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;
  
  import java.util.HashMap;
  import java.util.Map;
  import org.apache.beam.runners.flink.translation.types.CoderTypeInformation;
  import org.apache.beam.runners.flink.translation.utils.CountingPipelineVisitor;
  import org.apache.beam.runners.flink.translation.utils.LookupPipelineVisitor;
  import org.apache.beam.sdk.Pipeline;
  import org.apache.beam.sdk.coders.Coder;
  import org.apache.beam.sdk.options.PipelineOptions;
  import org.apache.beam.sdk.runners.AppliedPTransform;
  import org.apache.beam.sdk.transforms.PTransform;
  import org.apache.beam.sdk.values.PCollection;
  import org.apache.beam.sdk.values.PCollectionView;
  import org.apache.beam.sdk.values.PValue;
  import org.apache.beam.sdk.values.TupleTag;
  import org.apache.beam.sdk.values.WindowedValue;
  import org.apache.beam.sdk.values.WindowedValues;
  import org.apache.beam.sdk.values.WindowingStrategy;
  import org.apache.flink.api.common.typeinfo.TypeInformation;
  import org.apache.flink.api.java.DataSet;
  import org.apache.flink.api.java.ExecutionEnvironment;
  
  /**
   * Helper for {@link FlinkBatchPipelineTranslator} and translators in {@link
   * FlinkBatchTransformTranslators}.
   */
  @SuppressWarnings({
    "nullness" // TODO(https://github.com/apache/beam/issues/20497)
  })
  class FlinkBatchTranslationContext {
  
    private final Map<PValue, DataSet<?>> dataSets;
    private final Map<PCollectionView<?>, DataSet<?>> broadcastDataSets;
  
    /**
     * For keeping track about which DataSets don't have a successor. We need to terminate these with
     * a discarding sink because the Beam model allows dangling operations.
     */
    private final Map<PValue, DataSet<?>> danglingDataSets;
  
    private final ExecutionEnvironment env;
    private final PipelineOptions options;
  
    private AppliedPTransform<?, ?, ?> currentTransform;
  
    private final CountingPipelineVisitor countingPipelineVisitor = new CountingPipelineVisitor();
    private final LookupPipelineVisitor lookupPipelineVisitor = new LookupPipelineVisitor();
  
    // ------------------------------------------------------------------------
  
    FlinkBatchTranslationContext(ExecutionEnvironment env, PipelineOptions options) {
      this.env = env;
      this.options = options;
      this.dataSets = new HashMap<>();
      this.broadcastDataSets = new HashMap<>();
  
      this.danglingDataSets = new HashMap<>();
    }
  
    void init(Pipeline pipeline) {
      pipeline.traverseTopologically(countingPipelineVisitor);
      pipeline.traverseTopologically(lookupPipelineVisitor);
    }
  
    // ------------------------------------------------------------------------
  
    Map<PValue, DataSet<?>> getDanglingDataSets() {
      return danglingDataSets;
    }
  
    ExecutionEnvironment getExecutionEnvironment() {
      return env;
    }
  
    public PipelineOptions getPipelineOptions() {
      return options;
    }
  
    @SuppressWarnings("unchecked")
    <T> DataSet<WindowedValue<T>> getInputDataSet(PValue value) {
      // assume that the DataSet is used as an input if retrieved here
      danglingDataSets.remove(value);
      return (DataSet<WindowedValue<T>>) dataSets.get(value);
    }
  
    <T> void setOutputDataSet(PValue value, DataSet<WindowedValue<T>> set) {
      if (!dataSets.containsKey(value)) {
        dataSets.put(value, set);
        danglingDataSets.put(value, set);
      }
    }
  
    /**
     * Sets the AppliedPTransform which carries input/output.
     *
     * @param currentTransform Current transformation.
     */
    void setCurrentTransform(AppliedPTransform<?, ?, ?> currentTransform) {
      this.currentTransform = currentTransform;
    }
  
    AppliedPTransform<?, ?, ?> getCurrentTransform() {
      return currentTransform;
    }
  
    Map<TupleTag<?>, Coder<?>> getOutputCoders(PTransform<?, ?> transform) {
      return lookupPipelineVisitor.getOutputCoders(transform);
    }
  
    @SuppressWarnings("unchecked")
    <T> DataSet<T> getSideInputDataSet(PCollectionView<?> value) {
      return (DataSet<T>) broadcastDataSets.get(value);
    }
  
    <ViewT, ElemT> void setSideInputDataSet(
        PCollectionView<ViewT> value, DataSet<WindowedValue<ElemT>> set) {
      if (!broadcastDataSets.containsKey(value)) {
        broadcastDataSets.put(value, set);
      }
    }
  
    <T> TypeInformation<WindowedValue<T>> getTypeInfo(PCollection<T> collection) {
      return getTypeInfo(collection.getCoder(), collection.getWindowingStrategy());
    }
  
    <T> TypeInformation<WindowedValue<T>> getTypeInfo(
        Coder<T> coder, WindowingStrategy<?, ?> windowingStrategy) {
      WindowedValues.FullWindowedValueCoder<T> windowedValueCoder =
          WindowedValues.getFullCoder(coder, windowingStrategy.getWindowFn().windowCoder());
  
      return new CoderTypeInformation<>(windowedValueCoder, options);
    }
  
    Map<TupleTag<?>, PCollection<?>> getInputs(PTransform<?, ?> transform) {
      return lookupPipelineVisitor.getInputs(transform);
    }
  
    <T extends PValue> T getInput(PTransform<T, ?> transform) {
      return lookupPipelineVisitor.getInput(transform);
    }
  
    Map<TupleTag<?>, PCollection<?>> getOutputs(PTransform<?, ?> transform) {
      return lookupPipelineVisitor.getOutputs(transform);
    }
  
    <T extends PValue> T getOutput(PTransform<?, T> transform) {
      return lookupPipelineVisitor.getOutput(transform);
    }
  
    /** {@link CountingPipelineVisitor#getNumConsumers(PValue)}. */
    int getNumConsumers(PValue value) {
      return countingPipelineVisitor.getNumConsumers(value);
    }
  }
  