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.image.publisher;
  
  import org.apache.kafka.common.Endpoint;
  import org.apache.kafka.common.message.DescribeClusterResponseData.DescribeClusterBroker;
  import org.apache.kafka.common.message.DescribeClusterResponseData.DescribeClusterBrokerCollection;
  import org.apache.kafka.image.MetadataDelta;
  import org.apache.kafka.image.MetadataImage;
  import org.apache.kafka.image.loader.LoaderManifest;
  import org.apache.kafka.image.loader.LoaderManifestType;
  import org.apache.kafka.metadata.ControllerRegistration;
  
  import java.util.Map;
  
  
  /**
   * A publisher to track controller registrations.
   */
  public class ControllerRegistrationsPublisher implements MetadataPublisher {
      private volatile Map<Integer, ControllerRegistration> controllers;
  
      public ControllerRegistrationsPublisher() {
          this.controllers = Map.of();
      }
  
      @Override
      public String name() {
          return "ControllerRegistrationsPublisher";
      }
  
      @Override
      public void onMetadataUpdate(
          MetadataDelta delta,
          MetadataImage newImage,
          LoaderManifest manifest
      ) {
          if (manifest.type() == LoaderManifestType.LOG_DELTA || delta.clusterDelta() != null) {
              controllers = newImage.cluster().controllers();
          }
      }
  
      public DescribeClusterBrokerCollection describeClusterControllers(
          String endpointName
      ) {
          DescribeClusterBrokerCollection results = new DescribeClusterBrokerCollection();
          for (ControllerRegistration registration : controllers.values()) {
              Endpoint endpoint = registration.listeners().get(endpointName);
              if (endpoint != null) {
                  results.add(new DescribeClusterBroker().
                          setBrokerId(registration.id()).
                          setHost(endpoint.host()).
                          setPort(endpoint.port()).
                          setRack(null));
              }
          }
          return results;
      }
  
      public Map<Integer, ControllerRegistration> controllers() {
          return controllers;
      }
  
      @Override
      public void close() {
      }
  }
  