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         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     }
  76
  77     @Override
  78     public void onDataTreeChanged(@Nonnull Collection<DataTreeCandidate> dataTreeCandidates) {
  79         this.dataTreeCandidates = dataTreeCandidates;
  80         final String xml = prepareXml();
  81         if (checkQueryParams(xml, this)) {
  82             prepareAndPostData(xml);
  83         }
  84     }
  85
  86     /**
  87      * Gets the name of the stream.
  88      *
  89      * @return The name of the stream.
  90      */
  91     @Override
  92     public String getStreamName() {
  93         return this.streamName;
  94     }
  95
  96     @Override
  97     public String getOutputType() {
  98         return this.outputType.getName();
  99     }
 100
 101     /**
 102      * Get path pointed to data in data store.
 103      *
 104      * @return Path pointed to data in data store.
 105      */
 106     public YangInstanceIdentifier getPath() {
 107         return this.path;
 108     }
 109
 110     /**
 111      * Prepare data of notification and data to client.
 112      *
 113      * @param xml   data
 114      */
 115     private void prepareAndPostData(final String xml) {
 116         final Event event = new Event(EventType.NOTIFY);
 117         if (this.outputType.equals(NotificationOutputType.JSON)) {
 118             event.setData(XML.toJSONObject(xml).toString());
 119         } else {
 120             event.setData(xml);
 121         }
 122         post(event);
 123     }
 124
 125     /**
 126      * Tracks events of data change by customer.
 127      */
 128
 129     /**
 130      * Prepare data in printable form and transform it to String.
 131      *
 132      * @return Data in printable form.
 133      */
 134     private String prepareXml() {
 135         final SchemaContext schemaContext = ControllerContext.getInstance().getGlobalSchema();
 136         final DataSchemaContextTree dataContextTree = DataSchemaContextTree.from(schemaContext);
 137         final Document doc = createDocument();
 138         final Element notificationElement = basePartDoc(doc);
 139
 140         final Element dataChangedNotificationEventElement = doc.createElementNS(
 141                 "urn:opendaylight:params:xml:ns:yang:controller:md:sal:remote", "data-changed-notification");
 142
 143         addValuesToDataChangedNotificationEventElement(doc, dataChangedNotificationEventElement,
 144                                                             this.dataTreeCandidates, schemaContext, dataContextTree);
 145         notificationElement.appendChild(dataChangedNotificationEventElement);
 146         return transformDoc(doc);
 147     }
 148
 149     /**
 150      * Adds values to data changed notification event element.
 151      *
 152      * @param doc
 153      *            {@link Document}
 154      * @param dataChangedNotificationEventElement
 155      *            {@link Element}
 156      * @param dataTreeCandidates
 157      *            {@link DataTreeCandidate}
 158      */
 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, DataTreeCandidateNode candidateNode,
 177                              YangInstanceIdentifier parentYiid, SchemaContext schemaContext,
 178                              DataSchemaContextTree dataSchemaContextTree) {
 179
 180         Optional<NormalizedNode<?,?>> optionalNormalizedNode = Optional.absent();
 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 = ControllerContext.getInstance().isNodeMixin(yiid);
 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);
 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      * @return {@link Node} node represented by changed event element.
