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.assignment;
  
  import org.apache.kafka.streams.errors.TaskAssignmentException;
  import org.apache.kafka.streams.processor.TaskId;
  
  import java.util.Map;
  
  /**
   * A read-only metadata class representing the state of the application and the current rebalance.
   * This class wraps all the input parameters to the task assignment, including the current state
   * of each KafkaStreams client with at least one StreamThread participating in this rebalance, the
   * assignment-related configs, and the tasks to be assigned.
   */
  public interface ApplicationState {
      /**
       * @param computeTaskLags whether to include task lag information in the returned metadata. Note that passing
       * in "true" will result in a remote call to fetch changelog topic end offsets, and you should pass in "false" unless
       * you specifically need the task lag information.
       *
       * @return a map from the {@code processId} to {@link KafkaStreamsState} for all KafkaStreams clients in this app
       *
       * @throws TaskAssignmentException if a retriable error occurs while computing KafkaStreamsState metadata. Re-throw
       *                                 this exception to have Kafka Streams retry the rebalance by returning the same
       *                                 assignment and scheduling an immediate followup rebalance
       */
      Map<ProcessId, KafkaStreamsState> kafkaStreamsStates(boolean computeTaskLags);
  
      /**
       * @return a simple container class with the Streams configs relevant to assignment
       */
      AssignmentConfigs assignmentConfigs();
  
      /**
       * @return a map of task ids to all tasks in this topology to be assigned
       */
      Map<TaskId, TaskInfo> allTasks();
  }