restconf/restconf-nb/src/main/java/org/opendaylight/restconf/nb/rfc8040/streams/DataTreeChangeSource.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 com.google.common.collect.ImmutableMap;
  14 import java.time.Instant;
  15 import java.util.List;
  16 import org.eclipse.jdt.annotation.NonNull;
  17 import org.opendaylight.mdsal.common.api.LogicalDatastoreType;
  18 import org.opendaylight.mdsal.dom.api.ClusteredDOMDataTreeChangeListener;
  19 import org.opendaylight.mdsal.dom.api.DOMDataBroker;
  20 import org.opendaylight.mdsal.dom.api.DOMDataTreeChangeService;
  21 import org.opendaylight.mdsal.dom.api.DOMDataTreeIdentifier;
  22 import org.opendaylight.restconf.nb.rfc8040.databind.DatabindProvider;
  23 import org.opendaylight.restconf.nb.rfc8040.streams.RestconfStream.EncodingName;
  24 import org.opendaylight.restconf.nb.rfc8040.streams.RestconfStream.Sink;
  25 import org.opendaylight.restconf.nb.rfc8040.streams.RestconfStream.Source;
  26 import org.opendaylight.yangtools.concepts.Registration;
  27 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  28 import org.opendaylight.yangtools.yang.data.tree.api.DataTreeCandidate;
  29
  30 /**
  31  * A {@link RestconfStream} reporting changes on a particular data tree.
  32  */
  33 public final class DataTreeChangeSource extends Source<List<DataTreeCandidate>> {
  34     private static final ImmutableMap<EncodingName, DataTreeCandidateFormatterFactory> ENCODINGS = ImmutableMap.of(
  35         EncodingName.RFC8040_JSON, JSONDataTreeCandidateFormatter.FACTORY,
  36         EncodingName.RFC8040_XML, XMLDataTreeCandidateFormatter.FACTORY);
  37
  38     private final @NonNull DOMDataTreeChangeService changeService;
  39     private final @NonNull DatabindProvider databindProvider;
  40     private final @NonNull LogicalDatastoreType datastore;
  41     private final @NonNull YangInstanceIdentifier path;
  42
  43     DataTreeChangeSource(final DatabindProvider databindProvider, final DOMDataBroker dataBroker,
  44             final LogicalDatastoreType datastore, final YangInstanceIdentifier path) {
  45         super(ENCODINGS);
  46         this.databindProvider = requireNonNull(databindProvider);
  47         this.datastore = requireNonNull(datastore);
  48         this.path = requireNonNull(path);
  49
  50         final var dtcs = dataBroker.getExtensions().getInstance(DOMDataTreeChangeService.class);
  51         if (dtcs == null) {
  52             throw new UnsupportedOperationException("DOMDataBroker does not support the DOMDataTreeChangeService");
  53         }
  54         changeService = dtcs;
  55     }
  56
  57     @Override
  58     protected Registration start(final Sink<List<DataTreeCandidate>> sink) {
  59         return changeService.registerDataTreeChangeListener(new DOMDataTreeIdentifier(datastore, path),
  60             new ClusteredDOMDataTreeChangeListener() {
  61                 @Override
  62                 public void onDataTreeChanged(final List<DataTreeCandidate> changes) {
  63                     // FIXME: format one change at a time?
  64                     sink.publish(databindProvider.currentContext().modelContext(), changes, Instant.now());
  65                 }
  66
  67                 @Override
  68                 public void onInitialData() {
  69                     // No-op
  70                 }
  71             });
  72     }
  73
  74     @Override
  75     protected ToStringHelper addToStringAttributes(final ToStringHelper helper) {
  76         return super.addToStringAttributes(helper.add("path", path));
  77     }
  78 }