 246      */
 247     private Node createDataChangeEventElement(final Document doc, final YangInstanceIdentifier path,
 248             final Operation operation) {
 249         final Element dataChangeEventElement = doc.createElement("data-change-event");
 250         final Element pathElement = doc.createElement("path");
 251         addPathAsValueToElement(path, pathElement);
 252         dataChangeEventElement.appendChild(pathElement);
 253
 254         final Element operationElement = doc.createElement("operation");
 255         operationElement.setTextContent(operation.value);
 256         dataChangeEventElement.appendChild(operationElement);
 257
 258         return dataChangeEventElement;
 259     }
 260
 261     private Node createCreatedChangedDataChangeEventElement(final Document doc,
 262             YangInstanceIdentifier path, NormalizedNode normalized, final Operation operation,
 263             final SchemaContext schemaContext, final DataSchemaContextTree dataSchemaContextTree) {
 264         final Element dataChangeEventElement = doc.createElement("data-change-event");
 265         final Element pathElement = doc.createElement("path");
 266         addPathAsValueToElement(path, pathElement);
 267         dataChangeEventElement.appendChild(pathElement);
 268
 269         final Element operationElement = doc.createElement("operation");
 270         operationElement.setTextContent(operation.value);
 271         dataChangeEventElement.appendChild(operationElement);
 272
 273         try {
 274             SchemaPath nodePath;
 275             if ((normalized instanceof MapEntryNode) || (normalized instanceof UnkeyedListEntryNode)) {
 276                 nodePath = dataSchemaContextTree.getChild(path).getDataSchemaNode().getPath();
 277             } else {
 278                 nodePath = dataSchemaContextTree.getChild(path).getDataSchemaNode().getPath().getParent();
 279             }
 280             final DOMResult domResult = writeNormalizedNode(normalized, schemaContext, nodePath);
 281             final Node result = doc.importNode(domResult.getNode().getFirstChild(), true);
 282             final Element dataElement = doc.createElement("data");
 283             dataElement.appendChild(result);
 284             dataChangeEventElement.appendChild(dataElement);
 285         } catch (final IOException e) {
 286             LOG.error("Error in writer ", e);
 287         } catch (final XMLStreamException e) {
 288             LOG.error("Error processing stream", e);
 289         }
 290
 291         return dataChangeEventElement;
 292     }
 293
 294     /**
 295      * Adds path as value to element.
 296      *
 297      * @param path
 298      *            Path to data in data store.
 299      * @param element
 300      *            {@link Element}
 301      */
 302     @SuppressWarnings("rawtypes")
 303     private void addPathAsValueToElement(final YangInstanceIdentifier path, final Element element) {
 304         final YangInstanceIdentifier normalizedPath = ControllerContext.getInstance().toXpathRepresentation(path);
 305         final StringBuilder textContent = new StringBuilder();
 306
 307         for (final PathArgument pathArgument : normalizedPath.getPathArguments()) {
 308             if (pathArgument instanceof YangInstanceIdentifier.AugmentationIdentifier) {
 309                 continue;
 310             }
 311             textContent.append("/");
 312             writeIdentifierWithNamespacePrefix(element, textContent, pathArgument.getNodeType());
 313             if (pathArgument instanceof NodeIdentifierWithPredicates) {
 314                 final Map<QName, Object> predicates = ((NodeIdentifierWithPredicates) pathArgument).getKeyValues();
 315                 for (final QName keyValue : predicates.keySet()) {
 316                     final String predicateValue = String.valueOf(predicates.get(keyValue));
 317                     textContent.append("[");
 318                     writeIdentifierWithNamespacePrefix(element, textContent, keyValue);
 319                     textContent.append("='");
 320                     textContent.append(predicateValue);
 321                     textContent.append("'");
 322                     textContent.append("]");
 323                 }
 324             } else if (pathArgument instanceof NodeWithValue) {
 325                 textContent.append("[.='");
 326                 textContent.append(((NodeWithValue) pathArgument).getValue());
 327                 textContent.append("'");
 328                 textContent.append("]");
 329             }
 330         }
 331         element.setTextContent(textContent.toString());
 332     }
 333
 334     /**
 335      * Writes identifier that consists of prefix and QName.
 336      *
 337      * @param element
 338      *            {@link Element}
 339      * @param textContent
 340      *            StringBuilder
 341      * @param qualifiedName
 342      *            QName
 343      */
 344     private static void writeIdentifierWithNamespacePrefix(final Element element, final StringBuilder textContent,
 345             final QName qualifiedName) {
 346         final Module module = ControllerContext.getInstance().getGlobalSchema()
 347                 .findModuleByNamespaceAndRevision(qualifiedName.getNamespace(), qualifiedName.getRevision());
 348
 349         textContent.append(module.getName());
 350         textContent.append(":");
 351         textContent.append(qualifiedName.getLocalName());
 352     }
 353
 354     /**
 355      * Consists of three types {@link Operation#CREATED},
 356      * {@link Operation#UPDATED} and {@link Operation#DELETED}.
 357      */
 358     private enum Operation {
 359         CREATED("created"), UPDATED("updated"), DELETED("deleted");
 360
 361         private final String value;
 362
 363         Operation(final String value) {
 364             this.value = value;
 365         }
 366     }
 367 }