restconf/restconf-nb/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.Strings.isNullOrEmpty;
  11
  12 import com.google.common.base.Splitter;
  13 import java.net.URI;
  14 import java.util.HashMap;
  15 import java.util.Map;
  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.DOMDataTreeWriteOperations;
  23 import org.opendaylight.mdsal.dom.api.DOMDataTreeWriteTransaction;
  24 import org.opendaylight.restconf.common.errors.RestconfDocumentedException;
  25 import org.opendaylight.restconf.nb.rfc8040.NotificationQueryParams;
  26 import org.opendaylight.restconf.nb.rfc8040.URLConstants;
  27 import org.opendaylight.restconf.nb.rfc8040.databind.DatabindProvider;
  28 import org.opendaylight.restconf.nb.rfc8040.monitoring.RestconfStateStreams;
  29 import org.opendaylight.restconf.nb.rfc8040.rests.services.impl.RestconfStreamsSubscriptionServiceImpl.HandlersHolder;
  30 import org.opendaylight.restconf.nb.rfc8040.rests.utils.RestconfStreamsConstants;
  31 import org.opendaylight.restconf.nb.rfc8040.streams.listeners.ListenerAdapter;
  32 import org.opendaylight.restconf.nb.rfc8040.streams.listeners.ListenersBroker;
  33 import org.opendaylight.restconf.nb.rfc8040.streams.listeners.NotificationListenerAdapter;
  34 import org.opendaylight.restconf.nb.rfc8040.utils.parser.IdentifierCodec;
  35 import org.opendaylight.yangtools.yang.common.ErrorTag;
  36 import org.opendaylight.yangtools.yang.common.ErrorType;
  37 import org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode;
  38 import org.opendaylight.yangtools.yang.model.api.EffectiveModelContext;
  39 import org.slf4j.Logger;
  40 import org.slf4j.LoggerFactory;
  41
  42 /**
  43  * Subscribe to stream util class.
  44  */
  45 abstract class SubscribeToStreamUtil {
  46     /**
  47      * Implementation of SubscribeToStreamUtil for Server-sent events.
  48      */
  49     private static final class ServerSentEvents extends SubscribeToStreamUtil {
  50         static final ServerSentEvents INSTANCE = new ServerSentEvents();
  51
  52         @Override
  53         public URI prepareUriByStreamName(final UriInfo uriInfo, final String streamName) {
  54             return uriInfo.getBaseUriBuilder()
  55                 .replacePath(URLConstants.BASE_PATH + '/' + URLConstants.SSE_SUBPATH + '/' + streamName)
  56                 .build();
  57         }
  58     }
  59
  60     /**
  61      * Implementation of SubscribeToStreamUtil for Web sockets.
  62      */
  63     private static final class WebSockets extends SubscribeToStreamUtil {
  64         static final WebSockets INSTANCE = new WebSockets();
  65
  66         @Override
  67         public URI prepareUriByStreamName(final UriInfo uriInfo, final String streamName) {
  68             final String scheme = uriInfo.getAbsolutePath().getScheme();
  69             final UriBuilder uriBuilder = uriInfo.getBaseUriBuilder();
  70             switch (scheme) {
  71                 case "https":
  72                     // Secured HTTP goes to Secured WebSockets
  73                     uriBuilder.scheme("wss");
  74                     break;
  75                 case "http":
  76                 default:
  77                     // Unsecured HTTP and others go to unsecured WebSockets
  78                     uriBuilder.scheme("ws");
  79             }
  80             return uriBuilder.replacePath(URLConstants.BASE_PATH + '/' + streamName).build();
  81         }
  82     }
  83
  84     private static final Logger LOG = LoggerFactory.getLogger(SubscribeToStreamUtil.class);
  85     private static final Splitter SLASH_SPLITTER = Splitter.on('/');
  86
  87     SubscribeToStreamUtil() {
  88         // Hidden on purpose
  89     }
  90
  91     static SubscribeToStreamUtil serverSentEvents() {
  92         return ServerSentEvents.INSTANCE;
  93     }
  94
  95     static SubscribeToStreamUtil webSockets() {
  96         return WebSockets.INSTANCE;
  97     }
  98
  99     /**
 100      * Prepare URL from base name and stream name.
