DeletePolicySelector(final MetaConfig metaConfig) {
   for (final String topic : metaConfig.getTopics()) {
     final TopicConfig topicConfig = metaConfig.getTopicConfig(topic);
     final String deletePolicy =
         topicConfig != null ? topicConfig.getDeletePolicy() : metaConfig.getDeletePolicy();
     this.deletePolicyMap.put(topic, DeletePolicyFactory.getDeletePolicy(deletePolicy));
   }
 }
 private Set<File> getDataDirSet(final MetaConfig metaConfig) throws IOException {
   final Set<String> paths = new HashSet<String>();
   // public data path
   paths.add(metaConfig.getDataPath());
   // topic data path
   for (final String topic : metaConfig.getTopics()) {
     final TopicConfig topicConfig = metaConfig.getTopicConfig(topic);
     if (topicConfig != null) {
       paths.add(topicConfig.getDataPath());
     }
   }
   final Set<File> fileSet = new HashSet<File>();
   for (final String path : paths) {
     fileSet.add(this.getDataDir(path));
   }
   return fileSet;
 }