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.Charsets;
11 import com.google.common.base.Preconditions;
12 import com.google.common.eventbus.AsyncEventBus;
13 import com.google.common.eventbus.EventBus;
14 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;
18 import java.io.ByteArrayOutputStream;
19 import java.io.OutputStreamWriter;
20 import java.io.UnsupportedEncodingException;
21 import java.text.SimpleDateFormat;
22 import java.util.Collection;
23 import java.util.Date;
24 import java.util.HashMap;
26 import java.util.Random;
28 import java.util.concurrent.Executors;
29 import java.util.regex.Pattern;
30 import javax.xml.parsers.DocumentBuilder;
31 import javax.xml.parsers.DocumentBuilderFactory;
32 import javax.xml.parsers.ParserConfigurationException;
33 import javax.xml.transform.OutputKeys;
34 import javax.xml.transform.Transformer;
35 import javax.xml.transform.TransformerException;
36 import javax.xml.transform.TransformerFactory;
37 import javax.xml.transform.dom.DOMSource;
38 import javax.xml.transform.stream.StreamResult;
39 import org.opendaylight.controller.md.sal.common.api.data.AsyncDataChangeEvent;
40 import org.opendaylight.controller.md.sal.dom.api.DOMDataChangeListener;
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.YangInstanceIdentifier;
45 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifierWithPredicates;
46 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeWithValue;
47 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
48 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
49 import org.slf4j.Logger;
50 import org.slf4j.LoggerFactory;
51 import org.w3c.dom.Document;
52 import org.w3c.dom.Element;
53 import org.w3c.dom.Node;
56 * {@link ListenerAdapter} is responsible to track events, which occurred by changing data in data source.
58 public class ListenerAdapter implements DOMDataChangeListener {
60 private static final Logger LOG = LoggerFactory.getLogger(ListenerAdapter.class);
61 private static final DocumentBuilderFactory DBF = DocumentBuilderFactory.newInstance();
62 private static final TransformerFactory FACTORY = TransformerFactory.newInstance();
63 private static final Pattern RFC3339_PATTERN = Pattern.compile("(\\d\\d)(\\d\\d)$");
65 private final SimpleDateFormat rfc3339 = new SimpleDateFormat("yyyy-MM-dd'T'hh:mm:ssZ");
67 private final YangInstanceIdentifier path;
68 private ListenerRegistration<DOMDataChangeListener> registration;
69 private final String streamName;
70 private Set<Channel> subscribers = new ConcurrentSet<>();
71 private final EventBus eventBus;
72 private final EventBusChangeRecorder eventBusChangeRecorder;
75 * Creates new {@link ListenerAdapter} listener specified by path and stream name.
78 * Path to data in data store.
80 * The name of the stream.
82 ListenerAdapter(final YangInstanceIdentifier path, final String streamName) {
83 Preconditions.checkNotNull(path);
84 Preconditions.checkArgument(streamName != null && !streamName.isEmpty());
86 this.streamName = streamName;
87 eventBus = new AsyncEventBus(Executors.newSingleThreadExecutor());
88 eventBusChangeRecorder = new EventBusChangeRecorder();
89 eventBus.register(eventBusChangeRecorder);
93 public void onDataChanged(final AsyncDataChangeEvent<YangInstanceIdentifier, NormalizedNode<?, ?>> change) {
94 // TODO Auto-generated method stub
96 if (!change.getCreatedData().isEmpty() || !change.getUpdatedData().isEmpty()
97 || !change.getRemovedPaths().isEmpty()) {
98 final String xml = prepareXmlFrom(change);
99 final Event event = new Event(EventType.NOTIFY);
101 eventBus.post(event);
106 * Tracks events of data change by customer.
108 private final class EventBusChangeRecorder {
110 public void recordCustomerChange(final Event event) {
111 if (event.getType() == EventType.REGISTER) {
112 final Channel subscriber = event.getSubscriber();
113 if (!subscribers.contains(subscriber)) {
114 subscribers.add(subscriber);
116 } else if (event.getType() == EventType.DEREGISTER) {
117 subscribers.remove(event.getSubscriber());
118 Notificator.removeListenerIfNoSubscriberExists(ListenerAdapter.this);
119 } else if (event.getType() == EventType.NOTIFY) {
120 for (final Channel subscriber : subscribers) {
121 if (subscriber.isActive()) {
122 LOG.debug("Data are sent to subscriber {}:", subscriber.remoteAddress());
123 subscriber.writeAndFlush(new TextWebSocketFrame(event.getData()));
125 LOG.debug("Subscriber {} is removed - channel is not active yet.", subscriber.remoteAddress());
126 subscribers.remove(subscriber);
134 * Represents event of specific {@link EventType} type, holds data and {@link Channel} subscriber.
136 private final class Event {
137 private final EventType type;
138 private Channel subscriber;
142 * Creates new event specified by {@link EventType} type.
