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
   *
   *    https://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.bigtop.manager.server.command.scheduler;
  
  import org.apache.bigtop.manager.server.command.job.Job;
  import org.apache.bigtop.manager.server.holder.SessionUserHolder;
  
  import org.springframework.stereotype.Component;
  
  import lombok.extern.slf4j.Slf4j;
  
  import jakarta.annotation.PostConstruct;
  import java.util.concurrent.Executor;
  import java.util.concurrent.Executors;
  import java.util.concurrent.LinkedBlockingQueue;
  
  @Slf4j
  @Component
  public class DefaultJobScheduler implements JobScheduler {
  
      private final LinkedBlockingQueue<Runnable> queue = new LinkedBlockingQueue<>();
  
      private final Executor executor = Executors.newSingleThreadExecutor();
  
      private volatile boolean running = true;
  
      @Override
      public void submit(Job job) {
          Long userId = SessionUserHolder.getUserId();
          queue.offer(() -> {
              try {
                  SessionUserHolder.setUserId(userId);
                  job.run();
              } finally {
                  SessionUserHolder.clear();
              }
          });
      }
  
      @Override
      public void start() {
          running = true;
      }
  
      @Override
      public void stop() {
          running = false;
      }
  
      @PostConstruct
      public void init() {
          executor.execute(() -> {
              while (running) {
                  try {
                      Runnable runnable = queue.take();
                      runnable.run();
                  } catch (InterruptedException e) {
                      log.warn("Error when polling new job", e);
                  }
              }
          });
      }
  }
  