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 static com.google.common.base.Preconditions.checkArgument;
  11
  12 import com.google.common.base.Strings;
  13 import java.net.URI;
  14 import java.util.HashMap;
  15 import java.util.Map;
  16 import java.util.Optional;
  17 import java.util.concurrent.ExecutionException;
  18 import javax.ws.rs.core.UriBuilder;
  19 import javax.ws.rs.core.UriInfo;
  20 import org.eclipse.jdt.annotation.NonNull;
  21 import org.opendaylight.mdsal.common.api.LogicalDatastoreType;
  22 import org.opendaylight.mdsal.dom.api.DOMDataBroker;
  23 import org.opendaylight.mdsal.dom.api.DOMDataTreeChangeService;
  24 import org.opendaylight.mdsal.dom.api.DOMDataTreeIdentifier;
  25 import org.opendaylight.mdsal.dom.api.DOMDataTreeReadWriteTransaction;
  26 import org.opendaylight.mdsal.dom.api.DOMNotificationListener;
  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.handlers.NotificationServiceHandler;
  34 import org.opendaylight.restconf.nb.rfc8040.rests.services.impl.RestconfStreamsSubscriptionServiceImpl.HandlersHolder;
  35 import org.opendaylight.restconf.nb.rfc8040.rests.services.impl.RestconfStreamsSubscriptionServiceImpl.NotificationQueryParams;
  36 import org.opendaylight.restconf.nb.rfc8040.rests.utils.ResolveEnumUtil;
  37 import org.opendaylight.restconf.nb.rfc8040.rests.utils.RestconfStreamsConstants;
  38 import org.opendaylight.restconf.nb.rfc8040.streams.listeners.ListenerAdapter;
  39 import org.opendaylight.restconf.nb.rfc8040.streams.listeners.ListenersBroker;
  40 import org.opendaylight.restconf.nb.rfc8040.streams.listeners.NotificationListenerAdapter;
  41 import org.opendaylight.restconf.nb.rfc8040.utils.RestconfConstants;
  42 import org.opendaylight.restconf.nb.rfc8040.utils.mapping.RestconfMappingNodeUtil;
  43 import org.opendaylight.restconf.nb.rfc8040.utils.parser.IdentifierCodec;
  44 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  45 import org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode;
  46 import org.opendaylight.yangtools.yang.model.api.EffectiveModelContext;
  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 SubscribeToStreamUtil 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 SubscribeToStreamUtil 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      * @return Stream location for listening.
 126      */
 127     final @NonNull URI subscribeToYangStream(final String identifier, final UriInfo uriInfo,
 128             final NotificationQueryParams notificationQueryParams, final HandlersHolder handlersHolder) {
 129         final String streamName = ListenersBroker.createStreamNameFromUri(identifier);
 130         if (Strings.isNullOrEmpty(streamName)) {
 131             throw new RestconfDocumentedException("Stream name is empty.", ErrorType.PROTOCOL, ErrorTag.INVALID_VALUE);
 132         }
 133         final Optional<NotificationListenerAdapter> notificationListenerAdapter =
 134                 ListenersBroker.getInstance().getNotificationListenerFor(streamName);
 135
 136         if (notificationListenerAdapter.isEmpty()) {
 137             throw new RestconfDocumentedException(String.format(
 138                     "Stream with name %s was not found.", streamName),
 139                     ErrorType.PROTOCOL,
 140                     ErrorTag.UNKNOWN_ELEMENT);
 141         }
 142
 143         final DOMTransactionChain transactionChain = handlersHolder.getTransactionChainHandler().get();
 144         final DOMDataTreeReadWriteTransaction writeTransaction = transactionChain.newReadWriteTransaction();
 145         final EffectiveModelContext schemaContext = handlersHolder.getSchemaHandler().get();
 146
 147         final URI uri = prepareUriByStreamName(uriInfo, streamName);
 148         registerToListenNotification(
 149                 notificationListenerAdapter.get(), handlersHolder.getNotificationServiceHandler());
 150         notificationListenerAdapter.get().setQueryParams(
 151                 notificationQueryParams.getStart(),
 152                 notificationQueryParams.getStop().orElse(null),
 153                 notificationQueryParams.getFilter().orElse(null),
 154                 false, notificationQueryParams.isSkipNotificationData());
 155         notificationListenerAdapter.get().setCloseVars(
 156                 handlersHolder.getTransactionChainHandler(), handlersHolder.getSchemaHandler());
 157         final MapEntryNode mapToStreams = RestconfMappingNodeUtil.mapYangNotificationStreamByIetfRestconfMonitoring(
 158                     notificationListenerAdapter.get().getSchemaPath().lastNodeIdentifier(),
 159                     schemaContext.getNotifications(), notificationQueryParams.getStart(),
 160                     notificationListenerAdapter.get().getOutputType(), uri);
 161         writeDataToDS(writeTransaction, mapToStreams);
 162         submitData(writeTransaction);
 163         transactionChain.close();
 164         return uri;
 165     }
 166
 167     /**
 168      * Register listener by streamName in identifier to listen to data change notifications, and put or delete
 169      * information about listener to DS according to ietf-restconf-monitoring.
 170      *
 171      * @param identifier              Identifier as stream name.
 172      * @param uriInfo                 Base URI information.
 173      * @param notificationQueryParams Query parameters of notification.
 174      * @param handlersHolder          Holder of handlers for notifications.
 175      * @return Location for listening.
