plugins/netconf-client-mdsal/src/main/java/org/opendaylight/netconf/client/mdsal/NetconfDevice.java

   1 /*
   2  * Copyright (c) 2014 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.netconf.client.mdsal;
   9
  10 import static com.google.common.base.Preconditions.checkState;
  11 import static java.util.Objects.requireNonNull;
  12 import static org.opendaylight.netconf.client.mdsal.impl.NetconfMessageTransformUtil.NETCONF_GET_NODEID;
  13
  14 import com.google.common.base.Predicates;
  15 import com.google.common.collect.Collections2;
  16 import com.google.common.collect.ImmutableMap;
  17 import com.google.common.collect.ImmutableSet;
  18 import com.google.common.collect.Sets;
  19 import com.google.common.util.concurrent.FutureCallback;
  20 import com.google.common.util.concurrent.Futures;
  21 import com.google.common.util.concurrent.ListenableFuture;
  22 import com.google.common.util.concurrent.MoreExecutors;
  23 import com.google.common.util.concurrent.SettableFuture;
  24 import java.io.Serial;
  25 import java.util.ArrayList;
  26 import java.util.Collection;
  27 import java.util.HashMap;
  28 import java.util.HashSet;
  29 import java.util.List;
  30 import java.util.Map;
  31 import java.util.Objects;
  32 import java.util.Set;
  33 import java.util.concurrent.CancellationException;
  34 import java.util.concurrent.ExecutionException;
  35 import java.util.concurrent.Executor;
  36 import java.util.stream.Collectors;
  37 import org.checkerframework.checker.lock.qual.GuardedBy;
  38 import org.eclipse.jdt.annotation.NonNull;
  39 import org.opendaylight.mdsal.dom.api.DOMRpcResult;
  40 import org.opendaylight.netconf.api.CapabilityURN;
  41 import org.opendaylight.netconf.api.messages.NetconfMessage;
  42 import org.opendaylight.netconf.client.mdsal.api.BaseNetconfSchemas;
  43 import org.opendaylight.netconf.client.mdsal.api.DeviceActionFactory;
  44 import org.opendaylight.netconf.client.mdsal.api.NetconfDeviceSchemasResolver;
  45 import org.opendaylight.netconf.client.mdsal.api.NetconfSessionPreferences;
  46 import org.opendaylight.netconf.client.mdsal.api.RemoteDevice;
  47 import org.opendaylight.netconf.client.mdsal.api.RemoteDeviceCommunicator;
  48 import org.opendaylight.netconf.client.mdsal.api.RemoteDeviceHandler;
  49 import org.opendaylight.netconf.client.mdsal.api.RemoteDeviceId;
  50 import org.opendaylight.netconf.client.mdsal.api.RemoteDeviceServices;
  51 import org.opendaylight.netconf.client.mdsal.api.RemoteDeviceServices.Rpcs;
  52 import org.opendaylight.netconf.client.mdsal.impl.BaseSchema;
  53 import org.opendaylight.netconf.client.mdsal.impl.NetconfMessageTransformUtil;
  54 import org.opendaylight.netconf.client.mdsal.impl.NetconfMessageTransformer;
  55 import org.opendaylight.netconf.client.mdsal.spi.NetconfDeviceRpc;
  56 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.netconf.base._1._0.rev110601.Get;
  57 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.netconf.notification._1._0.rev080714.CreateSubscription;
  58 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.netconf.notification._1._0.rev080714.CreateSubscriptionInput;
  59 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.netconf.notifications.rev120206.NetconfCapabilityChange;
  60 import org.opendaylight.yang.gen.v1.urn.opendaylight.netconf.device.rev240120.connection.oper.available.capabilities.AvailableCapability;
  61 import org.opendaylight.yang.gen.v1.urn.opendaylight.netconf.device.rev240120.connection.oper.available.capabilities.AvailableCapabilityBuilder;
  62 import org.opendaylight.yang.gen.v1.urn.opendaylight.netconf.device.rev240120.connection.oper.unavailable.capabilities.UnavailableCapability;
