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.MoreObjects;
  11 import com.google.common.base.Preconditions;
  12 import java.io.IOException;
  13 import java.time.Instant;
  14 import java.util.Collection;
  15 import java.util.Map;
  16 import java.util.Map.Entry;
  17 import java.util.Optional;
  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.yang.gen.v1.urn.sal.restconf.event.subscription.rev140708.NotificationOutputTypeGrouping.NotificationOutputType;
  23 import org.opendaylight.yangtools.yang.common.QName;
  24 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  25 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifierWithPredicates;
  26 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeWithValue;
  27 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
  28 import org.opendaylight.yangtools.yang.data.api.schema.LeafNode;
  29 import org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode;
  30 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  31 import org.opendaylight.yangtools.yang.data.api.schema.UnkeyedListEntryNode;
  32 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  33 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidateNode;
  34 import org.opendaylight.yangtools.yang.data.util.DataSchemaContextNode;
  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 changing data in data source.
  47  */
  48 public class ListenerAdapter extends AbstractCommonSubscriber implements ClusteredDOMDataTreeChangeListener {
  49
  50     private static final Logger LOG = LoggerFactory.getLogger(ListenerAdapter.class);
  51
  52     private final YangInstanceIdentifier path;
  53     private final String streamName;
  54     private final NotificationOutputType outputType;
  55
  56     /**
  57      * Creates new {@link ListenerAdapter} listener specified by path and stream name and register for subscribing.
  58      *
  59      * @param path       Path to data in data store.
  60      * @param streamName The name of the stream.
  61      * @param outputType Type of output on notification (JSON, XML).
  62      */
  63     ListenerAdapter(final YangInstanceIdentifier path, final String streamName,
  64             final NotificationOutputType outputType) {
  65         register(this);
  66         setLocalNameOfPath(path.getLastPathArgument().getNodeType().getLocalName());
  67
  68         this.outputType = Preconditions.checkNotNull(outputType);
  69         this.path = Preconditions.checkNotNull(path);
  70         Preconditions.checkArgument(streamName != null && !streamName.isEmpty());
  71         this.streamName = streamName;
  72     }
  73
  74     @Override
  75     public void onDataTreeChanged(final Collection<DataTreeCandidate> dataTreeCandidates) {
  76         final Instant now = Instant.now();
  77         if (!checkStartStop(now, this)) {
  78             return;
  79         }
  80
  81         final String xml = prepareXml(dataTreeCandidates);
  82         if (checkFilter(xml)) {
  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 XML-formatted 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      * Prepare data in printable form and transform it to String.
 128      *
 129      * @param dataTreeCandidates Data-tree candidates to be transformed.
 130      * @return Data in printable form.
 131      */
 132     private String prepareXml(final Collection<DataTreeCandidate> dataTreeCandidates) {
 133         final SchemaContext schemaContext = schemaHandler.get();
 134         final DataSchemaContextTree dataContextTree = DataSchemaContextTree.from(schemaContext);
 135         final Document doc = createDocument();
 136         final Element notificationElement = basePartDoc(doc);
 137
 138         final Element dataChangedNotificationEventElement = doc.createElementNS(
 139                 "urn:opendaylight:params:xml:ns:yang:controller:md:sal:remote", "data-changed-notification");
 140
 141         addValuesToDataChangedNotificationEventElement(doc, dataChangedNotificationEventElement, dataTreeCandidates,
 142                 schemaContext, dataContextTree);
 143         notificationElement.appendChild(dataChangedNotificationEventElement);
 144         return transformDoc(doc);
 145     }
 146
 147     /**
 148      * Adds values to data changed notification event element.
