opendaylight/md-sal/sal-rest-connector/src/main/java/org/opendaylight/controller/sal/streams/listeners/ListenerAdapter.java

   1 /*
   2  * Copyright (c) 2014 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.controller.sal.streams.listeners;
   9
  10 import io.netty.channel.Channel;
  11 import io.netty.handler.codec.http.websocketx.TextWebSocketFrame;
  12 import io.netty.util.internal.ConcurrentSet;
  13
  14 import java.io.ByteArrayOutputStream;
  15 import java.io.OutputStreamWriter;
  16 import java.io.UnsupportedEncodingException;
  17 import java.text.SimpleDateFormat;
  18 import java.util.Collection;
  19 import java.util.Date;
  20 import java.util.HashMap;
  21 import java.util.Map;
  22 import java.util.Map.Entry;
  23 import java.util.Random;
  24 import java.util.Set;
  25 import java.util.concurrent.Executors;
  26
  27 import javax.activation.UnsupportedDataTypeException;
  28 import javax.xml.parsers.DocumentBuilder;
  29 import javax.xml.parsers.DocumentBuilderFactory;
  30 import javax.xml.parsers.ParserConfigurationException;
  31 import javax.xml.transform.OutputKeys;
  32 import javax.xml.transform.Transformer;
  33 import javax.xml.transform.TransformerException;
  34 import javax.xml.transform.TransformerFactory;
  35 import javax.xml.transform.dom.DOMSource;
  36 import javax.xml.transform.stream.StreamResult;
  37
  38 import org.opendaylight.controller.md.sal.common.api.data.DataChangeEvent;
  39 import org.opendaylight.controller.sal.core.api.data.DataChangeListener;
  40 import org.opendaylight.controller.sal.rest.impl.XmlMapper;
  41 import org.opendaylight.controller.sal.restconf.impl.ControllerContext;
  42 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  43 import org.opendaylight.yangtools.yang.common.QName;
  44 import org.opendaylight.yangtools.yang.data.api.CompositeNode;
  45 import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier;
  46 import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier.NodeIdentifierWithPredicates;
  47 import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier.NodeWithValue;
  48 import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier.PathArgument;
  49 import org.opendaylight.yangtools.yang.model.api.DataNodeContainer;
  50 import org.slf4j.Logger;
  51 import org.slf4j.LoggerFactory;
  52 import org.w3c.dom.Document;
  53 import org.w3c.dom.Element;
  54 import org.w3c.dom.Node;
  55
  56 import com.google.common.base.Preconditions;
  57 import com.google.common.eventbus.AsyncEventBus;
  58 import com.google.common.eventbus.EventBus;
  59 import com.google.common.eventbus.Subscribe;
  60
  61 /**
  62  * {@link ListenerAdapter} is responsible to track events, which occurred by
  63  * changing data in data source.
  64  */
  65 public class ListenerAdapter implements DataChangeListener {
  66
  67     private static final Logger logger = LoggerFactory
  68             .getLogger(ListenerAdapter.class);
  69     private final XmlMapper xmlMapper = new XmlMapper();
  70     private final SimpleDateFormat rfc3339 = new SimpleDateFormat(
  71             "yyyy-MM-dd'T'hh:mm:ssZ");
  72
  73     private final InstanceIdentifier path;
  74     private ListenerRegistration<DataChangeListener> registration;
  75     private final String streamName;
  76     private Set<Channel> subscribers = new ConcurrentSet<>();
  77     private final EventBus eventBus;
  78     private final EventBusChangeRecorder eventBusChangeRecorder;
  79
  80     /**
  81      * Creates new {@link ListenerAdapter} listener specified by path and stream
  82      * name.
  83      *
  84      * @param path
  85      *            Path to data in data store.
  86      * @param streamName
  87      *            The name of the stream.
