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 static com.google.common.base.Preconditions.checkArgument;
  11 import static com.google.common.base.Preconditions.checkState;
  12 import static java.util.Objects.requireNonNull;
  13
  14 import com.google.common.base.MoreObjects;
  15 import java.io.IOException;
  16 import java.time.Instant;
  17 import java.util.Collection;
  18 import java.util.Map.Entry;
  19 import java.util.Optional;
  20 import javax.xml.stream.XMLStreamException;
  21 import javax.xml.transform.dom.DOMResult;
  22 import org.json.XML;
  23 import org.opendaylight.mdsal.dom.api.ClusteredDOMDataTreeChangeListener;
  24 import org.opendaylight.yang.gen.v1.urn.sal.restconf.event.subscription.rev140708.NotificationOutputTypeGrouping.NotificationOutputType;
  25 import org.opendaylight.yangtools.yang.common.QName;
  26 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  27 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifierWithPredicates;
  28 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeWithValue;
  29 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
  30 import org.opendaylight.yangtools.yang.data.api.schema.LeafNode;
  31 import org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode;
  32 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  33 import org.opendaylight.yangtools.yang.data.api.schema.UnkeyedListEntryNode;
  34 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  35 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidateNode;
  36 import org.opendaylight.yangtools.yang.data.util.DataSchemaContextNode;
  37 import org.opendaylight.yangtools.yang.data.util.DataSchemaContextTree;
  38 import org.opendaylight.yangtools.yang.model.api.Module;
  39 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  40 import org.opendaylight.yangtools.yang.model.api.SchemaPath;
  41 import org.slf4j.Logger;
  42 import org.slf4j.LoggerFactory;
  43 import org.w3c.dom.Document;
  44 import org.w3c.dom.Element;
  45 import org.w3c.dom.Node;
  46
  47 /**
  48  * {@link ListenerAdapter} is responsible to track events, which occurred by changing data in data source.
  49  */
  50 public class ListenerAdapter extends AbstractCommonSubscriber implements ClusteredDOMDataTreeChangeListener {
  51
  52     private static final Logger LOG = LoggerFactory.getLogger(ListenerAdapter.class);
  53
  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 name and register for subscribing.
  60      *
  61      * @param path       Path to data in data store.
  62      * @param streamName The name of the stream.
  63      * @param outputType Type of output on notification (JSON, XML).
  64      */
  65     ListenerAdapter(final YangInstanceIdentifier path, final String streamName,
  66             final NotificationOutputType outputType) {
  67         setLocalNameOfPath(path.getLastPathArgument().getNodeType().getLocalName());
  68
  69         this.outputType = requireNonNull(outputType);
  70         this.path = requireNonNull(path);
  71         this.streamName = requireNonNull(streamName);
  72         checkArgument(!streamName.isEmpty());
  73     }
  74
  75     @Override
  76     public void onDataTreeChanged(final Collection<DataTreeCandidate> dataTreeCandidates) {
  77         final Instant now = Instant.now();
  78         if (!checkStartStop(now, this)) {
  79             return;
  80         }
  81
  82         final String xml = prepareXml(dataTreeCandidates);
  83         if (checkFilter(xml)) {
  84             prepareAndPostData(xml);
  85         }
  86     }
  87
  88     /**
  89      * Gets the name of the stream.
  90      *
  91      * @return The name of the stream.
  92      */
  93     @Override
  94     public String getStreamName() {
  95         return this.streamName;
  96     }
  97
  98     @Override
  99     public String getOutputType() {
 100         return this.outputType.getName();
 101     }
 102
 103     /**
 104      * Get path pointed to data in data store.
 105      *
 106      * @return Path pointed to data in data store.
 107      */
 108     public YangInstanceIdentifier getPath() {
 109         return this.path;
 110     }
 111
 112     /**
 113      * Prepare data of notification and data to client.
 114      *
 115      * @param xml XML-formatted data.
 116      */
 117     private void prepareAndPostData(final String xml) {
 118         if (this.outputType.equals(NotificationOutputType.JSON)) {
 119             post(XML.toJSONObject(xml).toString());
 120         } else {
 121             post(xml);
 122         }
 123     }
 124
 125     /**
 126      * Prepare data in printable form and transform it to String.
 127      *
 128      * @param dataTreeCandidates Data-tree candidates to be transformed.
 129      * @return Data in printable form.
 130      */
 131     private String prepareXml(final Collection<DataTreeCandidate> dataTreeCandidates) {
 132         final SchemaContext schemaContext = schemaHandler.get();
 133         final DataSchemaContextTree dataContextTree = DataSchemaContextTree.from(schemaContext);
 134         final Document doc = createDocument();
 135         final Element notificationElement = basePartDoc(doc);
 136
 137         final Element dataChangedNotificationEventElement = doc.createElementNS(
 138                 "urn:opendaylight:params:xml:ns:yang:controller:md:sal:remote", "data-changed-notification");
 139
 140         addValuesToDataChangedNotificationEventElement(doc, dataChangedNotificationEventElement, dataTreeCandidates,
 141                 schemaContext, dataContextTree);
 142         notificationElement.appendChild(dataChangedNotificationEventElement);
 143         return transformDoc(doc);
 144     }
 145
 146     /**
 147      * Adds values to data changed notification event element.
