restconf/restconf-nb-bierman02/src/main/java/org/opendaylight/netconf/sal/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.netconf.sal.streams.listeners;
   9
  10 import com.google.common.base.Preconditions;
  11 import java.io.IOException;
  12 import java.time.Instant;
  13 import java.util.Collection;
  14 import java.util.Map;
  15 import java.util.Map.Entry;
  16 import javax.annotation.Nonnull;
  17 import javax.xml.stream.XMLStreamException;
  18 import javax.xml.transform.dom.DOMResult;
  19 import org.json.XML;
  20 import org.opendaylight.mdsal.dom.api.ClusteredDOMDataTreeChangeListener;
  21 import org.opendaylight.netconf.sal.restconf.impl.ControllerContext;
  22 import org.opendaylight.yang.gen.v1.urn.sal.restconf.event.subscription.rev140708.NotificationOutputTypeGrouping.NotificationOutputType;
  23 import org.opendaylight.yangtools.yang.common.QName;
  24 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  25 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifierWithPredicates;
  26 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeWithValue;
  27 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
  28 import org.opendaylight.yangtools.yang.data.api.schema.LeafNode;
  29 import org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode;
  30 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  31 import org.opendaylight.yangtools.yang.data.api.schema.UnkeyedListEntryNode;
  32 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  33 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidateNode;
  34 import org.opendaylight.yangtools.yang.data.util.DataSchemaContextTree;
  35 import org.opendaylight.yangtools.yang.model.api.Module;
  36 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  37 import org.opendaylight.yangtools.yang.model.api.SchemaPath;
  38 import org.slf4j.Logger;
  39 import org.slf4j.LoggerFactory;
  40 import org.w3c.dom.Document;
  41 import org.w3c.dom.Element;
  42 import org.w3c.dom.Node;
  43
  44 /**
  45  * {@link ListenerAdapter} is responsible to track events, which occurred by
  46  * changing data in data source.
  47  */
  48 public class ListenerAdapter extends AbstractCommonSubscriber implements ClusteredDOMDataTreeChangeListener {
  49
  50     private static final Logger LOG = LoggerFactory.getLogger(ListenerAdapter.class);
  51
  52     private final ControllerContext controllerContext;
  53     private final YangInstanceIdentifier path;
  54     private final String streamName;
  55     private final NotificationOutputType outputType;
  56
  57     /**
  58      * Creates new {@link ListenerAdapter} listener specified by path and stream
  59      * name and register for subscribing.
  60      *
  61      * @param path
  62      *            Path to data in data store.
  63      * @param streamName
  64      *            The name of the stream.
  65      * @param outputType
  66      *            Type of output on notification (JSON, XML)
  67      */
  68     ListenerAdapter(final YangInstanceIdentifier path, final String streamName,
  69             final NotificationOutputType outputType, final ControllerContext controllerContext) {
  70         register(this);
  71         this.outputType = Preconditions.checkNotNull(outputType);
  72         this.path = Preconditions.checkNotNull(path);
  73         Preconditions.checkArgument(streamName != null && !streamName.isEmpty());
  74         this.streamName = streamName;
  75         this.controllerContext = controllerContext;
  76     }
  77
  78     @Override
  79     public void onDataTreeChanged(@Nonnull final Collection<DataTreeCandidate> dataTreeCandidates) {
  80         final Instant now = Instant.now();
  81         if (!checkStartStop(now, this)) {
  82             return;
  83         }
  84
  85         final String xml = prepareXml(dataTreeCandidates);
  86         if (checkFilter(xml)) {
  87             prepareAndPostData(xml);
  88         }
  89     }
  90
  91     /**
  92      * Gets the name of the stream.
  93      *
  94      * @return The name of the stream.
  95      */
  96     @Override
  97     public String getStreamName() {
  98         return this.streamName;
  99     }
 100
 101     @Override
 102     public String getOutputType() {
 103         return this.outputType.getName();
 104     }
 105
 106     /**
 107      * Get path pointed to data in data store.
 108      *
 109      * @return Path pointed to data in data store.
 110      */
 111     public YangInstanceIdentifier getPath() {
 112         return this.path;
 113     }
 114
 115     /**
 116      * Prepare data of notification and data to client.
 117      *
 118      * @param xml   data
 119      */
 120     private void prepareAndPostData(final String xml) {
 121         final Event event = new Event(EventType.NOTIFY);
 122         if (this.outputType.equals(NotificationOutputType.JSON)) {
 123             event.setData(XML.toJSONObject(xml).toString());
 124         } else {
 125             event.setData(xml);
 126         }
 127         post(event);
 128     }
 129
 130     /**
 131      * Tracks events of data change by customer.
 132      */
 133
 134     /**
 135      * Prepare data in printable form and transform it to String.
 136      *
 137      * @return Data in printable form.
