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.DOMTransactionChain;
  27 import org.opendaylight.restconf.common.errors.RestconfDocumentedException;
  28 import org.opendaylight.restconf.common.errors.RestconfError.ErrorTag;
  29 import org.opendaylight.restconf.common.errors.RestconfError.ErrorType;
  30 import org.opendaylight.restconf.common.util.DataChangeScope;
  31 import org.opendaylight.restconf.nb.rfc8040.Rfc8040.MonitoringModule;
  32 import org.opendaylight.restconf.nb.rfc8040.handlers.NotificationServiceHandler;
  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.Module;
  47 import org.opendaylight.yangtools.yang.model.api.stmt.SchemaNodeIdentifier.Absolute;
  48 import org.slf4j.Logger;
  49 import org.slf4j.LoggerFactory;
  50
  51 /**
  52  * Subscribe to stream util class.
  53  */
  54 abstract class SubscribeToStreamUtil {
  55     /**
  56      * Implementation of {@link UrlResolver} for Server-sent events.
  57      */
  58     private static final class ServerSentEvents extends SubscribeToStreamUtil {
  59         static final ServerSentEvents INSTANCE = new ServerSentEvents();
  60
  61         @Override
  62         public URI prepareUriByStreamName(final UriInfo uriInfo, final String streamName) {
  63             final UriBuilder uriBuilder = uriInfo.getBaseUriBuilder();
  64             return uriBuilder.replacePath(RestconfConstants.BASE_URI_PATTERN + '/'
  65                     + RestconfConstants.NOTIF + '/' + streamName).build();
  66         }
  67     }
  68
  69     /**
  70      * Implementation of {@link UrlResolver} for Web sockets.
  71      */
  72     private static final class WebSockets extends SubscribeToStreamUtil {
  73         static final WebSockets INSTANCE = new WebSockets();
  74
  75         @Override
  76         public URI prepareUriByStreamName(final UriInfo uriInfo, final String streamName) {
  77             final String scheme = uriInfo.getAbsolutePath().getScheme();
  78             final UriBuilder uriBuilder = uriInfo.getBaseUriBuilder();
  79             switch (scheme) {
  80                 case "https":
  81                     // Secured HTTP goes to Secured WebSockets
  82                     uriBuilder.scheme("wss");
  83                     break;
  84                 case "http":
  85                 default:
  86                     // Unsecured HTTP and others go to unsecured WebSockets
  87                     uriBuilder.scheme("ws");
  88             }
  89             return uriBuilder.replacePath(RestconfConstants.BASE_URI_PATTERN + '/' + streamName).build();
  90         }
  91     }
  92
  93
  94     private static final Logger LOG = LoggerFactory.getLogger(SubscribeToStreamUtil.class);
  95
  96     SubscribeToStreamUtil() {
  97         // Hidden on purpose
  98     }
  99
 100     static SubscribeToStreamUtil serverSentEvents() {
 101         return ServerSentEvents.INSTANCE;
 102     }
 103
 104     static SubscribeToStreamUtil webSockets() {
 105         return WebSockets.INSTANCE;
 106     }
 107
 108     /**
 109      * Prepare URL from base name and stream name.
 110      *
 111      * @param uriInfo base URL information
 112      * @param streamName name of stream for create
 113      * @return final URL
 114      */
 115     abstract @NonNull URI prepareUriByStreamName(UriInfo uriInfo, String streamName);
 116
 117     /**
 118      * Register listener by streamName in identifier to listen to yang notifications, and put or delete information
 119      * about listener to DS according to ietf-restconf-monitoring.
 120      *
 121      * @param identifier              Name of the stream.
 122      * @param uriInfo                 URI information.
 123      * @param notificationQueryParams Query parameters of notification.
 124      * @param handlersHolder          Holder of handlers for notifications.
 125      * @param urlResolver             Resolver for proper implementation. Possibilities is WS or SSE.
 126      * @return Stream location for listening.
