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.core.GroupByKeyViaGroupByKeyOnly.GroupAlsoByWindow;
  import org.apache.beam.runners.core.SideInputReader;
  import org.apache.beam.runners.core.StepContext;
  import org.apache.beam.runners.core.TimerInternals;
  import org.apache.beam.sdk.options.PipelineOptions;
  import org.apache.beam.sdk.util.WindowedValueReceiver;
  
  /**
   * An interface for functions that execute {@link GroupAlsoByWindow}-like machinery and need access
   * to worker internals, such as {@link TimerInternals} and {@link WindowedValueReceiver}.
   */
  public abstract class GroupAlsoByWindowFn<InputT, OutputT> {
    /** Processes one input element. */
    public abstract void processElement(
        InputT element,
        PipelineOptions options,
        StepContext stepContext,
        SideInputReader sideInputReader,
        WindowedValueReceiver<OutputT> output)
        throws Exception;
  }
  