 148      */
 149     private void addValuesToDataChangedNotificationEventElement(final Document doc,
 150             final Element dataChangedNotificationEventElement, final Collection<DataTreeCandidate> dataTreeCandidates,
 151             final SchemaContext schemaContext, final DataSchemaContextTree dataSchemaContextTree) {
 152
 153         for (DataTreeCandidate dataTreeCandidate : dataTreeCandidates) {
 154             DataTreeCandidateNode candidateNode = dataTreeCandidate.getRootNode();
 155             if (candidateNode == null) {
 156                 continue;
 157             }
 158             YangInstanceIdentifier yiid = dataTreeCandidate.getRootPath();
 159             addNodeToDataChangeNotificationEventElement(doc, dataChangedNotificationEventElement, candidateNode,
 160                     yiid.getParent(), schemaContext, dataSchemaContextTree);
 161         }
 162     }
 163
 164     private void addNodeToDataChangeNotificationEventElement(final Document doc,
 165             final Element dataChangedNotificationEventElement, final DataTreeCandidateNode candidateNode,
 166             final YangInstanceIdentifier parentYiid, final SchemaContext schemaContext,
 167             final DataSchemaContextTree dataSchemaContextTree) {
 168
 169         Optional<NormalizedNode<?, ?>> optionalNormalizedNode = Optional.empty();
 170         switch (candidateNode.getModificationType()) {
 171             case APPEARED:
 172             case SUBTREE_MODIFIED:
 173             case WRITE:
 174                 optionalNormalizedNode = candidateNode.getDataAfter();
 175                 break;
 176             case DELETE:
 177             case DISAPPEARED:
 178                 optionalNormalizedNode = candidateNode.getDataBefore();
 179                 break;
 180             case UNMODIFIED:
 181             default:
 182                 break;
 183         }
 184
 185         if (!optionalNormalizedNode.isPresent()) {
 186             LOG.error("No node present in notification for {}", candidateNode);
 187             return;
 188         }
 189
 190         NormalizedNode<?, ?> normalizedNode = optionalNormalizedNode.get();
 191         YangInstanceIdentifier yiid = YangInstanceIdentifier.builder(parentYiid)
 192                 .append(normalizedNode.getIdentifier()).build();
 193
 194         final Optional<DataSchemaContextNode<?>> childrenSchemaNode = dataSchemaContextTree.findChild(yiid);
 195         checkState(childrenSchemaNode.isPresent());
 196         boolean isNodeMixin = childrenSchemaNode.get().isMixin();
 197         boolean isSkippedNonLeaf = getLeafNodesOnly() && !(normalizedNode instanceof LeafNode);
 198         if (!isNodeMixin && !isSkippedNonLeaf) {
 199             Node node = null;
 200             switch (candidateNode.getModificationType()) {
 201                 case APPEARED:
 202                 case SUBTREE_MODIFIED:
 203                 case WRITE:
 204                     Operation op = candidateNode.getDataBefore().isPresent() ? Operation.UPDATED : Operation.CREATED;
 205                     node = createCreatedChangedDataChangeEventElement(doc, yiid, normalizedNode, op,
 206                             schemaContext, dataSchemaContextTree);
 207                     break;
 208                 case DELETE:
 209                 case DISAPPEARED:
 210                     node = createDataChangeEventElement(doc, yiid, schemaContext);
 211                     break;
 212                 case UNMODIFIED:
 213                 default:
 214                     break;
 215             }
 216             if (node != null) {
 217                 dataChangedNotificationEventElement.appendChild(node);
 218             }
 219         }
 220
 221         for (DataTreeCandidateNode childNode : candidateNode.getChildNodes()) {
 222             addNodeToDataChangeNotificationEventElement(
 223                     doc, dataChangedNotificationEventElement, childNode, yiid, schemaContext, dataSchemaContextTree);
 224         }
 225     }
 226
 227     /**
 228      * Creates data-changed event element from data.
 229      *
 230      * @param doc           {@link Document}
 231      * @param schemaContext Schema context.
 232      * @return {@link Node} represented by changed event element.