 127      */
 128     final @NonNull URI subscribeToYangStream(final String identifier, final UriInfo uriInfo,
 129             final NotificationQueryParams notificationQueryParams, final HandlersHolder handlersHolder) {
 130         final String streamName = ListenersBroker.createStreamNameFromUri(identifier);
 131         if (Strings.isNullOrEmpty(streamName)) {
 132             throw new RestconfDocumentedException("Stream name is empty.", ErrorType.PROTOCOL, ErrorTag.INVALID_VALUE);
 133         }
 134         final Optional<NotificationListenerAdapter> notificationListenerAdapter =
 135                 ListenersBroker.getInstance().getNotificationListenerFor(streamName);
 136
 137         if (!notificationListenerAdapter.isPresent()) {
 138             throw new RestconfDocumentedException(String.format(
 139                     "Stream with name %s was not found.", streamName),
 140                     ErrorType.PROTOCOL,
 141                     ErrorTag.UNKNOWN_ELEMENT);
 142         }
 143
 144         final DOMTransactionChain transactionChain = handlersHolder.getTransactionChainHandler().get();
 145         final DOMDataTreeReadWriteTransaction writeTransaction = transactionChain.newReadWriteTransaction();
 146         final EffectiveModelContext schemaContext = handlersHolder.getSchemaHandler().get();
 147
 148         final URI uri = prepareUriByStreamName(uriInfo, streamName);
 149         registerToListenNotification(
 150                 notificationListenerAdapter.get(), handlersHolder.getNotificationServiceHandler());
 151         notificationListenerAdapter.get().setQueryParams(
 152                 notificationQueryParams.getStart(),
 153                 notificationQueryParams.getStop().orElse(null),
 154                 notificationQueryParams.getFilter().orElse(null),
 155                 false, notificationQueryParams.isSkipNotificationData());
 156         notificationListenerAdapter.get().setCloseVars(
 157                 handlersHolder.getTransactionChainHandler(), handlersHolder.getSchemaHandler());
 158         final MapEntryNode mapToStreams = RestconfMappingNodeUtil.mapYangNotificationStreamByIetfRestconfMonitoring(
 159                     notificationListenerAdapter.get().getSchemaPath().lastNodeIdentifier(),
 160                     schemaContext.getNotifications(), notificationQueryParams.getStart(),
 161                     notificationListenerAdapter.get().getOutputType(), uri, getMonitoringModule(schemaContext));
 162         writeDataToDS(schemaContext,
 163             notificationListenerAdapter.get().getSchemaPath().lastNodeIdentifier().getLocalName(), writeTransaction,
 164             mapToStreams);
 165         submitData(writeTransaction);
 166         transactionChain.close();
 167         return uri;
 168     }
 169
 170     /**
 171      * Register listener by streamName in identifier to listen to data change notifications, and put or delete
 172      * information about listener to DS according to ietf-restconf-monitoring.
 173      *
 174      * @param identifier              Identifier as stream name.
 175      * @param uriInfo                 Base URI information.
 176      * @param notificationQueryParams Query parameters of notification.
 177      * @param handlersHolder          Holder of handlers for notifications.
 178      * @return Location for listening.
 179      */
 180     final URI subscribeToDataStream(final String identifier, final UriInfo uriInfo,
 181             final NotificationQueryParams notificationQueryParams, final HandlersHolder handlersHolder) {
 182         final Map<String, String> mapOfValues = mapValuesFromUri(identifier);
 183         final LogicalDatastoreType datastoreType = parseURIEnum(
 184                 LogicalDatastoreType.class,
 185                 mapOfValues.get(RestconfStreamsConstants.DATASTORE_PARAM_NAME));
 186         if (datastoreType == null) {
 187             final String message = "Stream name doesn't contain datastore value (pattern /datastore=)";
 188             LOG.debug(message);
 189             throw new RestconfDocumentedException(message, ErrorType.APPLICATION, ErrorTag.MISSING_ATTRIBUTE);
 190         }
 191
 192         final DataChangeScope scope = parseURIEnum(
 193                 DataChangeScope.class,
 194                 mapOfValues.get(RestconfStreamsConstants.SCOPE_PARAM_NAME));
 195         if (scope == null) {
 196             final String message = "Stream name doesn't contains datastore value (pattern /scope=)";
 197             LOG.warn(message);
 198             throw new RestconfDocumentedException(message, ErrorType.APPLICATION, ErrorTag.MISSING_ATTRIBUTE);
 199         }
 200
 201         final String streamName = ListenersBroker.createStreamNameFromUri(identifier);
 202         final Optional<ListenerAdapter> listener = ListenersBroker.getInstance().getDataChangeListenerFor(streamName);
 203         Preconditions.checkArgument(listener.isPresent(), "Listener doesn't exist : " + streamName);
 204
 205         listener.get().setQueryParams(
 206                 notificationQueryParams.getStart(),
 207                 notificationQueryParams.getStop().orElse(null),
 208                 notificationQueryParams.getFilter().orElse(null),
 209                 false, notificationQueryParams.isSkipNotificationData());
