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.streams.assignor;
  
  import java.util.List;
  import java.util.NoSuchElementException;
  
  /**
   * The topology describer is used by the {@link TaskAssignor} to get topic and task metadata of the group's topology.
   */
  public interface TopologyDescriber {
  
      /**
       * Map of topic names to topic metadata.
       *
       * @return The list of subtopologies IDs.
       */
      List<String> subtopologies();
  
      /**
       * The maximal number of input partitions among all source topics for the given subtopology.
       *
       * @param subtopologyId String identifying the subtopology.
       *
       * @throws NoSuchElementException if the subtopology ID does not exist.
       * @throws IllegalStateException if the subtopology contains no source topics.
       * @return The maximal number of input partitions among all source topics for the given subtopology.
       */
      int maxNumInputPartitions(String subtopologyId) throws NoSuchElementException;
  
      /**
       * Checks whether the given subtopology is associated with a changelog topic.
       *
       * @param subtopologyId String identifying the subtopology.
       * @throws NoSuchElementException if the subtopology ID does not exist.
       * @return true if the subtopology is associated with a changelog topic, false otherwise.
       */
      boolean isStateful(String subtopologyId);
  
  }
  