restconf/restconf-nb-rfc8040/src/main/java/org/opendaylight/restconf/nb/rfc8040/rests/services/impl/SubscribeToStreamUtil.java

   1 /*
   2  * Copyright (c) 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.rests.services.impl;
   9
  10 import com.google.common.base.Preconditions;
  11 import com.google.common.base.Strings;
  12 import java.net.URI;
  13 import java.util.HashMap;
  14 import java.util.Map;
  15 import java.util.Optional;
  16 import java.util.concurrent.ExecutionException;
  17 import javax.ws.rs.core.UriBuilder;
  18 import javax.ws.rs.core.UriInfo;
  19 import org.eclipse.jdt.annotation.NonNull;
  20 import org.opendaylight.mdsal.common.api.LogicalDatastoreType;
  21 import org.opendaylight.mdsal.dom.api.DOMDataBroker;
  22 import org.opendaylight.mdsal.dom.api.DOMDataTreeChangeService;
  23 import org.opendaylight.mdsal.dom.api.DOMDataTreeIdentifier;
  24 import org.opendaylight.mdsal.dom.api.DOMDataTreeReadWriteTransaction;
  25 import org.opendaylight.mdsal.dom.api.DOMNotificationListener;
  26 import org.opendaylight.mdsal.dom.api.DOMNotificationService;
  27 import org.opendaylight.mdsal.dom.api.DOMTransactionChain;
  28 import org.opendaylight.restconf.common.errors.RestconfDocumentedException;
  29 import org.opendaylight.restconf.common.errors.RestconfError.ErrorTag;
  30 import org.opendaylight.restconf.common.errors.RestconfError.ErrorType;
  31 import org.opendaylight.restconf.common.util.DataChangeScope;
  32 import org.opendaylight.restconf.nb.rfc8040.Rfc8040.MonitoringModule;
  33 import org.opendaylight.restconf.nb.rfc8040.rests.services.impl.RestconfStreamsSubscriptionServiceImpl.HandlersHolder;
  34 import org.opendaylight.restconf.nb.rfc8040.rests.services.impl.RestconfStreamsSubscriptionServiceImpl.NotificationQueryParams;
  35 import org.opendaylight.restconf.nb.rfc8040.rests.utils.ResolveEnumUtil;
  36 import org.opendaylight.restconf.nb.rfc8040.rests.utils.RestconfStreamsConstants;
  37 import org.opendaylight.restconf.nb.rfc8040.streams.listeners.ListenerAdapter;
  38 import org.opendaylight.restconf.nb.rfc8040.streams.listeners.ListenersBroker;
  39 import org.opendaylight.restconf.nb.rfc8040.streams.listeners.NotificationListenerAdapter;
  40 import org.opendaylight.restconf.nb.rfc8040.utils.RestconfConstants;
  41 import org.opendaylight.restconf.nb.rfc8040.utils.mapping.RestconfMappingNodeUtil;
  42 import org.opendaylight.restconf.nb.rfc8040.utils.parser.IdentifierCodec;
  43 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  44 import org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode;
  45 import org.opendaylight.yangtools.yang.model.api.EffectiveModelContext;
  46 import org.opendaylight.yangtools.yang.model.api.stmt.SchemaNodeIdentifier.Absolute;
  47 import org.slf4j.Logger;
  48 import org.slf4j.LoggerFactory;
  49
  50 /**
  51  * Subscribe to stream util class.
  52  */
  53 abstract class SubscribeToStreamUtil {
  54     /**
  55      * Implementation of SubscribeToStreamUtil for Server-sent events.
  56      */
  57     private static final class ServerSentEvents extends SubscribeToStreamUtil {
  58         static final ServerSentEvents INSTANCE = new ServerSentEvents();
  59
  60         @Override
  61         public URI prepareUriByStreamName(final UriInfo uriInfo, final String streamName) {
  62             final UriBuilder uriBuilder = uriInfo.getBaseUriBuilder();
  63             return uriBuilder.replacePath(RestconfConstants.BASE_URI_PATTERN + '/'
  64                     + RestconfConstants.NOTIF + '/' + streamName).build();
  65         }
  66     }
  67
  68     /**
  69      * Implementation of SubscribeToStreamUtil for Web sockets.