 210         listener.get().setCloseVars(handlersHolder.getTransactionChainHandler(), handlersHolder.getSchemaHandler());
 211         registration(datastoreType, listener.get(), handlersHolder.getDomDataBrokerHandler().get());
 212
 213         final URI uri = prepareUriByStreamName(uriInfo, streamName);
 214         final DOMTransactionChain transactionChain = handlersHolder.getTransactionChainHandler().get();
 215         final DOMDataTreeReadWriteTransaction writeTransaction = transactionChain.newReadWriteTransaction();
 216         final EffectiveModelContext schemaContext = handlersHolder.getSchemaHandler().get();
 217
 218         final MapEntryNode mapToStreams =
 219             RestconfMappingNodeUtil.mapDataChangeNotificationStreamByIetfRestconfMonitoring(listener.get().getPath(),
 220                 notificationQueryParams.getStart(), listener.get().getOutputType(), uri,
 221                 getMonitoringModule(schemaContext), schemaContext);
 222         writeDataToDS(schemaContext, listener.get().getPath().getLastPathArgument().getNodeType().getLocalName(),
 223                 writeTransaction, mapToStreams);
 224         submitData(writeTransaction);
 225         transactionChain.close();
 226         return uri;
 227     }
 228
 229     static Module getMonitoringModule(final EffectiveModelContext schemaContext) {
 230         return schemaContext.findModule(MonitoringModule.MODULE_QNAME).orElse(null);
 231     }
 232
 233     private static void writeDataToDS(final EffectiveModelContext schemaContext, final String name,
 234             final DOMDataTreeReadWriteTransaction readWriteTransaction, final MapEntryNode mapToStreams) {
 235         readWriteTransaction.merge(LogicalDatastoreType.OPERATIONAL,
 236             // FIXME: do not use IdentifierCodec here
 237             IdentifierCodec.deserialize(MonitoringModule.PATH_TO_STREAM_WITHOUT_KEY + name, schemaContext),
 238             mapToStreams);
 239     }
 240
 241     private static void submitData(final DOMDataTreeReadWriteTransaction readWriteTransaction) {
 242         try {
 243             readWriteTransaction.commit().get();
 244         } catch (final InterruptedException | ExecutionException e) {
 245             throw new RestconfDocumentedException("Problem while putting data to DS.", e);
 246         }
 247     }
 248
 249     /**
 250      * Prepare map of URI parameter-values.
 251      *
 252      * @param identifier String identification of URI.
 253      * @return Map od URI parameters and values.
 254      */
 255     private static Map<String, String> mapValuesFromUri(final String identifier) {
 256         final HashMap<String, String> result = new HashMap<>();
 257         for (final String token : RestconfConstants.SLASH_SPLITTER.split(identifier)) {
 258             final String[] paramToken = token.split("=");
 259             if (paramToken.length == 2) {
 260                 result.put(paramToken[0], paramToken[1]);
 261             }
 262         }
 263         return result;
 264     }
 265
 266     /**
 267      * Register data change listener in DOM data broker and set it to listener on stream.
 268      *
 269      * @param datastore     {@link LogicalDatastoreType}
 270      * @param listener      listener on specific stream
 271      * @param domDataBroker data broker for register data change listener
 272      */
 273     private static void registration(final LogicalDatastoreType datastore, final ListenerAdapter listener,
 274             final DOMDataBroker domDataBroker) {
 275         if (listener.isListening()) {
 276             return;
 277         }
 278
 279         final DOMDataTreeChangeService changeService = domDataBroker.getExtensions()
 280                 .getInstance(DOMDataTreeChangeService.class);
 281         if (changeService == null) {
 282             throw new UnsupportedOperationException("DOMDataBroker does not support the DOMDataTreeChangeService");
 283         }
 284
 285         final DOMDataTreeIdentifier root = new DOMDataTreeIdentifier(datastore, listener.getPath());
 286         final ListenerRegistration<ListenerAdapter> registration =
 287                 changeService.registerDataTreeChangeListener(root, listener);
 288         listener.setRegistration(registration);
 289     }
 290
 291     private static void registerToListenNotification(final NotificationListenerAdapter listener,
 292             final NotificationServiceHandler notificationServiceHandler) {
 293         if (listener.isListening()) {
 294             return;
 295         }
 296
 297         final Absolute path = listener.getSchemaPath();
 298         final ListenerRegistration<DOMNotificationListener> registration =
 299                 notificationServiceHandler.get().registerNotificationListener(listener, path);
 300         listener.setRegistration(registration);
 301     }
 302
 303     /**
 304      * Parse out enumeration from URI.
 305      *
 306      * @param clazz Target enumeration type.
 307      * @param value String representation of enumeration value.
 308      * @return Parsed enumeration type.
 309      */
 310     private static <T> T parseURIEnum(final Class<T> clazz, final String value) {
 311         if (value == null || value.equals("")) {
 312             return null;
 313         }
 314         return ResolveEnumUtil.resolveEnum(clazz, value);
 315     }
 316 }