  88      */
  89     ListenerAdapter(InstanceIdentifier path, String streamName) {
  90         Preconditions.checkNotNull(path);
  91         Preconditions
  92                 .checkArgument(streamName != null && !streamName.isEmpty());
  93         this.path = path;
  94         this.streamName = streamName;
  95         eventBus = new AsyncEventBus(Executors.newSingleThreadExecutor());
  96         eventBusChangeRecorder = new EventBusChangeRecorder();
  97         eventBus.register(eventBusChangeRecorder);
  98     }
  99
 100     @Override
 101     public void onDataChanged(
 102             DataChangeEvent<InstanceIdentifier, CompositeNode> change) {
 103         if (!change.getCreatedConfigurationData().isEmpty()
 104                 || !change.getCreatedOperationalData().isEmpty()
 105                 || !change.getUpdatedConfigurationData().isEmpty()
 106                 || !change.getUpdatedOperationalData().isEmpty()
 107                 || !change.getRemovedConfigurationData().isEmpty()
 108                 || !change.getRemovedOperationalData().isEmpty()) {
 109             String xml = prepareXmlFrom(change);
 110             Event event = new Event(EventType.NOTIFY);
 111             event.setData(xml);
 112             eventBus.post(event);
 113         }
 114     }
 115
 116     /**
 117      * Tracks events of data change by customer.
 118      */
 119     private final class EventBusChangeRecorder {
 120         @Subscribe
 121         public void recordCustomerChange(Event event) {
 122             if (event.getType() == EventType.REGISTER) {
 123                 Channel subscriber = event.getSubscriber();
 124                 if (!subscribers.contains(subscriber)) {
 125                     subscribers.add(subscriber);
 126                 }
 127             } else if (event.getType() == EventType.DEREGISTER) {
 128                 subscribers.remove(event.getSubscriber());
 129                 Notificator
 130                         .removeListenerIfNoSubscriberExists(ListenerAdapter.this);
 131             } else if (event.getType() == EventType.NOTIFY) {
 132                 for (Channel subscriber : subscribers) {
 133                     if (subscriber.isActive()) {
 134                         logger.debug("Data are sent to subscriber {}:",
 135                                 subscriber.remoteAddress());
 136                         subscriber.writeAndFlush(new TextWebSocketFrame(event
 137                                 .getData()));
 138                     } else {
 139                         logger.debug(
 140                                 "Subscriber {} is removed - channel is not active yet.",
 141                                 subscriber.remoteAddress());
 142                         subscribers.remove(subscriber);
 143                     }
 144                 }
 145             }
 146         }
 147     }
 148
 149     /**
 150      * Represents event of specific {@link EventType} type, holds data and
 151      * {@link Channel} subscriber.
 152      */
 153     private final class Event {
 154         private final EventType type;
 155         private Channel subscriber;
 156         private String data;
 157
 158         /**
 159          * Creates new event specified by {@link EventType} type.
 160          *
 161          * @param type
 162          *            EventType
 163          */
 164         public Event(EventType type) {
 165             this.type = type;
 166         }
 167
 168         /**
 169          * Gets the {@link Channel} subscriber.
 170          *
 171          * @return Channel
 172          */
 173         public Channel getSubscriber() {
 174             return subscriber;
 175         }
 176
 177         /**
 178          * Sets subscriber for event.
 179          *
 180          * @param subscriber
 181          *            Channel
 182          */
 183         public void setSubscriber(Channel subscriber) {
 184             this.subscriber = subscriber;
 185         }
 186
 187         /**
 188          * Gets event data.
 189          *
 190          * @return String representation of event data.
 191          */
 192         public String getData() {
 193             return data;
 194         }
 195
 196         /**
 197          * Sets event data.
 198          *
 199          * @param String
 200          *            data.
 201          */
 202         public void setData(String data) {
 203             this.data = data;
 204         }
 205
 206         /**
 207          * Gets event type.
 208          *
 209          * @return The type of the event.
 210          */
 211         public EventType getType() {
 212             return type;
 213         }
 214     }
 215
 216     /**
 217      * Type of the event.
 218      */
 219     private enum EventType {
 220         REGISTER, DEREGISTER, NOTIFY;
 221     }
 222
 223     /**
 224      * Prepare data in printable form and transform it to String.