  70      */
  71     private static final class WebSockets extends SubscribeToStreamUtil {
  72         static final WebSockets INSTANCE = new WebSockets();
  73
  74         @Override
  75         public URI prepareUriByStreamName(final UriInfo uriInfo, final String streamName) {
  76             final String scheme = uriInfo.getAbsolutePath().getScheme();
  77             final UriBuilder uriBuilder = uriInfo.getBaseUriBuilder();
  78             switch (scheme) {
  79                 case "https":
  80                     // Secured HTTP goes to Secured WebSockets
  81                     uriBuilder.scheme("wss");
  82                     break;
  83                 case "http":
  84                 default:
  85                     // Unsecured HTTP and others go to unsecured WebSockets
  86                     uriBuilder.scheme("ws");
  87             }
  88             return uriBuilder.replacePath(RestconfConstants.BASE_URI_PATTERN + '/' + streamName).build();
  89         }
  90     }
  91
  92
  93     private static final Logger LOG = LoggerFactory.getLogger(SubscribeToStreamUtil.class);
  94
  95     SubscribeToStreamUtil() {
  96         // Hidden on purpose
  97     }
  98
  99     static SubscribeToStreamUtil serverSentEvents() {
 100         return ServerSentEvents.INSTANCE;
 101     }
 102
 103     static SubscribeToStreamUtil webSockets() {
 104         return WebSockets.INSTANCE;
 105     }
 106
 107     /**
 108      * Prepare URL from base name and stream name.
 109      *
 110      * @param uriInfo base URL information
 111      * @param streamName name of stream for create
 112      * @return final URL
 113      */
 114     abstract @NonNull URI prepareUriByStreamName(UriInfo uriInfo, String streamName);
 115
 116     /**
 117      * Register listener by streamName in identifier to listen to yang notifications, and put or delete information
 118      * about listener to DS according to ietf-restconf-monitoring.
 119      *
 120      * @param identifier              Name of the stream.
 121      * @param uriInfo                 URI information.
 122      * @param notificationQueryParams Query parameters of notification.
 123      * @param handlersHolder          Holder of handlers for notifications.
 124      * @return Stream location for listening.
 125      */
 126     final @NonNull URI subscribeToYangStream(final String identifier, final UriInfo uriInfo,
 127             final NotificationQueryParams notificationQueryParams, final HandlersHolder handlersHolder) {
 128         final String streamName = ListenersBroker.createStreamNameFromUri(identifier);
 129         if (Strings.isNullOrEmpty(streamName)) {
 130             throw new RestconfDocumentedException("Stream name is empty.", ErrorType.PROTOCOL, ErrorTag.INVALID_VALUE);
 131         }
 132
 133         final NotificationListenerAdapter notificationListenerAdapter = ListenersBroker.getInstance()
 134             .getNotificationListenerFor(streamName)
 135             .orElseThrow(() -> new RestconfDocumentedException(
 136                 String.format("Stream with name %s was not found.", streamName),
 137                 ErrorType.PROTOCOL, ErrorTag.UNKNOWN_ELEMENT));
 138
 139         final DOMTransactionChain transactionChain = handlersHolder.getTransactionChainHandler().get();
 140         final DOMDataTreeReadWriteTransaction writeTransaction = transactionChain.newReadWriteTransaction();
 141         final EffectiveModelContext schemaContext = handlersHolder.getSchemaHandler().get();
 142
 143         final URI uri = prepareUriByStreamName(uriInfo, streamName);
 144         registerToListenNotification(notificationListenerAdapter, handlersHolder.getNotificationServiceHandler());
 145         notificationListenerAdapter.setQueryParams(
 146                 notificationQueryParams.getStart(),
 147                 notificationQueryParams.getStop().orElse(null),
 148                 notificationQueryParams.getFilter().orElse(null),
 149                 false, notificationQueryParams.isSkipNotificationData());
 150         notificationListenerAdapter.setCloseVars(
 151                 handlersHolder.getTransactionChainHandler(), handlersHolder.getSchemaHandler());
 152         final MapEntryNode mapToStreams = RestconfMappingNodeUtil.mapYangNotificationStreamByIetfRestconfMonitoring(
 153                     notificationListenerAdapter.getSchemaPath().lastNodeIdentifier(),
 154                     schemaContext.getNotifications(), notificationQueryParams.getStart(),
 155                     notificationListenerAdapter.getOutputType(), uri);
 156         writeDataToDS(schemaContext,
 157             notificationListenerAdapter.getSchemaPath().lastNodeIdentifier().getLocalName(), writeTransaction,
 158             mapToStreams);
 159         submitData(writeTransaction);
 160         transactionChain.close();
 161         return uri;
 162     }
 163
 164     /**
 165      * Register listener by streamName in identifier to listen to data change notifications, and put or delete
 166      * information about listener to DS according to ietf-restconf-monitoring.
