2 * Copyright (c) 2014 Cisco Systems, Inc. and others. All rights reserved.
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
8 package org.opendaylight.controller.sal.streams.listeners;
10 import com.google.common.base.Preconditions;
11 import com.google.common.eventbus.AsyncEventBus;
12 import com.google.common.eventbus.EventBus;
13 import com.google.common.eventbus.Subscribe;
15 import io.netty.channel.Channel;
16 import io.netty.handler.codec.http.websocketx.TextWebSocketFrame;
17 import io.netty.util.internal.ConcurrentSet;
19 import java.io.ByteArrayOutputStream;
20 import java.io.OutputStreamWriter;
21 import java.io.UnsupportedEncodingException;
22 import java.text.SimpleDateFormat;
23 import java.util.Collection;
24 import java.util.Date;
25 import java.util.HashMap;
27 import java.util.Map.Entry;
28 import java.util.Random;
30 import java.util.concurrent.Executors;
32 import javax.activation.UnsupportedDataTypeException;
33 import javax.xml.parsers.DocumentBuilder;
34 import javax.xml.parsers.DocumentBuilderFactory;
35 import javax.xml.parsers.ParserConfigurationException;
36 import javax.xml.transform.OutputKeys;
37 import javax.xml.transform.Transformer;
38 import javax.xml.transform.TransformerException;
39 import javax.xml.transform.TransformerFactory;
40 import javax.xml.transform.dom.DOMSource;
41 import javax.xml.transform.stream.StreamResult;
43 import org.opendaylight.controller.md.sal.common.api.data.DataChangeEvent;
44 import org.opendaylight.controller.sal.core.api.data.DataChangeListener;
45 import org.opendaylight.controller.sal.rest.impl.XmlMapper;
46 import org.opendaylight.controller.sal.restconf.impl.ControllerContext;
47 import org.opendaylight.yangtools.concepts.ListenerRegistration;
48 import org.opendaylight.yangtools.yang.common.QName;
49 import org.opendaylight.yangtools.yang.data.api.CompositeNode;
50 import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier;
51 import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier.NodeIdentifierWithPredicates;
52 import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier.NodeWithValue;
53 import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier.PathArgument;
54 import org.opendaylight.yangtools.yang.model.api.DataNodeContainer;
55 import org.slf4j.Logger;
56 import org.slf4j.LoggerFactory;
57 import org.w3c.dom.Document;
58 import org.w3c.dom.Element;
59 import org.w3c.dom.Node;
62 * {@link ListenerAdapter} is responsible to track events, which occurred by
63 * changing data in data source.
65 public class ListenerAdapter implements DataChangeListener {
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");
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;
81 * Creates new {@link ListenerAdapter} listener specified by path and stream
85 * Path to data in data store.
87 * The name of the stream.
89 ListenerAdapter(final InstanceIdentifier path, final String streamName) {
90 Preconditions.checkNotNull(path);
92 .checkArgument(streamName != null && !streamName.isEmpty());
94 this.streamName = streamName;
95 eventBus = new AsyncEventBus(Executors.newSingleThreadExecutor());
96 eventBusChangeRecorder = new EventBusChangeRecorder();
97 eventBus.register(eventBusChangeRecorder);
101 public void onDataChanged(
102 final 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);
112 eventBus.post(event);
117 * Tracks events of data change by customer.
119 private final class EventBusChangeRecorder {
121 public void recordCustomerChange(final Event event) {
122 if (event.getType() == EventType.REGISTER) {
123 Channel subscriber = event.getSubscriber();
124 if (!subscribers.contains(subscriber)) {
125 subscribers.add(subscriber);
127 } else if (event.getType() == EventType.DEREGISTER) {
128 subscribers.remove(event.getSubscriber());
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
140 "Subscriber {} is removed - channel is not active yet.",
141 subscriber.remoteAddress());
142 subscribers.remove(subscriber);
150 * Represents event of specific {@link EventType} type, holds data and
151 * {@link Channel} subscriber.
153 private final class Event {
154 private final EventType type;
155 private Channel subscriber;
159 * Creates new event specified by {@link EventType} type.
164 public Event(final EventType type) {
169 * Gets the {@link Channel} subscriber.
173 public Channel getSubscriber() {
178 * Sets subscriber for event.
183 public void setSubscriber(final Channel subscriber) {
184 this.subscriber = subscriber;
190 * @return String representation of event data.
192 public String getData() {
202 public void setData(final String data) {
209 * @return The type of the event.
211 public EventType getType() {
219 private enum EventType {
220 REGISTER, DEREGISTER, NOTIFY;
224 * Prepare data in printable form and transform it to String.
228 * @return Data in printable form.
