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