com.hazelcast.jet.pipeline.WindowGroupAggregateBuilder Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2024, Hazelcast, Inc. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.hazelcast.jet.pipeline;
import com.hazelcast.jet.aggregate.AggregateOperation;
import com.hazelcast.jet.aggregate.AggregateOperation1;
import com.hazelcast.jet.aggregate.CoAggregateOperationBuilder;
import com.hazelcast.jet.datamodel.ItemsByTag;
import com.hazelcast.jet.datamodel.KeyedWindowResult;
import com.hazelcast.jet.datamodel.Tag;
import com.hazelcast.jet.impl.pipeline.GrAggBuilder;
import javax.annotation.Nonnull;
import static com.hazelcast.jet.aggregate.AggregateOperations.coAggregateOperationBuilder;
/**
* 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 {@link
* 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 {@code
* AggregateOperation}. If that's what you are looking for, go {@link
* AggregateOperation#withCreate here}.
*
* @param type of the key
* @param type of the aggregation result for stream-0
*
* @since Jet 3.0
*/
public class WindowGroupAggregateBuilder {
private final GrAggBuilder grAggBuilder;
private final CoAggregateOperationBuilder aggrOpBuilder = coAggregateOperationBuilder();
WindowGroupAggregateBuilder(
@Nonnull StageWithKeyAndWindow stage0,
@Nonnull AggregateOperation1 aggrOp0
) {
grAggBuilder = new GrAggBuilder<>(stage0);
aggrOpBuilder.add(Tag.tag0(), aggrOp0);
}
/**
* 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.
*/
@Nonnull
public Tag tag0() {
return Tag.tag0();
}
/**
* 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 {@code AggregateOperation} that
* you'll pass to {@link #build build()}.
*/
@Nonnull
public Tag add(
@Nonnull StreamStageWithKey stage,
@Nonnull AggregateOperation1 aggrOp
) {
Tag tag = grAggBuilder.add(stage);
return aggrOpBuilder.add(tag, aggrOp);
}
/**
* 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 {@code ItemsByTag}. Use the
* tags you got from this builder to access the results.
*/
@Nonnull
public StreamStage> build() {
AggregateOperation aggrOp = aggrOpBuilder.build();
return grAggBuilder.buildStream(aggrOp);
}
}