 167      *
 168      * @param identifier              Identifier as stream name.
 169      * @param uriInfo                 Base URI information.
 170      * @param notificationQueryParams Query parameters of notification.
 171      * @param handlersHolder          Holder of handlers for notifications.
 172      * @return Location for listening.
 173      */
 174     final URI subscribeToDataStream(final String identifier, final UriInfo uriInfo,
 175             final NotificationQueryParams notificationQueryParams, final HandlersHolder handlersHolder) {
 176         final Map<String, String> mapOfValues = mapValuesFromUri(identifier);
 177         final LogicalDatastoreType datastoreType = parseURIEnum(
 178                 LogicalDatastoreType.class,
 179                 mapOfValues.get(RestconfStreamsConstants.DATASTORE_PARAM_NAME));
 180         if (datastoreType == null) {
 181             final String message = "Stream name doesn't contain datastore value (pattern /datastore=)";
 182             LOG.debug(message);
 183             throw new RestconfDocumentedException(message, ErrorType.APPLICATION, ErrorTag.MISSING_ATTRIBUTE);
 184         }
 185
 186         final DataChangeScope scope = parseURIEnum(
 187                 DataChangeScope.class,
 188                 mapOfValues.get(RestconfStreamsConstants.SCOPE_PARAM_NAME));
 189         if (scope == null) {
 190             final String message = "Stream name doesn't contains datastore value (pattern /scope=)";
 191             LOG.warn(message);
 192             throw new RestconfDocumentedException(message, ErrorType.APPLICATION, ErrorTag.MISSING_ATTRIBUTE);
 193         }
 194
 195         final String streamName = ListenersBroker.createStreamNameFromUri(identifier);
 196         final Optional<ListenerAdapter> listener = ListenersBroker.getInstance().getDataChangeListenerFor(streamName);
 197         Preconditions.checkArgument(listener.isPresent(), "Listener doesn't exist : " + streamName);
 198
 199         listener.get().setQueryParams(
 200                 notificationQueryParams.getStart(),
 201                 notificationQueryParams.getStop().orElse(null),
 202                 notificationQueryParams.getFilter().orElse(null),
 203                 false, notificationQueryParams.isSkipNotificationData());
 204         listener.get().setCloseVars(handlersHolder.getTransactionChainHandler(), handlersHolder.getSchemaHandler());
 205         registration(datastoreType, listener.get(), handlersHolder.getDataBroker());
 206
 207         final URI uri = prepareUriByStreamName(uriInfo, streamName);
 208         final DOMTransactionChain transactionChain = handlersHolder.getTransactionChainHandler().get();
 209         final DOMDataTreeReadWriteTransaction writeTransaction = transactionChain.newReadWriteTransaction();
 210         final EffectiveModelContext schemaContext = handlersHolder.getSchemaHandler().get();
 211         final String serializedPath = IdentifierCodec.serialize(listener.get().getPath(), schemaContext);
 212
 213         final MapEntryNode mapToStreams =
 214             RestconfMappingNodeUtil.mapDataChangeNotificationStreamByIetfRestconfMonitoring(listener.get().getPath(),
 215                 notificationQueryParams.getStart(), listener.get().getOutputType(), uri, schemaContext, serializedPath);
 216         writeDataToDS(schemaContext, serializedPath, writeTransaction, mapToStreams);
 217         submitData(writeTransaction);
 218         transactionChain.close();
 219         return uri;
 220     }
 221
 222     private static void writeDataToDS(final EffectiveModelContext schemaContext, final String name,
 223             final DOMDataTreeReadWriteTransaction readWriteTransaction, final MapEntryNode mapToStreams) {