 138      */
 139     private String prepareXml(final Collection<DataTreeCandidate> candidates) {
 140         final SchemaContext schemaContext = controllerContext.getGlobalSchema();
 141         final DataSchemaContextTree dataContextTree = DataSchemaContextTree.from(schemaContext);
 142         final Document doc = createDocument();
 143         final Element notificationElement = basePartDoc(doc);
 144
 145         final Element dataChangedNotificationEventElement = doc.createElementNS(
 146                 "urn:opendaylight:params:xml:ns:yang:controller:md:sal:remote", "data-changed-notification");
 147
 148         addValuesToDataChangedNotificationEventElement(doc, dataChangedNotificationEventElement, candidates,
 149             schemaContext, dataContextTree);
 150         notificationElement.appendChild(dataChangedNotificationEventElement);
 151         return transformDoc(doc);
 152     }
 153
 154     /**
 155      * Adds values to data changed notification event element.
 156      *
 157      * @param doc
 158      *            {@link Document}
 159      * @param dataChangedNotificationEventElement
 160      *            {@link Element}
 161      * @param dataTreeCandidates
 162      *            {@link DataTreeCandidate}
 163      */
 164     private void addValuesToDataChangedNotificationEventElement(final Document doc,
 165             final Element dataChangedNotificationEventElement,
 166             final Collection<DataTreeCandidate> dataTreeCandidates,
 167             final SchemaContext schemaContext, final DataSchemaContextTree dataSchemaContextTree) {
 168
 169         for (DataTreeCandidate dataTreeCandidate : dataTreeCandidates) {
 170             DataTreeCandidateNode candidateNode = dataTreeCandidate.getRootNode();
 171             if (candidateNode == null) {
 172                 continue;
 173             }
 174             YangInstanceIdentifier yiid = dataTreeCandidate.getRootPath();
 175             addNodeToDataChangeNotificationEventElement(doc, dataChangedNotificationEventElement, candidateNode,
 176                     yiid.getParent(), schemaContext, dataSchemaContextTree);
 177         }
 178     }
 179
 180     private void addNodeToDataChangeNotificationEventElement(final Document doc,
 181             final Element dataChangedNotificationEventElement, final DataTreeCandidateNode candidateNode,
 182             final YangInstanceIdentifier parentYiid, final SchemaContext schemaContext,
 183             final DataSchemaContextTree dataSchemaContextTree) {
 184
 185         java.util.Optional<NormalizedNode<?,?>> optionalNormalizedNode = java.util.Optional.empty();
 186         switch (candidateNode.getModificationType()) {
 187             case APPEARED:
 188             case SUBTREE_MODIFIED:
 189             case WRITE:
 190                 optionalNormalizedNode = candidateNode.getDataAfter();
 191                 break;
 192             case DELETE:
 193             case DISAPPEARED:
 194                 optionalNormalizedNode = candidateNode.getDataBefore();
 195                 break;
 196             case UNMODIFIED:
 197             default:
 198                 break;
 199         }
 200
 201         if (!optionalNormalizedNode.isPresent()) {
 202             LOG.error("No node present in notification for {}", candidateNode);
 203             return;
 204         }
 205
 206         NormalizedNode<?,?> normalizedNode = optionalNormalizedNode.get();
 207         YangInstanceIdentifier yiid = YangInstanceIdentifier.builder(parentYiid)
 208                                                             .append(normalizedNode.getIdentifier()).build();
 209
 210         boolean isNodeMixin = controllerContext.isNodeMixin(yiid);
 211         boolean isSkippedNonLeaf = getLeafNodesOnly() && !(normalizedNode instanceof LeafNode);
 212         if (!isNodeMixin && !isSkippedNonLeaf) {
 213             Node node = null;
 214             switch (candidateNode.getModificationType()) {
 215                 case APPEARED:
 216                 case SUBTREE_MODIFIED:
 217                 case WRITE:
 218                     Operation op = candidateNode.getDataBefore().isPresent() ? Operation.UPDATED : Operation.CREATED;
 219                     node = createCreatedChangedDataChangeEventElement(doc, yiid, normalizedNode, op,
 220                             schemaContext, dataSchemaContextTree);
 221                     break;
 222                 case DELETE:
 223                 case DISAPPEARED:
 224                     node = createDataChangeEventElement(doc, yiid, Operation.DELETED);
 225                     break;
 226                 case UNMODIFIED:
 227                 default:
 228                     break;
 229             }
 230             if (node != null) {
 231                 dataChangedNotificationEventElement.appendChild(node);
 232             }
 233         }
 234
 235         for (DataTreeCandidateNode childNode : candidateNode.getChildNodes()) {
 236             addNodeToDataChangeNotificationEventElement(doc, dataChangedNotificationEventElement, childNode,
 237                                                                         yiid, schemaContext, dataSchemaContextTree);
 238         }
 239     }
 240
 241     /**
 242      * Creates changed event element from data.
 243      *
 244      * @param doc
 245      *            {@link Document}
 246      * @param dataPath
 247      *            Path to data in data store.
 248      * @param operation
 249      *            {@link Operation}
 250      * @return {@link Node} node represented by changed event element.