 225      *
 226      * @param change
 227      *            DataChangeEvent
 228      * @return Data in printable form.
 229      */
 230     private String prepareXmlFrom(
 231             DataChangeEvent<InstanceIdentifier, CompositeNode> change) {
 232         Document doc = createDocument();
 233         Element notificationElement = doc.createElementNS(
 234                 "urn:ietf:params:xml:ns:netconf:notification:1.0",
 235                 "notification");
 236         doc.appendChild(notificationElement);
 237
 238         Element eventTimeElement = doc.createElement("eventTime");
 239         eventTimeElement.setTextContent(toRFC3339(new Date()));
 240         notificationElement.appendChild(eventTimeElement);
 241
 242         Element dataChangedNotificationEventElement = doc.createElementNS(
 243                 "urn:opendaylight:params:xml:ns:yang:controller:md:sal:remote",
 244                 "data-changed-notification");
 245         addValuesToDataChangedNotificationEventElement(doc,
 246                 dataChangedNotificationEventElement, change);
 247         notificationElement.appendChild(dataChangedNotificationEventElement);
 248
 249         try {
 250             ByteArrayOutputStream out = new ByteArrayOutputStream();
 251             TransformerFactory tf = TransformerFactory.newInstance();
 252             Transformer transformer = tf.newTransformer();
 253             transformer
 254                     .setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "no");
 255             transformer.setOutputProperty(OutputKeys.METHOD, "xml");
 256             transformer.setOutputProperty(OutputKeys.INDENT, "yes");
 257             transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8");
 258             transformer.setOutputProperty(
 259                     "{http://xml.apache.org/xslt}indent-amount", "4");
 260             transformer.transform(new DOMSource(doc), new StreamResult(
 261                     new OutputStreamWriter(out, "UTF-8")));
 262             byte[] charData = out.toByteArray();
 263             return new String(charData, "UTF-8");
 264         } catch (TransformerException | UnsupportedEncodingException e) {
 265             String msg = "Error during transformation of Document into String";
 266             logger.error(msg, e);
 267             return msg;
 268         }
 269     }
 270
 271     /**
 272      * Formats data specified by RFC3339.
 273      *
 274      * @param d
 275      *            Date
 276      * @return Data specified by RFC3339.
 277      */
 278     private String toRFC3339(Date d) {
 279         return rfc3339.format(d).replaceAll("(\\d\\d)(\\d\\d)$", "$1:$2");
 280     }
 281
 282     /**
 283      * Creates {@link Document} document.
 284      *
 285      * @return {@link Document} document.
 286      */
 287     private Document createDocument() {
 288         DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
 289         Document doc = null;
 290         try {
 291             DocumentBuilder bob = dbf.newDocumentBuilder();
 292             doc = bob.newDocument();
 293         } catch (ParserConfigurationException e) {
 294             return null;
 295         }
 296         return doc;
 297     }
 298
 299     /**
 300      * Adds values to data changed notification event element.
 301      *
 302      * @param doc
 303      *            {@link Document}
 304      * @param dataChangedNotificationEventElement
 305      *            {@link Element}
 306      * @param change
 307      *            {@link DataChangeEvent}
 308      */
 309     private void addValuesToDataChangedNotificationEventElement(Document doc,
 310             Element dataChangedNotificationEventElement,
 311             DataChangeEvent<InstanceIdentifier, CompositeNode> change) {
 312         addValuesFromDataToElement(doc, change.getCreatedConfigurationData(),
 313                 dataChangedNotificationEventElement, Store.CONFIG,
 314                 Operation.CREATED);
 315         addValuesFromDataToElement(doc, change.getCreatedOperationalData(),
 316                 dataChangedNotificationEventElement, Store.OPERATION,
 317                 Operation.CREATED);
 318         if (change.getCreatedConfigurationData().isEmpty()) {
 319             addValuesFromDataToElement(doc,
 320                     change.getUpdatedConfigurationData(),
 321                     dataChangedNotificationEventElement, Store.CONFIG,
 322                     Operation.UPDATED);
 323         }
 324         if (change.getCreatedOperationalData().isEmpty()) {
 325             addValuesFromDataToElement(doc, change.getUpdatedOperationalData(),
 326                     dataChangedNotificationEventElement, Store.OPERATION,
 327                     Operation.UPDATED);
 328         }
 329         addValuesFromDataToElement(doc, change.getRemovedConfigurationData(),
 330                 dataChangedNotificationEventElement, Store.CONFIG,
 331                 Operation.DELETED);
 332         addValuesFromDataToElement(doc, change.getRemovedOperationalData(),
 333                 dataChangedNotificationEventElement, Store.OPERATION,
 334                 Operation.DELETED);
 335     }
 336
 337     /**
 338      * Adds values from data to element.
