netconf/mdsal-netconf-notification/src/main/java/org/opendaylight/netconf/mdsal/notification/impl/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;
   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.List;
  15 import java.util.Optional;
  16 import org.opendaylight.netconf.api.DocumentedException;
  17 import org.opendaylight.netconf.api.NetconfSession;
  18 import org.opendaylight.netconf.api.messages.NotificationMessage;
  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.notifications.NetconfNotificationListener;
  23 import org.opendaylight.netconf.notifications.NetconfNotificationRegistry;
  24 import org.opendaylight.netconf.util.mapping.AbstractSingletonNetconfOperation;
  25 import org.opendaylight.netconf.util.messages.SubtreeFilter;
  26 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.netconf.notification._1._0.rev080714.CreateSubscriptionInput;
  27 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.netconf.notification._1._0.rev080714.StreamNameType;
  28 import org.opendaylight.yangtools.concepts.Registration;
  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<Registration> 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         checkArgument(startTime.isEmpty(), "StartTime element not yet supported");
  71
  72         // Stop time not supported
  73         final Optional<XmlElement> stopTime =
  74                 operationElement.getOnlyChildElementWithSameNamespaceOptionally("stopTime");
  75         checkArgument(stopTime.isEmpty(), "StopTime element not yet supported");
  76
  77         final StreamNameType streamNameType = parseStreamIfPresent(operationElement);
  78
  79         requireNonNull(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         subscriptions.add(notifications.registerNotificationListener(streamNameType,
  87             new NotificationSubscription(netconfSession, filter)));
  88
  89         return document.createElement(XmlNetconfConstants.OK);
  90     }
  91
  92     private static StreamNameType parseStreamIfPresent(final XmlElement operationElement) throws DocumentedException {
  93         final Optional<XmlElement> stream = operationElement.getOnlyChildElementWithSameNamespaceOptionally("stream");
  94         return stream.isPresent() ? new StreamNameType(stream.orElseThrow().getTextContent())
  95                 : NetconfNotificationManager.BASE_STREAM_NAME;
  96     }
  97
  98     @Override
  99     protected String getOperationName() {
 100         return CREATE_SUBSCRIPTION;
 101     }
 102
 103     @Override
 104     protected String getOperationNamespace() {
 105         return CreateSubscriptionInput.QNAME.getNamespace().toString();
 106     }
 107
 108     @Override
 109     public void setSession(final NetconfSession session) {
 110         netconfSession = session;
 111     }
 112
 113     @Override
 114     public void close() {
 115         netconfSession = null;
 116         // Unregister from notification streams
 117         subscriptions.forEach(Registration::close);
 118         subscriptions.clear();
 119     }
 120
 121     private static class NotificationSubscription implements NetconfNotificationListener {
 122         private final NetconfSession currentSession;
 123         private final XmlElement filter;
 124
 125         NotificationSubscription(final NetconfSession currentSession, final Optional<XmlElement> filter) {
 126             this.currentSession = currentSession;
 127             this.filter = filter.orElse(null);
 128         }
 129
 130         @Override
 131         public void onNotification(final StreamNameType stream, final NotificationMessage notification) {
 132             if (filter == null) {
 133                 currentSession.sendMessage(notification);
 134                 return;
 135             }
 136
 137             try {
 138                 final Optional<Document> filtered =
 139                         SubtreeFilter.applySubtreeNotificationFilter(filter, notification.getDocument());
 140                 if (filtered.isPresent()) {
 141                     currentSession.sendMessage(new NotificationMessage(filtered.orElseThrow(),
 142                         notification.getEventTime()));
 143                 }
 144             } catch (DocumentedException e) {
 145                 LOG.warn("Failed to process notification {}", notification, e);
 146                 currentSession.sendMessage(notification);
 147             }
 148         }
 149     }
 150 }