+package org.opendaylight.controller.sal.streams.listeners;
+
+import io.netty.channel.Channel;
+import io.netty.handler.codec.http.websocketx.TextWebSocketFrame;
+import io.netty.util.internal.ConcurrentSet;
+
+import java.io.ByteArrayOutputStream;
+import java.io.OutputStreamWriter;
+import java.io.UnsupportedEncodingException;
+import java.text.SimpleDateFormat;
+import java.util.Collection;
+import java.util.Date;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.Random;
+import java.util.Set;
+import java.util.concurrent.Executors;
+
+import javax.activation.UnsupportedDataTypeException;
+import javax.xml.parsers.DocumentBuilder;
+import javax.xml.parsers.DocumentBuilderFactory;
+import javax.xml.parsers.ParserConfigurationException;
+import javax.xml.transform.OutputKeys;
+import javax.xml.transform.Transformer;
+import javax.xml.transform.TransformerException;
+import javax.xml.transform.TransformerFactory;
+import javax.xml.transform.dom.DOMSource;
+import javax.xml.transform.stream.StreamResult;
+
+import org.opendaylight.controller.md.sal.common.api.data.DataChangeEvent;
+import org.opendaylight.controller.sal.core.api.data.DataChangeListener;
+import org.opendaylight.controller.sal.rest.impl.XmlMapper;
+import org.opendaylight.controller.sal.restconf.impl.ControllerContext;
+import org.opendaylight.yangtools.concepts.ListenerRegistration;
+import org.opendaylight.yangtools.yang.common.QName;
+import org.opendaylight.yangtools.yang.data.api.CompositeNode;
+import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier;
+import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier.NodeIdentifierWithPredicates;
+import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier.NodeWithValue;
+import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier.PathArgument;
+import org.opendaylight.yangtools.yang.model.api.DataNodeContainer;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.w3c.dom.Document;
+import org.w3c.dom.Element;
+import org.w3c.dom.Node;
+
+import com.google.common.base.Preconditions;
+import com.google.common.eventbus.AsyncEventBus;
+import com.google.common.eventbus.EventBus;
+import com.google.common.eventbus.Subscribe;
+
+public class ListenerAdapter implements DataChangeListener {
+
+ private static final Logger logger = LoggerFactory.getLogger(ListenerAdapter.class);
+ private final XmlMapper xmlMapper = new XmlMapper();
+ private final SimpleDateFormat rfc3339 = new SimpleDateFormat("yyyy-MM-dd'T'hh:mm:ssZ");
+
+ private final InstanceIdentifier path;
+ private ListenerRegistration<DataChangeListener> registration;
+ private final String streamName;
+ private Set<Channel> subscribers = new ConcurrentSet<>();
+ private final EventBus eventBus;
+ private final EventBusChangeRecorder eventBusChangeRecorder;
+
+ ListenerAdapter(InstanceIdentifier path, String streamName) {
+ Preconditions.checkNotNull(path);
+ Preconditions.checkArgument(streamName != null && !streamName.isEmpty());
+ this.path = path;
+ this.streamName = streamName;
+ eventBus = new AsyncEventBus(Executors.newSingleThreadExecutor());
+ eventBusChangeRecorder = new EventBusChangeRecorder();
+ eventBus.register(eventBusChangeRecorder);
+ }
+
+ @Override
+ public void onDataChanged(DataChangeEvent<InstanceIdentifier, CompositeNode> change) {
+ if (!change.getCreatedConfigurationData().isEmpty() || !change.getCreatedOperationalData().isEmpty()
+ || !change.getUpdatedConfigurationData().isEmpty() || !change.getUpdatedOperationalData().isEmpty()
+ || !change.getRemovedConfigurationData().isEmpty() || !change.getRemovedOperationalData().isEmpty()) {
+ String xml = prepareXmlFrom(change);