 339      *
 340      * @param doc
 341      *            {@link Document}
 342      * @param data
 343      *            Set of {@link InstanceIdentifier}.
 344      * @param element
 345      *            {@link Element}
 346      * @param store
 347      *            {@link Store}
 348      * @param operation
 349      *            {@link Operation}
 350      */
 351     private void addValuesFromDataToElement(Document doc,
 352             Set<InstanceIdentifier> data, Element element, Store store,
 353             Operation operation) {
 354         if (data == null || data.isEmpty()) {
 355             return;
 356         }
 357         for (InstanceIdentifier path : data) {
 358             Node node = createDataChangeEventElement(doc, path, null, store,
 359                     operation);
 360             element.appendChild(node);
 361         }
 362     }
 363
 364     /**
 365      * Adds values from data to element.
 366      *
 367      * @param doc
 368      *            {@link Document}
 369      * @param data
 370      *            Map of {@link InstanceIdentifier} and {@link CompositeNode}.
 371      * @param element
 372      *            {@link Element}
 373      * @param store
 374      *            {@link Store}
 375      * @param operation
 376      *            {@link Operation}
 377      */
 378     private void addValuesFromDataToElement(Document doc,
 379             Map<InstanceIdentifier, CompositeNode> data, Element element,
 380             Store store, Operation operation) {
 381         if (data == null || data.isEmpty()) {
 382             return;
 383         }
 384         for (Entry<InstanceIdentifier, CompositeNode> entry : data.entrySet()) {
 385             Node node = createDataChangeEventElement(doc, entry.getKey(),
 386                     entry.getValue(), store, operation);
 387             element.appendChild(node);
 388         }
 389     }
 390
 391     /**
 392      * Creates changed event element from data.
 393      *
 394      * @param doc
 395      *            {@link Document}
 396      * @param path
 397      *            Path to data in data store.
 398      * @param data
 399      *            {@link CompositeNode}
 400      * @param store
 401      *            {@link Store}
 402      * @param operation
 403      *            {@link Operation}
 404      * @return {@link Node} node represented by changed event element.
 405      */
 406     private Node createDataChangeEventElement(Document doc,
 407             InstanceIdentifier path, CompositeNode data, Store store,
 408             Operation operation) {
 409         Element dataChangeEventElement = doc.createElement("data-change-event");
 410
 411         Element pathElement = doc.createElement("path");
 412         addPathAsValueToElement(path, pathElement);
 413         dataChangeEventElement.appendChild(pathElement);
 414
 415         Element storeElement = doc.createElement("store");
 416         storeElement.setTextContent(store.value);
 417         dataChangeEventElement.appendChild(storeElement);
 418
 419         Element operationElement = doc.createElement("operation");
 420         operationElement.setTextContent(operation.value);
 421         dataChangeEventElement.appendChild(operationElement);
 422
 423         if (data != null) {
 424             Element dataElement = doc.createElement("data");
 425             Node dataAnyXml = translateToXml(path, data);
 426             Node adoptedNode = doc.adoptNode(dataAnyXml);
 427             dataElement.appendChild(adoptedNode);
 428             dataChangeEventElement.appendChild(dataElement);
 429         }
 430
 431         return dataChangeEventElement;
 432     }
 433
 434     /**
 435      * Translates {@link CompositeNode} data to XML format.
