content: /*
   * Copyright (c) 2024, Alibaba Cloud;
   * Licensed 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 com.aliyun.dataworks.migrationx.transformer.core.spark.command;
  
  import java.io.Serializable;
  
  /**
   * Message definitions for the launcher communication protocol. These messages must remain backwards-compatible, so that
   * the launcher can talk to older versions of Spark that support the protocol.
   */
  final class LauncherProtocol {
  
      /**
       * Environment variable where the server port is stored.
       */
      static final String ENV_LAUNCHER_PORT = "_SPARK_LAUNCHER_PORT";
  
      /**
       * Environment variable where the secret for connecting back to the server is stored.
       */
      static final String ENV_LAUNCHER_SECRET = "_SPARK_LAUNCHER_SECRET";
  
      /**
       * Spark conf key used to propagate the server port for in-process launches.
       */
      static final String CONF_LAUNCHER_PORT = "spark.launcher.port";
  
      /**
       * Spark conf key used to propagate the app secret for in-process launches.
       */
      static final String CONF_LAUNCHER_SECRET = "spark.launcher.secret";
  
      static class Message implements Serializable {
  
      }
  
      /**
       * Hello message, sent from client to server.
       */
      static class Hello extends Message {
  
          final String secret;
          final String sparkVersion;
  
          Hello(String secret, String version) {
              this.secret = secret;
              this.sparkVersion = version;
          }
  
      }
  
      /**
       * SetAppId message, sent from client to server.
       */
      static class SetAppId extends Message {
  
          final String appId;
  
          SetAppId(String appId) {
              this.appId = appId;
          }
  
      }
  
      /**
       * SetState message, sent from client to server.
       */
      static class SetState extends Message {
  
          final SparkAppHandle.State state;
  
          SetState(SparkAppHandle.State state) {
              this.state = state;
          }
  
      }
  
      /**
       * Stop message, send from server to client to stop the application.
       */
      static class Stop extends Message {
  
      }
  
  }
  