 149      */
 150     @SuppressWarnings("checkstyle:hiddenField")
 151     private void addValuesToDataChangedNotificationEventElement(final Document doc,
 152             final Element dataChangedNotificationEventElement, final Collection<DataTreeCandidate> dataTreeCandidates,
 153             final SchemaContext schemaContext, final DataSchemaContextTree dataSchemaContextTree) {
 154
 155         for (DataTreeCandidate dataTreeCandidate : dataTreeCandidates) {
 156             DataTreeCandidateNode candidateNode = dataTreeCandidate.getRootNode();
 157             if (candidateNode == null) {
 158                 continue;
 159             }
 160             YangInstanceIdentifier yiid = dataTreeCandidate.getRootPath();
 161             addNodeToDataChangeNotificationEventElement(doc, dataChangedNotificationEventElement, candidateNode,
 162                     yiid.getParent(), schemaContext, dataSchemaContextTree);
 163         }
 164     }
 165
 166     private void addNodeToDataChangeNotificationEventElement(final Document doc,
 167             final Element dataChangedNotificationEventElement, final DataTreeCandidateNode candidateNode,
 168             final YangInstanceIdentifier parentYiid, final SchemaContext schemaContext,
 169             final DataSchemaContextTree dataSchemaContextTree) {
 170
 171         Optional<NormalizedNode<?, ?>> optionalNormalizedNode = Optional.empty();
 172         switch (candidateNode.getModificationType()) {
 173             case APPEARED:
 174             case SUBTREE_MODIFIED:
 175             case WRITE:
 176                 optionalNormalizedNode = candidateNode.getDataAfter();
 177                 break;
 178             case DELETE:
 179             case DISAPPEARED:
 180                 optionalNormalizedNode = candidateNode.getDataBefore();
 181                 break;
 182             case UNMODIFIED:
 183             default:
 184                 break;
 185         }
 186
 187         if (!optionalNormalizedNode.isPresent()) {
 188             LOG.error("No node present in notification for {}", candidateNode);
 189             return;
 190         }
 191
 192         NormalizedNode<?, ?> normalizedNode = optionalNormalizedNode.get();
 193         YangInstanceIdentifier yiid = YangInstanceIdentifier.builder(parentYiid)
 194                 .append(normalizedNode.getIdentifier()).build();
 195
 196         final Optional<DataSchemaContextNode<?>> childrenSchemaNode = dataSchemaContextTree.findChild(yiid);
 197         Preconditions.checkState(childrenSchemaNode.isPresent());
 198         boolean isNodeMixin = childrenSchemaNode.get().isMixin();
 199         boolean isSkippedNonLeaf = getLeafNodesOnly() && !(normalizedNode instanceof LeafNode);
 200         if (!isNodeMixin && !isSkippedNonLeaf) {
 201             Node node = null;
 202             switch (candidateNode.getModificationType()) {
 203                 case APPEARED:
 204                 case SUBTREE_MODIFIED:
 205                 case WRITE:
 206                     Operation op = candidateNode.getDataBefore().isPresent() ? Operation.UPDATED : Operation.CREATED;
 207                     node = createCreatedChangedDataChangeEventElement(doc, yiid, normalizedNode, op,
 208                             schemaContext, dataSchemaContextTree);
 209                     break;
 210                 case DELETE:
 211                 case DISAPPEARED:
 212                     node = createDataChangeEventElement(doc, yiid, schemaContext);
 213                     break;
 214                 case UNMODIFIED:
 215                 default:
 216                     break;
 217             }
 218             if (node != null) {
 219                 dataChangedNotificationEventElement.appendChild(node);
 220             }
 221         }
 222
 223         for (DataTreeCandidateNode childNode : candidateNode.getChildNodes()) {
 224             addNodeToDataChangeNotificationEventElement(
 225                     doc, dataChangedNotificationEventElement, childNode, yiid, schemaContext, dataSchemaContextTree);
 226         }
 227     }
 228
 229     /**
 230      * Creates data-changed event element from data.
 231      *
 232      * @param doc           {@link Document}
 233      * @param schemaContext Schema context.
 234      * @return {@link Node} represented by changed event element.
 235      */
 236     private Node createDataChangeEventElement(final Document doc, final YangInstanceIdentifier eventPath,
 237             final SchemaContext schemaContext) {
 238         final Element dataChangeEventElement = doc.createElement("data-change-event");
 239         final Element pathElement = doc.createElement("path");
 240         addPathAsValueToElement(eventPath, pathElement, schemaContext);
 241         dataChangeEventElement.appendChild(pathElement);
 242
 243         final Element operationElement = doc.createElement("operation");
 244         operationElement.setTextContent(Operation.DELETED.value);
 245         dataChangeEventElement.appendChild(operationElement);
 246
 247         return dataChangeEventElement;
 248     }
 249
 250     private Node createCreatedChangedDataChangeEventElement(final Document doc, final YangInstanceIdentifier eventPath,
 251             final NormalizedNode<?, ?> normalized, final Operation operation, final SchemaContext schemaContext,
 252             final DataSchemaContextTree dataSchemaContextTree) {
 253         final Element dataChangeEventElement = doc.createElement("data-change-event");
 254         final Element pathElement = doc.createElement("path");
 255         addPathAsValueToElement(eventPath, pathElement, schemaContext);
 256         dataChangeEventElement.appendChild(pathElement);
 257
 258         final Element operationElement = doc.createElement("operation");
 259         operationElement.setTextContent(operation.value);
 260         dataChangeEventElement.appendChild(operationElement);
 261
 262         try {
 263             SchemaPath nodePath;
 264             final Optional<DataSchemaContextNode<?>> childrenSchemaNode = dataSchemaContextTree.findChild(eventPath);
 265             Preconditions.checkState(childrenSchemaNode.isPresent());
 266             if (normalized instanceof MapEntryNode || normalized instanceof UnkeyedListEntryNode) {
 267                 nodePath = childrenSchemaNode.get().getDataSchemaNode().getPath();
 268             } else {
 269                 nodePath = childrenSchemaNode.get().getDataSchemaNode().getPath().getParent();
 270             }
 271             final DOMResult domResult = writeNormalizedNode(normalized, schemaContext, nodePath);
 272             final Node result = doc.importNode(domResult.getNode().getFirstChild(), true);
 273             final Element dataElement = doc.createElement("data");
 274             dataElement.appendChild(result);
 275             dataChangeEventElement.appendChild(dataElement);
 276         } catch (final IOException e) {
 277             LOG.error("Error in writer ", e);
 278         } catch (final XMLStreamException e) {
 279             LOG.error("Error processing stream", e);
 280         }
 281
 282         return dataChangeEventElement;
 283     }
 284
 285     /**
 286      * Adds path as value to element.
