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.kafka.streams.processor.internals.assignment;
  
  import org.apache.kafka.common.TopicPartition;
  import org.apache.kafka.streams.processor.assignment.TaskTopicPartition;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.util.Objects;
  import java.util.Optional;
  import java.util.Set;
  
  /**
   * This is a simple container class used during the assignment process to distinguish
   * TopicPartitions type. Since the assignment logic can depend on the type of topic we're
   * looking at, and the rack information of the partition, this container class should have
   * everything necessary to make informed task assignment decisions.
   * One detail worth noting is the fact that the rack id information can be fetched lazily
   * when requested, so as to not make RPC calls when the rack information is unnecessary for
   * the assignor that is currently making decisions.
   */
  public class DefaultTaskTopicPartition implements TaskTopicPartition {
      private static final Logger LOG = LoggerFactory.getLogger(DefaultTaskTopicPartition.class);
  
      private final TopicPartition topicPartition;
      private final boolean isSourceTopic;
      private final boolean isChangelogTopic;
      private final Runnable rackIdInformationFetcher;
  
      private Optional<Set<String>> rackIds;
  
  
      public DefaultTaskTopicPartition(final TopicPartition topicPartition,
                                       final boolean isSourceTopic,
                                       final boolean isChangelogTopic,
                                       final Runnable rackIdInformationFetcher) {
          this.topicPartition = topicPartition;
          this.isSourceTopic = isSourceTopic;
          this.isChangelogTopic = isChangelogTopic;
          this.rackIdInformationFetcher = rackIdInformationFetcher;
          this.rackIds = Optional.empty();
      }
  
      @Override
      public TopicPartition topicPartition() {
          return topicPartition;
      }
  
      @Override
      public boolean isSource() {
          return isSourceTopic;
      }
  
      @Override
      public boolean isChangelog() {
          return isChangelogTopic;
      }
  
      @Override
      public Optional<Set<String>> rackIds() {
          this.rackIdInformationFetcher.run();
          return rackIds;
      }
  
      @Override
      public int hashCode() {
          int result = topicPartition.hashCode();
          result = 31 * result + Objects.hashCode(isSourceTopic);
          result = 31 * result + Objects.hashCode(isChangelogTopic);
          return result;
      }
  
      @Override
      public boolean equals(final Object obj) {
          if (this == obj)
              return true;
          if (obj == null)
              return false;
          if (getClass() != obj.getClass())
              return false;
          final TaskTopicPartition other = (TaskTopicPartition) obj;
          return topicPartition.equals(other.topicPartition()) &&
                 isSourceTopic == other.isSource() &&
                 isChangelogTopic == other.isChangelog();
      }
  
      public void annotateWithRackIds(final Set<String> rackIds) {
          this.rackIds = Optional.of(rackIds);
      }
  }
  