 251      */
 252     private Node createDataChangeEventElement(final Document doc, final YangInstanceIdentifier dataPath,
 253             final Operation operation) {
 254         final Element dataChangeEventElement = doc.createElement("data-change-event");
 255         final Element pathElement = doc.createElement("path");
 256         addPathAsValueToElement(dataPath, pathElement);
 257         dataChangeEventElement.appendChild(pathElement);
 258
 259         final Element operationElement = doc.createElement("operation");
 260         operationElement.setTextContent(operation.value);
 261         dataChangeEventElement.appendChild(operationElement);
 262
 263         return dataChangeEventElement;
 264     }
 265
 266     private Node createCreatedChangedDataChangeEventElement(final Document doc,
 267             final YangInstanceIdentifier eventPath, final NormalizedNode normalized, final Operation operation,
 268             final SchemaContext schemaContext, final DataSchemaContextTree dataSchemaContextTree) {
 269         final Element dataChangeEventElement = doc.createElement("data-change-event");
 270         final Element pathElement = doc.createElement("path");
 271         addPathAsValueToElement(eventPath, pathElement);
 272         dataChangeEventElement.appendChild(pathElement);
 273
 274         final Element operationElement = doc.createElement("operation");
 275         operationElement.setTextContent(operation.value);
 276         dataChangeEventElement.appendChild(operationElement);
 277
 278         try {
 279             SchemaPath nodePath;
 280             if (normalized instanceof MapEntryNode || normalized instanceof UnkeyedListEntryNode) {
 281                 nodePath = dataSchemaContextTree.getChild(eventPath).getDataSchemaNode().getPath();
 282             } else {
 283                 nodePath = dataSchemaContextTree.getChild(eventPath).getDataSchemaNode().getPath().getParent();
 284             }
 285             final DOMResult domResult = writeNormalizedNode(normalized, schemaContext, nodePath);
 286             final Node result = doc.importNode(domResult.getNode().getFirstChild(), true);
 287             final Element dataElement = doc.createElement("data");
 288             dataElement.appendChild(result);
 289             dataChangeEventElement.appendChild(dataElement);
 290         } catch (final IOException e) {
 291             LOG.error("Error in writer ", e);
 292         } catch (final XMLStreamException e) {
 293             LOG.error("Error processing stream", e);
 294         }
 295
 296         return dataChangeEventElement;
 297     }
 298
 299     /**
 300      * Adds path as value to element.
 301      *
 302      * @param dataPath
 303      *            Path to data in data store.
 304      * @param element
 305      *            {@link Element}
 306      */
 307     @SuppressWarnings("rawtypes")
 308     private void addPathAsValueToElement(final YangInstanceIdentifier dataPath, final Element element) {
 309         final YangInstanceIdentifier normalizedPath = controllerContext.toXpathRepresentation(dataPath);
 310         final StringBuilder textContent = new StringBuilder();
 311
 312         for (final PathArgument pathArgument : normalizedPath.getPathArguments()) {
 313             if (pathArgument instanceof YangInstanceIdentifier.AugmentationIdentifier) {
 314                 continue;
 315             }
 316             textContent.append("/");
 317             writeIdentifierWithNamespacePrefix(element, textContent, pathArgument.getNodeType());
 318             if (pathArgument instanceof NodeIdentifierWithPredicates) {
 319                 final Map<QName, Object> predicates = ((NodeIdentifierWithPredicates) pathArgument).getKeyValues();
 320                 for (final Entry<QName, Object> entry : predicates.entrySet()) {
 321                     final QName keyValue = entry.getKey();
 322                     final String predicateValue = String.valueOf(entry.getValue());
 323                     textContent.append("[");
 324                     writeIdentifierWithNamespacePrefix(element, textContent, keyValue);
 325                     textContent.append("='");
 326                     textContent.append(predicateValue);
 327                     textContent.append("'");
 328                     textContent.append("]");
 329                 }
 330             } else if (pathArgument instanceof NodeWithValue) {
 331                 textContent.append("[.='");
 332                 textContent.append(((NodeWithValue) pathArgument).getValue());
 333                 textContent.append("'");
 334                 textContent.append("]");
 335             }
 336         }
 337         element.setTextContent(textContent.toString());
 338     }
 339
 340     /**
 341      * Writes identifier that consists of prefix and QName.
 342      *
 343      * @param element
 344      *            {@link Element}
 345      * @param textContent
 346      *            StringBuilder
 347      * @param qualifiedName
 348      *            QName
 349      */
 350     private void writeIdentifierWithNamespacePrefix(final Element element, final StringBuilder textContent,
 351             final QName qualifiedName) {
 352         final Module module = controllerContext.getGlobalSchema().findModule(qualifiedName.getModule())
 353                 .get();
 354
 355         textContent.append(module.getName());
 356         textContent.append(":");
 357         textContent.append(qualifiedName.getLocalName());
 358     }
 359
 360     /**
 361      * Consists of three types {@link Operation#CREATED},
 362      * {@link Operation#UPDATED} and {@link Operation#DELETED}.
 363      */
 364     private enum Operation {
 365         CREATED("created"), UPDATED("updated"), DELETED("deleted");
 366
 367         private final String value;
 368
 369         Operation(final String value) {
 370             this.value = value;
 371         }
 372     }
 373 }