 287      *
 288      * @param eventPath     Path to data in data store.
 289      * @param element       {@link Element}
 290      * @param schemaContext Schema context.
 291      */
 292     @SuppressWarnings("rawtypes")
 293     private void addPathAsValueToElement(final YangInstanceIdentifier eventPath, final Element element,
 294             final SchemaContext schemaContext) {
 295         final StringBuilder textContent = new StringBuilder();
 296
 297         for (final PathArgument pathArgument : eventPath.getPathArguments()) {
 298             if (pathArgument instanceof YangInstanceIdentifier.AugmentationIdentifier) {
 299                 continue;
 300             }
 301             textContent.append("/");
 302             writeIdentifierWithNamespacePrefix(textContent, pathArgument.getNodeType(), schemaContext);
 303             if (pathArgument instanceof NodeIdentifierWithPredicates) {
 304                 final Map<QName, Object> predicates = ((NodeIdentifierWithPredicates) pathArgument).getKeyValues();
 305                 for (final Entry<QName, Object> entry : predicates.entrySet()) {
 306                     final QName keyValue = entry.getKey();
 307                     final String predicateValue = String.valueOf(entry.getValue());
 308                     textContent.append("[");
 309                     writeIdentifierWithNamespacePrefix(textContent, keyValue, schemaContext);
 310                     textContent.append("='");
 311                     textContent.append(predicateValue);
 312                     textContent.append("'");
 313                     textContent.append("]");
 314                 }
 315             } else if (pathArgument instanceof NodeWithValue) {
 316                 textContent.append("[.='");
 317                 textContent.append(((NodeWithValue) pathArgument).getValue());
 318                 textContent.append("'");
 319                 textContent.append("]");
 320             }
 321         }
 322         element.setTextContent(textContent.toString());
 323     }
 324
 325     /**
 326      * Writes identifier that consists of prefix and QName.
 327      *
 328      * @param textContent   Text builder that should be supplemented by QName and its modules name.
 329      * @param qualifiedName QName of the element.
 330      * @param schemaContext Schema context that holds modules which should contain module specified in QName.
 331      */
 332     private static void writeIdentifierWithNamespacePrefix(final StringBuilder textContent, final QName qualifiedName,
 333             final SchemaContext schemaContext) {
 334         final Optional<Module> module = schemaContext.findModule(qualifiedName.getModule());
 335         if (module.isPresent()) {
 336             textContent.append(module.get().getName());
 337             textContent.append(":");
 338             textContent.append(qualifiedName.getLocalName());
 339         } else {
 340             LOG.error("Cannot write identifier with namespace prefix in data-change listener adapter: "
 341                     + "Cannot find module in schema context for input QName {}.", qualifiedName);
 342             throw new IllegalStateException(String.format("Cannot find module in schema context for input QName %s.",
 343                     qualifiedName));
 344         }
 345     }
 346
 347     /**
 348      * Consists of three types {@link Operation#CREATED}, {@link Operation#UPDATED} and {@link Operation#DELETED}.
 349      */
 350     private enum Operation {
 351         CREATED("created"),
 352         UPDATED("updated"),
 353         DELETED("deleted");
 354
 355         private final String value;
 356
 357         Operation(final String value) {
 358             this.value = value;
 359         }
 360     }
 361
 362     @Override
 363     public String toString() {
 364         return MoreObjects.toStringHelper(this)
 365                 .add("path", path)
 366                 .add("stream-name", streamName)
 367                 .add("output-type", outputType)
 368                 .toString();
 369     }
 370 }