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.clients.admin;
  
  import java.util.List;
  import java.util.Map;
  
  /**
   * Describes new partitions for a particular topic in a call to {@link Admin#createPartitions(Map)}.
   */
  public class NewPartitions {
  
      private final int totalCount;
  
      private final List<List<Integer>> newAssignments;
  
      private NewPartitions(int totalCount, List<List<Integer>> newAssignments) {
          this.totalCount = totalCount;
          this.newAssignments = newAssignments;
      }
  
      /**
       * Increase the partition count for a topic to the given {@code totalCount}.
       * The assignment of new replicas to brokers will be decided by the broker.
       *
       * @param totalCount The total number of partitions after the operation succeeds.
       */
      public static NewPartitions increaseTo(int totalCount) {
          return new NewPartitions(totalCount, null);
      }
  
      /**
       * <p>Increase the partition count for a topic to the given {@code totalCount}
       * assigning the new partitions according to the given {@code newAssignments}.
       * The length of the given {@code newAssignments} should equal {@code totalCount - oldCount}, since
       * the assignment of existing partitions are not changed.
       * Each inner list of {@code newAssignments} should have a length equal to
       * the topic's replication factor.
       * The first broker id in each inner list is the "preferred replica".</p>
       *
       * <p>For example, suppose a topic currently has a replication factor of 2, and
       * has 3 partitions. The number of partitions can be increased to 6 using a
       * {@code NewPartition} constructed like this:</p>
       *
       * <pre><code>
       * NewPartitions.increaseTo(6, asList(asList(1, 2),
       *                                    asList(2, 3),
       *                                    asList(3, 1)))
       * </code></pre>
       * <p>In this example partition 3's preferred leader will be broker 1, partition 4's preferred leader will be
       * broker 2 and partition 5's preferred leader will be broker 3.</p>
       *
       * @param totalCount The total number of partitions after the operation succeeds.
       * @param newAssignments The replica assignments for the new partitions.
       */
      public static NewPartitions increaseTo(int totalCount, List<List<Integer>> newAssignments) {
          return new NewPartitions(totalCount, newAssignments);
      }
  
      /**
       * The total number of partitions after the operation succeeds.
       */
      public int totalCount() {
          return totalCount;
      }
  
      /**
       * The replica assignments for the new partitions, or null if the assignment will be done by the controller.
       */
      public List<List<Integer>> assignments() {
          return newAssignments;
      }
  
      @Override
      public String toString() {
          return "(totalCount=" + totalCount() + ", newAssignments=" + assignments() + ")";
      }
  
  }
  