netconf/mdsal-netconf-notification/src/main/java/org/opendaylight/netconf/mdsal/notification/impl/NetconfNotificationManager.java

   1 /*
   2  * Copyright (c) 2015 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.netconf.mdsal.notification.impl;
   9
  10 import static com.google.common.base.Preconditions.checkArgument;
  11 import static com.google.common.base.Preconditions.checkState;
  12 import static java.util.Objects.requireNonNull;
  13
  14 import com.google.common.collect.HashMultimap;
  15 import com.google.common.collect.HashMultiset;
  16 import com.google.common.collect.Lists;
  17 import com.google.common.collect.Multimap;
  18 import com.google.common.collect.Multiset;
  19 import java.util.HashMap;
  20 import java.util.HashSet;
  21 import java.util.Map;
  22 import java.util.Set;
  23 import org.checkerframework.checker.lock.qual.GuardedBy;
  24 import org.opendaylight.netconf.mdsal.notification.impl.ops.NotificationsTransformUtil;
  25 import org.opendaylight.netconf.notifications.BaseNotificationPublisherRegistration;
  26 import org.opendaylight.netconf.notifications.NetconfNotification;
  27 import org.opendaylight.netconf.notifications.NetconfNotificationCollector;
  28 import org.opendaylight.netconf.notifications.NetconfNotificationListener;
  29 import org.opendaylight.netconf.notifications.NetconfNotificationRegistry;
  30 import org.opendaylight.netconf.notifications.NotificationListenerRegistration;
  31 import org.opendaylight.netconf.notifications.NotificationPublisherRegistration;
  32 import org.opendaylight.netconf.notifications.NotificationRegistration;
  33 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.netconf.notification._1._0.rev080714.StreamNameType;
  34 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.netmod.notification.rev080714.netconf.Streams;
  35 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.netmod.notification.rev080714.netconf.StreamsBuilder;
  36 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.netmod.notification.rev080714.netconf.streams.Stream;
  37 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.netmod.notification.rev080714.netconf.streams.StreamBuilder;
  38 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.netmod.notification.rev080714.netconf.streams.StreamKey;
  39 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.netconf.notifications.rev120206.NetconfCapabilityChange;
  40 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.netconf.notifications.rev120206.NetconfSessionEnd;
  41 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.netconf.notifications.rev120206.NetconfSessionStart;
  42 import org.opendaylight.yangtools.yang.binding.Notification;
  43 import org.opendaylight.yangtools.yang.model.api.SchemaPath;
  44 import org.slf4j.Logger;
  45 import org.slf4j.LoggerFactory;
  46
  47 /**
  48  *  A thread-safe implementation NetconfNotificationRegistry.
  49  */
  50 public class NetconfNotificationManager implements NetconfNotificationCollector, NetconfNotificationRegistry,
  51         NetconfNotificationListener, AutoCloseable {
  52
  53     public static final StreamNameType BASE_STREAM_NAME = new StreamNameType("NETCONF");
  54     public static final Stream BASE_NETCONF_STREAM;
  55
  56     static {
  57         BASE_NETCONF_STREAM = new StreamBuilder()
  58                 .setName(BASE_STREAM_NAME)
  59                 .withKey(new StreamKey(BASE_STREAM_NAME))
  60                 .setReplaySupport(false)
  61                 .setDescription("Default Event Stream")
  62                 .build();
  63     }
  64
  65     private static final Logger LOG = LoggerFactory.getLogger(NetconfNotificationManager.class);
  66
  67     // TODO excessive synchronization provides thread safety but is most likely not optimal
  68     // (combination of concurrent collections might improve performance)
  69     // And also calling callbacks from a synchronized block is dangerous
  70     // since the listeners/publishers can block the whole notification processing
  71
  72     @GuardedBy("this")
  73     private final Multimap<StreamNameType, GenericNotificationListenerReg> notificationListeners =
  74             HashMultimap.create();
  75
  76     @GuardedBy("this")
  77     private final Set<NetconfNotificationStreamListener> streamListeners = new HashSet<>();
  78
  79     @GuardedBy("this")
  80     private final Map<StreamNameType, Stream> streamMetadata = new HashMap<>();
  81
  82     @GuardedBy("this")
  83     private final Multiset<StreamNameType> availableStreams = HashMultiset.create();
  84
  85     @GuardedBy("this")
  86     private final Set<GenericNotificationPublisherReg> notificationPublishers = new HashSet<>();
  87
  88     @Override
  89     public synchronized void onNotification(final StreamNameType stream, final NetconfNotification notification) {
  90         LOG.debug("Notification of type {} detected", stream);