230 private String prepareXmlFrom(
231 final DataChangeEvent<InstanceIdentifier, CompositeNode> change) {
232 Document doc = createDocument();
233 Element notificationElement = doc.createElementNS(
234 "urn:ietf:params:xml:ns:netconf:notification:1.0",
236 doc.appendChild(notificationElement);
238 Element eventTimeElement = doc.createElement("eventTime");
239 eventTimeElement.setTextContent(toRFC3339(new Date()));
240 notificationElement.appendChild(eventTimeElement);
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);
250 ByteArrayOutputStream out = new ByteArrayOutputStream();
251 TransformerFactory tf = TransformerFactory.newInstance();
252 Transformer transformer = tf.newTransformer();
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);
272 * Formats data specified by RFC3339.
276 * @return Data specified by RFC3339.
278 private String toRFC3339(final Date d) {
279 return rfc3339.format(d).replaceAll("(\\d\\d)(\\d\\d)$", "$1:$2");
283 * Creates {@link Document} document.
285 * @return {@link Document} document.
287 private Document createDocument() {
288 DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
291 DocumentBuilder bob = dbf.newDocumentBuilder();
292 doc = bob.newDocument();
293 } catch (ParserConfigurationException e) {
300 * Adds values to data changed notification event element.
304 * @param dataChangedNotificationEventElement
307 * {@link DataChangeEvent}
309 private void addValuesToDataChangedNotificationEventElement(final Document doc,
310 final Element dataChangedNotificationEventElement,
311 final DataChangeEvent<InstanceIdentifier, CompositeNode> change) {
312 addValuesFromDataToElement(doc, change.getCreatedConfigurationData(),
313 dataChangedNotificationEventElement, Store.CONFIG,
315 addValuesFromDataToElement(doc, change.getCreatedOperationalData(),
316 dataChangedNotificationEventElement, Store.OPERATION,
318 if (change.getCreatedConfigurationData().isEmpty()) {
319 addValuesFromDataToElement(doc,
320 change.getUpdatedConfigurationData(),
321 dataChangedNotificationEventElement, Store.CONFIG,
324 if (change.getCreatedOperationalData().isEmpty()) {
325 addValuesFromDataToElement(doc, change.getUpdatedOperationalData(),
326 dataChangedNotificationEventElement, Store.OPERATION,
329 addValuesFromDataToElement(doc, change.getRemovedConfigurationData(),
330 dataChangedNotificationEventElement, Store.CONFIG,
332 addValuesFromDataToElement(doc, change.getRemovedOperationalData(),
333 dataChangedNotificationEventElement, Store.OPERATION,
338 * Adds values from data to element.
343 * Set of {@link InstanceIdentifier}.
351 private void addValuesFromDataToElement(final Document doc,
352 final Set<InstanceIdentifier> data, final Element element, final Store store,
353 final Operation operation) {
354 if (data == null || data.isEmpty()) {
357 for (InstanceIdentifier path : data) {
358 Node node = createDataChangeEventElement(doc, path, null, store,
360 element.appendChild(node);
365 * Adds values from data to element.
370 * Map of {@link InstanceIdentifier} and {@link CompositeNode}.
378 private void addValuesFromDataToElement(final Document doc,
379 final Map<InstanceIdentifier, CompositeNode> data, final Element element,
380 final Store store, final Operation operation) {
381 if (data == null || data.isEmpty()) {
384 for (Entry<InstanceIdentifier, CompositeNode> entry : data.entrySet()) {
385 Node node = createDataChangeEventElement(doc, entry.getKey(),
386 entry.getValue(), store, operation);
387 element.appendChild(node);
392 * Creates changed event element from data.
397 * Path to data in data store.
399 * {@link CompositeNode}
404 * @return {@link Node} node represented by changed event element.
406 private Node createDataChangeEventElement(final Document doc,
407 final InstanceIdentifier path, final CompositeNode data, final Store store,
408 final Operation operation) {
409 Element dataChangeEventElement = doc.createElement("data-change-event");
411 Element pathElement = doc.createElement("path");
412 addPathAsValueToElement(path, pathElement);
413 dataChangeEventElement.appendChild(pathElement);
415 Element storeElement = doc.createElement("store");
416 storeElement.setTextContent(store.value);
417 dataChangeEventElement.appendChild(storeElement);
419 Element operationElement = doc.createElement("operation");
420 operationElement.setTextContent(operation.value);
421 dataChangeEventElement.appendChild(operationElement);
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);
431 return dataChangeEventElement;
435 * Translates {@link CompositeNode} data to XML format.
438 * Path to data in data store.
440 * {@link CompositeNode}
441 * @return Data in XML format.
