content: /*
   * 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.beam.runners.flink.translation.wrappers.streaming.io.source.unbounded;
  
  import javax.annotation.Nullable;
  import org.apache.beam.runners.core.construction.SerializablePipelineOptions;
  import org.apache.beam.runners.flink.translation.wrappers.streaming.io.source.FlinkSource;
  import org.apache.beam.runners.flink.translation.wrappers.streaming.io.source.FlinkSourceSplit;
  import org.apache.beam.sdk.io.UnboundedSource;
  import org.apache.beam.sdk.values.ValueWithRecordId;
  import org.apache.beam.sdk.values.WindowedValue;
  import org.apache.flink.api.connector.source.Boundedness;
  import org.apache.flink.api.connector.source.SourceReader;
  import org.apache.flink.api.connector.source.SourceReaderContext;
  
  /**
   * A Flink {@link org.apache.flink.api.connector.source.Source Source} implementation that wraps a
   * Beam {@link org.apache.beam.sdk.io.UnboundedSource UnboundedSource}.
   *
   * @param <T> The output type of the wrapped Beam {@link org.apache.beam.sdk.io.UnboundedSource
   *     UnboundedSource}.
   */
  public class FlinkUnboundedSource<T> extends FlinkSource<T, WindowedValue<ValueWithRecordId<T>>> {
    private final @Nullable TimestampExtractor<WindowedValue<ValueWithRecordId<T>>>
        timestampExtractor;
  
    public FlinkUnboundedSource(
        String stepName,
        UnboundedSource<T, ?> beamSource,
        SerializablePipelineOptions serializablePipelineOptions,
        int numSplits) {
      this(stepName, beamSource, serializablePipelineOptions, numSplits, null);
    }
  
    public FlinkUnboundedSource(
        String stepName,
        UnboundedSource<T, ?> beamSource,
        SerializablePipelineOptions serializablePipelineOptions,
        int numSplits,
        @Nullable TimestampExtractor<WindowedValue<ValueWithRecordId<T>>> timestampExtractor) {
      super(
          stepName,
          beamSource,
          serializablePipelineOptions,
          Boundedness.CONTINUOUS_UNBOUNDED,
          numSplits);
      this.timestampExtractor = timestampExtractor;
    }
  
    @Override
    public SourceReader<WindowedValue<ValueWithRecordId<T>>, FlinkSourceSplit<T>> createReader(
        SourceReaderContext readerContext) throws Exception {
      return new FlinkUnboundedSourceReader<>(
          stepName, readerContext, serializablePipelineOptions.get(), timestampExtractor);
    }
  }
  