  63 import org.opendaylight.yang.gen.v1.urn.opendaylight.netconf.device.rev240120.connection.oper.unavailable.capabilities.UnavailableCapability.FailureReason;
  64 import org.opendaylight.yangtools.concepts.Registration;
  65 import org.opendaylight.yangtools.rfc8528.model.api.SchemaMountConstants;
  66 import org.opendaylight.yangtools.yang.common.QName;
  67 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  68 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifier;
  69 import org.opendaylight.yangtools.yang.data.api.schema.MountPointContext;
  70 import org.opendaylight.yangtools.yang.data.impl.schema.Builders;
  71 import org.opendaylight.yangtools.yang.data.spi.node.ImmutableNodes;
  72 import org.opendaylight.yangtools.yang.model.api.EffectiveModelContext;
  73 import org.opendaylight.yangtools.yang.model.api.source.SourceIdentifier;
  74 import org.opendaylight.yangtools.yang.model.api.source.YangTextSource;
  75 import org.opendaylight.yangtools.yang.model.repo.api.EffectiveModelContextFactory;
  76 import org.opendaylight.yangtools.yang.model.repo.api.MissingSchemaSourceException;
  77 import org.opendaylight.yangtools.yang.model.repo.api.SchemaRepository;
  78 import org.opendaylight.yangtools.yang.model.repo.api.SchemaResolutionException;
  79 import org.opendaylight.yangtools.yang.model.repo.spi.SchemaSourceRegistry;
  80 import org.slf4j.Logger;
  81 import org.slf4j.LoggerFactory;
  82
  83 /**
  84  *  This is a mediator between NetconfDeviceCommunicator and NetconfDeviceSalFacade.
  85  */
  86 public class NetconfDevice implements RemoteDevice<NetconfDeviceCommunicator> {
  87     private static final Logger LOG = LoggerFactory.getLogger(NetconfDevice.class);
  88
  89     private static final QName RFC8528_SCHEMA_MOUNTS_QNAME = QName.create(
  90         SchemaMountConstants.RFC8528_MODULE, "schema-mounts").intern();
  91     private static final YangInstanceIdentifier RFC8528_SCHEMA_MOUNTS = YangInstanceIdentifier.of(
  92         NodeIdentifier.create(RFC8528_SCHEMA_MOUNTS_QNAME));
  93
  94     protected final RemoteDeviceId id;
  95     protected final EffectiveModelContextFactory schemaContextFactory;
  96     protected final SchemaSourceRegistry schemaRegistry;
  97     protected final SchemaRepository schemaRepository;
  98
  99     protected final List<Registration> sourceRegistrations = new ArrayList<>();
 100
 101     private final RemoteDeviceHandler salFacade;
 102     private final Executor processingExecutor;
 103     private final DeviceActionFactory deviceActionFactory;
 104     private final NetconfDeviceSchemasResolver stateSchemasResolver;
 105     private final NotificationHandler notificationHandler;
 106     private final boolean reconnectOnSchemasChange;
 107     private final BaseNetconfSchemas baseSchemas;
 108
 109     @GuardedBy("this")
 110     private ListenableFuture<List<Object>> schemaFuturesList;
 111     @GuardedBy("this")
 112     private boolean connected = false;
 113
 114     public NetconfDevice(final SchemaResourcesDTO schemaResourcesDTO, final BaseNetconfSchemas baseSchemas,
 115             final RemoteDeviceId id, final RemoteDeviceHandler salFacade, final Executor globalProcessingExecutor,
 116             final boolean reconnectOnSchemasChange) {
 117         this(schemaResourcesDTO, baseSchemas, id, salFacade, globalProcessingExecutor, reconnectOnSchemasChange, null);
 118     }
 119
 120     public NetconfDevice(final SchemaResourcesDTO schemaResourcesDTO, final BaseNetconfSchemas baseSchemas,
 121             final RemoteDeviceId id, final RemoteDeviceHandler salFacade, final Executor globalProcessingExecutor,
