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.api.xml.XmlUtil;
  20 import org.opendaylight.netconf.mapping.api.SessionAwareNetconfOperation;
  21 import org.opendaylight.netconf.notifications.NetconfNotification;
  22 import org.opendaylight.netconf.notifications.NetconfNotificationListener;
  23 import org.opendaylight.netconf.notifications.NetconfNotificationRegistry;
  24 import org.opendaylight.netconf.notifications.NotificationListenerRegistration;
  25 import org.opendaylight.netconf.notifications.impl.NetconfNotificationManager;
  26 import org.opendaylight.netconf.util.mapping.AbstractSingletonNetconfOperation;
  27 import org.opendaylight.netconf.util.messages.SubtreeFilter;
  28 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.netconf.notification._1._0.rev080714.CreateSubscriptionInput;
  29 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.netconf.notification._1._0.rev080714.StreamNameType;
  30 import org.slf4j.Logger;
  31 import org.slf4j.LoggerFactory;
  32 import org.w3c.dom.Document;
  33 import org.w3c.dom.Element;
  34
  35 /**
  36  * Create subscription listens for create subscription requests
  37  * and registers notification listeners into notification registry.
  38  * Received notifications are sent to the client right away
  39  */
  40 public class CreateSubscription extends AbstractSingletonNetconfOperation
  41         implements SessionAwareNetconfOperation, AutoCloseable {
  42
  43     private static final Logger LOG = LoggerFactory.getLogger(CreateSubscription.class);
  44
  45     static final String CREATE_SUBSCRIPTION = "create-subscription";
  46
  47     private final NetconfNotificationRegistry notifications;
  48     private final List<NotificationListenerRegistration> subscriptions = new ArrayList<>();
  49     private NetconfSession netconfSession;
  50
  51     public CreateSubscription(final String netconfSessionIdForReporting,
  52                               final NetconfNotificationRegistry notifications) {
  53         super(netconfSessionIdForReporting);
  54         this.notifications = notifications;
  55     }
  56
  57     @Override
  58     protected Element handleWithNoSubsequentOperations(final Document document,
  59                                                        final XmlElement operationElement) throws DocumentedException {
  60         operationElement.checkName(CREATE_SUBSCRIPTION);
  61         operationElement.checkNamespace(CreateSubscriptionInput.QNAME.getNamespace().toString());
  62         // FIXME reimplement using CODEC_REGISTRY and parse everything into generated class instance
  63         // Binding doesn't support anyxml nodes yet, so filter could not be retrieved
  64         // xml -> normalized node -> CreateSubscriptionInput conversion could be slower than current approach
  65
  66         final Optional<XmlElement> filter = operationElement.getOnlyChildElementWithSameNamespaceOptionally("filter");
  67
  68         // Replay not supported
  69         final Optional<XmlElement> startTime =
  70                 operationElement.getOnlyChildElementWithSameNamespaceOptionally("startTime");
  71         Preconditions.checkArgument(!startTime.isPresent(), "StartTime element not yet supported");
  72
  73         // Stop time not supported
  74         final Optional<XmlElement> stopTime =
  75                 operationElement.getOnlyChildElementWithSameNamespaceOptionally("stopTime");
  76         Preconditions.checkArgument(!stopTime.isPresent(), "StopTime element not yet supported");
  77
  78         final StreamNameType streamNameType = parseStreamIfPresent(operationElement);
  79
  80         Preconditions.checkNotNull(netconfSession);
  81         // Premature streams are allowed (meaning listener can register even if no provider is available yet)
  82         if (!notifications.isStreamAvailable(streamNameType)) {
  83             LOG.warn("Registering premature stream {}. No publisher available yet for session {}", streamNameType,
  84                     getNetconfSessionIdForReporting());
  85         }
  86
  87         final NotificationListenerRegistration notificationListenerRegistration = notifications
  88                 .registerNotificationListener(streamNameType, new NotificationSubscription(netconfSession, filter));
  89         subscriptions.add(notificationListenerRegistration);
  90
  91         return XmlUtil.createElement(document, XmlNetconfConstants.OK);
  92     }
  93
  94     private static StreamNameType parseStreamIfPresent(final XmlElement operationElement) throws DocumentedException {
  95         final Optional<XmlElement> stream = operationElement.getOnlyChildElementWithSameNamespaceOptionally("stream");
  96         return stream.isPresent() ? new StreamNameType(stream.get().getTextContent())
  97                 : NetconfNotificationManager.BASE_STREAM_NAME;
  98     }
  99
 100     @Override
 101     protected String getOperationName() {
 102         return CREATE_SUBSCRIPTION;
 103     }
 104
 105     @Override
 106     protected String getOperationNamespace() {
 107         return CreateSubscriptionInput.QNAME.getNamespace().toString();
 108     }
 109
 110     @Override
 111     public void setSession(final NetconfSession session) {
 112         this.netconfSession = session;
 113     }
 114
 115     @Override
 116     public void close() {
 117         netconfSession = null;
 118         // Unregister from notification streams
 119         for (final NotificationListenerRegistration subscription : subscriptions) {
 120             subscription.close();
 121         }
 122     }
 123
 124     private static class NotificationSubscription implements NetconfNotificationListener {
 125         private final NetconfSession currentSession;
 126         private final Optional<XmlElement> filter;
 127
 128         NotificationSubscription(final NetconfSession currentSession, final Optional<XmlElement> filter) {
 129             this.currentSession = currentSession;
 130             this.filter = filter;
 131         }
 132
 133         @Override
 134         public void onNotification(final StreamNameType stream, final NetconfNotification notification) {
 135             if (filter.isPresent()) {
 136                 try {
 137                     final Optional<Document> filtered =
 138                             SubtreeFilter.applySubtreeNotificationFilter(this.filter.get(), notification.getDocument());
 139                     if (filtered.isPresent()) {
 140                         final Date eventTime = notification.getEventTime();
 141                         currentSession.sendMessage(new NetconfNotification(filtered.get(), eventTime));
 142                     }
 143                 } catch (DocumentedException e) {
 144                     LOG.warn("Failed to process notification {}", notification, e);
 145                     currentSession.sendMessage(notification);
 146                 }
 147             } else {
 148                 currentSession.sendMessage(notification);
 149             }
 150         }
 151     }
 152 }