hlteoh37 commented on code in PR #49: URL: https://github.com/apache/flink-connector-aws/pull/49#discussion_r1193435598
########## flink-connector-aws-kinesis-streams/src/main/java/org/apache/flink/connector/kinesis/source/reader/PollingKinesisShardSplitReader.java: ########## @@ -0,0 +1,152 @@ +/* + * 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.kinesis.source.reader; + +import org.apache.flink.annotation.Internal; +import org.apache.flink.connector.base.source.reader.RecordsWithSplitIds; +import org.apache.flink.connector.base.source.reader.splitreader.SplitReader; +import org.apache.flink.connector.base.source.reader.splitreader.SplitsChange; +import org.apache.flink.connector.kinesis.source.proxy.StreamProxy; +import org.apache.flink.connector.kinesis.source.split.KinesisShardSplit; +import org.apache.flink.connector.kinesis.source.split.KinesisShardSplitState; +import org.apache.flink.connector.kinesis.source.split.StartingPosition; + +import org.apache.flink.shaded.guava30.com.google.common.collect.ImmutableSet; + +import software.amazon.awssdk.services.kinesis.model.GetRecordsResponse; +import software.amazon.awssdk.services.kinesis.model.Record; + +import javax.annotation.Nullable; + +import java.io.IOException; +import java.util.ArrayDeque; +import java.util.Collections; +import java.util.Deque; +import java.util.Iterator; +import java.util.Set; + +/** + * An implementation of the SplitReader that periodically polls the Kinesis stream to retrieve + * records. + */ +@Internal +public class PollingKinesisShardSplitReader implements SplitReader<Record, KinesisShardSplit> { + + private static final RecordsWithSplitIds<Record> INCOMPLETE_SHARD_EMPTY_RECORDS = + new KinesisRecordsWithSplitIds(Collections.emptyIterator(), null, false); + + private final StreamProxy kinesis; + private final Deque<KinesisShardSplitState> assignedSplits = new ArrayDeque<>(); + + public PollingKinesisShardSplitReader(StreamProxy kinesisProxy) { + this.kinesis = kinesisProxy; + } + + @Override + public RecordsWithSplitIds<Record> fetch() throws IOException { + KinesisShardSplitState splitState = assignedSplits.poll(); + if (splitState == null) { + return INCOMPLETE_SHARD_EMPTY_RECORDS; + } + + GetRecordsResponse getRecordsResponse = + kinesis.getRecords( + splitState.getStreamArn(), + splitState.getShardId(), + splitState.getNextStartingPosition()); + boolean isComplete = getRecordsResponse.nextShardIterator() == null; + + if (hasNoRecords(getRecordsResponse)) { + if (isComplete) { + return new KinesisRecordsWithSplitIds( + Collections.emptyIterator(), splitState.splitId(), true); + } else { + assignedSplits.add(splitState); + return INCOMPLETE_SHARD_EMPTY_RECORDS; + } + } + + splitState.setNextStartingPosition( + StartingPosition.continueFromSequenceNumber( + getRecordsResponse + .records() + .get(getRecordsResponse.records().size() - 1) + .sequenceNumber())); + + assignedSplits.add(splitState); + return new KinesisRecordsWithSplitIds( + getRecordsResponse.records().iterator(), splitState.splitId(), isComplete); + } + + private boolean hasNoRecords(GetRecordsResponse getRecordsResponse) { + return !getRecordsResponse.hasRecords() || getRecordsResponse.records().isEmpty(); + } + + @Override + public void handleSplitsChanges(SplitsChange<KinesisShardSplit> splitsChanges) { + for (KinesisShardSplit split : splitsChanges.splits()) { + assignedSplits.add(new KinesisShardSplitState(split)); + } + } + + @Override + public void wakeUp() { + // Do nothing because we don't have any sleep mechanism + } + + @Override + public void close() throws Exception {} + + private static class KinesisRecordsWithSplitIds implements RecordsWithSplitIds<Record> { + + private final Iterator<Record> recordsIterator; Review Comment: > We need to keep this as it might be a blocker for many users Yes that is correct, we had a discussion recently, and we decided it's important. Created followup https://issues.apache.org/jira/browse/FLINK-32097 -- 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: issues-unsubscr...@flink.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