+ Event event = new Event(EventType.NOTIFY);
+ event.setData(xml);
+ eventBus.post(event);
+ }
+ }
+
+ private final class EventBusChangeRecorder {
+ @Subscribe public void recordCustomerChange(Event event) {
+ if (event.getType() == EventType.REGISTER) {
+ Channel subscriber = event.getSubscriber();
+ if (!subscribers.contains(subscriber)) {
+ subscribers.add(subscriber);
+ }
+ } else if (event.getType() == EventType.DEREGISTER) {
+ subscribers.remove(event.getSubscriber());
+ Notificator.removeListenerIfNoSubscriberExists(ListenerAdapter.this);
+ } else if (event.getType() == EventType.NOTIFY) {
+ for (Channel subscriber : subscribers) {
+ if (subscriber.isActive()) {
+ logger.debug("Data are sent to subscriber {}:", subscriber.remoteAddress());
+ subscriber.writeAndFlush(new TextWebSocketFrame(event.getData()));
+ } else {
+ logger.debug("Subscriber {} is removed - channel is not active yet.", subscriber.remoteAddress());
+ subscribers.remove(subscriber);
+ }
+ }
+ }
+ }
+ }
+
+ private final class Event {
+ private final EventType type;
+ private Channel subscriber;
+ private String data;
+
+ public Event(EventType type) {
+ this.type = type;
+ }
+
+ public Channel getSubscriber() {
+ return subscriber;
+ }
+
+ public void setSubscriber(Channel subscriber) {
+ this.subscriber = subscriber;
+ }
+
+ public String getData() {
+ return data;
+ }
+
+ public void setData(String data) {
+ this.data = data;
+ }
+
+ public EventType getType() {
+ return type;
+ }
+ }
+
+ private enum EventType {
+ REGISTER,
+ DEREGISTER,
+ NOTIFY;
+ }
+
+ private String prepareXmlFrom(DataChangeEvent<InstanceIdentifier, CompositeNode> change) {
+ Document doc = createDocument();
+ Element notificationElement = doc.createElementNS("urn:ietf:params:xml:ns:netconf:notification:1.0",
+ "notification");
+ doc.appendChild(notificationElement);
+
+ Element eventTimeElement = doc.createElement("eventTime");
+ eventTimeElement.setTextContent(toRFC3339(new Date()));
+ notificationElement.appendChild(eventTimeElement);
+
+ Element dataChangedNotificationEventElement = doc.createElementNS(
+ "urn:opendaylight:params:xml:ns:yang:controller:md:sal:remote", "data-changed-notification");
+ addValuesToDataChangedNotificationEventElement(doc, dataChangedNotificationEventElement, change);
+ notificationElement.appendChild(dataChangedNotificationEventElement);
+
+ try {
+ ByteArrayOutputStream out = new ByteArrayOutputStream();
+ TransformerFactory tf = TransformerFactory.newInstance();
+ Transformer transformer = tf.newTransformer();
+ transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "no");
+ transformer.setOutputProperty(OutputKeys.METHOD, "xml");
+ transformer.setOutputProperty(OutputKeys.INDENT, "yes");
+ transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8");
+ transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "4");
+ transformer.transform(new DOMSource(doc), new StreamResult(new OutputStreamWriter(out, "UTF-8")));
+ byte[] charData = out.toByteArray();
+ return new String(charData, "UTF-8");
+ } catch (TransformerException | UnsupportedEncodingException e) {
+ String msg = "Error during transformation of Document into String";
+ logger.error(msg, e);
+ return msg;
+ }
+ }
+
+ private String toRFC3339(Date d) {
+ return rfc3339.format(d).replaceAll("(\\d\\d)(\\d\\d)$", "$1:$2");
+ }
+
+ private Document createDocument() {
+ DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
+ Document doc = null;
+ try {
+ DocumentBuilder bob = dbf.newDocumentBuilder();
+ doc = bob.newDocument();
+ } catch (ParserConfigurationException e) {
+ return null;
+ }
+ return doc;
+ }
+
+ private void addValuesToDataChangedNotificationEventElement(Document doc,
