netconf/netconf-notifications-impl/src/main/java/org/opendaylight/netconf/notifications/impl/ops/CreateSubscription.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.notifications.impl.ops;
   9
  10 import com.google.common.base.Preconditions;
  11 import java.util.ArrayList;
  12 import java.util.Date;
  13 import java.util.List;
  14 import java.util.Optional;
  15 import org.opendaylight.netconf.api.DocumentedException;
  16 import org.opendaylight.netconf.api.NetconfSession;
  17 import org.opendaylight.netconf.api.xml.XmlElement;
  18 import org.opendaylight.netconf.api.xml.XmlNetconfConstants;
  19 import org.opendaylight.netconf.mapping.api.SessionAwareNetconfOperation;
  20 import org.opendaylight.netconf.notifications.NetconfNotification;
  21 import org.opendaylight.netconf.notifications.NetconfNotificationListener;
  22 import org.opendaylight.netconf.notifications.NetconfNotificationRegistry;
  23 import org.opendaylight.netconf.notifications.NotificationListenerRegistration;
  24 import org.opendaylight.netconf.notifications.impl.NetconfNotificationManager;
  25 import org.opendaylight.netconf.util.mapping.AbstractSingletonNetconfOperation;
  26 import org.opendaylight.netconf.util.messages.SubtreeFilter;
  27 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.netconf.notification._1._0.rev080714.CreateSubscriptionInput;
  28 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.netconf.notification._1._0.rev080714.StreamNameType;
  29 import org.slf4j.Logger;
  30 import org.slf4j.LoggerFactory;
  31 import org.w3c.dom.Document;
  32 import org.w3c.dom.Element;
  33
  34 /**
  35  * Create subscription listens for create subscription requests
  36  * and registers notification listeners into notification registry.
  37  * Received notifications are sent to the client right away
  38  */
  39 public class CreateSubscription extends AbstractSingletonNetconfOperation
  40         implements SessionAwareNetconfOperation, AutoCloseable {
  41
  42     private static final Logger LOG = LoggerFactory.getLogger(CreateSubscription.class);
  43
  44     static final String CREATE_SUBSCRIPTION = "create-subscription";
  45
  46     private final NetconfNotificationRegistry notifications;
  47     private final List<NotificationListenerRegistration> subscriptions = new ArrayList<>();
  48     private NetconfSession netconfSession;
  49
  50     public CreateSubscription(final String netconfSessionIdForReporting,
  51                               final NetconfNotificationRegistry notifications) {
  52         super(netconfSessionIdForReporting);
  53         this.notifications = notifications;
  54     }
  55
  56     @Override
  57     protected Element handleWithNoSubsequentOperations(final Document document,
  58                                                        final XmlElement operationElement) throws DocumentedException {
  59         operationElement.checkName(CREATE_SUBSCRIPTION);
  60         operationElement.checkNamespace(CreateSubscriptionInput.QNAME.getNamespace().toString());
  61         // FIXME reimplement using CODEC_REGISTRY and parse everything into generated class instance
  62         // Binding doesn't support anyxml nodes yet, so filter could not be retrieved
  63         // xml -> normalized node -> CreateSubscriptionInput conversion could be slower than current approach
  64
  65         final Optional<XmlElement> filter = operationElement.getOnlyChildElementWithSameNamespaceOptionally("filter");
  66
  67         // Replay not supported
  68         final Optional<XmlElement> startTime =
  69                 operationElement.getOnlyChildElementWithSameNamespaceOptionally("startTime");
  70         Preconditions.checkArgument(!startTime.isPresent(), "StartTime element not yet supported");
  71
  72         // Stop time not supported
  73         final Optional<XmlElement> stopTime =
  74                 operationElement.getOnlyChildElementWithSameNamespaceOptionally("stopTime");
  75         Preconditions.checkArgument(!stopTime.isPresent(), "StopTime element not yet supported");
  76
  77         final StreamNameType streamNameType = parseStreamIfPresent(operationElement);
  78
  79         Preconditions.checkNotNull(netconfSession);
  80         // Premature streams are allowed (meaning listener can register even if no provider is available yet)
  81         if (!notifications.isStreamAvailable(streamNameType)) {
  82             LOG.warn("Registering premature stream {}. No publisher available yet for session {}", streamNameType,
  83                     getNetconfSessionIdForReporting());
  84         }
  85
  86         final NotificationListenerRegistration notificationListenerRegistration = notifications
  87                 .registerNotificationListener(streamNameType, new NotificationSubscription(netconfSession, filter));
  88         subscriptions.add(notificationListenerRegistration);
  89
  90         return document.createElement(XmlNetconfConstants.OK);
  91     }
  92
  93     private static StreamNameType parseStreamIfPresent(final XmlElement operationElement) throws DocumentedException {
  94         final Optional<XmlElement> stream = operationElement.getOnlyChildElementWithSameNamespaceOptionally("stream");
  95         return stream.isPresent() ? new StreamNameType(stream.get().getTextContent())
  96                 : NetconfNotificationManager.BASE_STREAM_NAME;
  97     }
  98
  99     @Override
 100     protected String getOperationName() {
 101         return CREATE_SUBSCRIPTION;
 102     }
 103
 104     @Override
 105     protected String getOperationNamespace() {
 106         return CreateSubscriptionInput.QNAME.getNamespace().toString();
 107     }
 108
 109     @Override
 110     public void setSession(final NetconfSession session) {
 111         this.netconfSession = session;
 112     }
 113
 114     @Override
 115     public void close() {
 116         netconfSession = null;
 117         // Unregister from notification streams
 118         for (final NotificationListenerRegistration subscription : subscriptions) {
 119             subscription.close();
 120         }
 121     }
 122
 123     private static class NotificationSubscription implements NetconfNotificationListener {
 124         private final NetconfSession currentSession;
 125         private final Optional<XmlElement> filter;
 126
 127         NotificationSubscription(final NetconfSession currentSession, final Optional<XmlElement> filter) {
 128             this.currentSession = currentSession;
 129             this.filter = filter;
 130         }
 131
 132         @Override
 133         public void onNotification(final StreamNameType stream, final NetconfNotification notification) {
 134             if (filter.isPresent()) {
 135                 try {
 136                     final Optional<Document> filtered =
 137                             SubtreeFilter.applySubtreeNotificationFilter(this.filter.get(), notification.getDocument());
 138                     if (filtered.isPresent()) {
 139                         final Date eventTime = notification.getEventTime();
 140                         currentSession.sendMessage(new NetconfNotification(filtered.get(), eventTime));
 141                     }
 142                 } catch (DocumentedException e) {
 143                     LOG.warn("Failed to process notification {}", notification, e);
 144                     currentSession.sendMessage(notification);
 145                 }
 146             } else {
 147                 currentSession.sendMessage(notification);
 148             }
 149         }
 150     }
 151 }