restconf/restconf-nb-rfc8040/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 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 java.util.Optional;
  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.yang.gen.v1.urn.sal.restconf.event.subscription.rev140708.NotificationOutputTypeGrouping.NotificationOutputType;
  22 import org.opendaylight.yangtools.yang.common.QName;
  23 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  24 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifierWithPredicates;
  25 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeWithValue;
  26 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
  27 import org.opendaylight.yangtools.yang.data.api.schema.LeafNode;
  28 import org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode;
  29 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  30 import org.opendaylight.yangtools.yang.data.api.schema.UnkeyedListEntryNode;
  31 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  32 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidateNode;
  33 import org.opendaylight.yangtools.yang.data.util.DataSchemaContextTree;
  34 import org.opendaylight.yangtools.yang.model.api.Module;
  35 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  36 import org.opendaylight.yangtools.yang.model.api.SchemaPath;
  37 import org.slf4j.Logger;
  38 import org.slf4j.LoggerFactory;
  39 import org.w3c.dom.Document;
  40 import org.w3c.dom.Element;
  41 import org.w3c.dom.Node;
  42
  43 /**
  44  * {@link ListenerAdapter} is responsible to track events, which occurred by
  45  * changing data in data source.
  46  */
  47 public class ListenerAdapter extends AbstractCommonSubscriber implements ClusteredDOMDataTreeChangeListener {
  48
  49     private static final Logger LOG = LoggerFactory.getLogger(ListenerAdapter.class);
  50
  51     private final YangInstanceIdentifier path;
  52     private final String streamName;
  53     private final NotificationOutputType outputType;
  54
  55     /**
  56      * Creates new {@link ListenerAdapter} listener specified by path and stream
  57      * name and register for subscribing.
  58      *
  59      * @param path
  60      *            Path to data in data store.
  61      * @param streamName
  62      *            The name of the stream.
  63      * @param outputType
  64      *            Type of output on notification (JSON, XML)
  65      */
  66     ListenerAdapter(final YangInstanceIdentifier path, final String streamName,
  67             final NotificationOutputType outputType) {
  68         register(this);
  69         setLocalNameOfPath(path.getLastPathArgument().getNodeType().getLocalName());
  70
  71         this.outputType = Preconditions.checkNotNull(outputType);
  72         this.path = Preconditions.checkNotNull(path);
  73         Preconditions.checkArgument(streamName != null && !streamName.isEmpty());
  74         this.streamName = streamName;
  75     }
  76
  77     @Override
  78     public void onDataTreeChanged(final Collection<DataTreeCandidate> dataTreeCandidates) {
  79         final Instant now = Instant.now();
  80         if (!checkStartStop(now, this)) {
  81             return;
  82         }
  83
  84         final String xml = prepareXml(dataTreeCandidates);
  85         if (checkFilter(xml)) {
  86             prepareAndPostData(xml);
  87         }
  88     }
  89
  90     /**
  91      * Gets the name of the stream.
  92      *
  93      * @return The name of the stream.
  94      */
  95     @Override
  96     public String getStreamName() {
  97         return this.streamName;
  98     }
  99
 100     @Override
 101     public String getOutputType() {
 102         return this.outputType.getName();
 103     }
 104
 105     /**
 106      * Get path pointed to data in data store.
 107      *
 108      * @return Path pointed to data in data store.
 109      */
 110     public YangInstanceIdentifier getPath() {
 111         return this.path;
 112     }
 113
 114     /**
 115      * Prepare data of notification and data to client.
 116      *
 117      * @param xml   data
 118      */
 119     private void prepareAndPostData(final String xml) {
 120         final Event event = new Event(EventType.NOTIFY);
 121         if (this.outputType.equals(NotificationOutputType.JSON)) {
 122             event.setData(XML.toJSONObject(xml).toString());
 123         } else {
 124             event.setData(xml);
 125         }
 126         post(event);
 127     }
 128
 129     /**
 130      * Tracks events of data change by customer.
 131      */
 132
 133     /**
 134      * Prepare data in printable form and transform it to String.
 135      *
 136      * @param dataTreeCandidates the DataTreeCandidates to transform
 137      *
 138      * @return Data in printable form.
 139      */
 140     private String prepareXml(final Collection<DataTreeCandidate> dataTreeCandidates) {
 141         final SchemaContext schemaContext = schemaHandler.get();
 142         final DataSchemaContextTree dataContextTree = DataSchemaContextTree.from(schemaContext);
 143         final Document doc = createDocument();
 144         final Element notificationElement = basePartDoc(doc);
 145
 146         final Element dataChangedNotificationEventElement = doc.createElementNS(
 147                 "urn:opendaylight:params:xml:ns:yang:controller:md:sal:remote", "data-changed-notification");
 148
 149         addValuesToDataChangedNotificationEventElement(doc, dataChangedNotificationEventElement, dataTreeCandidates,
 150                 schemaContext, dataContextTree);
 151         notificationElement.appendChild(dataChangedNotificationEventElement);
 152         return transformDoc(doc);
 153     }
 154
 155     /**
 156      * Adds values to data changed notification event element.