147 public Event(final EventType type) {
152 * Gets the {@link Channel} subscriber.
156 public Channel getSubscriber() {
161 * Sets subscriber for event.
166 public void setSubscriber(final Channel subscriber) {
167 this.subscriber = subscriber;
173 * @return String representation of event data.
175 public String getData() {
182 * @param data String.
184 public void setData(final String data) {
191 * @return The type of the event.
193 public EventType getType() {
201 private enum EventType {
208 * Prepare data in printable form and transform it to String.
212 * @return Data in printable form.
214 private String prepareXmlFrom(final AsyncDataChangeEvent<YangInstanceIdentifier, NormalizedNode<?, ?>> change) {
215 final Document doc = createDocument();
216 final Element notificationElement = doc.createElementNS("urn:ietf:params:xml:ns:netconf:notification:1.0",
218 doc.appendChild(notificationElement);
220 final Element eventTimeElement = doc.createElement("eventTime");
221 eventTimeElement.setTextContent(toRFC3339(new Date()));
222 notificationElement.appendChild(eventTimeElement);
224 final Element dataChangedNotificationEventElement = doc.createElementNS(
225 "urn:opendaylight:params:xml:ns:yang:controller:md:sal:remote", "data-changed-notification");
226 addValuesToDataChangedNotificationEventElement(doc, dataChangedNotificationEventElement, change);
227 notificationElement.appendChild(dataChangedNotificationEventElement);
230 final ByteArrayOutputStream out = new ByteArrayOutputStream();
231 final Transformer transformer = FACTORY.newTransformer();
232 transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "no");
233 transformer.setOutputProperty(OutputKeys.METHOD, "xml");
234 transformer.setOutputProperty(OutputKeys.INDENT, "yes");
235 transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8");
236 transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "4");
237 transformer.transform(new DOMSource(doc), new StreamResult(new OutputStreamWriter(out, Charsets.UTF_8)));
238 final byte[] charData = out.toByteArray();
239 return new String(charData, "UTF-8");
240 } catch (TransformerException | UnsupportedEncodingException e) {
241 final String msg = "Error during transformation of Document into String";
248 * Formats data specified by RFC3339.
252 * @return Data specified by RFC3339.
254 private String toRFC3339(final Date d) {
255 return RFC3339_PATTERN.matcher(rfc3339.format(d)).replaceAll("$1:$2");
259 * Creates {@link Document} document.
260 * @return {@link Document} document.
262 private Document createDocument() {
263 final DocumentBuilder bob;
265 bob = DBF.newDocumentBuilder();
266 } catch (final ParserConfigurationException e) {
269 return bob.newDocument();
273 * Adds values to data changed notification event element.
277 * @param dataChangedNotificationEventElement
280 * {@link AsyncDataChangeEvent}
282 private void addValuesToDataChangedNotificationEventElement(final Document doc,
283 final Element dataChangedNotificationEventElement,
284 final AsyncDataChangeEvent<YangInstanceIdentifier, NormalizedNode<?, ?>> change) {
285 addValuesFromDataToElement(doc, change.getCreatedData().keySet(), dataChangedNotificationEventElement,
287 if (change.getCreatedData().isEmpty()) {
288 addValuesFromDataToElement(doc, change.getUpdatedData().keySet(), dataChangedNotificationEventElement,
291 addValuesFromDataToElement(doc, change.getRemovedPaths(), dataChangedNotificationEventElement,
296 * Adds values from data to element.
301 * Set of {@link YangInstanceIdentifier}.
307 private void addValuesFromDataToElement(final Document doc, final Set<YangInstanceIdentifier> data, final Element element,
308 final Operation operation) {
309 if (data == null || data.isEmpty()) {
312 for (final YangInstanceIdentifier path : data) {
313 if (!ControllerContext.getInstance().isNodeMixin(path)) {
314 final Node node = createDataChangeEventElement(doc, path, operation);
315 element.appendChild(node);
322 * Creates changed event element from data.
327 * Path to data in data store.
330 * @return {@link Node} node represented by changed event element.
332 private Node createDataChangeEventElement(final Document doc, final YangInstanceIdentifier path, final Operation operation) {
333 final Element dataChangeEventElement = doc.createElement("data-change-event");
334 final Element pathElement = doc.createElement("path");
335 addPathAsValueToElement(path, pathElement);
336 dataChangeEventElement.appendChild(pathElement);
338 final Element operationElement = doc.createElement("operation");
339 operationElement.setTextContent(operation.value);
340 dataChangeEventElement.appendChild(operationElement);
342 return dataChangeEventElement;
347 * Adds path as value to element.
350 * Path to data in data store.