 436      *
 437      * @param path
 438      *            Path to data in data store.
 439      * @param data
 440      *            {@link CompositeNode}
 441      * @return Data in XML format.
 442      */
 443     private Node translateToXml(InstanceIdentifier path, CompositeNode data) {
 444         DataNodeContainer schemaNode = ControllerContext.getInstance()
 445                 .getDataNodeContainerFor(path);
 446         if (schemaNode == null) {
 447             logger.info(
 448                     "Path '{}' contains node with unsupported type (supported type is Container or List) or some node was not found.",
 449                     path);
 450             return null;
 451         }
 452         try {
 453             Document xml = xmlMapper.write(data, schemaNode);
 454             return xml.getFirstChild();
 455         } catch (UnsupportedDataTypeException e) {
 456             logger.error(
 457                     "Error occured during translation of notification to XML.",
 458                     e);
 459             return null;
 460         }
 461     }
 462
 463     /**
 464      * Adds path as value to element.
 465      *
 466      * @param path
 467      *            Path to data in data store.
 468      * @param element
 469      *            {@link Element}
 470      */
 471     private void addPathAsValueToElement(InstanceIdentifier path,
 472             Element element) {
 473         // Map< key = namespace, value = prefix>
 474         Map<String, String> prefixes = new HashMap<>();
 475         InstanceIdentifier instanceIdentifier = path;
 476         StringBuilder textContent = new StringBuilder();
 477         for (PathArgument pathArgument : instanceIdentifier.getPath()) {
 478             textContent.append("/");
 479             writeIdentifierWithNamespacePrefix(element, textContent,
 480                     pathArgument.getNodeType(), prefixes);
 481             if (pathArgument instanceof NodeIdentifierWithPredicates) {
 482                 Map<QName, Object> predicates = ((NodeIdentifierWithPredicates) pathArgument)
 483                         .getKeyValues();
 484                 for (QName keyValue : predicates.keySet()) {
 485                     String predicateValue = String.valueOf(predicates
 486                             .get(keyValue));
 487                     textContent.append("[");
 488                     writeIdentifierWithNamespacePrefix(element, textContent,
 489                             keyValue, prefixes);
 490                     textContent.append("='");
 491                     textContent.append(predicateValue);
 492                     textContent.append("'");
 493                     textContent.append("]");
 494                 }
 495             } else if (pathArgument instanceof NodeWithValue) {
 496                 textContent.append("[.='");
 497                 textContent.append(((NodeWithValue) pathArgument).getValue());
 498                 textContent.append("'");
 499                 textContent.append("]");
 500             }
 501         }
 502         element.setTextContent(textContent.toString());
 503     }
 504
 505     /**
 506      * Writes identifier that consists of prefix and QName.
 507      *
 508      * @param element
 509      *            {@link Element}
 510      * @param textContent
 511      *            StringBuilder
 512      * @param qName
 513      *            QName
 514      * @param prefixes
 515      *            Map of namespaces and prefixes.
 516      */
 517     private static void writeIdentifierWithNamespacePrefix(Element element,
 518             StringBuilder textContent, QName qName, Map<String, String> prefixes) {
 519         String namespace = qName.getNamespace().toString();
 520         String prefix = prefixes.get(namespace);
 521         if (prefix == null) {
 522             prefix = qName.getPrefix();
 523             if (prefix == null || prefix.isEmpty()
 524                     || prefixes.containsValue(prefix)) {
 525                 prefix = generateNewPrefix(prefixes.values());
 526             }
 527         }
 528
 529         element.setAttribute("xmlns:" + prefix, namespace);
 530         textContent.append(prefix);
 531         prefixes.put(namespace, prefix);
 532
 533         textContent.append(":");
 534         textContent.append(qName.getLocalName());
 535     }
 536
 537     /**
 538      * Generates new prefix which consists of four random characters <a-z>.
 539      *
 540      * @param prefixes
 541      *            Collection of prefixes.
 542      * @return New prefix which consists of four random characters <a-z>.
