fredia commented on code in PR #26117: URL: https://github.com/apache/flink/pull/26117#discussion_r1945921637
########## flink-examples/flink-examples-streaming/src/main/java/org/apache/flink/streaming/examples/asyncstate/AsyncStateWordCount.java: ########## @@ -0,0 +1,161 @@ +/* + * 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.flink.streaming.examples.asyncstate; + +import org.apache.flink.api.common.eventtime.WatermarkStrategy; +import org.apache.flink.api.common.functions.FlatMapFunction; +import org.apache.flink.api.common.functions.OpenContext; +import org.apache.flink.api.common.functions.RichFlatMapFunction; +import org.apache.flink.api.common.state.StateTtlConfig; +import org.apache.flink.api.common.state.v2.ValueState; +import org.apache.flink.api.common.state.v2.ValueStateDescriptor; +import org.apache.flink.api.common.typeinfo.BasicTypeInfo; +import org.apache.flink.api.common.typeinfo.Types; +import org.apache.flink.api.connector.source.util.ratelimit.RateLimiterStrategy; +import org.apache.flink.api.java.tuple.Tuple2; +import org.apache.flink.connector.datagen.source.DataGeneratorSource; +import org.apache.flink.connector.datagen.source.GeneratorFunction; +import org.apache.flink.streaming.api.datastream.DataStream; +import org.apache.flink.streaming.api.datastream.KeyedStream; +import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment; +import org.apache.flink.streaming.api.operators.StreamingRuntimeContext; +import org.apache.flink.util.Collector; +import org.apache.flink.util.MultipleParameterTool; + +import java.time.Duration; +import java.util.Random; + +/** + * Implements the "WordCount" program that computes a simple word occurrence histogram generated by + * datagen. This Job can only be executed with async state enabled. + * + * <p>This example shows how to: + * + * <ul> + * <li>Create a state via state V2 interface. + * <li>Use async state in a user-defined function. + * </ul> + */ +public class AsyncStateWordCount { + static final String[] INPUTS = { + "This", + "is", + "an", + "example", + "for", + "state", + "V2", + "usage", + "This", + "Job", + "can", + "only", + "be", + "executed", + "with", + "async", + "state", + "enabled" + }; + + public static void main(String[] args) throws Exception { + MultipleParameterTool params = MultipleParameterTool.fromArgs(args); + int ttl = params.getInt("ttl", 0); + final StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment(); + + // Use DataGenerator to generate data + final Random rnd = new Random(); + GeneratorFunction<Long, String> generatorFunction = + index -> INPUTS[rnd.nextInt(INPUTS.length)]; + DataGeneratorSource<String> source = + new DataGeneratorSource<>( + generatorFunction, + Long.MAX_VALUE, + RateLimiterStrategy.perSecond(100), + Types.STRING); + + KeyedStream<String, String> streamSource = + env.fromSource(source, WatermarkStrategy.noWatermarks(), "Data Generator") + .keyBy(e -> e); + + FlatMapFunction<String, Tuple2<String, Long>> flatMapFunction = new WordCounter(ttl); + + DataStream<Tuple2<String, Long>> mapper = + streamSource + .enableAsyncState() // enable async state + .flatMap(flatMapFunction) + .setParallelism(3); + + mapper.print().setParallelism(1); + env.execute("Async state Word Count example"); + } + + /** A simple word counter that uses state V2. */ + public static class WordCounter extends RichFlatMapFunction<String, Tuple2<String, Long>> { + + private transient ValueState<Integer> wordCounter; + + private final long ttl; + + public WordCounter(long ttl) { + this.ttl = ttl; + } + + @Override + public void open(OpenContext context) { + ValueStateDescriptor<Integer> descriptor = + new ValueStateDescriptor<>("Counter", BasicTypeInfo.INT_TYPE_INFO); + if (ttl > 0) { + StateTtlConfig ttlConfig = + StateTtlConfig.newBuilder(Duration.ofMillis(ttl)) + .setUpdateType(StateTtlConfig.UpdateType.OnCreateAndWrite) + .setStateVisibility( + StateTtlConfig.StateVisibility.ReturnExpiredIfNotCleanedUp) + .build(); + descriptor.enableTimeToLive(ttlConfig); + } + wordCounter = ((StreamingRuntimeContext) getRuntimeContext()).getValueState(descriptor); + } + + @Override + public void flatMap(String value, Collector<Tuple2<String, Long>> out) throws Exception { + wordCounter + .asyncValue() + .thenAccept( Review Comment: Since `StateMachineExample` has `RichFlatMapFunction`, I removed this example and rewrite `StateMachineExample#StateMachineMapper` into state-v2 style. -- This is an automated message from the Apache Git Service. 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