 233      */
 234     private static Node createDataChangeEventElement(final Document doc, final YangInstanceIdentifier eventPath,
 235             final SchemaContext schemaContext) {
 236         final Element dataChangeEventElement = doc.createElement("data-change-event");
 237         final Element pathElement = doc.createElement("path");
 238         addPathAsValueToElement(eventPath, pathElement, schemaContext);
 239         dataChangeEventElement.appendChild(pathElement);
 240
 241         final Element operationElement = doc.createElement("operation");
 242         operationElement.setTextContent(Operation.DELETED.value);
 243         dataChangeEventElement.appendChild(operationElement);
 244
 245         return dataChangeEventElement;
 246     }
 247
 248     private Node createCreatedChangedDataChangeEventElement(final Document doc, final YangInstanceIdentifier eventPath,
 249             final NormalizedNode<?, ?> normalized, final Operation operation, final SchemaContext schemaContext,
 250             final DataSchemaContextTree dataSchemaContextTree) {
 251         final Element dataChangeEventElement = doc.createElement("data-change-event");
 252         final Element pathElement = doc.createElement("path");
 253         addPathAsValueToElement(eventPath, pathElement, schemaContext);
 254         dataChangeEventElement.appendChild(pathElement);
 255
 256         final Element operationElement = doc.createElement("operation");
 257         operationElement.setTextContent(operation.value);
 258         dataChangeEventElement.appendChild(operationElement);
 259
 260         try {
 261             SchemaPath nodePath;
 262             final Optional<DataSchemaContextNode<?>> childrenSchemaNode = dataSchemaContextTree.findChild(eventPath);
 263             checkState(childrenSchemaNode.isPresent());
 264             if (normalized instanceof MapEntryNode || normalized instanceof UnkeyedListEntryNode) {
 265                 nodePath = childrenSchemaNode.get().getDataSchemaNode().getPath();
 266             } else {
 267                 nodePath = childrenSchemaNode.get().getDataSchemaNode().getPath().getParent();
 268             }
 269             final DOMResult domResult = writeNormalizedNode(normalized, schemaContext, nodePath);
 270             final Node result = doc.importNode(domResult.getNode().getFirstChild(), true);
 271             final Element dataElement = doc.createElement("data");
 272             dataElement.appendChild(result);
 273             dataChangeEventElement.appendChild(dataElement);
 274         } catch (final IOException e) {
 275             LOG.error("Error in writer ", e);
 276         } catch (final XMLStreamException e) {
 277             LOG.error("Error processing stream", e);
 278         }
 279
 280         return dataChangeEventElement;
 281     }
 282
 283     /**
 284      * Adds path as value to element.
 285      *
 286      * @param eventPath     Path to data in data store.
 287      * @param element       {@link Element}
 288      * @param schemaContext Schema context.
 289      */
 290     private static void addPathAsValueToElement(final YangInstanceIdentifier eventPath, final Element element,
 291             final SchemaContext schemaContext) {
 292         final StringBuilder textContent = new StringBuilder();
 293
 294         for (final PathArgument pathArgument : eventPath.getPathArguments()) {
 295             if (pathArgument instanceof YangInstanceIdentifier.AugmentationIdentifier) {
 296                 continue;
 297             }
 298             textContent.append("/");
 299             writeIdentifierWithNamespacePrefix(textContent, pathArgument.getNodeType(), schemaContext);
 300             if (pathArgument instanceof NodeIdentifierWithPredicates) {
 301                 for (final Entry<QName, Object> entry : ((NodeIdentifierWithPredicates) pathArgument).entrySet()) {
 302                     final QName keyValue = entry.getKey();
 303                     final String predicateValue = String.valueOf(entry.getValue());
 304                     textContent.append("[");
 305                     writeIdentifierWithNamespacePrefix(textContent, keyValue, schemaContext);
 306                     textContent.append("='").append(predicateValue).append("']");
 307                 }
 308             } else if (pathArgument instanceof NodeWithValue) {
 309                 textContent.append("[.='").append(((NodeWithValue<?>) pathArgument).getValue()).append("']");
 310             }
 311         }
 312         element.setTextContent(textContent.toString());
 313     }
 314
 315     /**
 316      * Writes identifier that consists of prefix and QName.
 317      *
 318      * @param textContent   Text builder that should be supplemented by QName and its modules name.
 319      * @param qualifiedName QName of the element.
 320      * @param schemaContext Schema context that holds modules which should contain module specified in QName.
 321      */
 322     private static void writeIdentifierWithNamespacePrefix(final StringBuilder textContent, final QName qualifiedName,
 323             final SchemaContext schemaContext) {
 324         final Optional<Module> module = schemaContext.findModule(qualifiedName.getModule());
 325         if (module.isPresent()) {
 326             textContent.append(module.get().getName());
 327             textContent.append(":");
 328             textContent.append(qualifiedName.getLocalName());
 329         } else {
 330             LOG.error("Cannot write identifier with namespace prefix in data-change listener adapter: "
 331                     + "Cannot find module in schema context for input QName {}.", qualifiedName);
 332             throw new IllegalStateException(String.format("Cannot find module in schema context for input QName %s.",
 333                     qualifiedName));
 334         }
 335     }
 336
 337     /**
 338      * Consists of three types {@link Operation#CREATED}, {@link Operation#UPDATED} and {@link Operation#DELETED}.
 339      */
 340     private enum Operation {
 341         CREATED("created"),
 342         UPDATED("updated"),
 343         DELETED("deleted");
 344
 345         private final String value;
 346
 347         Operation(final String value) {
 348             this.value = value;
 349         }
 350     }
 351
 352     @Override
 353     public String toString() {
 354         return MoreObjects.toStringHelper(this)
 355                 .add("path", path)
 356                 .add("stream-name", streamName)
 357                 .add("output-type", outputType)
 358                 .toString();
 359     }
 360 }