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.common.runtime;
  
  import org.apache.kafka.common.protocol.ApiMessage;
  import org.apache.kafka.server.common.ApiMessageAndVersion;
  
  import java.util.Objects;
  
  /**
   * A Record which contains an {{@link ApiMessage}} as key and
   * an {{@link ApiMessageAndVersion}} as value. The value could be null to
   * represent a tombstone.
   *
   * This class is immutable.
   */
  public class CoordinatorRecord {
  
      public static CoordinatorRecord record(
          ApiMessage key,
          ApiMessageAndVersion value
      ) {
          return new CoordinatorRecord(key, value);
      }
  
      public static CoordinatorRecord tombstone(
          ApiMessage key
      ) {
          return new CoordinatorRecord(key, null);
      }
  
      /**
       * The key of the record.
       */
      private final ApiMessage key;
  
      /**
       * The value of the record or null if the record is
       * a tombstone.
       */
      private final ApiMessageAndVersion value;
  
      /**
       * Constructs a CoordinatorRecord.
       *
       * @param key   A non-null key.
       * @param value A key or null.
       */
      private CoordinatorRecord(
          ApiMessage key,
          ApiMessageAndVersion value
      ) {
          this.key = Objects.requireNonNull(key);
          if (key.apiKey() < 0) {
              throw new IllegalArgumentException("The key must have a type.");
          }
  
          this.value = value;
          if (value != null) {
              if (value.message().apiKey() < 0) {
                  throw new IllegalArgumentException("The value must have a type.");
              }
              if (value.message().apiKey() != key.apiKey()) {
                  throw new IllegalArgumentException("The key and the value must have the same type.");
              }
          }
      }
  
      /**
       * @return The key.
       */
      public ApiMessage key() {
          return this.key;
      }
  
      /**
       * @return The value or null.
       */
      public ApiMessageAndVersion value() {
          return this.value;
      }
  
      @Override
      public boolean equals(Object o) {
          if (this == o) return true;
          if (o == null || getClass() != o.getClass()) return false;
          CoordinatorRecord that = (CoordinatorRecord) o;
          return Objects.equals(key, that.key) && Objects.equals(value, that.value);
      }
  
      @Override
      public int hashCode() {
          return Objects.hash(key, value);
      }
  
      @Override
      public String toString() {
          return "CoordinatorRecord(key=" + key + ", value=" + value + ")";
      }
  }
  