package com.ctrip.apollo.internals;

 import com.google.common.collect.Lists;

 import com.ctrip.apollo.util.ExceptionUtil;

 import com.dianping.cat.Cat;

 import org.slf4j.Logger;

 import org.slf4j.LoggerFactory;

 import java.util.List;

 import java.util.Properties;

 /**

  * @author Jason Song(song_s@ctrip.com)

  */

 public abstract class AbstractConfigRepository implements ConfigRepository {

   private static final Logger logger = LoggerFactory.getLogger(AbstractConfigRepository.class);

   private List<RepositoryChangeListener> m_listeners = Lists.newCopyOnWriteArrayList();

   protected boolean trySync() {

     try {

       sync();

       return true;

     } catch (Throwable ex) {

       Cat.logError(ex);

       logger

           .warn("Sync config failed, will retry. Repository {}, reason: {}", this.getClass(), ExceptionUtil

               .getDetailMessage(ex));

     }

     return false;

   }

   protected abstract void sync();

   @Override

   public void addChangeListener(RepositoryChangeListener listener) {

     if (!m_listeners.contains(listener)) {

       m_listeners.add(listener);

     }

   }

   @Override

   public void removeChangeListener(RepositoryChangeListener listener) {

     m_listeners.remove(listener);

   }

   protected void fireRepositoryChange(String namespace, Properties newProperties) {

     for (RepositoryChangeListener listener : m_listeners) {

       try {

         listener.onRepositoryChange(namespace, newProperties);

       } catch (Throwable ex) {

         Cat.logError(ex);

         logger.error("Failed to invoke repository change listener {}", listener.getClass(), ex);

       }

     }

   }

 }