stevenzwu commented on a change in pull request #15924: URL: https://github.com/apache/flink/pull/15924#discussion_r639410926
########## File path: flink-connectors/flink-connector-base/src/main/java/org/apache/flink/connector/base/source/hybrid/HybridSource.java ########## @@ -0,0 +1,216 @@ +/* + * 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.base.source.hybrid; + +import org.apache.flink.annotation.PublicEvolving; +import org.apache.flink.api.connector.source.Boundedness; +import org.apache.flink.api.connector.source.Source; +import org.apache.flink.api.connector.source.SourceReader; +import org.apache.flink.api.connector.source.SourceReaderContext; +import org.apache.flink.api.connector.source.SourceSplit; +import org.apache.flink.api.connector.source.SplitEnumerator; +import org.apache.flink.api.connector.source.SplitEnumeratorContext; +import org.apache.flink.api.java.tuple.Tuple2; +import org.apache.flink.core.io.SimpleVersionedSerializer; +import org.apache.flink.util.Preconditions; + +import java.io.ByteArrayInputStream; +import java.io.ByteArrayOutputStream; +import java.io.DataInputStream; +import java.io.DataOutputStream; +import java.io.IOException; +import java.io.Serializable; +import java.util.ArrayList; +import java.util.Collections; +import java.util.List; +import java.util.function.Function; + +/** Hybrid source that switches underlying sources based on configurable source chain. */ +@PublicEvolving +public class HybridSource<T> implements Source<T, HybridSourceSplit, HybridSourceEnumState> { + + private final SourceChain<T, ? extends SourceSplit, ?> sourceChain; + + public HybridSource(SourceChain<T, ? extends SourceSplit, ?> sourceChain) { + Preconditions.checkArgument(!sourceChain.sources.isEmpty()); + for (int i = 0; i < sourceChain.sources.size() - 1; i++) { + Preconditions.checkArgument( + Boundedness.BOUNDED.equals(sourceChain.sources.get(i).f0.getBoundedness()), + "All sources except the final source need to be bounded."); + } + this.sourceChain = sourceChain; + } + + @Override + public Boundedness getBoundedness() { + return sourceChain.sources.get(sourceChain.sources.size() - 1).f0.getBoundedness(); + } + + @Override + public SourceReader<T, HybridSourceSplit> createReader(SourceReaderContext readerContext) + throws Exception { + List<SourceReader<?, ? extends SourceSplit>> readers = new ArrayList<>(); Review comment: should the first wildcard char be `T`? -- 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. For queries about this service, please contact Infrastructure at: us...@infra.apache.org