 157      */
 158     @SuppressWarnings("checkstyle:hiddenField")
 159     private void addValuesToDataChangedNotificationEventElement(final Document doc,
 160             final Element dataChangedNotificationEventElement,
 161             final Collection<DataTreeCandidate> dataTreeCandidates,
 162             final SchemaContext schemaContext, final DataSchemaContextTree dataSchemaContextTree) {
 163
 164         for (DataTreeCandidate dataTreeCandidate : dataTreeCandidates) {
 165             DataTreeCandidateNode candidateNode = dataTreeCandidate.getRootNode();
 166             if (candidateNode == null) {
 167                 continue;
 168             }
 169             YangInstanceIdentifier yiid = dataTreeCandidate.getRootPath();
 170             addNodeToDataChangeNotificationEventElement(doc, dataChangedNotificationEventElement, candidateNode,
 171                     yiid.getParent(), schemaContext, dataSchemaContextTree);
 172         }
 173     }
 174
 175     private void addNodeToDataChangeNotificationEventElement(final Document doc,
 176             final Element dataChangedNotificationEventElement, final DataTreeCandidateNode candidateNode,
 177             final YangInstanceIdentifier parentYiid, final SchemaContext schemaContext,
 178             final DataSchemaContextTree dataSchemaContextTree) {
 179
 180         Optional<NormalizedNode<?,?>> optionalNormalizedNode = Optional.empty();
 181         switch (candidateNode.getModificationType()) {
 182             case APPEARED:
 183             case SUBTREE_MODIFIED:
 184             case WRITE:
 185                 optionalNormalizedNode = candidateNode.getDataAfter();
 186                 break;
 187             case DELETE:
 188             case DISAPPEARED:
 189                 optionalNormalizedNode = candidateNode.getDataBefore();
 190                 break;
 191             case UNMODIFIED:
 192             default:
 193                 break;
 194         }
 195
 196         if (!optionalNormalizedNode.isPresent()) {
 197             LOG.error("No node present in notification for {}", candidateNode);
 198             return;
 199         }
 200
 201         NormalizedNode<?,?> normalizedNode = optionalNormalizedNode.get();
 202         YangInstanceIdentifier yiid = YangInstanceIdentifier.builder(parentYiid)
 203                                                             .append(normalizedNode.getIdentifier()).build();
 204
 205         boolean isNodeMixin = dataSchemaContextTree.getChild(yiid).isMixin();
 206         boolean isSkippedNonLeaf = getLeafNodesOnly() && !(normalizedNode instanceof LeafNode);
 207         if (!isNodeMixin && !isSkippedNonLeaf) {
 208             Node node = null;
 209             switch (candidateNode.getModificationType()) {
 210                 case APPEARED:
 211                 case SUBTREE_MODIFIED:
 212                 case WRITE:
 213                     Operation op = candidateNode.getDataBefore().isPresent() ? Operation.UPDATED : Operation.CREATED;
 214                     node = createCreatedChangedDataChangeEventElement(doc, yiid, normalizedNode, op,
 215                             schemaContext, dataSchemaContextTree);
 216                     break;
 217                 case DELETE:
 218                 case DISAPPEARED:
 219                     node = createDataChangeEventElement(doc, yiid, Operation.DELETED, schemaContext);
 220                     break;
 221                 case UNMODIFIED:
 222                 default:
 223                     break;
 224             }
 225             if (node != null) {
 226                 dataChangedNotificationEventElement.appendChild(node);
 227             }
 228         }
 229
 230         for (DataTreeCandidateNode childNode : candidateNode.getChildNodes()) {
 231             addNodeToDataChangeNotificationEventElement(doc, dataChangedNotificationEventElement, childNode,
 232                                                                         yiid, schemaContext, dataSchemaContextTree);
 233         }
 234     }
 235
 236     /**
 237      * Creates changed event element from data.
 238      *
 239      * @param doc
 240      *            {@link Document}
 241      * @param path
 242      *            Path to data in data store.
 243      * @param operation
 244      *            {@link Operation}
 245      * @param schemaContext
 246      *            schema context
 247      * @return {@link Node} node represented by changed event element.