+ Element dataChangedNotificationEventElement, DataChangeEvent<InstanceIdentifier, CompositeNode> change) {
+ addValuesFromDataToElement(doc, change.getCreatedConfigurationData(), dataChangedNotificationEventElement, Store.CONFIG, Operation.CREATED);
+ addValuesFromDataToElement(doc, change.getCreatedOperationalData(), dataChangedNotificationEventElement, Store.OPERATION, Operation.CREATED);
+ if (change.getCreatedConfigurationData().isEmpty()) {
+ addValuesFromDataToElement(doc, change.getUpdatedConfigurationData(), dataChangedNotificationEventElement, Store.CONFIG, Operation.UPDATED);
+ }
+ if (change.getCreatedOperationalData().isEmpty()) {
+ addValuesFromDataToElement(doc, change.getUpdatedOperationalData(), dataChangedNotificationEventElement, Store.OPERATION, Operation.UPDATED);
+ }
+ addValuesFromDataToElement(doc, change.getRemovedConfigurationData(), dataChangedNotificationEventElement, Store.CONFIG, Operation.DELETED);
+ addValuesFromDataToElement(doc, change.getRemovedOperationalData(), dataChangedNotificationEventElement, Store.OPERATION, Operation.DELETED);
+ }
+
+ private void addValuesFromDataToElement(Document doc, Set<InstanceIdentifier> data, Element element, Store store,
+ Operation operation) {
+ if (data == null || data.isEmpty()) {
+ return;
+ }
+ for (InstanceIdentifier path : data) {
+ Node node = createDataChangeEventElement(doc, path, null, store, operation);
+ element.appendChild(node);
+ }
+ }
+
+ private void addValuesFromDataToElement(Document doc, Map<InstanceIdentifier, CompositeNode> data, Element element, Store store,
+ Operation operation) {
+ if (data == null || data.isEmpty()) {
+ return;
+ }
+ for (Entry<InstanceIdentifier, CompositeNode> entry : data.entrySet()) {
+ Node node = createDataChangeEventElement(doc, entry.getKey(), entry.getValue(), store, operation);
+ element.appendChild(node);
+ }
+ }
+
+ private Node createDataChangeEventElement(Document doc, InstanceIdentifier path, CompositeNode data, Store store,
+ Operation operation) {
+ Element dataChangeEventElement = doc.createElement("data-change-event");
+
+ Element pathElement = doc.createElement("path");
+ addPathAsValueToElement(path, pathElement);
+ dataChangeEventElement.appendChild(pathElement);
+
+ Element storeElement = doc.createElement("store");
+ storeElement.setTextContent(store.value);
+ dataChangeEventElement.appendChild(storeElement);
+
+ Element operationElement = doc.createElement("operation");
+ operationElement.setTextContent(operation.value);
+ dataChangeEventElement.appendChild(operationElement);
+
+ if (data != null) {
+ Element dataElement = doc.createElement("data");
+ Node dataAnyXml = translateToXml(path, data);
+ Node adoptedNode = doc.adoptNode(dataAnyXml);
+ dataElement.appendChild(adoptedNode);
+ dataChangeEventElement.appendChild(dataElement);
+ }
+
+ return dataChangeEventElement;
+ }
+
+ private Node translateToXml(InstanceIdentifier path, CompositeNode data) {
+ DataNodeContainer schemaNode = ControllerContext.getInstance().getDataNodeContainerFor(path);
+ if (schemaNode == null) {
+ logger.info("Path '{}' contains node with unsupported type (supported type is Container or List) or some node was not found.", path);
+ return null;
+ }
+ try {
+ Document xml = xmlMapper.write(data, schemaNode);
+ return xml.getFirstChild();
+ } catch (UnsupportedDataTypeException e) {
+ logger.error("Error occured during translation of notification to XML.", e);
+ return null;
+ }
+ }
+
+ private void addPathAsValueToElement(InstanceIdentifier path, Element element) {
+ // Map< key = namespace, value = prefix>
+ Map<String, String> prefixes = new HashMap<>();