  91         if (LOG.isTraceEnabled()) {
  92             LOG.debug("Notification of type {} detected: {}", stream, notification);
  93         }
  94
  95         for (final GenericNotificationListenerReg listenerReg : notificationListeners.get(BASE_STREAM_NAME)) {
  96             listenerReg.getListener().onNotification(BASE_STREAM_NAME, notification);
  97         }
  98     }
  99
 100     @Override
 101     public synchronized NotificationListenerRegistration registerNotificationListener(
 102             final StreamNameType stream,
 103             final NetconfNotificationListener listener) {
 104         requireNonNull(stream);
 105         requireNonNull(listener);
 106
 107         LOG.trace("Notification listener registered for stream: {}", stream);
 108
 109         final GenericNotificationListenerReg genericNotificationListenerReg =
 110                 new GenericNotificationListenerReg(listener) {
 111             @Override
 112             public void close() {
 113                 synchronized (NetconfNotificationManager.this) {
 114                     LOG.trace("Notification listener unregistered for stream: {}", stream);
 115                     super.close();
 116                 }
 117             }
 118         };
 119
 120         notificationListeners.put(BASE_STREAM_NAME, genericNotificationListenerReg);
 121         return genericNotificationListenerReg;
 122     }
 123
 124     @Override
 125     public synchronized Streams getNotificationPublishers() {
 126         return new StreamsBuilder().setStream(Lists.newArrayList(streamMetadata.values())).build();
 127     }
 128
 129     @Override
 130     public synchronized boolean isStreamAvailable(final StreamNameType streamNameType) {
 131         return availableStreams.contains(streamNameType);
 132     }
 133
 134     @Override
 135     public synchronized NotificationRegistration registerStreamListener(
 136             final NetconfNotificationStreamListener listener) {
 137         streamListeners.add(listener);
 138
 139         // Notify about all already available
 140         for (final Stream availableStream : streamMetadata.values()) {
 141             listener.onStreamRegistered(availableStream);
 142         }
 143
 144         return () -> {
 145             synchronized (NetconfNotificationManager.this) {
 146                 streamListeners.remove(listener);
 147             }
 148         };
 149     }
 150
 151     @Override
 152     public synchronized void close() {
 153         // Unregister all listeners
 154         for (final GenericNotificationListenerReg genericNotificationListenerReg : notificationListeners.values()) {
 155             genericNotificationListenerReg.close();
 156         }
 157         notificationListeners.clear();
 158
 159         // Unregister all publishers
 160         for (final GenericNotificationPublisherReg notificationPublisher : notificationPublishers) {
 161             notificationPublisher.close();
 162         }
 163         notificationPublishers.clear();
 164
 165         // Clear stream Listeners
 166         streamListeners.clear();
 167     }
 168
 169     @Override
 170     public synchronized NotificationPublisherRegistration registerNotificationPublisher(final Stream stream) {
 171         final StreamNameType streamName = requireNonNull(stream).getName();
 172
 173         LOG.debug("Notification publisher registered for stream: {}", streamName);
 174         if (LOG.isTraceEnabled()) {
 175             LOG.trace("Notification publisher registered for stream: {}", stream);
 176         }
 177
 178         if (streamMetadata.containsKey(streamName)) {
 179             LOG.warn("Notification stream {} already registered as: {}. Will be reused", streamName,
 180                     streamMetadata.get(streamName));
 181         } else {
 182             streamMetadata.put(streamName, stream);
 183         }
 184
 185         availableStreams.add(streamName);
 186
 187         final GenericNotificationPublisherReg genericNotificationPublisherReg =
 188                 new GenericNotificationPublisherReg(this, streamName) {
 189             @Override
 190             public void close() {
 191                 synchronized (NetconfNotificationManager.this) {
 192                     super.close();
 193                 }
 194             }
 195         };
 196
 197         notificationPublishers.add(genericNotificationPublisherReg);
 198
 199         notifyStreamAdded(stream);
 200         return genericNotificationPublisherReg;
 201     }
 202
 203     private void unregisterNotificationPublisher(
 204             final StreamNameType streamName,
 205             final GenericNotificationPublisherReg genericNotificationPublisherReg) {
 206         availableStreams.remove(streamName);
 207         notificationPublishers.remove(genericNotificationPublisherReg);
 208
