netconf/mdsal-netconf-notification/src/main/java/org/opendaylight/netconf/mdsal/notification/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.mdsal.notification.impl.ops;
   9
  10 import static com.google.common.base.Preconditions.checkArgument;
  11 import static java.util.Objects.requireNonNull;
  12
  13 import java.util.ArrayList;
  14 import java.util.Date;
  15 import java.util.List;
  16 import java.util.Optional;
  17 import org.opendaylight.netconf.api.DocumentedException;
  18 import org.opendaylight.netconf.api.NetconfSession;
  19 import org.opendaylight.netconf.api.xml.XmlElement;
  20 import org.opendaylight.netconf.api.xml.XmlNetconfConstants;
  21 import org.opendaylight.netconf.mapping.api.SessionAwareNetconfOperation;
  22 import org.opendaylight.netconf.mdsal.notification.impl.NetconfNotificationManager;
  23 import org.opendaylight.netconf.notifications.NetconfNotification;
  24 import org.opendaylight.netconf.notifications.NetconfNotificationListener;
  25 import org.opendaylight.netconf.notifications.NetconfNotificationRegistry;
  26 import org.opendaylight.netconf.notifications.NotificationListenerRegistration;
  27 import org.opendaylight.netconf.util.mapping.AbstractSingletonNetconfOperation;
  28 import org.opendaylight.netconf.util.messages.SubtreeFilter;
  29 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.netconf.notification._1._0.rev080714.CreateSubscriptionInput;
  30 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.netconf.notification._1._0.rev080714.StreamNameType;
  31 import org.slf4j.Logger;
  32 import org.slf4j.LoggerFactory;
  33 import org.w3c.dom.Document;
  34 import org.w3c.dom.Element;
  35
  36 /**
  37  * Create subscription listens for create subscription requests
  38  * and registers notification listeners into notification registry.
  39  * Received notifications are sent to the client right away
  40  */
  41 public class CreateSubscription extends AbstractSingletonNetconfOperation
  42         implements SessionAwareNetconfOperation, AutoCloseable {
  43
  44     private static final Logger LOG = LoggerFactory.getLogger(CreateSubscription.class);
  45
  46     static final String CREATE_SUBSCRIPTION = "create-subscription";
  47
  48     private final NetconfNotificationRegistry notifications;
  49     private final List<NotificationListenerRegistration> subscriptions = new ArrayList<>();
  50     private NetconfSession netconfSession;
  51
  52     public CreateSubscription(final String netconfSessionIdForReporting,
  53                               final NetconfNotificationRegistry notifications) {
  54         super(netconfSessionIdForReporting);
  55         this.notifications = notifications;
  56     }
  57
  58     @Override
  59     protected Element handleWithNoSubsequentOperations(final Document document,
  60                                                        final XmlElement operationElement) throws DocumentedException {
  61         operationElement.checkName(CREATE_SUBSCRIPTION);
  62         operationElement.checkNamespace(CreateSubscriptionInput.QNAME.getNamespace().toString());
  63         // FIXME reimplement using CODEC_REGISTRY and parse everything into generated class instance
  64         // Binding doesn't support anyxml nodes yet, so filter could not be retrieved
  65         // xml -> normalized node -> CreateSubscriptionInput conversion could be slower than current approach
  66
  67         final Optional<XmlElement> filter = operationElement.getOnlyChildElementWithSameNamespaceOptionally("filter");
  68
  69         // Replay not supported
  70         final Optional<XmlElement> startTime =
  71                 operationElement.getOnlyChildElementWithSameNamespaceOptionally("startTime");
  72         checkArgument(!startTime.isPresent(), "StartTime element not yet supported");
  73
  74         // Stop time not supported
  75         final Optional<XmlElement> stopTime =
  76                 operationElement.getOnlyChildElementWithSameNamespaceOptionally("stopTime");
  77         checkArgument(!stopTime.isPresent(), "StopTime element not yet supported");
  78
  79         final StreamNameType streamNameType = parseStreamIfPresent(operationElement);
  80
  81         requireNonNull(netconfSession);
  82         // Premature streams are allowed (meaning listener can register even if no provider is available yet)
  83         if (!notifications.isStreamAvailable(streamNameType)) {
  84             LOG.warn("Registering premature stream {}. No publisher available yet for session {}", streamNameType,
  85                     getNetconfSessionIdForReporting());
  86         }
  87
  88         final NotificationListenerRegistration notificationListenerRegistration = notifications
  89                 .registerNotificationListener(streamNameType, new NotificationSubscription(netconfSession, filter));
  90         subscriptions.add(notificationListenerRegistration);
  91
  92         return document.createElement(XmlNetconfConstants.OK);
  93     }
  94
  95     private static StreamNameType parseStreamIfPresent(final XmlElement operationElement) throws DocumentedException {
  96         final Optional<XmlElement> stream = operationElement.getOnlyChildElementWithSameNamespaceOptionally("stream");
  97         return stream.isPresent() ? new StreamNameType(stream.get().getTextContent())
  98                 : NetconfNotificationManager.BASE_STREAM_NAME;
  99     }
 100
 101     @Override
 102     protected String getOperationName() {
 103         return CREATE_SUBSCRIPTION;
 104     }
 105
 106     @Override
 107     protected String getOperationNamespace() {
 108         return CreateSubscriptionInput.QNAME.getNamespace().toString();
 109     }
 110
 111     @Override
 112     public void setSession(final NetconfSession session) {
 113         this.netconfSession = session;
 114     }
 115
 116     @Override
 117     public void close() {
 118         netconfSession = null;
 119         // Unregister from notification streams
 120         for (final NotificationListenerRegistration subscription : subscriptions) {
 121             subscription.close();
 122         }
 123     }
 124
 125     private static class NotificationSubscription implements NetconfNotificationListener {
 126         private final NetconfSession currentSession;
 127         private final Optional<XmlElement> filter;
 128
 129         NotificationSubscription(final NetconfSession currentSession, final Optional<XmlElement> filter) {
 130             this.currentSession = currentSession;
 131             this.filter = filter;
 132         }
 133
 134         @Override
 135         public void onNotification(final StreamNameType stream, final NetconfNotification notification) {
 136             if (filter.isPresent()) {
 137                 try {
 138                     final Optional<Document> filtered =
 139                             SubtreeFilter.applySubtreeNotificationFilter(this.filter.get(), notification.getDocument());
 140                     if (filtered.isPresent()) {
 141                         final Date eventTime = notification.getEventTime();
 142                         currentSession.sendMessage(new NetconfNotification(filtered.get(), eventTime));
 143                     }
 144                 } catch (DocumentedException e) {
 145                     LOG.warn("Failed to process notification {}", notification, e);
 146                     currentSession.sendMessage(notification);
 147                 }
 148             } else {
 149                 currentSession.sendMessage(notification);
 150             }
 151         }
 152     }
 153 }