afedulov commented on code in PR #23777: URL: https://github.com/apache/flink/pull/23777#discussion_r1403385649
########## flink-connectors/flink-connector-datagen/src/main/java/org/apache/flink/connector/datagen/source/SourceReaderWithCheckpointsLatch.java: ########## @@ -0,0 +1,158 @@ +/* + * 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.connector.datagen.source; + +import org.apache.flink.annotation.Experimental; +import org.apache.flink.api.connector.source.ReaderOutput; +import org.apache.flink.api.connector.source.SourceReader; +import org.apache.flink.api.connector.source.SourceReaderContext; +import org.apache.flink.api.connector.source.lib.util.IteratorSourceReaderBase; +import org.apache.flink.api.connector.source.lib.util.IteratorSourceSplit; +import org.apache.flink.core.io.InputStatus; +import org.apache.flink.util.FlinkRuntimeException; + +import javax.annotation.Nullable; + +import java.util.Iterator; +import java.util.concurrent.CompletableFuture; +import java.util.function.BooleanSupplier; + +import static org.apache.flink.util.Preconditions.checkNotNull; + +/** + * A {@link SourceReader} that synchronizes emission of N elements on the arrival of the checkpoint + * barriers It 1) emits a list of elements without checkpoints in-between, 2) then waits for two + * checkpoints to complete, 3) then re-emits the same elements before 4) waiting for another two + * checkpoints and 5) exiting. + * + * <p>This lockstep execution is possible because {@code pollNext} and {@code snapshotState} are + * executed in the same thread and the fact that {@code pollNext} can emit N elements at once. This + * reader is meant to be used solely for testing purposes as the substitution for the {@code + * FiniteTestSource} which implements the deprecated {@code SourceFunction} API. + */ +@Experimental +public class SourceReaderWithCheckpointsLatch< + E, O, IterT extends Iterator<E>, SplitT extends IteratorSourceSplit<E, IterT>> + extends IteratorSourceReaderBase<E, O, IterT, SplitT> { + + private final GeneratorFunction<E, O> generatorFunction; + + private BooleanSupplier couldExit; + private int snapshotsCompleted; + private int snapshotsToWaitFor = Integer.MAX_VALUE; + private boolean done; + + public SourceReaderWithCheckpointsLatch( + SourceReaderContext context, + GeneratorFunction<E, O> generatorFunction, + @Nullable BooleanSupplier couldExit) { Review Comment: Good idea, it is based on the existing naming in FiniteTestSource https://github.com/apache/flink/blob/0234027c55ce743e3340391c77348f100f712e90/flink-test-utils-parent/flink-test-utils/src/main/java/org/apache/flink/streaming/util/FiniteTestSource.java#L77 But changing it makes sense. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
