+/*
+ * Copyright (c) 2015 Cisco Systems, Inc. and others. All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v1.0 which accompanies this distribution,
+ * and is available at http://www.eclipse.org/legal/epl-v10.html
+ */
+
+package org.opendaylight.controller.netconf.notifications.impl;
+
+import com.google.common.base.Preconditions;
+import com.google.common.collect.HashMultimap;
+import com.google.common.collect.HashMultiset;
+import com.google.common.collect.Lists;
+import com.google.common.collect.Maps;
+import com.google.common.collect.Multimap;
+import com.google.common.collect.Multiset;
+import com.google.common.collect.Sets;
+import java.util.Map;
+import java.util.Set;
+import javax.annotation.concurrent.GuardedBy;
+import javax.annotation.concurrent.ThreadSafe;
+import org.opendaylight.controller.netconf.notifications.BaseNotificationPublisherRegistration;
+import org.opendaylight.controller.netconf.notifications.NetconfNotification;
+import org.opendaylight.controller.netconf.notifications.NetconfNotificationCollector;
+import org.opendaylight.controller.netconf.notifications.NetconfNotificationListener;
+import org.opendaylight.controller.netconf.notifications.NetconfNotificationRegistry;
+import org.opendaylight.controller.netconf.notifications.NotificationListenerRegistration;
+import org.opendaylight.controller.netconf.notifications.NotificationPublisherRegistration;
+import org.opendaylight.controller.netconf.notifications.NotificationRegistration;
+import org.opendaylight.controller.netconf.notifications.impl.ops.NotificationsTransformUtil;
+import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.netconf.notification._1._0.rev080714.StreamNameType;
+import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.netmod.notification.rev080714.netconf.Streams;
+import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.netmod.notification.rev080714.netconf.StreamsBuilder;
+import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.netmod.notification.rev080714.netconf.streams.Stream;
+import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.netmod.notification.rev080714.netconf.streams.StreamBuilder;
+import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.netmod.notification.rev080714.netconf.streams.StreamKey;
+import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.netconf.notifications.rev120206.NetconfCapabilityChange;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+@ThreadSafe
+public class NetconfNotificationManager implements NetconfNotificationCollector, NetconfNotificationRegistry, NetconfNotificationListener, AutoCloseable {
+
+ public static final StreamNameType BASE_STREAM_NAME = new StreamNameType("NETCONF");
+ public static final Stream BASE_NETCONF_STREAM;
+
+ static {
+ BASE_NETCONF_STREAM = new StreamBuilder()
+ .setName(BASE_STREAM_NAME)
+ .setKey(new StreamKey(BASE_STREAM_NAME))
+ .setReplaySupport(false)
+ .setDescription("Default Event Stream")
+ .build();
+ }
+
+ private static final Logger LOG = LoggerFactory.getLogger(NetconfNotificationManager.class);
+
+ // TODO excessive synchronization provides thread safety but is most likely not optimal (combination of concurrent collections might improve performance)
+ // And also calling callbacks from a synchronized block is dangerous since the listeners/publishers can block the whole notification processing
+
+ @GuardedBy("this")
+ private final Multimap<StreamNameType, GenericNotificationListenerReg> notificationListeners = HashMultimap.create();
+
+ @GuardedBy("this")
+ private final Set<NetconfNotificationStreamListener> streamListeners = Sets.newHashSet();
+
+ @GuardedBy("this")
+ private final Map<StreamNameType, Stream> streamMetadata = Maps.newHashMap();
+
+ @GuardedBy("this")
+ private final Multiset<StreamNameType> availableStreams = HashMultiset.create();
+
+ @GuardedBy("this")
+ private final Set<GenericNotificationPublisherReg> notificationPublishers = Sets.newHashSet();
+
+ @Override
+ public synchronized void onNotification(final StreamNameType stream, final NetconfNotification notification) {
+ LOG.debug("Notification of type {} detected", stream);
+ if(LOG.isTraceEnabled()) {
+ LOG.debug("Notification of type {} detected: {}", stream, notification);
+ }
+
+ for (final GenericNotificationListenerReg listenerReg : notificationListeners.get(BASE_STREAM_NAME)) {
+ listenerReg.getListener().onNotification(BASE_STREAM_NAME, notification);
+ }
+ }
+
+ @Override
+ public synchronized NotificationListenerRegistration registerNotificationListener(final StreamNameType stream, final NetconfNotificationListener listener) {
+ Preconditions.checkNotNull(stream);
+ Preconditions.checkNotNull(listener);
+
+ LOG.trace("Notification listener registered for stream: {}", stream);
+
+ final GenericNotificationListenerReg genericNotificationListenerReg = new GenericNotificationListenerReg(listener) {
+ @Override
+ public void close() {
+ synchronized (NetconfNotificationManager.this) {
+ LOG.trace("Notification listener unregistered for stream: {}", stream);
+ super.close();
+ }
+ }
+ };
+
+ notificationListeners.put(BASE_STREAM_NAME, genericNotificationListenerReg);
+ return genericNotificationListenerReg;
+ }
+
+ @Override
+ public synchronized Streams getNotificationPublishers() {
+ return new StreamsBuilder().setStream(Lists.newArrayList(streamMetadata.values())).build();
+ }
+
+ @Override
+ public synchronized boolean isStreamAvailable(final StreamNameType streamNameType) {
+ return availableStreams.contains(streamNameType);
+ }
+
