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.util;
  
  import org.apache.beam.runners.core.StateInternalsFactory;
  import org.apache.beam.runners.core.SystemReduceFn;
  import org.apache.beam.runners.dataflow.worker.util.GroupAlsoByWindowProperties.GroupAlsoByWindowDoFnFactory;
  import org.apache.beam.sdk.coders.Coder;
  import org.apache.beam.sdk.coders.CoderRegistry;
  import org.apache.beam.sdk.coders.KvCoder;
  import org.apache.beam.sdk.coders.StringUtf8Coder;
  import org.apache.beam.sdk.coders.VarLongCoder;
  import org.apache.beam.sdk.transforms.Combine.CombineFn;
  import org.apache.beam.sdk.transforms.Sum;
  import org.apache.beam.sdk.transforms.windowing.BoundedWindow;
  import org.apache.beam.sdk.util.AppliedCombineFn;
  import org.apache.beam.sdk.values.WindowingStrategy;
  import org.junit.Test;
  import org.junit.runner.RunWith;
  import org.junit.runners.JUnit4;
  
  /**
   * Tests for {@link BatchGroupAlsoByWindowViaOutputBufferFn} that use a combining {@link
   * SystemReduceFn}.
   */
  @RunWith(JUnit4.class)
  public class CombiningGroupAlsoByWindowsViaOutputBufferDoFnTest {
  
    private static class CombiningGABWViaOutputBufferDoFnFactory<K, InputT, AccumT, OutputT>
        implements GroupAlsoByWindowDoFnFactory<K, InputT, OutputT> {
  
      private final Coder<K> keyCoder;
      private final AppliedCombineFn<K, InputT, AccumT, OutputT> combineFn;
  
      public CombiningGABWViaOutputBufferDoFnFactory(
          Coder<K> keyCoder, AppliedCombineFn<K, InputT, AccumT, OutputT> combineFn) {
        this.keyCoder = keyCoder;
        this.combineFn = combineFn;
      }
  
      @Override
      public <W extends BoundedWindow> BatchGroupAlsoByWindowFn<K, InputT, OutputT> forStrategy(
          WindowingStrategy<?, W> windowingStrategy, StateInternalsFactory<K> stateInternalsFactory) {
        return new BatchGroupAlsoByWindowViaOutputBufferFn<>(
            windowingStrategy,
            stateInternalsFactory,
            SystemReduceFn.<K, InputT, AccumT, OutputT, W>combining(keyCoder, combineFn));
      }
    }
  
    @Test
    public void testCombinesElementsInSlidingWindows() throws Exception {
      CombineFn<Long, ?, Long> combineFn = Sum.ofLongs();
      AppliedCombineFn<String, Long, ?, Long> appliedFn =
          AppliedCombineFn.withInputCoder(
              combineFn,
              CoderRegistry.createDefault(),
              KvCoder.of(StringUtf8Coder.of(), VarLongCoder.of()));
  
      GroupAlsoByWindowProperties.combinesElementsInSlidingWindows(
          new CombiningGABWViaOutputBufferDoFnFactory<>(StringUtf8Coder.of(), appliedFn), combineFn);
    }
  
    @Test
    public void testCombinesIntoSessions() throws Exception {
      CombineFn<Long, ?, Long> combineFn = Sum.ofLongs();
      AppliedCombineFn<String, Long, ?, Long> appliedFn =
          AppliedCombineFn.withInputCoder(
              combineFn,
              CoderRegistry.createDefault(),
              KvCoder.of(StringUtf8Coder.of(), VarLongCoder.of()));
  
      GroupAlsoByWindowProperties.combinesElementsPerSession(
          new CombiningGABWViaOutputBufferDoFnFactory<>(StringUtf8Coder.of(), appliedFn), combineFn);
    }
  
    @Test
    public void testCombinesIntoSessionsWithEndOfWindowTimestamp() throws Exception {
      CombineFn<Long, ?, Long> combineFn = Sum.ofLongs();
      AppliedCombineFn<String, Long, ?, Long> appliedFn =
          AppliedCombineFn.withInputCoder(
              combineFn,
              CoderRegistry.createDefault(),
              KvCoder.of(StringUtf8Coder.of(), VarLongCoder.of()));
  
      GroupAlsoByWindowProperties.combinesElementsPerSessionWithEndOfWindowTimestamp(
          new CombiningGABWViaOutputBufferDoFnFactory<>(StringUtf8Coder.of(), appliedFn), combineFn);
    }
  }
  