 101      *
 102      * @param uriInfo base URL information
 103      * @param streamName name of stream for create
 104      * @return final URL
 105      */
 106     abstract @NonNull URI prepareUriByStreamName(UriInfo uriInfo, String streamName);
 107
 108     /**
 109      * Register listener by streamName in identifier to listen to yang notifications, and put or delete information
 110      * about listener to DS according to ietf-restconf-monitoring.
 111      *
 112      * @param identifier              Name of the stream.
 113      * @param uriInfo                 URI information.
 114      * @param notificationQueryParams Query parameters of notification.
 115      * @param handlersHolder          Holder of handlers for notifications.
 116      * @return Stream location for listening.
 117      */
 118     final @NonNull URI subscribeToYangStream(final String identifier, final UriInfo uriInfo,
 119             final NotificationQueryParams notificationQueryParams, final HandlersHolder handlersHolder) {
 120         final String streamName = ListenersBroker.createStreamNameFromUri(identifier);
 121         if (isNullOrEmpty(streamName)) {
 122             throw new RestconfDocumentedException("Stream name is empty.", ErrorType.PROTOCOL, ErrorTag.INVALID_VALUE);
 123         }
 124
 125         final NotificationListenerAdapter notificationListenerAdapter = ListenersBroker.getInstance()
 126             .notificationListenerFor(streamName);
 127         if (notificationListenerAdapter == null) {
 128             throw new RestconfDocumentedException(String.format("Stream with name %s was not found.", streamName),
 129                 ErrorType.PROTOCOL, ErrorTag.UNKNOWN_ELEMENT);
 130         }
 131
 132         final EffectiveModelContext schemaContext = handlersHolder.getDatabindProvider().currentContext()
 133             .modelContext();
 134         final URI uri = prepareUriByStreamName(uriInfo, streamName);
 135         notificationListenerAdapter.setQueryParams(notificationQueryParams);
 136         notificationListenerAdapter.listen(handlersHolder.getNotificationServiceHandler());
 137         final DOMDataBroker dataBroker = handlersHolder.getDataBroker();
 138         notificationListenerAdapter.setCloseVars(dataBroker, handlersHolder.getDatabindProvider());
 139         final MapEntryNode mapToStreams = RestconfStateStreams.notificationStreamEntry(schemaContext,
 140             notificationListenerAdapter.getSchemaPath().lastNodeIdentifier(), notificationListenerAdapter.getStart(),
 141             notificationListenerAdapter.getOutputType(), uri);
 142
 143         // FIXME: how does this correlate with the transaction notificationListenerAdapter.close() will do?
 144         final DOMDataTreeWriteTransaction writeTransaction = dataBroker.newWriteOnlyTransaction();
 145         writeDataToDS(writeTransaction, mapToStreams);
 146         submitData(writeTransaction);
 147         return uri;
 148     }
 149
 150     /**
 151      * Register listener by streamName in identifier to listen to data change notifications, and put or delete
 152      * information about listener to DS according to ietf-restconf-monitoring.
 153      *
 154      * @param identifier              Identifier as stream name.
 155      * @param uriInfo                 Base URI information.
 156      * @param notificationQueryParams Query parameters of notification.
 157      * @param handlersHolder          Holder of handlers for notifications.
 158      * @return Location for listening.
