package fr.in2p3.jsaga.engine.job.monitor.poll;
   
   import fr.in2p3.jsaga.engine.job.monitor.JobMonitorCallback;
   import fr.in2p3.jsaga.engine.job.monitor.JobRegistry;
   
   import java.util.HashMap;
   import java.util.Map;
   
   /* ***************************************************
  * *** Centre de Calcul de l'IN2P3 - Lyon (France) ***
  * ***             http://cc.in2p3.fr/             ***
  * ***************************************************
  * File:   AbstractJobStatusPoller
  * Author: Sylvain Reynaud (sreynaud@in2p3.fr)
  * Date:   10 janv. 2008
  * ***************************************************
  * Description:                                      */
  /**
   *
   */
  public abstract class AbstractJobStatusPoller implements JobRegistry, Runnable {
      protected final Map<String,JobMonitorCallback> m_subscribedJobs;
      private JobStatusPollerTask m_pollerTask;
  
      public AbstractJobStatusPoller() {
          m_subscribedJobs = new HashMap<String,JobMonitorCallback>();
      }
  
      public void subscribeJob(String nativeJobId, JobMonitorCallback callback) {
          synchronized(m_subscribedJobs) {
              boolean toBeStarted = m_subscribedJobs.isEmpty();
  
              // subscribe job
              m_subscribedJobs.put(nativeJobId, callback);
  
              // may start timer
              if (toBeStarted) {
                  m_pollerTask = new JobStatusPollerTask(this);
                  m_pollerTask.start();
              }
          }
      }
  
      public void unsubscribeJob(String nativeJobId) {
          synchronized(m_subscribedJobs) {
              // unsubscribe job
              m_subscribedJobs.remove(nativeJobId);
  
              // may stop timer
              if (m_subscribedJobs.isEmpty() && m_pollerTask!=null) {
                  m_pollerTask.stop();
                  m_pollerTask = null;
              }
          }
      }
  }