restconf/restconf-nb/src/main/java/org/opendaylight/restconf/server/spi/AbstractRestconfStreamRegistry.java

   1 /*
   2  * Copyright (c) 2023 PANTHEON.tech, s.r.o. 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.server.spi;
   9
  10 import static java.util.Objects.requireNonNull;
  11
  12 import com.google.common.annotations.VisibleForTesting;
  13 import com.google.common.util.concurrent.FutureCallback;
  14 import com.google.common.util.concurrent.Futures;
  15 import com.google.common.util.concurrent.ListenableFuture;
  16 import com.google.common.util.concurrent.MoreExecutors;
  17 import java.net.URI;
  18 import java.net.URISyntaxException;
  19 import java.util.Set;
  20 import java.util.UUID;
  21 import java.util.concurrent.ConcurrentHashMap;
  22 import java.util.concurrent.ConcurrentMap;
  23 import org.eclipse.jdt.annotation.NonNull;
  24 import org.eclipse.jdt.annotation.Nullable;
  25 import org.opendaylight.restconf.common.errors.RestconfDocumentedException;
  26 import org.opendaylight.restconf.common.errors.RestconfFuture;
  27 import org.opendaylight.restconf.common.errors.SettableRestconfFuture;
  28 import org.opendaylight.restconf.nb.rfc8040.URLConstants;
  29 import org.opendaylight.restconf.server.spi.RestconfStream.EncodingName;
  30 import org.opendaylight.restconf.server.spi.RestconfStream.Source;
  31 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.restconf.monitoring.rev170126.restconf.state.streams.Stream;
  32 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.restconf.monitoring.rev170126.restconf.state.streams.stream.Access;
  33 import org.opendaylight.yangtools.yang.common.QName;
  34 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifier;
  35 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifierWithPredicates;
  36 import org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode;
  37 import org.opendaylight.yangtools.yang.data.spi.node.ImmutableNodes;
  38 import org.slf4j.Logger;
  39 import org.slf4j.LoggerFactory;
  40
  41 /**
  42  * Reference base class for {@link RestconfStream.Registry} implementations.
  43  */
  44 public abstract class AbstractRestconfStreamRegistry implements RestconfStream.Registry {
  45     private static final Logger LOG = LoggerFactory.getLogger(AbstractRestconfStreamRegistry.class);
  46
  47     @VisibleForTesting
  48     public static final QName NAME_QNAME =  QName.create(Stream.QNAME, "name").intern();
  49     @VisibleForTesting
  50     public static final QName DESCRIPTION_QNAME = QName.create(Stream.QNAME, "description").intern();
  51     @VisibleForTesting
  52     public static final QName ENCODING_QNAME =  QName.create(Stream.QNAME, "encoding").intern();
  53     @VisibleForTesting
  54     public static final QName LOCATION_QNAME =  QName.create(Stream.QNAME, "location").intern();
  55
  56     private final ConcurrentMap<String, RestconfStream<?>> streams = new ConcurrentHashMap<>();
  57     private final boolean useWebsockets;
  58
  59     protected AbstractRestconfStreamRegistry(final boolean useWebsockets) {
  60         this.useWebsockets = useWebsockets;
  61     }
  62
  63     @Override
  64     public final @Nullable RestconfStream<?> lookupStream(final String name) {
  65         return streams.get(requireNonNull(name));
  66     }
  67
  68     @Override
  69     public final <T> RestconfFuture<RestconfStream<T>> createStream(final URI restconfURI, final Source<T> source,
  70             final String description) {
  71         final var baseStreamLocation = baseStreamLocation(restconfURI);
  72         final var stream = allocateStream(source);
  73         final var name = stream.name();
  74         if (description.isBlank()) {
  75             throw new IllegalArgumentException("Description must be descriptive");
  76         }
  77
  78         final var ret = new SettableRestconfFuture<RestconfStream<T>>();
  79         Futures.addCallback(putStream(streamEntry(name, description, baseStreamLocation, stream.encodings())),
  80             new FutureCallback<Object>() {
  81                 @Override
  82                 public void onSuccess(final Object result) {
  83                     LOG.debug("Stream {} added", name);
  84                     ret.set(stream);
  85                 }
  86
  87                 @Override
  88                 public void onFailure(final Throwable cause) {
  89                     LOG.debug("Failed to add stream {}", name, cause);
  90                     streams.remove(name, stream);
  91                     ret.setFailure(new RestconfDocumentedException("Failed to allocate stream " + name, cause));
  92                 }
  93             }, MoreExecutors.directExecutor());
  94         return ret;
  95     }
  96
  97     private <T> RestconfStream<T> allocateStream(final Source<T> source) {
  98         String name;
  99         RestconfStream<T> stream;
 100         do {
 101             // Use Type 4 (random) UUID. While we could just use it as a plain string, be nice to observers and anchor
 102             // it into UUID URN namespace as defined by RFC4122
 103             name = "urn:uuid:" + UUID.randomUUID().toString();
 104             stream = new RestconfStream<>(this, source, name);
 105         } while (streams.putIfAbsent(name, stream) != null);
 106
 107         return stream;
 108     }
 109
 110     protected abstract @NonNull ListenableFuture<?> putStream(@NonNull MapEntryNode stream);
 111
 112     /**
 113      * Remove a particular stream and remove its entry from operational datastore.
