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

   1 /*
   2  * Copyright (c) 2013 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.sal.dom.broker;
   9
  10 import java.util.Collection;
  11 import java.util.Collections;
  12 import java.util.HashSet;
  13 import java.util.Map;
  14 import java.util.Map.Entry;
  15 import java.util.Set;
  16
  17 import org.opendaylight.controller.sal.core.api.BrokerService;
  18 import org.opendaylight.controller.sal.core.api.Broker.ConsumerSession;
  19 import org.opendaylight.controller.sal.core.api.Broker.ProviderSession;
  20 import org.opendaylight.controller.sal.core.api.Consumer.ConsumerFunctionality;
  21 import org.opendaylight.controller.sal.core.api.Provider.ProviderFunctionality;
  22 import org.opendaylight.controller.sal.core.api.notify.NotificationListener;
  23 import org.opendaylight.controller.sal.core.api.notify.NotificationPublishService;
  24 import org.opendaylight.controller.sal.core.api.notify.NotificationService;
  25 import org.opendaylight.controller.sal.core.spi.BrokerModule;
  26 import org.opendaylight.yangtools.concepts.Registration;
  27 import org.opendaylight.yangtools.yang.common.QName;
  28 import org.opendaylight.yangtools.yang.data.api.CompositeNode;
  29 import org.slf4j.Logger;
  30 import org.slf4j.LoggerFactory;
  31
  32 import com.google.common.collect.HashMultimap;
  33 import com.google.common.collect.ImmutableSet;
  34 import com.google.common.collect.Multimap;
  35
  36 public class NotificationModule implements BrokerModule {
  37     private static Logger log = LoggerFactory
  38             .getLogger(NotificationModule.class);
  39
  40     private Multimap<QName, NotificationListener> listeners = HashMultimap
  41             .create();
  42
  43     private static final Set<Class<? extends BrokerService>> PROVIDED_SERVICE_TYPE = ImmutableSet
  44             .<Class<? extends BrokerService>>of(NotificationService.class,
  45                     NotificationPublishService.class);
  46
  47     private static final Set<Class<? extends ConsumerFunctionality>> SUPPORTED_CONSUMER_FUNCTIONALITY = ImmutableSet
  48             .of((Class<? extends ConsumerFunctionality>) NotificationListener.class,
  49                     NotificationListener.class); // Workaround: if we use the
  50                                                  // version of method with only
  51                                                  // one argument, the generics
  52                                                  // inference will not work
  53
  54     @Override
  55     public Set<Class<? extends BrokerService>> getProvidedServices() {
  56         return PROVIDED_SERVICE_TYPE;
  57     }
  58
  59     @Override
  60     public Set<Class<? extends ConsumerFunctionality>> getSupportedConsumerFunctionality() {
  61         return SUPPORTED_CONSUMER_FUNCTIONALITY;
  62     }
  63
  64     @Override
  65     public <T extends BrokerService> T getServiceForSession(Class<T> service,
  66             ConsumerSession session) {
  67         if (NotificationPublishService.class.equals(service)
  68                 && session instanceof ProviderSession) {
  69             @SuppressWarnings("unchecked")
  70             T ret = (T) newNotificationPublishService(session);
  71             return ret;
  72         } else if (NotificationService.class.equals(service)) {
  73
  74             @SuppressWarnings("unchecked")
  75             T ret = (T) newNotificationConsumerService(session);
  76             return ret;
  77         }
  78
  79         throw new IllegalArgumentException(
  80                 "The requested session-specific service is not provided by this module.");
  81     }
  82
  83     private void sendNotification(CompositeNode notification) {
  84         QName type = notification.getNodeType();
  85         Collection<NotificationListener> toNotify = listeners.get(type);
  86         log.trace("Publishing notification " + type);
  87
  88         if (toNotify == null) {
  89             // No listeners were registered - returns.
  90             return;
  91         }
  92
  93         for (NotificationListener listener : toNotify) {
  94             try {
  95                 // FIXME: ensure that notification is immutable
  96                 listener.onNotification(notification);
  97             } catch (Exception e) {
  98                 log.error("Uncaught exception in NotificationListener", e);
  99             }
 100         }
 101
 102     }
 103
 104     private NotificationService newNotificationConsumerService(
 105             ConsumerSession session) {
 106         return new NotificationConsumerSessionImpl();
 107     }
 108
 109     private NotificationPublishService newNotificationPublishService(
 110             ConsumerSession session) {
 111         return new NotificationProviderSessionImpl();
 112     }
 113
 114     private class NotificationConsumerSessionImpl implements
 115             NotificationService {
 116
 117         private Multimap<QName, NotificationListener> consumerListeners = HashMultimap
 118                 .create();
 119         private boolean closed = false;
 120
 121
 122         public Registration<NotificationListener> addNotificationListener(QName notification,
 123                 NotificationListener listener) {
 124             checkSessionState();
 125             if (notification == null) {
 126                 throw new IllegalArgumentException(
 127                         "Notification type must not be null.");
 128             }
 129             if (listener == null) {
 130                 throw new IllegalArgumentException("Listener must not be null.");
 131             }
 132
 133             consumerListeners.put(notification, listener);
 134             listeners.put(notification, listener);
 135             log.trace("Registered listener for notification: " + notification);
 136             return null; // Return registration Object.
 137         }
 138
 139         public void removeNotificationListener(QName notification,
 140                 NotificationListener listener) {
 141             checkSessionState();
 142             if (notification == null) {
 143                 throw new IllegalArgumentException(
 144                         "Notification type must not be null.");
 145             }
 146             if (listener == null) {
 147                 throw new IllegalArgumentException("Listener must not be null.");
 148             }
 149             consumerListeners.remove(notification, listener);
 150             listeners.remove(notification, listener);
 151         }
 152
 153         public void closeSession() {
 154             closed = true;
 155             Map<QName, Collection<NotificationListener>> toRemove = consumerListeners
 156                     .asMap();
 157             for (Entry<QName, Collection<NotificationListener>> entry : toRemove
 158                     .entrySet()) {
 159                 listeners.remove(entry.getKey(), entry.getValue());
 160             }
 161         }
 162
 163         protected void checkSessionState() {
 164             if (closed)
 165                 throw new IllegalStateException("Session is closed");
 166         }
 167     }
 168
 169     private class NotificationProviderSessionImpl extends
 170             NotificationConsumerSessionImpl implements
 171             NotificationPublishService {
 172
 173         @Override
 174         public void sendNotification(CompositeNode notification) {
 175             checkSessionState();
 176             if (notification == null)
 177                 throw new IllegalArgumentException(
 178                         "Notification must not be null.");
 179             NotificationModule.this.sendNotification(notification);
 180         }
 181
 182         @Override
 183         public void publish(CompositeNode notification) {
 184             sendNotification(notification);
 185         }
 186     }
 187
 188     @Override
 189     public Set<Class<? extends ProviderFunctionality>> getSupportedProviderFunctionality() {
 190         return Collections.emptySet();
 191     }
 192 }