 248      */
 249     private Node createDataChangeEventElement(final Document doc, final YangInstanceIdentifier eventPath,
 250             final Operation operation, final SchemaContext schemaContext) {
 251         final Element dataChangeEventElement = doc.createElement("data-change-event");
 252         final Element pathElement = doc.createElement("path");
 253         addPathAsValueToElement(eventPath, pathElement, schemaContext);
 254         dataChangeEventElement.appendChild(pathElement);
 255
 256         final Element operationElement = doc.createElement("operation");
 257         operationElement.setTextContent(operation.value);
 258         dataChangeEventElement.appendChild(operationElement);
 259
 260         return dataChangeEventElement;
 261     }
 262
 263     private Node createCreatedChangedDataChangeEventElement(final Document doc,
 264             final YangInstanceIdentifier eventPath, final NormalizedNode<?, ?> normalized, final Operation operation,
 265             final SchemaContext schemaContext, final DataSchemaContextTree dataSchemaContextTree) {
 266         final Element dataChangeEventElement = doc.createElement("data-change-event");
 267         final Element pathElement = doc.createElement("path");
 268         addPathAsValueToElement(eventPath, pathElement, schemaContext);
 269         dataChangeEventElement.appendChild(pathElement);
 270
 271         final Element operationElement = doc.createElement("operation");
 272         operationElement.setTextContent(operation.value);
 273         dataChangeEventElement.appendChild(operationElement);
 274
 275         try {
 276             SchemaPath nodePath;
 277             if (normalized instanceof MapEntryNode || normalized instanceof UnkeyedListEntryNode) {
 278                 nodePath = dataSchemaContextTree.getChild(eventPath).getDataSchemaNode().getPath();
 279             } else {
 280                 nodePath = dataSchemaContextTree.getChild(eventPath).getDataSchemaNode().getPath().getParent();
 281             }
 282             final DOMResult domResult = writeNormalizedNode(normalized, schemaContext, nodePath);
 283             final Node result = doc.importNode(domResult.getNode().getFirstChild(), true);
 284             final Element dataElement = doc.createElement("data");
 285             dataElement.appendChild(result);
 286             dataChangeEventElement.appendChild(dataElement);
 287         } catch (final IOException e) {
 288             LOG.error("Error in writer ", e);
 289         } catch (final XMLStreamException e) {
 290             LOG.error("Error processing stream", e);
 291         }
 292
 293         return dataChangeEventElement;
 294     }
 295
 296     /**
 297      * Adds path as value to element.
 298      *
 299      * @param eventPath
 300      *            Path to data in data store.
 301      * @param element
 302      *            {@link Element}
 303      * @param schemaContext
 304      *            schema context
 305      */
 306     @SuppressWarnings("rawtypes")
 307     private void addPathAsValueToElement(final YangInstanceIdentifier eventPath, final Element element,
 308             final SchemaContext schemaContext) {
 309         final StringBuilder textContent = new StringBuilder();
 310
 311         for (final PathArgument pathArgument : eventPath.getPathArguments()) {
 312             if (pathArgument instanceof YangInstanceIdentifier.AugmentationIdentifier) {
 313                 continue;
 314             }
 315             textContent.append("/");
 316             writeIdentifierWithNamespacePrefix(element, textContent, pathArgument.getNodeType(), schemaContext);
 317             if (pathArgument instanceof NodeIdentifierWithPredicates) {
 318                 final Map<QName, Object> predicates = ((NodeIdentifierWithPredicates) pathArgument).getKeyValues();
 319                 for (final Entry<QName, Object> entry : predicates.entrySet()) {
 320                     final QName keyValue = entry.getKey();
 321                     final String predicateValue = String.valueOf(entry.getValue());
 322                     textContent.append("[");
 323                     writeIdentifierWithNamespacePrefix(element, textContent, keyValue, schemaContext);
 324                     textContent.append("='");
 325                     textContent.append(predicateValue);
 326                     textContent.append("'");
 327                     textContent.append("]");
 328                 }
 329             } else if (pathArgument instanceof NodeWithValue) {
 330                 textContent.append("[.='");
 331                 textContent.append(((NodeWithValue) pathArgument).getValue());
 332                 textContent.append("'");
 333                 textContent.append("]");
 334             }
 335         }
 336         element.setTextContent(textContent.toString());
 337     }
 338
 339     /**
 340      * Writes identifier that consists of prefix and QName.
 341      *
 342      * @param element
 343      *            {@link Element}
 344      * @param textContent
 345      *            StringBuilder
 346      * @param qualifiedName
 347      *            QName
 348      * @param schemaContext
 349      *            schema context
 350      */
 351     private static void writeIdentifierWithNamespacePrefix(final Element element, final StringBuilder textContent,
 352             final QName qualifiedName, final SchemaContext schemaContext) {
 353         final Module module = schemaContext.findModule(qualifiedName.getModule()).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 }