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 static com.google.common.base.Preconditions.checkArgument;
  11 import static java.util.Objects.requireNonNull;
  12
  13 import java.io.IOException;
  14 import java.time.Instant;
  15 import java.util.Collection;
  16 import java.util.Map;
  17 import java.util.Map.Entry;
  18 import javax.xml.stream.XMLStreamException;
  19 import javax.xml.transform.dom.DOMResult;
  20 import org.json.XML;
  21 import org.opendaylight.mdsal.dom.api.ClusteredDOMDataTreeChangeListener;
  22 import org.opendaylight.netconf.sal.restconf.impl.ControllerContext;
  23 import org.opendaylight.yang.gen.v1.urn.sal.restconf.event.subscription.rev140708.NotificationOutputTypeGrouping.NotificationOutputType;
  24 import org.opendaylight.yangtools.yang.common.QName;
  25 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  26 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifierWithPredicates;
  27 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeWithValue;
  28 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
  29 import org.opendaylight.yangtools.yang.data.api.schema.LeafNode;
  30 import org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode;
  31 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  32 import org.opendaylight.yangtools.yang.data.api.schema.UnkeyedListEntryNode;
  33 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  34 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidateNode;
  35 import org.opendaylight.yangtools.yang.data.util.DataSchemaContextTree;
  36 import org.opendaylight.yangtools.yang.model.api.Module;
  37 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  38 import org.opendaylight.yangtools.yang.model.api.SchemaPath;
  39 import org.slf4j.Logger;
  40 import org.slf4j.LoggerFactory;
  41 import org.w3c.dom.Document;
  42 import org.w3c.dom.Element;
  43 import org.w3c.dom.Node;
  44
  45 /**
  46  * {@link ListenerAdapter} is responsible to track events, which occurred by
  47  * changing data in data source.
  48  */
  49 public class ListenerAdapter extends AbstractCommonSubscriber implements ClusteredDOMDataTreeChangeListener {
  50
  51     private static final Logger LOG = LoggerFactory.getLogger(ListenerAdapter.class);
  52
  53     private final ControllerContext controllerContext;
  54     private final YangInstanceIdentifier path;
  55     private final String streamName;
  56     private final NotificationOutputType outputType;
  57
  58     /**
  59      * Creates new {@link ListenerAdapter} listener specified by path and stream
  60      * name and register for subscribing.
  61      *
  62      * @param path
  63      *            Path to data in data store.
  64      * @param streamName
  65      *            The name of the stream.
  66      * @param outputType
  67      *            Type of output on notification (JSON, XML)
  68      */
  69     ListenerAdapter(final YangInstanceIdentifier path, final String streamName,
  70             final NotificationOutputType outputType, final ControllerContext controllerContext) {
  71         register(this);
  72         this.outputType = requireNonNull(outputType);
  73         this.path = requireNonNull(path);
  74         checkArgument(streamName != null && !streamName.isEmpty());
  75         this.streamName = streamName;
  76         this.controllerContext = controllerContext;
  77     }
  78
  79     @Override
  80     public void onDataTreeChanged(final Collection<DataTreeCandidate> dataTreeCandidates) {
  81         final Instant now = Instant.now();
  82         if (!checkStartStop(now, this)) {
  83             return;
  84         }
  85
  86         final String xml = prepareXml(dataTreeCandidates);
  87         if (checkFilter(xml)) {
  88             prepareAndPostData(xml);
  89         }
  90     }
  91
  92     /**
  93      * Gets the name of the stream.
  94      *
  95      * @return The name of the stream.
  96      */
  97     @Override
  98     public String getStreamName() {
  99         return this.streamName;
 100     }
 101
 102     @Override
 103     public String getOutputType() {
 104         return this.outputType.getName();
 105     }
 106
 107     /**
 108      * Get path pointed to data in data store.
 109      *
 110      * @return Path pointed to data in data store.
 111      */
 112     public YangInstanceIdentifier getPath() {
 113         return this.path;
 114     }
 115
 116     /**
 117      * Prepare data of notification and data to client.
 118      *
 119      * @param xml   data
 120      */
 121     private void prepareAndPostData(final String xml) {
 122         final Event event = new Event(EventType.NOTIFY);
 123         if (this.outputType.equals(NotificationOutputType.JSON)) {
 124             event.setData(XML.toJSONObject(xml).toString());
 125         } else {
 126             event.setData(xml);
 127         }
 128         post(event);
 129     }
 130
 131     /**
 132      * Tracks events of data change by customer.
 133      */
 134
 135     /**
 136      * Prepare data in printable form and transform it to String.
 137      *
 138      * @return Data in printable form.
