opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/broker/impl/DOMNotificationRouterEvent.java

   1 /*
   2  * Copyright (c) 2014 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8 package org.opendaylight.controller.md.sal.dom.broker.impl;
   9
  10 import com.google.common.base.Preconditions;
  11 import com.google.common.util.concurrent.ListenableFuture;
  12 import com.google.common.util.concurrent.SettableFuture;
  13 import com.lmax.disruptor.EventFactory;
  14 import java.util.Collection;
  15 import org.opendaylight.controller.md.sal.dom.api.DOMNotification;
  16 import org.opendaylight.controller.md.sal.dom.api.DOMNotificationListener;
  17 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  18 import org.slf4j.Logger;
  19 import org.slf4j.LoggerFactory;
  20
  21 /**
  22  * A single notification event in the disruptor ringbuffer. These objects are reused,
  23  * so they do have mutable state.
  24  */
  25 final class DOMNotificationRouterEvent {
  26     private static final Logger LOG = LoggerFactory.getLogger(DOMNotificationRouterEvent.class);
  27     public static final EventFactory<DOMNotificationRouterEvent> FACTORY = new EventFactory<DOMNotificationRouterEvent>() {
  28         @Override
  29         public DOMNotificationRouterEvent newInstance() {
  30             return new DOMNotificationRouterEvent();
  31         }
  32     };
  33
  34     private Collection<ListenerRegistration<? extends DOMNotificationListener>> subscribers;
  35     private DOMNotification notification;
  36     private SettableFuture<Void> future;
  37
  38     private DOMNotificationRouterEvent() {
  39         // Hidden on purpose, initialized in initialize()
  40     }
  41
  42     ListenableFuture<Void> initialize(final DOMNotification notification, final Collection<ListenerRegistration<? extends DOMNotificationListener>> subscribers) {
  43         this.notification = Preconditions.checkNotNull(notification);
  44         this.subscribers = Preconditions.checkNotNull(subscribers);
  45         this.future = SettableFuture.create();
  46         return this.future;
  47     }
  48
  49     void deliverNotification() {
  50         LOG.trace("Start delivery of notification {}", notification);
  51         for (ListenerRegistration<? extends DOMNotificationListener> r : subscribers) {
  52             final DOMNotificationListener listener = r.getInstance();
  53             if (listener != null) {
  54                 try {
  55                     LOG.trace("Notifying listener {}", listener);
  56                     listener.onNotification(notification);
  57                     LOG.trace("Listener notification completed");
  58                 } catch (Exception e) {
  59                     LOG.error("Delivery of notification {} caused an error in listener {}", notification, listener, e);
  60                 }
  61             }
  62         }
  63         LOG.trace("Delivery completed");
  64     }
  65
  66     void setFuture() {
  67         future.set(null);
  68         notification = null;
  69         subscribers = null;
  70         future = null;
  71     }
  72 }