Package com.hazelcast.jet.aggregate

Class CoAggregateOperationBuilder

java.lang.Object

com.hazelcast.jet.aggregate.CoAggregateOperationBuilder

public class CoAggregateOperationBuilder
extends Object

Offers a step-by-step API to create an aggregate operation that accepts multiple inputs. To obtain it, call AggregateOperations.coAggregateOperationBuilder(). and refer to that method's Javadoc for further details.

Since:

Jet 3.0

Method Summary

Modifier and Type	Method	Description
<T, R> Tag<R>	add(Tag<T> tag, AggregateOperation1<? super T,?,? extends R> operation)	Registers the given aggregate operation with the tag corresponding to an input to the co-aggregating operation being built.
AggregateOperation<Object[],ItemsByTag>	build()	Builds and returns the AggregateOperation.
<R> AggregateOperation<Object[],R>	build(FunctionEx<? super ItemsByTag,? extends R> exportFinishFn)	Builds and returns the multi-input AggregateOperation.

Methods inherited from class java.lang.Object

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

Method Details

add

@Nonnull
public <T,
R> Tag<R> add(@Nonnull
 Tag<T> tag,
 @Nonnull
 AggregateOperation1<? super T,?,? extends R> operation)

Registers the given aggregate operation with the tag corresponding to an input to the co-aggregating operation being built. If you are preparing an operation to pass to an aggregate builder, you must use the tags you obtained from it.

Returns the tag you'll use to retrieve the results of aggregating this input.

Type Parameters:

T - type of this operation's input

R - the result type of this operation

Returns:

the result tag

build

@Nonnull
public AggregateOperation<Object[],ItemsByTag> build()

Builds and returns the AggregateOperation. Its result type is ItemsByTag containing all the tags you got from the add(com.hazelcast.jet.datamodel.Tag<T>, com.hazelcast.jet.aggregate.AggregateOperation1<? super T, ?, ? extends R>) method.

build

@Nonnull
public <R> AggregateOperation<Object[],R> build(@Nonnull
 FunctionEx<? super ItemsByTag,? extends R> exportFinishFn)

Builds and returns the multi-input AggregateOperation. It will call the supplied exportFinishFn to transform the ItemsByTag it creates to the result type it emits as the actual result.

Parameters:

exportFinishFn - function to convert ItemsByTag to the target result type. It must be stateless and cooperative.