+ InstanceIdentifier instanceIdentifier = path;
+ StringBuilder textContent = new StringBuilder();
+ for (PathArgument pathArgument : instanceIdentifier.getPath()) {
+ textContent.append("/");
+ writeIdentifierWithNamespacePrefix(element, textContent, pathArgument.getNodeType(), prefixes);
+ if (pathArgument instanceof NodeIdentifierWithPredicates) {
+ Map<QName, Object> predicates = ((NodeIdentifierWithPredicates) pathArgument).getKeyValues();
+ for (QName keyValue : predicates.keySet()) {
+ String predicateValue = String.valueOf(predicates.get(keyValue));
+ textContent.append("[");
+ writeIdentifierWithNamespacePrefix(element, textContent, keyValue, prefixes);
+ textContent.append("='");
+ textContent.append(predicateValue);
+ textContent.append("'");
+ textContent.append("]");
+ }
+ } else if (pathArgument instanceof NodeWithValue) {
+ textContent.append("[.='");
+ textContent.append(((NodeWithValue)pathArgument).getValue());
+ textContent.append("'");
+ textContent.append("]");
+ }
+ }
+ element.setTextContent(textContent.toString());
+ }
+
+ private static void writeIdentifierWithNamespacePrefix(Element element, StringBuilder textContent, QName qName,
+ Map<String, String> prefixes) {
+ String namespace = qName.getNamespace().toString();
+ String prefix = prefixes.get(namespace);
+ if (prefix == null) {
+ prefix = qName.getPrefix();
+ if (prefix == null || prefix.isEmpty() || prefixes.containsValue(prefix)) {
+ prefix = generateNewPrefix(prefixes.values());
+ }
+ }
+
+ element.setAttribute("xmlns:" + prefix, namespace.toString());
+ textContent.append(prefix);
+ prefixes.put(namespace, prefix);
+
+ textContent.append(":");
+ textContent.append(qName.getLocalName());
+ }
+
+ private static String generateNewPrefix(Collection<String> prefixes) {
+ StringBuilder result = null;
+ Random random = new Random();
+ do {
+ result = new StringBuilder();
+ for (int i = 0; i < 4; i++) {
+ int randomNumber = 0x61 + (Math.abs(random.nextInt()) % 26);
+ result.append(Character.toChars(randomNumber));
+ }
+ } while (prefixes.contains(result.toString()));
+
+ return result.toString();
+ }
+
+ public InstanceIdentifier getPath() {
+ return path;
+ }
+
+ public void setRegistration(ListenerRegistration<DataChangeListener> registration) {
+ this.registration = registration;
+ }
+
+ public String getStreamName() {
+ return streamName;
+ }
+
+ public void close() throws Exception {
+ subscribers = new ConcurrentSet<>();
+ registration.close();
+ registration = null;
+ eventBus.unregister(eventBusChangeRecorder);
+ }
+
+ public boolean isListening() {
+ return registration == null ? false : true;
+ }
+
+ public void addSubscriber(Channel subscriber) {
+ if (!subscriber.isActive()) {
+ logger.debug("Channel is not active between websocket server and subscriber {}"
+ + subscriber.remoteAddress());
+ }
+ Event event = new Event(EventType.REGISTER);
+ event.setSubscriber(subscriber);
+ eventBus.post(event);
+ }
+
+ public void removeSubscriber(Channel subscriber) {
+ logger.debug("Subscriber {} is removed.", subscriber.remoteAddress());
+ Event event = new Event(EventType.DEREGISTER);
+ event.setSubscriber(subscriber);
+ eventBus.post(event);
+ }
+
+ public boolean hasSubscribers() {
+ return !subscribers.isEmpty();
+ }
+
+ private static enum Store {
+ CONFIG("config"),
+ OPERATION("operation");
+
+ private final String value;
+
+ private Store(String value) {
+ this.value = value;
+ }
+ }
+
+ private static enum Operation {
+ CREATED("created"),
+ UPDATED("updated"),
+ DELETED("deleted");
+
+ private final String value;
+
+ private Operation(String value) {
+ this.value = value;
+ }
+ }
+
+}