed cogroup-and-aggregate operation on the stages registered with this builder object. The composite aggregate operation places the results of the individual aggregate operations in an ItemsByTag. Use the tags you got from this builder to access the results.