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