354 private void addPathAsValueToElement(final YangInstanceIdentifier path, final Element element) {
355 // Map< key = namespace, value = prefix>
356 final Map<String, String> prefixes = new HashMap<>();
357 final YangInstanceIdentifier normalizedPath = ControllerContext.getInstance().toXpathRepresentation(path);
358 final StringBuilder textContent = new StringBuilder();
360 // FIXME: BUG-1281: this is duplicated code from yangtools (BUG-1275)
361 for (final PathArgument pathArgument : normalizedPath.getPathArguments()) {
362 if (pathArgument instanceof YangInstanceIdentifier.AugmentationIdentifier) {
365 textContent.append("/");
366 writeIdentifierWithNamespacePrefix(element, textContent, pathArgument.getNodeType(), prefixes);
367 if (pathArgument instanceof NodeIdentifierWithPredicates) {
368 final Map<QName, Object> predicates = ((NodeIdentifierWithPredicates) pathArgument).getKeyValues();
369 for (final QName keyValue : predicates.keySet()) {
370 final String predicateValue = String.valueOf(predicates.get(keyValue));
371 textContent.append("[");
372 writeIdentifierWithNamespacePrefix(element, textContent, keyValue, prefixes);
373 textContent.append("='");
374 textContent.append(predicateValue);
375 textContent.append("'");
376 textContent.append("]");
378 } else if (pathArgument instanceof NodeWithValue) {
379 textContent.append("[.='");
380 textContent.append(((NodeWithValue) pathArgument).getValue());
381 textContent.append("'");
382 textContent.append("]");
385 element.setTextContent(textContent.toString());
389 * Writes identifier that consists of prefix and QName.
398 * Map of namespaces and prefixes.
400 private static void writeIdentifierWithNamespacePrefix(final Element element, final StringBuilder textContent,
401 final QName qName, final Map<String, String> prefixes) {
402 final String namespace = qName.getNamespace().toString();
403 String prefix = prefixes.get(namespace);
404 if (prefix == null) {
405 prefix = generateNewPrefix(prefixes.values());
408 element.setAttribute("xmlns:" + prefix, namespace);
409 textContent.append(prefix);
410 prefixes.put(namespace, prefix);
412 textContent.append(":");
413 textContent.append(qName.getLocalName());
417 * Generates new prefix which consists of four random characters <a-z>.
420 * Collection of prefixes.
421 * @return New prefix which consists of four random characters <a-z>.
423 private static String generateNewPrefix(final Collection<String> prefixes) {
424 StringBuilder result = null;
425 final Random random = new Random();
427 result = new StringBuilder();
428 for (int i = 0; i < 4; i++) {
429 final int randomNumber = 0x61 + (Math.abs(random.nextInt()) % 26);
430 result.append(Character.toChars(randomNumber));
432 } while (prefixes.contains(result.toString()));
434 return result.toString();
438 * Gets path pointed to data in data store.
440 * @return Path pointed to data in data store.
442 public YangInstanceIdentifier getPath() {
447 * Sets {@link ListenerRegistration} registration.
449 * @param registration
450 * ListenerRegistration<DataChangeListener>
452 public void setRegistration(final ListenerRegistration<DOMDataChangeListener> registration) {
453 this.registration = registration;
457 * Gets the name of the stream.
459 * @return The name of the stream.
461 public String getStreamName() {
466 * Removes all subscribers and unregisters event bus change recorder form event bus.
468 public void close() throws Exception {
469 subscribers = new ConcurrentSet<>();
470 registration.close();
472 eventBus.unregister(eventBusChangeRecorder);
476 * Checks if {@link ListenerRegistration} registration exist.
478 * @return True if exist, false otherwise.
480 public boolean isListening() {
481 return registration == null ? false : true;
485 * Creates event of type {@link EventType#REGISTER}, set {@link Channel} subscriber to the event and post event into
491 public void addSubscriber(final Channel subscriber) {
492 if (!subscriber.isActive()) {
493 LOG.debug("Channel is not active between websocket server and subscriber {}" + subscriber.remoteAddress());
495 final Event event = new Event(EventType.REGISTER);
496 event.setSubscriber(subscriber);
497 eventBus.post(event);
501 * Creates event of type {@link EventType#DEREGISTER}, sets {@link Channel} subscriber to the event and posts event
506 public void removeSubscriber(final Channel subscriber) {
507 LOG.debug("Subscriber {} is removed.", subscriber.remoteAddress());
508 final Event event = new Event(EventType.DEREGISTER);
509 event.setSubscriber(subscriber);
510 eventBus.post(event);
514 * Checks if exists at least one {@link Channel} subscriber.
516 * @return True if exist at least one {@link Channel} subscriber, false otherwise.
518 public boolean hasSubscribers() {
519 return !subscribers.isEmpty();
523 * Consists of two types {@link Store#CONFIG} and {@link Store#OPERATION}.
525 private static enum Store {
527 OPERATION("operation");
529 private final String value;
531 private Store(final String value) {
537 * Consists of three types {@link Operation#CREATED}, {@link Operation#UPDATED} and {@link Operation#DELETED}.
539 private static enum Operation {
544 private final String value;
546 private Operation(final String value) {