 543      */
 544     private static String generateNewPrefix(Collection<String> prefixes) {
 545         StringBuilder result = null;
 546         Random random = new Random();
 547         do {
 548             result = new StringBuilder();
 549             for (int i = 0; i < 4; i++) {
 550                 int randomNumber = 0x61 + (Math.abs(random.nextInt()) % 26);
 551                 result.append(Character.toChars(randomNumber));
 552             }
 553         } while (prefixes.contains(result.toString()));
 554
 555         return result.toString();
 556     }
 557
 558     /**
 559      * Gets path pointed to data in data store.
 560      *
 561      * @return Path pointed to data in data store.
 562      */
 563     public InstanceIdentifier getPath() {
 564         return path;
 565     }
 566
 567     /**
 568      * Sets {@link ListenerRegistration} registration.
 569      *
 570      * @param registration
 571      *            ListenerRegistration<DataChangeListener>
 572      */
 573     public void setRegistration(
 574             ListenerRegistration<DataChangeListener> registration) {
 575         this.registration = registration;
 576     }
 577
 578     /**
 579      * Gets the name of the stream.
 580      *
 581      * @return The name of the stream.
 582      */
 583     public String getStreamName() {
 584         return streamName;
 585     }
 586
 587     /**
 588      * Removes all subscribers and unregisters event bus change recorder form
 589      * event bus.
 590      */
 591     public void close() throws Exception {
 592         subscribers = new ConcurrentSet<>();
 593         registration.close();
 594         registration = null;
 595         eventBus.unregister(eventBusChangeRecorder);
 596     }
 597
 598     /**
 599      * Checks if {@link ListenerRegistration} registration exist.
 600      *
 601      * @return True if exist, false otherwise.
 602      */
 603     public boolean isListening() {
 604         return registration == null ? false : true;
 605     }
 606
 607     /**
 608      * Creates event of type {@link EventType#REGISTER}, set {@link Channel}
 609      * subscriber to the event and post event into event bus.
 610      *
 611      * @param subscriber
 612      *            Channel
 613      */
 614     public void addSubscriber(Channel subscriber) {
 615         if (!subscriber.isActive()) {
 616             logger.debug("Channel is not active between websocket server and subscriber {}"
 617                     + subscriber.remoteAddress());
 618         }
 619         Event event = new Event(EventType.REGISTER);
 620         event.setSubscriber(subscriber);
 621         eventBus.post(event);
 622     }
 623
 624     /**
 625      * Creates event of type {@link EventType#DEREGISTER}, sets {@link Channel}
 626      * subscriber to the event and posts event into event bus.
 627      *
 628      * @param subscriber
 629      */
 630     public void removeSubscriber(Channel subscriber) {
 631         logger.debug("Subscriber {} is removed.", subscriber.remoteAddress());
 632         Event event = new Event(EventType.DEREGISTER);
 633         event.setSubscriber(subscriber);
 634         eventBus.post(event);
 635     }
 636
 637     /**
 638      * Checks if exists at least one {@link Channel} subscriber.
 639      *
 640      * @return True if exist at least one {@link Channel} subscriber, false
 641      *         otherwise.
 642      */
 643     public boolean hasSubscribers() {
 644         return !subscribers.isEmpty();
 645     }
 646
 647     /**
 648      * Consists of two types {@link Store#CONFIG} and {@link Store#OPERATION}.
 649      */
 650     private static enum Store {
 651         CONFIG("config"), OPERATION("operation");
 652
 653         private final String value;
 654
 655         private Store(String value) {
 656             this.value = value;
 657         }
 658     }
 659
 660     /**
 661      * Consists of three types {@link Operation#CREATED},
 662      * {@link Operation#UPDATED} and {@link Operation#DELETED}.
 663      */
 664     private static enum Operation {
 665         CREATED("created"), UPDATED("updated"), DELETED("deleted");
 666
 667         private final String value;
 668
 669         private Operation(String value) {
 670             this.value = value;
 671         }
 672     }
 673
 674 }