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

   1 /*
   2  * Copyright (c) 2014, 2016 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.restconf.nb.rfc8040.streams.listeners;
   9
  10 import static java.util.Objects.requireNonNull;
  11
  12 import com.google.common.annotations.VisibleForTesting;
  13 import com.google.common.base.MoreObjects.ToStringHelper;
  14 import java.time.Instant;
  15 import java.util.Collection;
  16 import java.util.List;
  17 import java.util.Optional;
  18 import java.util.stream.Collectors;
  19 import org.opendaylight.mdsal.common.api.LogicalDatastoreType;
  20 import org.opendaylight.mdsal.dom.api.ClusteredDOMDataTreeChangeListener;
  21 import org.opendaylight.mdsal.dom.api.DOMDataBroker;
  22 import org.opendaylight.mdsal.dom.api.DOMDataTreeChangeService;
  23 import org.opendaylight.mdsal.dom.api.DOMDataTreeIdentifier;
  24 import org.opendaylight.yang.gen.v1.urn.sal.restconf.event.subscription.rev140708.NotificationOutputTypeGrouping.NotificationOutputType;
  25 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  26 import org.opendaylight.yangtools.yang.data.codec.gson.JSONCodecFactorySupplier;
  27 import org.opendaylight.yangtools.yang.data.tree.api.DataTreeCandidate;
  28 import org.slf4j.Logger;
  29 import org.slf4j.LoggerFactory;
  30
  31 /**
  32  * {@link ListenerAdapter} is responsible to track events, which occurred by changing data in data source.
  33  */
  34 public class ListenerAdapter extends AbstractCommonSubscriber<Collection<DataTreeCandidate>>
  35         implements ClusteredDOMDataTreeChangeListener {
  36     private static final Logger LOG = LoggerFactory.getLogger(ListenerAdapter.class);
  37     private static final DataTreeCandidateFormatterFactory JSON_FORMATTER_FACTORY =
  38             JSONDataTreeCandidateFormatter.createFactory(JSONCodecFactorySupplier.RFC7951);
  39
  40     private final YangInstanceIdentifier path;
  41
  42     /**
  43      * Creates new {@link ListenerAdapter} listener specified by path and stream name and register for subscribing.
  44      *
  45      * @param path       Path to data in data store.
  46      * @param streamName The name of the stream.
  47      * @param outputType Type of output on notification (JSON, XML).
  48      */
  49     @VisibleForTesting
  50     public ListenerAdapter(final YangInstanceIdentifier path, final String streamName,
  51             final NotificationOutputType outputType) {
  52         super(streamName, outputType, getFormatterFactory(outputType));
  53         this.path = requireNonNull(path);
  54     }
  55
  56     private static DataTreeCandidateFormatterFactory getFormatterFactory(final NotificationOutputType outputType) {
  57         return switch (outputType) {
  58             case JSON -> JSON_FORMATTER_FACTORY;
  59             case XML -> XMLDataTreeCandidateFormatter.FACTORY;
  60         };
  61     }
  62
  63     @Override
  64     public void onInitialData() {
  65         // No-op
  66     }
  67
  68     @Override
  69     @SuppressWarnings("checkstyle:IllegalCatch")
  70     public void onDataTreeChanged(final List<DataTreeCandidate> dataTreeCandidates) {
  71         final Instant now = Instant.now();
  72         if (!checkStartStop(now)) {
  73             return;
  74         }
  75
  76         final Optional<String> maybeData;
  77         try {
  78             maybeData = formatter().eventData(databindProvider.currentContext().modelContext(), dataTreeCandidates, now,
  79                 getLeafNodesOnly(), isSkipNotificationData(), getChangedLeafNodesOnly());
  80         } catch (final Exception e) {
  81             LOG.error("Failed to process notification {}",
  82                     dataTreeCandidates.stream().map(Object::toString).collect(Collectors.joining(",")), e);
  83             return;
  84         }
  85
  86         maybeData.ifPresent(this::post);
  87     }
  88
  89     /**
  90      * Get path pointed to data in data store.
  91      *
  92      * @return Path pointed to data in data store.
  93      */
  94     public YangInstanceIdentifier getPath() {
  95         return path;
  96     }
  97
  98     /**
  99      * Register data change listener in DOM data broker and set it to listener on stream.
 100      *
 101      * @param domDataBroker data broker for register data change listener
 102      * @param datastore     {@link LogicalDatastoreType}
 103      */
 104     public final synchronized void listen(final DOMDataBroker domDataBroker, final LogicalDatastoreType datastore) {
 105         if (!isListening()) {
 106             final DOMDataTreeChangeService changeService = domDataBroker.getExtensions()
 107                 .getInstance(DOMDataTreeChangeService.class);
 108             if (changeService == null) {
 109                 throw new UnsupportedOperationException("DOMDataBroker does not support the DOMDataTreeChangeService");
 110             }
 111
 112             setRegistration(changeService.registerDataTreeChangeListener(
 113                 new DOMDataTreeIdentifier(datastore, getPath()), this));
 114         }
 115     }
 116
 117     @Override
 118     ToStringHelper addToStringAttributes(final ToStringHelper helper) {
 119         return super.addToStringAttributes(helper.add("path", path));
 120     }
 121 }