 139      */
 140     private String prepareXml(final Collection<DataTreeCandidate> candidates) {
 141         final SchemaContext schemaContext = controllerContext.getGlobalSchema();
 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, candidates,
 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      * @param doc
 159      *            {@link Document}
 160      * @param dataChangedNotificationEventElement
 161      *            {@link Element}
 162      * @param dataTreeCandidates
 163      *            {@link DataTreeCandidate}
 164      */
 165     private void addValuesToDataChangedNotificationEventElement(final Document doc,
 166             final Element dataChangedNotificationEventElement,
 167             final Collection<DataTreeCandidate> dataTreeCandidates,
 168             final SchemaContext schemaContext, final DataSchemaContextTree dataSchemaContextTree) {
 169
 170         for (DataTreeCandidate dataTreeCandidate : dataTreeCandidates) {
 171             DataTreeCandidateNode candidateNode = dataTreeCandidate.getRootNode();
 172             if (candidateNode == null) {
 173                 continue;
 174             }
 175             YangInstanceIdentifier yiid = dataTreeCandidate.getRootPath();
 176             addNodeToDataChangeNotificationEventElement(doc, dataChangedNotificationEventElement, candidateNode,
 177                     yiid.getParent(), schemaContext, dataSchemaContextTree);
 178         }
 179     }
 180
 181     private void addNodeToDataChangeNotificationEventElement(final Document doc,
 182             final Element dataChangedNotificationEventElement, final DataTreeCandidateNode candidateNode,
 183             final YangInstanceIdentifier parentYiid, final SchemaContext schemaContext,
 184             final DataSchemaContextTree dataSchemaContextTree) {
 185
 186         java.util.Optional<NormalizedNode<?,?>> optionalNormalizedNode = java.util.Optional.empty();
 187         switch (candidateNode.getModificationType()) {
 188             case APPEARED:
 189             case SUBTREE_MODIFIED:
 190             case WRITE:
 191                 optionalNormalizedNode = candidateNode.getDataAfter();
 192                 break;
 193             case DELETE:
 194             case DISAPPEARED:
 195                 optionalNormalizedNode = candidateNode.getDataBefore();
 196                 break;
 197             case UNMODIFIED:
 198             default:
 199                 break;
 200         }
 201
 202         if (!optionalNormalizedNode.isPresent()) {
 203             LOG.error("No node present in notification for {}", candidateNode);
 204             return;
 205         }
 206
 207         NormalizedNode<?,?> normalizedNode = optionalNormalizedNode.get();
 208         YangInstanceIdentifier yiid = YangInstanceIdentifier.builder(parentYiid)
 209                                                             .append(normalizedNode.getIdentifier()).build();
 210
 211         boolean isNodeMixin = controllerContext.isNodeMixin(yiid);
 212         boolean isSkippedNonLeaf = getLeafNodesOnly() && !(normalizedNode instanceof LeafNode);
 213         if (!isNodeMixin && !isSkippedNonLeaf) {
 214             Node node = null;
 215             switch (candidateNode.getModificationType()) {
 216                 case APPEARED:
 217                 case SUBTREE_MODIFIED:
 218                 case WRITE:
 219                     Operation op = candidateNode.getDataBefore().isPresent() ? Operation.UPDATED : Operation.CREATED;
 220                     node = createCreatedChangedDataChangeEventElement(doc, yiid, normalizedNode, op,
 221                             schemaContext, dataSchemaContextTree);
 222                     break;
 223                 case DELETE:
 224                 case DISAPPEARED:
 225                     node = createDataChangeEventElement(doc, yiid, Operation.DELETED);
 226                     break;
 227                 case UNMODIFIED:
 228                 default:
 229                     break;
 230             }
 231             if (node != null) {
 232                 dataChangedNotificationEventElement.appendChild(node);
 233             }
 234         }
 235
 236         for (DataTreeCandidateNode childNode : candidateNode.getChildNodes()) {
 237             addNodeToDataChangeNotificationEventElement(doc, dataChangedNotificationEventElement, childNode,
 238                                                                         yiid, schemaContext, dataSchemaContextTree);
 239         }
 240     }
 241
 242     /**
 243      * Creates changed event element from data.
 244      *
 245      * @param doc
 246      *            {@link Document}
 247      * @param dataPath
 248      *            Path to data in data store.
 249      * @param operation
 250      *            {@link Operation}
 251      * @return {@link Node} node represented by changed event element.
