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.runners.dataflow.worker.util.common.worker.ParDoFn;
  import org.apache.beam.runners.dataflow.worker.util.common.worker.Receiver;
  import org.apache.beam.sdk.values.KV;
  import org.apache.beam.sdk.values.WindowedValue;
  import org.joda.time.Instant;
  
  /**
   * A {@link ParDoFn} over per-key iterables that applies an underlying {@link ParDoFn} to the
   * elements of an underlying iterable, then processes its timers.
   *
   * <p>Each input element must be a {@link KV} where the value is an iterable of {@link WindowedValue
   * WindowedValues}.
   */
  @SuppressWarnings({
    "nullness" // TODO(https://github.com/apache/beam/issues/20497)
  })
  class BatchModeUngroupingParDoFn<K, V> implements ParDoFn {
  
    private final ParDoFn underlyingParDoFn;
    private final BatchModeExecutionContext.StepContext stepContext;
  
    BatchModeUngroupingParDoFn(
        BatchModeExecutionContext.StepContext stepContext, ParDoFn underlyingParDoFn) {
      this.underlyingParDoFn = underlyingParDoFn;
      this.stepContext = stepContext;
    }
  
    @Override
    public void startBundle(Receiver... receivers) throws Exception {
      underlyingParDoFn.startBundle(receivers);
    }
  
    @Override
    @SuppressWarnings("unchecked")
    public void processElement(Object untypedElem) throws Exception {
      WindowedValue<?> windowedValue = (WindowedValue<?>) untypedElem;
  
      KV<K, Iterable<KV<Instant, WindowedValue<V>>>> gbkElem =
          (KV<K, Iterable<KV<Instant, WindowedValue<V>>>>) windowedValue.getValue();
  
      // Each GBK output is the beginning of a key
      stepContext.setKey(gbkElem.getKey());
  
      for (KV<Instant, WindowedValue<V>> timestampedElem : gbkElem.getValue()) {
        underlyingParDoFn.processElement(timestampedElem.getValue());
      }
  
      // Process all the timers for the key, since the watermark is moved to infinity
      underlyingParDoFn.processTimers();
    }
  
    @Override
    public void processTimers() throws Exception {
      // The timers for the underlying ParDoFn are processed at the end of each element
    }
  
    @Override
    public void finishBundle() throws Exception {
      underlyingParDoFn.finishBundle();
    }
  
    @Override
    public void abort() throws Exception {
      underlyingParDoFn.abort();
    }
  }
  