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.dataflow.worker;
  
  import org.apache.beam.model.pipeline.v1.RunnerApi;
  import org.apache.beam.runners.core.KeyedWorkItem;
  import org.apache.beam.runners.core.ReduceFnRunner;
  import org.apache.beam.runners.core.SideInputReader;
  import org.apache.beam.runners.core.StateInternals;
  import org.apache.beam.runners.core.StateInternalsFactory;
  import org.apache.beam.runners.core.StepContext;
  import org.apache.beam.runners.core.SystemReduceFn;
  import org.apache.beam.runners.core.triggers.ExecutableTriggerStateMachine;
  import org.apache.beam.runners.core.triggers.TriggerStateMachines;
  import org.apache.beam.runners.dataflow.worker.util.BatchGroupAlsoByWindowFn;
  import org.apache.beam.runners.dataflow.worker.util.StreamingGroupAlsoByWindowFn;
  import org.apache.beam.sdk.options.PipelineOptions;
  import org.apache.beam.sdk.transforms.windowing.BoundedWindow;
  import org.apache.beam.sdk.util.WindowedValueReceiver;
  import org.apache.beam.sdk.util.construction.TriggerTranslation;
  import org.apache.beam.sdk.values.KV;
  import org.apache.beam.sdk.values.WindowingStrategy;
  
  /**
   * A general {@link BatchGroupAlsoByWindowFn}. This delegates all of the logic to the {@link
   * ReduceFnRunner}.
   */
  public class StreamingGroupAlsoByWindowViaWindowSetFn<K, InputT, OutputT, W extends BoundedWindow>
      extends StreamingGroupAlsoByWindowFn<K, InputT, OutputT> {
  
    public static <K, InputT, OutputT, W extends BoundedWindow>
        GroupAlsoByWindowFn<KeyedWorkItem<K, InputT>, KV<K, OutputT>> create(
            WindowingStrategy<?, W> strategy,
            StateInternalsFactory<K> stateInternalsFactory,
            SystemReduceFn<K, InputT, ?, OutputT, W> reduceFn) {
      return new StreamingGroupAlsoByWindowViaWindowSetFn<>(
          strategy, stateInternalsFactory, reduceFn);
    }
  
    private final WindowingStrategy<Object, W> windowingStrategy;
    private final RunnerApi.Trigger triggerProto;
    private final StateInternalsFactory<K> stateInternalsFactory;
    private SystemReduceFn<K, InputT, ?, OutputT, W> reduceFn;
  
    private StreamingGroupAlsoByWindowViaWindowSetFn(
        WindowingStrategy<?, W> windowingStrategy,
        StateInternalsFactory<K> stateInternalsFactory,
        SystemReduceFn<K, InputT, ?, OutputT, W> reduceFn) {
      @SuppressWarnings("unchecked")
      WindowingStrategy<Object, W> noWildcard = (WindowingStrategy<Object, W>) windowingStrategy;
      this.windowingStrategy = noWildcard;
      this.triggerProto = TriggerTranslation.toProto(windowingStrategy.getTrigger());
      this.reduceFn = reduceFn;
      this.stateInternalsFactory = stateInternalsFactory;
    }
  
    @Override
    public void processElement(
        KeyedWorkItem<K, InputT> keyedWorkItem,
        PipelineOptions options,
        StepContext stepContext,
        SideInputReader sideInputReader,
        WindowedValueReceiver<KV<K, OutputT>> output)
        throws Exception {
      K key = keyedWorkItem.key();
      StateInternals stateInternals = stateInternalsFactory.stateInternalsForKey(key);
  
      ReduceFnRunner<K, InputT, OutputT, W> reduceFnRunner =
          new ReduceFnRunner<K, InputT, OutputT, W>(
              key,
              windowingStrategy,
              ExecutableTriggerStateMachine.create(
                  TriggerStateMachines.stateMachineForTrigger(triggerProto)),
              stateInternals,
              stepContext.timerInternals(),
              output,
              sideInputReader,
              reduceFn,
              options);
  
      reduceFnRunner.processElements(keyedWorkItem.elementsIterable());
      reduceFnRunner.onTimers(keyedWorkItem.timersIterable());
      reduceFnRunner.persist();
    }
  
    public GroupAlsoByWindowFn<KeyedWorkItem<K, InputT>, KV<K, OutputT>> asDoFn() {
      // Safe contravariant cast
      @SuppressWarnings("unchecked")
      GroupAlsoByWindowFn<KeyedWorkItem<K, InputT>, KV<K, OutputT>> asFn =
          (GroupAlsoByWindowFn<KeyedWorkItem<K, InputT>, KV<K, OutputT>>) this;
      return asFn;
    }
  }
  