 114      *
 115      * @param stream Stream to remove
 116      */
 117     final void removeStream(final RestconfStream<?> stream) {
 118         // Defensive check to see if we are still tracking the stream
 119         final var name = stream.name();
 120         if (streams.get(name) != stream) {
 121             LOG.warn("Stream {} does not match expected instance {}, skipping datastore update", name, stream);
 122             return;
 123         }
 124
 125         Futures.addCallback(deleteStream(NodeIdentifierWithPredicates.of(Stream.QNAME, NAME_QNAME, name)),
 126             new FutureCallback<Object>() {
 127                 @Override
 128                 public void onSuccess(final Object result) {
 129                     LOG.debug("Stream {} removed", name);
 130                     streams.remove(name, stream);
 131                 }
 132
 133                 @Override
 134                 public void onFailure(final Throwable cause) {
 135                     LOG.warn("Failed to remove stream {}, operational datastore may be inconsistent", name, cause);
 136                     streams.remove(name, stream);
 137                 }
 138             }, MoreExecutors.directExecutor());
 139     }
 140
 141     protected abstract @NonNull ListenableFuture<?> deleteStream(@NonNull NodeIdentifierWithPredicates streamName);
 142
 143     /**
 144      * Return the base location URL of the streams service based on request URI.
 145      *
 146      * @param restconfURI request base URI, with trailing slash
 147      * @throws IllegalArgumentException if the result would have been malformed
 148      */
 149     protected final @NonNull String baseStreamLocation(final URI restconfURI) {
 150         var scheme = restconfURI.getScheme();
 151         if (useWebsockets) {
 152             scheme = switch (scheme) {
 153                 // Secured HTTP goes to Secured WebSockets
 154                 case "https" -> "wss";
 155                 // Unsecured HTTP and others go to unsecured WebSockets
 156                 default -> "ws";
 157             };
 158         }
 159
 160         try {
 161             return new URI(scheme, restconfURI.getRawUserInfo(), restconfURI.getHost(), restconfURI.getPort(),
 162                 restconfURI.getPath() + URLConstants.STREAMS_SUBPATH, null, null)
 163                 .toString();
 164         } catch (URISyntaxException e) {
 165             throw new IllegalArgumentException("Cannot derive streams location", e);
 166         }
 167     }
 168
 169     @VisibleForTesting
 170     public static final @NonNull MapEntryNode streamEntry(final String name, final String description,
 171             final String baseStreamLocation, final Set<EncodingName> encodings) {
 172         final var accessBuilder = ImmutableNodes.newSystemMapBuilder()
 173             .withNodeIdentifier(new NodeIdentifier(Access.QNAME));
 174         for (var encoding : encodings) {
 175             final var encodingName = encoding.name();
 176             accessBuilder.withChild(ImmutableNodes.newMapEntryBuilder()
 177                 .withNodeIdentifier(NodeIdentifierWithPredicates.of(Access.QNAME, ENCODING_QNAME, encodingName))
 178                 .withChild(ImmutableNodes.leafNode(ENCODING_QNAME, encodingName))
 179                 .withChild(ImmutableNodes.leafNode(LOCATION_QNAME,
 180                     baseStreamLocation + '/' + encodingName + '/' + name))
 181                 .build());
 182         }
 183
 184         return ImmutableNodes.newMapEntryBuilder()
 185             .withNodeIdentifier(NodeIdentifierWithPredicates.of(Stream.QNAME, NAME_QNAME, name))
 186             .withChild(ImmutableNodes.leafNode(NAME_QNAME, name))
 187             .withChild(ImmutableNodes.leafNode(DESCRIPTION_QNAME, description))
 188             .withChild(accessBuilder.build())
 189             .build();
 190     }
 191 }