org.apache.kafka.streams.kstream.internals.SessionWindowedKStreamImpl Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of kafka-streams Show documentation
The newest version!
/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.kafka.streams.kstream.internals;

import org.apache.kafka.common.serialization.Serde;
import org.apache.kafka.common.serialization.Serdes;
import org.apache.kafka.common.utils.Bytes;
import org.apache.kafka.streams.kstream.Aggregator;
import org.apache.kafka.streams.kstream.EmitStrategy;
import org.apache.kafka.streams.kstream.Initializer;
import org.apache.kafka.streams.kstream.KTable;
import org.apache.kafka.streams.kstream.Materialized;
import org.apache.kafka.streams.kstream.Merger;
import org.apache.kafka.streams.kstream.Named;
import org.apache.kafka.streams.kstream.Reducer;
import org.apache.kafka.streams.kstream.SessionWindowedKStream;
import org.apache.kafka.streams.kstream.SessionWindows;
import org.apache.kafka.streams.kstream.Windowed;
import org.apache.kafka.streams.kstream.WindowedSerdes;
import org.apache.kafka.streams.kstream.internals.graph.GraphNode;
import org.apache.kafka.streams.state.SessionStore;

import java.util.Objects;
import java.util.Set;

import static org.apache.kafka.streams.kstream.internals.KGroupedStreamImpl.AGGREGATE_NAME;
import static org.apache.kafka.streams.kstream.internals.KGroupedStreamImpl.REDUCE_NAME;

public class SessionWindowedKStreamImpl extends AbstractStream implements SessionWindowedKStream {
    private final SessionWindows windows;
    private final GroupedStreamAggregateBuilder aggregateBuilder;
    private final Merger countMerger = (aggKey, aggOne, aggTwo) -> aggOne + aggTwo;

    private EmitStrategy emitStrategy = EmitStrategy.onWindowUpdate();

    SessionWindowedKStreamImpl(final SessionWindows windows,
                               final InternalStreamsBuilder builder,
                               final Set subTopologySourceNodes,
                               final String name,
                               final Serde keySerde,
                               final Serde valueSerde,
                               final GroupedStreamAggregateBuilder aggregateBuilder,
                               final GraphNode graphNode) {
        super(name, keySerde, valueSerde, subTopologySourceNodes, graphNode, builder);
        Objects.requireNonNull(windows, "windows can't be null");
        this.windows = windows;
        this.aggregateBuilder = aggregateBuilder;
    }

    @Override
    public KTable, Long> count() {
        return count(NamedInternal.empty());
    }

    @Override
    public KTable, Long> count(final Named named) {
        return doCount(named, Materialized.with(keySerde, Serdes.Long()));
    }

    @Override
    public KTable, Long> count(final Materialized> materialized) {
        return count(NamedInternal.empty(), materialized);
    }

    @Override
    public KTable, Long> count(final Named named, final Materialized> materialized) {
        Objects.requireNonNull(materialized, "materialized can't be null");

        // TODO: remove this when we do a topology-incompatible release
        // we used to burn a topology name here, so we have to keep doing it for compatibility
        if (new MaterializedInternal<>(materialized).storeName() == null) {
            builder.newStoreName(AGGREGATE_NAME);
        }

        return doCount(named, materialized);
    }

    @Override
    public SessionWindowedKStream emitStrategy(final EmitStrategy emitStrategy) {
        this.emitStrategy = emitStrategy;
        return this;
    }

    private KTable, Long> doCount(final Named named,
                                              final Materialized> materialized) {
        final MaterializedInternal> materializedInternal =
            new MaterializedInternal<>(materialized, builder, AGGREGATE_NAME);

        if (materializedInternal.keySerde() == null) {
            materializedInternal.withKeySerde(keySerde);
        }
        if (materializedInternal.valueSerde() == null) {
            materializedInternal.withValueSerde(Serdes.Long());
        }

        final String aggregateName = new NamedInternal(named).orElseGenerateWithPrefix(builder, AGGREGATE_NAME);
        return aggregateBuilder.build(
            new NamedInternal(aggregateName),
            new SessionStoreMaterializer<>(materializedInternal, windows, emitStrategy),
            new KStreamSessionWindowAggregate<>(
                windows,
                materializedInternal.storeName(),
                emitStrategy,
                aggregateBuilder.countInitializer,
                aggregateBuilder.countAggregator,
                countMerger),
            materializedInternal.queryableStoreName(),
            materializedInternal.keySerde() != null ? new WindowedSerdes.SessionWindowedSerde<>(materializedInternal.keySerde()) : null,
            materializedInternal.valueSerde(),
            false);
    }

