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.core;
  
  import java.util.Collections;
  import java.util.Objects;
  import org.apache.beam.runners.core.TimerInternals.TimerData;
  import org.apache.beam.sdk.values.WindowedValue;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.base.MoreObjects;
  import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.Iterables;
  import org.checkerframework.checker.nullness.qual.Nullable;
  
  /** Static utility methods that provide {@link KeyedWorkItem} implementations. */
  public class KeyedWorkItems {
    /**
     * Returns an implementation of {@link KeyedWorkItem} that wraps around an elements iterable.
     *
     * @param <K> the key type
     * @param <ElemT> the element type
     */
    public static <K, ElemT> KeyedWorkItem<K, ElemT> elementsWorkItem(
        K key, Iterable<WindowedValue<ElemT>> elementsIterable) {
      return new ComposedKeyedWorkItem<>(key, Collections.emptyList(), elementsIterable);
    }
  
    /**
     * Returns an implementation of {@link KeyedWorkItem} that wraps around an timers iterable.
     *
     * @param <K> the key type
     * @param <ElemT> the element type
     */
    public static <K, ElemT> KeyedWorkItem<K, ElemT> timersWorkItem(
        K key, Iterable<TimerData> timersIterable) {
      return new ComposedKeyedWorkItem<>(
          key, timersIterable, Collections.<WindowedValue<ElemT>>emptyList());
    }
  
    /**
     * Returns an implementation of {@link KeyedWorkItem} that wraps around an timers iterable and an
     * elements iterable.
     *
     * @param <K> the key type
     * @param <ElemT> the element type
     */
    public static <K, ElemT> KeyedWorkItem<K, ElemT> workItem(
        K key, Iterable<TimerData> timersIterable, Iterable<WindowedValue<ElemT>> elementsIterable) {
      return new ComposedKeyedWorkItem<>(key, timersIterable, elementsIterable);
    }
  
    /**
     * A {@link KeyedWorkItem} composed of an underlying key, {@link TimerData} iterable, and element
     * iterable.
     */
    public static class ComposedKeyedWorkItem<K, ElemT> implements KeyedWorkItem<K, ElemT> {
      private final K key;
      private final Iterable<TimerData> timers;
      private final Iterable<WindowedValue<ElemT>> elements;
  
      private ComposedKeyedWorkItem(
          K key, Iterable<TimerData> timers, Iterable<WindowedValue<ElemT>> elements) {
        this.key = key;
        this.timers = timers;
        this.elements = elements;
      }
  
      @Override
      public K key() {
        return key;
      }
  
      @Override
      public Iterable<TimerData> timersIterable() {
        return timers;
      }
  
      @Override
      public Iterable<WindowedValue<ElemT>> elementsIterable() {
        return elements;
      }
  
      @Override
      public boolean equals(@Nullable Object other) {
        if (other == null || !(other instanceof ComposedKeyedWorkItem)) {
          return false;
        }
        KeyedWorkItem<?, ?> that = (KeyedWorkItem<?, ?>) other;
        return Objects.equals(this.key, that.key())
            && Iterables.elementsEqual(this.timersIterable(), that.timersIterable())
            && Iterables.elementsEqual(this.elementsIterable(), that.elementsIterable());
      }
  
      @Override
      public int hashCode() {
        return Objects.hash(key, timers, elements);
      }
  
      @Override
      public String toString() {
        return MoreObjects.toStringHelper(ComposedKeyedWorkItem.class)
            .add("key", key)
            .add("elements", elements)
            .add("timers", timers)
            .toString();
      }
    }
  }
  