 122             final boolean reconnectOnSchemasChange, final DeviceActionFactory deviceActionFactory) {
 123         this.baseSchemas = requireNonNull(baseSchemas);
 124         this.id = id;
 125         this.reconnectOnSchemasChange = reconnectOnSchemasChange;
 126         this.deviceActionFactory = deviceActionFactory;
 127         schemaRegistry = schemaResourcesDTO.getSchemaRegistry();
 128         schemaRepository = schemaResourcesDTO.getSchemaRepository();
 129         schemaContextFactory = schemaResourcesDTO.getSchemaContextFactory();
 130         this.salFacade = salFacade;
 131         stateSchemasResolver = schemaResourcesDTO.getStateSchemasResolver();
 132         processingExecutor = requireNonNull(globalProcessingExecutor);
 133         notificationHandler = new NotificationHandler(salFacade, id);
 134     }
 135
 136     @Override
 137     public synchronized void onRemoteSessionUp(final NetconfSessionPreferences remoteSessionCapabilities,
 138             final NetconfDeviceCommunicator listener) {
 139         // SchemaContext setup has to be performed in a dedicated thread since we are in a Netty thread in this method
 140         // YANG models are being downloaded in this method and it would cause a deadlock if we used the netty thread
 141         // https://netty.io/wiki/thread-model.html
 142         setConnected(true);
 143         LOG.debug("{}: Session to remote device established with {}", id, remoteSessionCapabilities);
 144
 145         final BaseSchema baseSchema = resolveBaseSchema(remoteSessionCapabilities.isNotificationsSupported());
 146         final NetconfDeviceRpc initRpc = new NetconfDeviceRpc(baseSchema.modelContext(), listener,
 147             new NetconfMessageTransformer(baseSchema.getMountPointContext(), false, baseSchema));
 148         final var sourceResolverFuture = Futures.submit(new DeviceSourcesResolver(id, baseSchema, initRpc,
 149                 remoteSessionCapabilities, stateSchemasResolver), processingExecutor);
 150
 151         if (shouldListenOnSchemaChange(remoteSessionCapabilities)) {
 152             registerToBaseNetconfStream(initRpc, listener);
 153         }
 154
 155         // Set up the EffectiveModelContext for the device
 156         final var futureSchema = Futures.transformAsync(sourceResolverFuture,
 157             deviceSources -> assembleSchemaContext(deviceSources, remoteSessionCapabilities), processingExecutor);
 158
 159         // Potentially acquire mount point list and interpret it
 160         final var netconfDeviceSchemaFuture = Futures.transformAsync(futureSchema,
 161             result -> Futures.transform(createMountPointContext(result.modelContext(), baseSchema, listener),
 162                 mount -> new NetconfDeviceSchema(result.capabilities(), mount), processingExecutor),
 163             processingExecutor);
 164         schemaFuturesList = Futures.allAsList(sourceResolverFuture, futureSchema, netconfDeviceSchemaFuture);
 165
 166         Futures.addCallback(netconfDeviceSchemaFuture, new FutureCallback<>() {
 167                 @Override
 168                 public void onSuccess(final NetconfDeviceSchema result) {
 169                     handleSalInitializationSuccess(listener, result, remoteSessionCapabilities,
 170                         getDeviceSpecificRpc(result.mountContext(), listener, baseSchema));
 171                 }
 172
 173                 @Override
 174                 public void onFailure(final Throwable cause) {
 175                     // The method onRemoteSessionDown was called while the EffectiveModelContext for the device
 176                     // was being processed.
