content: /*
   * Copyright 1999-2022 Alibaba Group Holding Ltd.
   *
   * 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.alibaba.nacos.naming.monitor.collector;
  
  import com.alibaba.nacos.common.executor.ExecutorFactory;
  import com.alibaba.nacos.common.notify.NotifyCenter;
  import com.alibaba.nacos.naming.core.v2.event.service.ServiceEvent;
  import com.alibaba.nacos.naming.monitor.MetricsMonitor;
  import org.springframework.stereotype.Service;
  
  import java.util.concurrent.ScheduledExecutorService;
  import java.util.concurrent.TimeUnit;
  
  /**
   * ServiceEvent queue size metrics collector.
   *
   * @author <a href="mailto:liuyixiao0821@gmail.com">liuyixiao</a>
   */
  @Service
  public class ServiceEventQueueSizeMetricsCollector {
      
      private static final long DELAY_SECONDS = 2;
      
      private static ScheduledExecutorService executorService = ExecutorFactory.newSingleScheduledExecutorService(r -> {
          Thread thread = new Thread(r, "nacos.naming.monitor.ServiceEventQueueSizeMetricsCollector");
          thread.setDaemon(true);
          return thread;
      });
      
      public ServiceEventQueueSizeMetricsCollector() {
          executorService.scheduleWithFixedDelay(() -> {
              MetricsMonitor.getServiceSubscribedEventQueueSize().set(
                      (int) NotifyCenter.getPublisher(ServiceEvent.ServiceSubscribedEvent.class).currentEventSize());
              MetricsMonitor.getServiceChangedEventQueueSize().set(
                      (int) NotifyCenter.getPublisher(ServiceEvent.ServiceChangedEvent.class).currentEventSize());
          }, DELAY_SECONDS, DELAY_SECONDS, TimeUnit.SECONDS);
      }
  }
  