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.coordinator.group.api.assignor;
  
  import org.apache.kafka.common.Uuid;
  
  import java.util.Set;
  
  /**
   * The subscribed topic describer is used by the {@link PartitionAssignor}
   * to obtain topic and partition metadata of the subscribed topics.
   */
  public interface SubscribedTopicDescriber {
      /**
       * The number of partitions for the given topic Id.
       *
       * @param topicId   Uuid corresponding to the topic.
       * @return The number of partitions corresponding to the given topic Id,
       *         or -1 if the topic id does not exist.
       */
      int numPartitions(Uuid topicId);
  
      /**
       * Returns all the available racks associated with the replicas of the given partition.
       *
       * @param topicId       Uuid corresponding to the partition's topic.
       * @param partition     Partition Id within topic.
       * @return The set of racks corresponding to the replicas of the topic's partition.
       *         If the topic Id does not exist, an empty set is returned.
       */
      Set<String> racksForPartition(Uuid topicId, int partition);
  }
  