443 private Node translateToXml(final InstanceIdentifier path, final CompositeNode data) {
444 DataNodeContainer schemaNode = ControllerContext.getInstance()
445 .getDataNodeContainerFor(path);
446 if (schemaNode == null) {
448 "Path '{}' contains node with unsupported type (supported type is Container or List) or some node was not found.",
453 Document xml = xmlMapper.write(data, schemaNode);
454 return xml.getFirstChild();
455 } catch (UnsupportedDataTypeException e) {
457 "Error occured during translation of notification to XML.",
464 * Adds path as value to element.
467 * Path to data in data store.
471 private void addPathAsValueToElement(final InstanceIdentifier path,
472 final 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.getPathArguments()) {
478 textContent.append("/");
479 writeIdentifierWithNamespacePrefix(element, textContent,
480 pathArgument.getNodeType(), prefixes);
481 if (pathArgument instanceof NodeIdentifierWithPredicates) {
482 Map<QName, Object> predicates = ((NodeIdentifierWithPredicates) pathArgument)
484 for (QName keyValue : predicates.keySet()) {
485 String predicateValue = String.valueOf(predicates
487 textContent.append("[");
488 writeIdentifierWithNamespacePrefix(element, textContent,
490 textContent.append("='");
491 textContent.append(predicateValue);
492 textContent.append("'");
493 textContent.append("]");
495 } else if (pathArgument instanceof NodeWithValue) {
496 textContent.append("[.='");
497 textContent.append(((NodeWithValue) pathArgument).getValue());
498 textContent.append("'");
499 textContent.append("]");
502 element.setTextContent(textContent.toString());
506 * Writes identifier that consists of prefix and QName.
515 * Map of namespaces and prefixes.
517 private static void writeIdentifierWithNamespacePrefix(final Element element,
518 final StringBuilder textContent, final QName qName, final 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());
529 element.setAttribute("xmlns:" + prefix, namespace);
530 textContent.append(prefix);
531 prefixes.put(namespace, prefix);
533 textContent.append(":");
534 textContent.append(qName.getLocalName());
538 * Generates new prefix which consists of four random characters <a-z>.
541 * Collection of prefixes.
542 * @return New prefix which consists of four random characters <a-z>.
544 private static String generateNewPrefix(final Collection<String> prefixes) {
545 StringBuilder result = null;
546 Random random = new Random();
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));
553 } while (prefixes.contains(result.toString()));
555 return result.toString();
559 * Gets path pointed to data in data store.
561 * @return Path pointed to data in data store.
563 public InstanceIdentifier getPath() {
568 * Sets {@link ListenerRegistration} registration.
570 * @param registration
571 * ListenerRegistration<DataChangeListener>
573 public void setRegistration(
574 final ListenerRegistration<DataChangeListener> registration) {
575 this.registration = registration;
579 * Gets the name of the stream.
581 * @return The name of the stream.
583 public String getStreamName() {
588 * Removes all subscribers and unregisters event bus change recorder form
591 public void close() throws Exception {
592 subscribers = new ConcurrentSet<>();
593 registration.close();
595 eventBus.unregister(eventBusChangeRecorder);
599 * Checks if {@link ListenerRegistration} registration exist.
601 * @return True if exist, false otherwise.
603 public boolean isListening() {
604 return registration == null ? false : true;
608 * Creates event of type {@link EventType#REGISTER}, set {@link Channel}
609 * subscriber to the event and post event into event bus.
614 public void addSubscriber(final Channel subscriber) {
615 if (!subscriber.isActive()) {
616 logger.debug("Channel is not active between websocket server and subscriber {}"
617 + subscriber.remoteAddress());
619 Event event = new Event(EventType.REGISTER);
620 event.setSubscriber(subscriber);
621 eventBus.post(event);
625 * Creates event of type {@link EventType#DEREGISTER}, sets {@link Channel}
626 * subscriber to the event and posts event into event bus.
630 public void removeSubscriber(final 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);
638 * Checks if exists at least one {@link Channel} subscriber.
640 * @return True if exist at least one {@link Channel} subscriber, false
643 public boolean hasSubscribers() {
644 return !subscribers.isEmpty();
648 * Consists of two types {@link Store#CONFIG} and {@link Store#OPERATION}.
650 private static enum Store {
651 CONFIG("config"), OPERATION("operation");
653 private final String value;
655 private Store(final String value) {
661 * Consists of three types {@link Operation#CREATED},
662 * {@link Operation#UPDATED} and {@link Operation#DELETED}.
664 private static enum Operation {
665 CREATED("created"), UPDATED("updated"), DELETED("deleted");
667 private final String value;
669 private Operation(final String value) {