 176      */
 177     final URI subscribeToDataStream(final String identifier, final UriInfo uriInfo,
 178             final NotificationQueryParams notificationQueryParams, final HandlersHolder handlersHolder) {
 179         final Map<String, String> mapOfValues = mapValuesFromUri(identifier);
 180         final LogicalDatastoreType datastoreType = parseURIEnum(
 181                 LogicalDatastoreType.class,
 182                 mapOfValues.get(RestconfStreamsConstants.DATASTORE_PARAM_NAME));
 183         if (datastoreType == null) {
 184             final String message = "Stream name doesn't contain datastore value (pattern /datastore=)";
 185             LOG.debug(message);
 186             throw new RestconfDocumentedException(message, ErrorType.APPLICATION, ErrorTag.MISSING_ATTRIBUTE);
 187         }
 188
 189         final DataChangeScope scope = parseURIEnum(
 190                 DataChangeScope.class,
 191                 mapOfValues.get(RestconfStreamsConstants.SCOPE_PARAM_NAME));
 192         if (scope == null) {
 193             final String message = "Stream name doesn't contains datastore value (pattern /scope=)";
 194             LOG.warn(message);
 195             throw new RestconfDocumentedException(message, ErrorType.APPLICATION, ErrorTag.MISSING_ATTRIBUTE);
 196         }
 197
 198         final String streamName = ListenersBroker.createStreamNameFromUri(identifier);
 199         final Optional<ListenerAdapter> listener = ListenersBroker.getInstance().getDataChangeListenerFor(streamName);
 200         checkArgument(listener.isPresent(), "Listener does not exist : %s", streamName);
 201
 202         listener.get().setQueryParams(
 203                 notificationQueryParams.getStart(),
 204                 notificationQueryParams.getStop().orElse(null),
 205                 notificationQueryParams.getFilter().orElse(null),
 206                 false, notificationQueryParams.isSkipNotificationData());
 207         listener.get().setCloseVars(handlersHolder.getTransactionChainHandler(), handlersHolder.getSchemaHandler());
 208         registration(datastoreType, listener.get(), handlersHolder.getDomDataBrokerHandler().get());
 209
 210         final URI uri = prepareUriByStreamName(uriInfo, streamName);
 211         final DOMTransactionChain transactionChain = handlersHolder.getTransactionChainHandler().get();
 212         final DOMDataTreeReadWriteTransaction writeTransaction = transactionChain.newReadWriteTransaction();
 213         final EffectiveModelContext schemaContext = handlersHolder.getSchemaHandler().get();
 214
 215         final MapEntryNode mapToStreams =
 216             RestconfMappingNodeUtil.mapDataChangeNotificationStreamByIetfRestconfMonitoring(listener.get().getPath(),
 217                 notificationQueryParams.getStart(), listener.get().getOutputType(), uri, schemaContext,
 218                 IdentifierCodec.serialize(listener.get().getPath(), schemaContext));
 219         writeDataToDS(writeTransaction, mapToStreams);
 220         submitData(writeTransaction);
 221         transactionChain.close();
 222         return uri;
 223     }
 224
 225     private static void writeDataToDS(final DOMDataTreeReadWriteTransaction readWriteTransaction,
 226             final MapEntryNode mapToStreams) {
 227         readWriteTransaction.merge(LogicalDatastoreType.OPERATIONAL,
 228             MonitoringModule.restconfStateStreamPath(mapToStreams.getIdentifier()), mapToStreams);
 229     }
 230
 231     private static void submitData(final DOMDataTreeReadWriteTransaction readWriteTransaction) {
 232         try {
 233             readWriteTransaction.commit().get();
 234         } catch (final InterruptedException | ExecutionException e) {
 235             throw new RestconfDocumentedException("Problem while putting data to DS.", e);
 236         }
 237     }
 238
 239     /**
 240      * Prepare map of URI parameter-values.
 241      *
 242      * @param identifier String identification of URI.
 243      * @return Map od URI parameters and values.
 244      */
 245     private static Map<String, String> mapValuesFromUri(final String identifier) {
 246         final HashMap<String, String> result = new HashMap<>();
 247         for (final String token : RestconfConstants.SLASH_SPLITTER.split(identifier)) {
 248             final String[] paramToken = token.split("=");
 249             if (paramToken.length == 2) {
 250                 result.put(paramToken[0], paramToken[1]);
 251             }
 252         }
 253         return result;
 254     }
 255
 256     /**
 257      * Register data change listener in DOM data broker and set it to listener on stream.
 258      *
 259      * @param datastore     {@link LogicalDatastoreType}
 260      * @param listener      listener on specific stream
 261      * @param domDataBroker data broker for register data change listener
 262      */
 263     private static void registration(final LogicalDatastoreType datastore, final ListenerAdapter listener,
 264             final DOMDataBroker domDataBroker) {
 265         if (listener.isListening()) {
 266             return;
 267         }
 268
 269         final DOMDataTreeChangeService changeService = domDataBroker.getExtensions()
 270                 .getInstance(DOMDataTreeChangeService.class);
 271         if (changeService == null) {
 272             throw new UnsupportedOperationException("DOMDataBroker does not support the DOMDataTreeChangeService");
 273         }
 274
 275         final DOMDataTreeIdentifier root = new DOMDataTreeIdentifier(datastore, listener.getPath());
 276         final ListenerRegistration<ListenerAdapter> registration =
 277                 changeService.registerDataTreeChangeListener(root, listener);
 278         listener.setRegistration(registration);
 279     }
 280
 281     private static void registerToListenNotification(final NotificationListenerAdapter listener,
 282             final NotificationServiceHandler notificationServiceHandler) {
 283         if (listener.isListening()) {
 284             return;
 285         }
 286
 287         final Absolute path = listener.getSchemaPath();
 288         final ListenerRegistration<DOMNotificationListener> registration =
 289                 notificationServiceHandler.get().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 }