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