 224         readWriteTransaction.merge(LogicalDatastoreType.OPERATIONAL,
 225             // FIXME: do not use IdentifierCodec here
 226             IdentifierCodec.deserialize(MonitoringModule.PATH_TO_STREAM_WITHOUT_KEY + name, schemaContext),
 227             mapToStreams);
 228     }
 229
 230     private static void submitData(final DOMDataTreeReadWriteTransaction readWriteTransaction) {
 231         try {
 232             readWriteTransaction.commit().get();
 233         } catch (final InterruptedException | ExecutionException e) {
 234             throw new RestconfDocumentedException("Problem while putting data to DS.", e);
 235         }
 236     }
 237
 238     /**
 239      * Prepare map of URI parameter-values.
 240      *
 241      * @param identifier String identification of URI.
 242      * @return Map od URI parameters and values.
 243      */
 244     private static Map<String, String> mapValuesFromUri(final String identifier) {
 245         final HashMap<String, String> result = new HashMap<>();
 246         for (final String token : RestconfConstants.SLASH_SPLITTER.split(identifier)) {
 247             final String[] paramToken = token.split("=");
 248             if (paramToken.length == 2) {
 249                 result.put(paramToken[0], paramToken[1]);
 250             }
 251         }
 252         return result;
 253     }
 254
 255     /**
 256      * Register data change listener in DOM data broker and set it to listener on stream.
 257      *
 258      * @param datastore     {@link LogicalDatastoreType}
 259      * @param listener      listener on specific stream
 260      * @param domDataBroker data broker for register data change listener
 261      */
 262     private static void registration(final LogicalDatastoreType datastore, final ListenerAdapter listener,
 263             final DOMDataBroker domDataBroker) {
 264         if (listener.isListening()) {
 265             return;
 266         }
 267
 268         final DOMDataTreeChangeService changeService = domDataBroker.getExtensions()
 269                 .getInstance(DOMDataTreeChangeService.class);
 270         if (changeService == null) {
 271             throw new UnsupportedOperationException("DOMDataBroker does not support the DOMDataTreeChangeService");
 272         }
 273
 274         final DOMDataTreeIdentifier root = new DOMDataTreeIdentifier(datastore, listener.getPath());
 275         final ListenerRegistration<ListenerAdapter> registration =
 276                 changeService.registerDataTreeChangeListener(root, listener);
 277         listener.setRegistration(registration);
 278     }
 279
 280     // FIXME: this method should be in NotificationListenerAdapter
 281     private static void registerToListenNotification(final NotificationListenerAdapter listener,
 282             final DOMNotificationService notificationService) {
 283         if (listener.isListening()) {
 284             return;
 285         }
 286
 287         final Absolute path = listener.getSchemaPath();
 288         final ListenerRegistration<DOMNotificationListener> registration =
 289                 notificationService.registerNotificationListener(listener, path);
 290         listener.setRegistration(registration);
 291     }
 292
 293     /**
 294      * Parse out enumeration from URI.
 295      *
 296      * @param clazz Target enumeration type.
 297      * @param value String representation of enumeration value.
 298      * @return Parsed enumeration type.
 299      */
 300     private static <T> T parseURIEnum(final Class<T> clazz, final String value) {
 301         if (value == null || value.equals("")) {
 302             return null;
 303         }
 304         return ResolveEnumUtil.resolveEnum(clazz, value);
 305     }
 306 }