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;
  
  import org.apache.kafka.image.node.ClusterImageNode;
  import org.apache.kafka.image.writer.ImageWriter;
  import org.apache.kafka.image.writer.ImageWriterOptions;
  import org.apache.kafka.metadata.BrokerRegistration;
  import org.apache.kafka.metadata.ControllerRegistration;
  
  import java.util.Collections;
  import java.util.Map;
  import java.util.Objects;
  
  
  /**
   * Represents the cluster in the metadata image.
   *
   * This class is thread-safe.
   */
  public final class ClusterImage {
      public static final ClusterImage EMPTY = new ClusterImage(
              Map.of(),
              Map.of());
  
      private final Map<Integer, BrokerRegistration> brokers;
  
      private final Map<Integer, ControllerRegistration> controllers;
  
      public ClusterImage(
          Map<Integer, BrokerRegistration> brokers,
          Map<Integer, ControllerRegistration> controllers
      ) {
          this.brokers = Collections.unmodifiableMap(brokers);
          this.controllers = Collections.unmodifiableMap(controllers);
      }
  
      public boolean isEmpty() {
          return brokers.isEmpty();
      }
  
      public Map<Integer, BrokerRegistration> brokers() {
          return brokers;
      }
  
      public BrokerRegistration broker(int nodeId) {
          return brokers.get(nodeId);
      }
  
      public Map<Integer, ControllerRegistration> controllers() {
          return controllers;
      }
  
      public long brokerEpoch(int brokerId) {
          BrokerRegistration brokerRegistration = broker(brokerId);
          if (brokerRegistration == null) {
              return -1L;
          }
          return brokerRegistration.epoch();
      }
  
      public void write(ImageWriter writer, ImageWriterOptions options) {
          for (BrokerRegistration broker : brokers.values()) {
              writer.write(broker.toRecord(options));
          }
          if (!controllers.isEmpty()) {
              if (!options.metadataVersion().isControllerRegistrationSupported()) {
                  options.handleLoss("controller registration data");
              } else {
                  for (ControllerRegistration controller : controllers.values()) {
                      writer.write(controller.toRecord(options));
                  }
              }
          }
      }
  
      @Override
      public int hashCode() {
          return Objects.hash(brokers, controllers);
      }
  
      @Override
      public boolean equals(Object o) {
          if (!(o instanceof ClusterImage other)) return false;
          return brokers.equals(other.brokers) &&
              controllers.equals(other.controllers);
      }
  
      @Override
      public String toString() {
          return new ClusterImageNode(this).stringify();
      }
  }
  