 252      */
 253     private Node createDataChangeEventElement(final Document doc, final YangInstanceIdentifier dataPath,
 254             final Operation operation) {
 255         final Element dataChangeEventElement = doc.createElement("data-change-event");
 256         final Element pathElement = doc.createElement("path");
 257         addPathAsValueToElement(dataPath, pathElement);
 258         dataChangeEventElement.appendChild(pathElement);
 259
 260         final Element operationElement = doc.createElement("operation");
 261         operationElement.setTextContent(operation.value);
 262         dataChangeEventElement.appendChild(operationElement);
 263
 264         return dataChangeEventElement;
 265     }
 266
 267     private Node createCreatedChangedDataChangeEventElement(final Document doc,
 268             final YangInstanceIdentifier eventPath, final NormalizedNode normalized, final Operation operation,
 269             final SchemaContext schemaContext, final DataSchemaContextTree dataSchemaContextTree) {
 270         final Element dataChangeEventElement = doc.createElement("data-change-event");
 271         final Element pathElement = doc.createElement("path");
 272         addPathAsValueToElement(eventPath, pathElement);
 273         dataChangeEventElement.appendChild(pathElement);
 274
 275         final Element operationElement = doc.createElement("operation");
 276         operationElement.setTextContent(operation.value);
 277         dataChangeEventElement.appendChild(operationElement);
 278
 279         try {
 280             SchemaPath nodePath;
 281             if (normalized instanceof MapEntryNode || normalized instanceof UnkeyedListEntryNode) {
 282                 nodePath = dataSchemaContextTree.getChild(eventPath).getDataSchemaNode().getPath();
 283             } else {
 284                 nodePath = dataSchemaContextTree.getChild(eventPath).getDataSchemaNode().getPath().getParent();
 285             }
 286             final DOMResult domResult = writeNormalizedNode(normalized, schemaContext, nodePath);
 287             final Node result = doc.importNode(domResult.getNode().getFirstChild(), true);
 288             final Element dataElement = doc.createElement("data");
 289             dataElement.appendChild(result);
 290             dataChangeEventElement.appendChild(dataElement);
 291         } catch (final IOException e) {
 292             LOG.error("Error in writer ", e);
 293         } catch (final XMLStreamException e) {
 294             LOG.error("Error processing stream", e);
 295         }
 296
 297         return dataChangeEventElement;
 298     }
 299
 300     /**
 301      * Adds path as value to element.
 302      *
 303      * @param dataPath
 304      *            Path to data in data store.
 305      * @param element
 306      *            {@link Element}
 307      */
 308     @SuppressWarnings("rawtypes")
 309     private void addPathAsValueToElement(final YangInstanceIdentifier dataPath, final Element element) {
 310         final YangInstanceIdentifier normalizedPath = controllerContext.toXpathRepresentation(dataPath);
 311         final StringBuilder textContent = new StringBuilder();
 312
 313         for (final PathArgument pathArgument : normalizedPath.getPathArguments()) {
 314             if (pathArgument instanceof YangInstanceIdentifier.AugmentationIdentifier) {
 315                 continue;
 316             }
 317             textContent.append("/");
 318             writeIdentifierWithNamespacePrefix(element, textContent, pathArgument.getNodeType());
 319             if (pathArgument instanceof NodeIdentifierWithPredicates) {
 320                 final Map<QName, Object> predicates = ((NodeIdentifierWithPredicates) pathArgument).getKeyValues();
 321                 for (final Entry<QName, Object> entry : predicates.entrySet()) {
 322                     final QName keyValue = entry.getKey();
 323                     final String predicateValue = String.valueOf(entry.getValue());
 324                     textContent.append("[");
 325                     writeIdentifierWithNamespacePrefix(element, textContent, keyValue);
 326                     textContent.append("='");
 327                     textContent.append(predicateValue);
 328                     textContent.append("'");
 329                     textContent.append("]");
 330                 }
 331             } else if (pathArgument instanceof NodeWithValue) {
 332                 textContent.append("[.='");
 333                 textContent.append(((NodeWithValue) pathArgument).getValue());
 334                 textContent.append("'");
 335                 textContent.append("]");
 336             }
 337         }
 338         element.setTextContent(textContent.toString());
 339     }
 340
 341     /**
 342      * Writes identifier that consists of prefix and QName.
 343      *
 344      * @param element
 345      *            {@link Element}
 346      * @param textContent
 347      *            StringBuilder
 348      * @param qualifiedName
 349      *            QName
 350      */
 351     private void writeIdentifierWithNamespacePrefix(final Element element, final StringBuilder textContent,
 352             final QName qualifiedName) {
 353         final Module module = controllerContext.getGlobalSchema().findModule(qualifiedName.getModule())
 354                 .get();
 355
 356         textContent.append(module.getName());
 357         textContent.append(":");
 358         textContent.append(qualifiedName.getLocalName());
 359     }
 360
 361     /**
 362      * Consists of three types {@link Operation#CREATED},
 363      * {@link Operation#UPDATED} and {@link Operation#DELETED}.
 364      */
 365     private enum Operation {
 366         CREATED("created"), UPDATED("updated"), DELETED("deleted");
 367
 368         private final String value;
 369
 370         Operation(final String value) {
 371             this.value = value;
 372         }
 373     }
 374 }