com.hazelcast.jet.core.function.KeyedWindowResultFunction Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2021, 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.core.function;
import com.hazelcast.jet.core.processor.Processors;
import com.hazelcast.jet.pipeline.WindowDefinition;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import java.io.Serializable;
/**
* Represents the function you pass to windowing processors
* such as {@link Processors#aggregateToSlidingWindowP aggregateToSlidingWindowP()}
* and {@link Processors#aggregateToSessionWindowP aggregateToSessionWindowP()} as
* {@code mapToOutputFn}.
* It creates the item to emit based on the results of a single aggregate
* operation performed for a particular window and a particular grouping
* key.
*
* @param type of the key
* @param the type of aggregation result this function receives
* @param the type of the output item this function returns
*
* @since Jet 3.0
*/
@FunctionalInterface
public interface KeyedWindowResultFunction extends Serializable {
/**
* Applies the function to the given arguments
*
* @param winStart the inclusive lower timestamp of the window
* @param winEnd the exclusive upper timestamp of the window
* @param key the grouping key
* @param windowResult the result of the aggregate operation
* @param isEarly whether the result is an early result as specified by
* {@link WindowDefinition#setEarlyResultsPeriod(long)}
* @return the function result
*/
@Nullable
OUT apply(long winStart, long winEnd, @Nonnull K key, @Nonnull R windowResult, boolean isEarly);
}