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 edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
  15 import java.util.Collection;
  16 import org.opendaylight.controller.md.sal.dom.api.DOMNotification;
  17 import org.opendaylight.controller.md.sal.dom.api.DOMNotificationListener;
  18 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  19 import org.slf4j.Logger;
  20 import org.slf4j.LoggerFactory;
  21
  22 /**
  23  * A single notification event in the disruptor ringbuffer. These objects are reused,
  24  * so they do have mutable state.
  25  */
  26 final class DOMNotificationRouterEvent {
  27     private static final Logger LOG = LoggerFactory.getLogger(DOMNotificationRouterEvent.class);
  28     public static final EventFactory<DOMNotificationRouterEvent> FACTORY = DOMNotificationRouterEvent::new;
  29
  30     private Collection<ListenerRegistration<? extends DOMNotificationListener>> subscribers;
  31     private DOMNotification notification;
  32     private SettableFuture<Void> future;
  33
  34     private DOMNotificationRouterEvent() {
  35         // Hidden on purpose, initialized in initialize()
  36     }
  37
  38     @SuppressWarnings("checkstyle:hiddenField")
  39     ListenableFuture<Void> initialize(final DOMNotification notification,
  40                                       final Collection<ListenerRegistration<? extends DOMNotificationListener>>
  41                                               subscribers) {
  42         this.notification = Preconditions.checkNotNull(notification);
  43         this.subscribers = Preconditions.checkNotNull(subscribers);
  44         this.future = SettableFuture.create();
  45         return this.future;
  46     }
  47
  48     void deliverNotification() {
  49         LOG.trace("Start delivery of notification {}", notification);
  50         for (ListenerRegistration<? extends DOMNotificationListener> r : subscribers) {
  51             final DOMNotificationListener listener = r.getInstance();
  52             LOG.trace("Notifying listener {}", listener);
  53             listener.onNotification(notification);
  54             LOG.trace("Listener notification completed");
  55         }
  56         LOG.trace("Delivery completed");
  57     }
  58
  59     @SuppressFBWarnings(value = "NP_NONNULL_PARAM_VIOLATION", justification = "Void is the only allowed value")
  60     void setFuture() {
  61         future.set(null);
  62         notification = null;
  63         subscribers = null;
  64         future = null;
  65     }
  66 }