 159      */
 160     final URI subscribeToDataStream(final String identifier, final UriInfo uriInfo,
 161             final NotificationQueryParams notificationQueryParams, final HandlersHolder handlersHolder) {
 162         final Map<String, String> mapOfValues = mapValuesFromUri(identifier);
 163
 164         final String datastoreParam = mapOfValues.get(RestconfStreamsConstants.DATASTORE_PARAM_NAME);
 165         if (isNullOrEmpty(datastoreParam)) {
 166             final String message = "Stream name does not contain datastore value (pattern /datastore=)";
 167             LOG.debug(message);
 168             throw new RestconfDocumentedException(message, ErrorType.APPLICATION, ErrorTag.MISSING_ATTRIBUTE);
 169         }
 170
 171         // FIXME: this is kept only for compatibility, we are not using this parameter
 172         if (isNullOrEmpty(mapOfValues.get(RestconfStreamsConstants.SCOPE_PARAM_NAME))) {
 173             final String message = "Stream name does not contain scope value (pattern /scope=)";
 174             LOG.warn(message);
 175             throw new RestconfDocumentedException(message, ErrorType.APPLICATION, ErrorTag.MISSING_ATTRIBUTE);
 176         }
 177
 178         final String streamName = ListenersBroker.createStreamNameFromUri(identifier);
 179         final ListenerAdapter listener = ListenersBroker.getInstance().dataChangeListenerFor(streamName);
 180         if (listener == null) {
 181             throw new RestconfDocumentedException("No listener found for stream " + streamName,
 182                 ErrorType.APPLICATION, ErrorTag.DATA_MISSING);
 183         }
 184
 185         listener.setQueryParams(notificationQueryParams);
 186
 187         final DOMDataBroker dataBroker = handlersHolder.getDataBroker();
 188         final DatabindProvider schemaHandler = handlersHolder.getDatabindProvider();
 189         listener.setCloseVars(dataBroker, schemaHandler);
 190         listener.listen(dataBroker, LogicalDatastoreType.valueOf(datastoreParam));
 191
 192         final URI uri = prepareUriByStreamName(uriInfo, streamName);
 193         final EffectiveModelContext schemaContext = schemaHandler.currentContext().modelContext();
 194         final String serializedPath = IdentifierCodec.serialize(listener.getPath(), schemaContext);
 195
 196         final MapEntryNode mapToStreams = RestconfStateStreams.dataChangeStreamEntry(listener.getPath(),
 197                 listener.getStart(), listener.getOutputType(), uri, schemaContext, serializedPath);
 198         final DOMDataTreeWriteTransaction writeTransaction = dataBroker.newWriteOnlyTransaction();
 199         writeDataToDS(writeTransaction, mapToStreams);
 200         submitData(writeTransaction);
 201         return uri;
 202     }
 203
 204     // FIXME: callers are utter duplicates, refactor them
 205     private static void writeDataToDS(final DOMDataTreeWriteOperations tx, final MapEntryNode mapToStreams) {
 206         // FIXME: use put() here
 207         tx.merge(LogicalDatastoreType.OPERATIONAL, RestconfStateStreams.restconfStateStreamPath(mapToStreams.name()),
 208             mapToStreams);
 209     }
 210
 211     private static void submitData(final DOMDataTreeWriteTransaction readWriteTransaction) {
 212         try {
 213             readWriteTransaction.commit().get();
 214         } catch (final InterruptedException | ExecutionException e) {
 215             throw new RestconfDocumentedException("Problem while putting data to DS.", e);
 216         }
 217     }
 218
 219     /**
 220      * Prepare map of URI parameter-values.
 221      *
 222      * @param identifier String identification of URI.
 223      * @return Map od URI parameters and values.
 224      */
 225     private static Map<String, String> mapValuesFromUri(final String identifier) {
 226         final var result = new HashMap<String, String>();
 227         for (final String token : SLASH_SPLITTER.split(identifier)) {
 228             final String[] paramToken = token.split("=");
 229             if (paramToken.length == 2) {
 230                 result.put(paramToken[0], paramToken[1]);
 231             }
 232         }
 233         return result;
 234     }
 235 }