restconf/restconf-nb/src/main/java/org/opendaylight/restconf/nb/rfc8040/streams/listeners/DeviceNotificationListenerAdaptor.java

   1 /*
   2  * Copyright (c) 2022 Opendaylight, 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.restconf.nb.rfc8040.streams.listeners;
   9
  10 import static java.util.Objects.requireNonNull;
  11
  12 import java.util.Set;
  13 import org.eclipse.jdt.annotation.NonNull;
  14 import org.opendaylight.mdsal.dom.api.DOMMountPointListener;
  15 import org.opendaylight.mdsal.dom.api.DOMMountPointService;
  16 import org.opendaylight.mdsal.dom.api.DOMNotificationService;
  17 import org.opendaylight.restconf.nb.rfc8040.streams.SSESessionHandler;
  18 import org.opendaylight.yang.gen.v1.urn.sal.restconf.event.subscription.rev140708.NotificationOutputTypeGrouping.NotificationOutputType;
  19 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  20 import org.opendaylight.yangtools.yang.common.QName;
  21 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  22 import org.opendaylight.yangtools.yang.model.api.EffectiveModelContext;
  23 import org.opendaylight.yangtools.yang.model.api.stmt.SchemaNodeIdentifier.Absolute;
  24 import org.slf4j.Logger;
  25 import org.slf4j.LoggerFactory;
  26
  27 /**
  28  * {@link DeviceNotificationListenerAdaptor} is responsible to track events on notifications.
  29  */
  30 public final class DeviceNotificationListenerAdaptor extends AbstractNotificationListenerAdaptor implements
  31     DOMMountPointListener {
  32
  33     private static final Logger LOG = LoggerFactory.getLogger(DeviceNotificationListenerAdaptor.class);
  34     private final @NonNull EffectiveModelContext effectiveModel;
  35
  36     private  final @NonNull DOMMountPointService mountPointService;
  37
  38     private ListenerRegistration<DOMMountPointListener> reg;
  39     private final YangInstanceIdentifier instanceIdentifier;
  40
  41
  42     public DeviceNotificationListenerAdaptor(final String streamName, final NotificationOutputType outputType,
  43             final EffectiveModelContext effectiveModel, final DOMMountPointService mountPointService,
  44             final YangInstanceIdentifier path) {
  45         // FIXME: a dummy QName due to contracts
  46         super(QName.create("dummy", "dummy"), streamName, outputType);
  47         this.effectiveModel = requireNonNull(effectiveModel);
  48         this.mountPointService = requireNonNull(mountPointService);
  49         instanceIdentifier = requireNonNull(path);
  50     }
  51
  52     public synchronized void listen(final DOMNotificationService notificationService, final Set<Absolute> paths) {
  53         if (!isListening()) {
  54             setRegistration(notificationService.registerNotificationListener(this, paths));
  55             reg = mountPointService.registerProvisionListener(this);
  56         }
  57     }
  58
  59     private synchronized void resetListenerRegistration() {
  60         if (reg != null) {
  61             reg.close();
  62             reg = null;
  63         }
  64     }
  65
  66     @Override
  67     EffectiveModelContext effectiveModel() {
  68         return effectiveModel;
  69     }
  70
  71     @Override
  72     public void onMountPointCreated(final YangInstanceIdentifier path) {
  73         // No-op
  74     }
  75
  76     @Override
  77     public void onMountPointRemoved(final YangInstanceIdentifier path) {
  78         if (instanceIdentifier.equals(path)) {
  79             getSubscribers().forEach(subscriber -> {
  80                 if (subscriber.isConnected()) {
  81                     subscriber.sendDataMessage("Device disconnected");
  82                 }
  83                 if (subscriber instanceof SSESessionHandler sseSessionHandler) {
  84                     try {
  85                         sseSessionHandler.close();
  86                     } catch (IllegalStateException e) {
  87                         LOG.warn("Ignoring exception while closing sse session");
  88                     }
  89                 }
  90             });
  91             ListenersBroker.getInstance().removeAndCloseDeviceNotificationListener(this);
  92             resetListenerRegistration();
  93         }
  94     }
  95
  96 }