 209         LOG.debug("Notification publisher unregistered for stream: {}", streamName);
 210
 211         // Notify stream listeners if all publishers are gone and also clear metadata for stream
 212         if (!isStreamAvailable(streamName)) {
 213             LOG.debug("Notification stream: {} became unavailable", streamName);
 214             streamMetadata.remove(streamName);
 215             notifyStreamRemoved(streamName);
 216         }
 217     }
 218
 219     private synchronized void notifyStreamAdded(final Stream stream) {
 220         for (final NetconfNotificationStreamListener streamListener : streamListeners) {
 221             streamListener.onStreamRegistered(stream);
 222         }
 223     }
 224
 225     private synchronized void notifyStreamRemoved(final StreamNameType stream) {
 226         for (final NetconfNotificationStreamListener streamListener : streamListeners) {
 227             streamListener.onStreamUnregistered(stream);
 228         }
 229     }
 230
 231     @Override
 232     public BaseNotificationPublisherRegistration registerBaseNotificationPublisher() {
 233         final NotificationPublisherRegistration notificationPublisherRegistration =
 234                 registerNotificationPublisher(BASE_NETCONF_STREAM);
 235         return new BaseNotificationPublisherReg(notificationPublisherRegistration);
 236     }
 237
 238     private static class GenericNotificationPublisherReg implements NotificationPublisherRegistration {
 239         private NetconfNotificationManager baseListener;
 240         private final StreamNameType registeredStream;
 241
 242         GenericNotificationPublisherReg(final NetconfNotificationManager baseListener,
 243                                         final StreamNameType registeredStream) {
 244             this.baseListener = baseListener;
 245             this.registeredStream = registeredStream;
 246         }
 247
 248         @Override
 249         public void close() {
 250             baseListener.unregisterNotificationPublisher(registeredStream, this);
 251             baseListener = null;
 252         }
 253
 254         @Override
 255         public void onNotification(final StreamNameType stream, final NetconfNotification notification) {
 256             checkState(baseListener != null, "Already closed");
 257             checkArgument(stream.equals(registeredStream));
 258             baseListener.onNotification(stream, notification);
 259         }
 260     }
 261
 262     private static class BaseNotificationPublisherReg implements BaseNotificationPublisherRegistration {
 263
 264         static final SchemaPath CAPABILITY_CHANGE_SCHEMA_PATH = SchemaPath.create(true, NetconfCapabilityChange.QNAME);
 265         static final SchemaPath SESSION_START_PATH = SchemaPath.create(true, NetconfSessionStart.QNAME);
 266         static final SchemaPath SESSION_END_PATH = SchemaPath.create(true, NetconfSessionEnd.QNAME);
 267
 268         private final NotificationPublisherRegistration baseRegistration;
 269
 270         BaseNotificationPublisherReg(final NotificationPublisherRegistration baseRegistration) {
 271             this.baseRegistration = baseRegistration;
 272         }
 273
 274         @Override
 275         public void close() {
 276             baseRegistration.close();
 277         }
 278
 279         private static NetconfNotification serializeNotification(final Notification notification,
 280                 final SchemaPath path) {
 281             return NotificationsTransformUtil.transform(notification, path);
 282         }
 283
 284         @Override
 285         public void onCapabilityChanged(final NetconfCapabilityChange capabilityChange) {
 286             baseRegistration.onNotification(BASE_STREAM_NAME,
 287                     serializeNotification(capabilityChange, CAPABILITY_CHANGE_SCHEMA_PATH));
 288         }
 289
 290         @Override
 291         public void onSessionStarted(final NetconfSessionStart start) {
 292             baseRegistration.onNotification(BASE_STREAM_NAME, serializeNotification(start, SESSION_START_PATH));
 293         }
 294
 295         @Override
 296         public void onSessionEnded(final NetconfSessionEnd end) {
 297             baseRegistration.onNotification(BASE_STREAM_NAME, serializeNotification(end, SESSION_END_PATH));
 298         }
 299     }
 300
 301     private class GenericNotificationListenerReg implements NotificationListenerRegistration {
 302         private final NetconfNotificationListener listener;
 303
 304         GenericNotificationListenerReg(final NetconfNotificationListener listener) {
 305             this.listener = listener;
 306         }
 307
 308         public NetconfNotificationListener getListener() {
 309             return listener;
 310         }
 311
 312         @Override
 313         public void close() {
 314             notificationListeners.remove(BASE_STREAM_NAME, this);
 315         }
 316     }
 317 }