    @Override
    public KTable, V> reduce(final Reducer reducer) {
        return reduce(reducer, NamedInternal.empty());
    }

    @Override
    public KTable, V> reduce(final Reducer reducer, final Named named) {
        return reduce(reducer, named, Materialized.with(keySerde, valueSerde));
    }

    @Override
    public KTable, V> reduce(final Reducer reducer,
                                         final Materialized> materialized) {
        return reduce(reducer, NamedInternal.empty(), materialized);
    }

    @Override
    public KTable, V> reduce(final Reducer reducer,
                                         final Named named,
                                         final Materialized> materialized) {
        Objects.requireNonNull(reducer, "reducer can't be null");
        Objects.requireNonNull(named, "named can't be null");
        Objects.requireNonNull(materialized, "materialized can't be null");
        final Aggregator reduceAggregator = aggregatorForReducer(reducer);
        final MaterializedInternal> materializedInternal =
            new MaterializedInternal<>(materialized, builder, REDUCE_NAME);
        if (materializedInternal.keySerde() == null) {
            materializedInternal.withKeySerde(keySerde);
        }
        if (materializedInternal.valueSerde() == null) {
            materializedInternal.withValueSerde(valueSerde);
        }

        final String reduceName = new NamedInternal(named).orElseGenerateWithPrefix(builder, REDUCE_NAME);
        return aggregateBuilder.build(
            new NamedInternal(reduceName),
            new SessionStoreMaterializer<>(materializedInternal, windows, emitStrategy),
            new KStreamSessionWindowAggregate<>(
                windows,
                materializedInternal.storeName(),
                emitStrategy,
                aggregateBuilder.reduceInitializer,
                reduceAggregator,
                mergerForAggregator(reduceAggregator)
            ),
            materializedInternal.queryableStoreName(),
            materializedInternal.keySerde() != null ? new WindowedSerdes.SessionWindowedSerde<>(materializedInternal.keySerde()) : null,
            materializedInternal.valueSerde(),
            false);
    }

    @Override
    public  KTable, T> aggregate(final Initializer initializer,
                                                final Aggregator aggregator,
                                                final Merger sessionMerger) {
        return aggregate(initializer, aggregator, sessionMerger, NamedInternal.empty());
    }

    @Override
    public  KTable, T> aggregate(final Initializer initializer,
                                                final Aggregator aggregator,
                                                final Merger sessionMerger,
                                                final Named named) {
        return aggregate(initializer, aggregator, sessionMerger, named, Materialized.with(keySerde, null));
    }

    @Override
    public  KTable, VR> aggregate(final Initializer initializer,
                                                  final Aggregator aggregator,
                                                  final Merger sessionMerger,
                                                  final Materialized> materialized) {
        return aggregate(initializer, aggregator, sessionMerger, NamedInternal.empty(), materialized);
    }

    @Override
    public  KTable, VR> aggregate(final Initializer initializer,
                                                  final Aggregator aggregator,
                                                  final Merger sessionMerger,
                                                  final Named named,
                                                  final Materialized> materialized) {
        Objects.requireNonNull(initializer, "initializer can't be null");
        Objects.requireNonNull(aggregator, "aggregator can't be null");
        Objects.requireNonNull(sessionMerger, "sessionMerger can't be null");
        Objects.requireNonNull(materialized, "materialized can't be null");
        final MaterializedInternal> materializedInternal =
            new MaterializedInternal<>(materialized, builder, AGGREGATE_NAME);

        if (materializedInternal.keySerde() == null) {
            materializedInternal.withKeySerde(keySerde);
        }

        final String aggregateName = new NamedInternal(named).orElseGenerateWithPrefix(builder, AGGREGATE_NAME);

        return aggregateBuilder.build(
            new NamedInternal(aggregateName),
            new SessionStoreMaterializer<>(materializedInternal, windows, emitStrategy),
            new KStreamSessionWindowAggregate<>(
                windows,
                materializedInternal.storeName(),
                emitStrategy,
                initializer,
                aggregator,
                sessionMerger),
            materializedInternal.queryableStoreName(),
            materializedInternal.keySerde() != null ? new WindowedSerdes.SessionWindowedSerde<>(materializedInternal.keySerde()) : null,
            materializedInternal.valueSerde(),
            false);
    }

    private Merger mergerForAggregator(final Aggregator aggregator) {
        return (aggKey, aggOne, aggTwo) -> aggregator.apply(aggKey, aggTwo, aggOne);
    }

    private Aggregator aggregatorForReducer(final Reducer reducer) {
        return (aggKey, value, aggregate) -> aggregate == null ? value : reducer.apply(aggregate, value);
    }
}