package com.ctrip.framework.apollo.spi;

 import com.google.common.collect.Maps;

 import org.unidal.lookup.ContainerHolder;

 import org.unidal.lookup.LookupException;

 import org.unidal.lookup.annotation.Inject;

 import org.unidal.lookup.annotation.Named;

 import java.util.Map;

 /**

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

  */

 @Named(type = ConfigFactoryManager.class)

 public class DefaultConfigFactoryManager extends ContainerHolder implements ConfigFactoryManager {

   @Inject

   private ConfigRegistry m_registry;

   private Map<String, ConfigFactory> m_factories = Maps.newConcurrentMap();

   @Override

   public ConfigFactory getFactory(String namespace) {

     // step 1: check hacked factory

     ConfigFactory factory = m_registry.getFactory(namespace);

     if (factory != null) {

       return factory;

     }

     // step 2: check cache

     factory = m_factories.get(namespace);

     if (factory != null) {

       return factory;

     }

     // step 3: check declared config factory

     try {

       factory = lookup(ConfigFactory.class, namespace);

     } catch (LookupException ex) {

       // ignore it

     }

     // step 4: check default config factory

     if (factory == null) {

       factory = lookup(ConfigFactory.class);

     }

     m_factories.put(namespace, factory);

     // factory should not be null

     return factory;

   }

 }