+ @Override
+ public synchronized NotificationRegistration registerStreamListener(final NetconfNotificationStreamListener listener) {
+ streamListeners.add(listener);
+
+ // Notify about all already available
+ for (final Stream availableStream : streamMetadata.values()) {
+ listener.onStreamRegistered(availableStream);
+ }
+
+ return new NotificationRegistration() {
+ @Override
+ public void close() {
+ synchronized(NetconfNotificationManager.this) {
+ streamListeners.remove(listener);
+ }
+ }
+ };
+ }
+
+ @Override
+ public synchronized void close() {
+ // Unregister all listeners
+ for (final GenericNotificationListenerReg genericNotificationListenerReg : notificationListeners.values()) {
+ genericNotificationListenerReg.close();
+ }
+ notificationListeners.clear();
+
+ // Unregister all publishers
+ for (final GenericNotificationPublisherReg notificationPublisher : notificationPublishers) {
+ notificationPublisher.close();
+ }
+ notificationPublishers.clear();
+
+ // Clear stream Listeners
+ streamListeners.clear();
+ }
+
+ @Override
+ public synchronized NotificationPublisherRegistration registerNotificationPublisher(final Stream stream) {
+ Preconditions.checkNotNull(stream);
+ final StreamNameType streamName = stream.getName();
+
+ LOG.debug("Notification publisher registered for stream: {}", streamName);
+ if(LOG.isTraceEnabled()) {
+ LOG.trace("Notification publisher registered for stream: {}", stream);
+ }
+
+ if(streamMetadata.containsKey(streamName)) {
+ LOG.warn("Notification stream {} already registered as: {}. Will be reused", streamName, streamMetadata.get(streamName));
+ } else {
+ streamMetadata.put(streamName, stream);
+ }
+
+ availableStreams.add(streamName);
+
+ final GenericNotificationPublisherReg genericNotificationPublisherReg = new GenericNotificationPublisherReg(this, streamName) {
+ @Override
+ public void close() {
+ synchronized (NetconfNotificationManager.this) {
+ super.close();
+ }
+ }
+ };
+
+ notificationPublishers.add(genericNotificationPublisherReg);
+
+ notifyStreamAdded(stream);
+ return genericNotificationPublisherReg;
+ }
+
+ private void unregisterNotificationPublisher(final StreamNameType streamName, final GenericNotificationPublisherReg genericNotificationPublisherReg) {
+ availableStreams.remove(streamName);
+ notificationPublishers.remove(genericNotificationPublisherReg);
+
+ LOG.debug("Notification publisher unregistered for stream: {}", streamName);
+
+ // Notify stream listeners if all publishers are gone and also clear metadata for stream
+ if (!isStreamAvailable(streamName)) {
+ LOG.debug("Notification stream: {} became unavailable", streamName);
+ streamMetadata.remove(streamName);
+ notifyStreamRemoved(streamName);
+ }
+ }
+
+ private synchronized void notifyStreamAdded(final Stream stream) {
+ for (final NetconfNotificationStreamListener streamListener : streamListeners) {
+ streamListener.onStreamRegistered(stream);
+ }
+ }
+ private synchronized void notifyStreamRemoved(final StreamNameType stream) {
+ for (final NetconfNotificationStreamListener streamListener : streamListeners) {
+ streamListener.onStreamUnregistered(stream);
+ }
+ }
+
+ @Override
+ public BaseNotificationPublisherRegistration registerBaseNotificationPublisher() {
+ final NotificationPublisherRegistration notificationPublisherRegistration = registerNotificationPublisher(BASE_NETCONF_STREAM);
+ return new BaseNotificationPublisherReg(notificationPublisherRegistration);
+ }
+
+ private static class GenericNotificationPublisherReg implements NotificationPublisherRegistration {
+ private NetconfNotificationManager baseListener;
+ private final StreamNameType registeredStream;
+
+ public GenericNotificationPublisherReg(final NetconfNotificationManager baseListener, final StreamNameType registeredStream) {
+ this.baseListener = baseListener;
+ this.registeredStream = registeredStream;
+ }
+
+ @Override
+ public void close() {
+ baseListener.unregisterNotificationPublisher(registeredStream, this);
+ baseListener = null;
+ }
+
+ @Override
+ public void onNotification(final StreamNameType stream, final NetconfNotification notification) {
+ Preconditions.checkState(baseListener != null, "Already closed");
+ Preconditions.checkArgument(stream.equals(registeredStream));
+ baseListener.onNotification(stream, notification);
+ }
+ }
+
+ private static class BaseNotificationPublisherReg implements BaseNotificationPublisherRegistration {
+
+ private final NotificationPublisherRegistration baseRegistration;
+
+ public BaseNotificationPublisherReg(final NotificationPublisherRegistration baseRegistration) {
+ this.baseRegistration = baseRegistration;
+ }
+
+ @Override
+ public void close() {
+ baseRegistration.close();
+ }
+
+ @Override
+ public void onCapabilityChanged(final NetconfCapabilityChange capabilityChange) {
+ baseRegistration.onNotification(BASE_STREAM_NAME, serializeNotification(capabilityChange));
+ }
+
+ private static NetconfNotification serializeNotification(final NetconfCapabilityChange capabilityChange) {
+ return NotificationsTransformUtil.transform(capabilityChange);
+ }
+ }
+
+ private class GenericNotificationListenerReg implements NotificationListenerRegistration {
+ private final NetconfNotificationListener listener;
+
+ public GenericNotificationListenerReg(final NetconfNotificationListener listener) {
+ this.listener = listener;
+ }
+
+ public NetconfNotificationListener getListener() {
+ return listener;
+ }
+
+ @Override
+ public void close() {
+ notificationListeners.remove(BASE_STREAM_NAME, this);
+ }
+ }
+}