 177                     if (cause instanceof CancellationException) {
 178                         LOG.warn("{}: Device communicator was tear down since the schema setup started", id);
 179                     } else {
 180                         handleSalInitializationFailure(listener, cause);
 181                     }
 182                 }
 183             }, MoreExecutors.directExecutor());
 184     }
 185
 186     private void registerToBaseNetconfStream(final NetconfDeviceRpc deviceRpc,
 187                                              final NetconfDeviceCommunicator listener) {
 188         // TODO check whether the model describing create subscription is present in schema
 189         // Perhaps add a default schema context to support create-subscription if the model was not provided
 190         // (same as what we do for base netconf operations in transformer)
 191         final var rpcResultListenableFuture = deviceRpc.domRpcService()
 192             .invokeRpc(CreateSubscription.QNAME, Builders.containerBuilder()
 193                 .withNodeIdentifier(NodeIdentifier.create(CreateSubscriptionInput.QNAME))
 194                 // Note: default 'stream' is 'NETCONF', we do not need to create an explicit leaf
 195                 .build());
 196
 197         Futures.addCallback(rpcResultListenableFuture, new FutureCallback<DOMRpcResult>() {
 198             @Override
 199             public void onSuccess(final DOMRpcResult domRpcResult) {
 200                 notificationHandler.addNotificationFilter(notification -> {
 201                     if (NetconfCapabilityChange.QNAME.equals(notification.getBody().name().getNodeType())) {
 202                         LOG.info("{}: Schemas change detected, reconnecting", id);
 203                         // Only disconnect is enough,
 204                         // the reconnecting nature of the connector will take care of reconnecting
 205                         listener.disconnect();
 206                         return false;
 207                     }
 208                     return true;
 209                 });
 210             }
 211
 212             @Override
 213             public void onFailure(final Throwable throwable) {
 214                 LOG.warn("Unable to subscribe to base notification stream. Schemas will not be reloaded on the fly",
 215                         throwable);
 216             }
 217         }, MoreExecutors.directExecutor());
 218     }
 219
 220     private boolean shouldListenOnSchemaChange(final NetconfSessionPreferences remoteSessionCapabilities) {
 221         return remoteSessionCapabilities.isNotificationsSupported() && reconnectOnSchemasChange;
 222     }
 223
 224     private synchronized void handleSalInitializationSuccess(final RemoteDeviceCommunicator listener,
 225             final NetconfDeviceSchema deviceSchema, final NetconfSessionPreferences remoteSessionCapabilities,
 226             final Rpcs deviceRpc) {
 227         // NetconfDevice.SchemaSetup can complete after NetconfDeviceCommunicator was closed. In that case do nothing,
 228         // since salFacade.onDeviceDisconnected was already called.
 229         if (!connected) {
 230             LOG.warn("{}: Device communicator was closed before schema setup finished.", id);
 231             return;
 232         }
 233
 234         final var messageTransformer = new NetconfMessageTransformer(deviceSchema.mountContext(), true,
 235             resolveBaseSchema(remoteSessionCapabilities.isNotificationsSupported()));
 236
 237         // Order is important here: salFacade has to see the device come up and then the notificationHandler can deliver
 238         // whatever notifications have been held back
 239         salFacade.onDeviceConnected(deviceSchema, remoteSessionCapabilities,
 240             new RemoteDeviceServices(deviceRpc, deviceActionFactory == null ? null
 241                 : deviceActionFactory.createDeviceAction(messageTransformer, listener)));
 242         notificationHandler.onRemoteSchemaUp(messageTransformer);
 243
 244         LOG.info("{}: Netconf connector initialized successfully", id);
 245     }
 246
 247     private void handleSalInitializationFailure(final RemoteDeviceCommunicator listener, final Throwable cause) {
 248         LOG.warn("{}: Unexpected error resolving device sources", id, cause);
 249         listener.close();
 250         cleanupInitialization();
 251         salFacade.onDeviceFailed(cause);
 252     }
 253
 254     private synchronized void cleanupInitialization() {
 255         connected = false;
 256         if (schemaFuturesList != null && !schemaFuturesList.isDone()) {
 257             if (!schemaFuturesList.cancel(true)) {
 258                 LOG.warn("The cleanup of Schema Futures for device {} was unsuccessful.", id);
 259             }
 260         }
 261         notificationHandler.onRemoteSchemaDown();
 262         sourceRegistrations.forEach(Registration::close);
 263         sourceRegistrations.clear();
 264     }
 265
 266     private synchronized void setConnected(final boolean connected) {
 267         this.connected = connected;
 268     }
 269
 270     private ListenableFuture<SchemaResult> assembleSchemaContext(final DeviceSources deviceSources,
 271             final NetconfSessionPreferences remoteSessionCapabilities) {
 272         LOG.debug("{}: Resolved device sources to {}", id, deviceSources);
 273
 274         sourceRegistrations.addAll(deviceSources.register(schemaRegistry));
 275
 276         return new SchemaSetup(deviceSources, remoteSessionCapabilities).startResolution();
 277     }
 278
 279     private ListenableFuture<@NonNull MountPointContext> createMountPointContext(
 280             final EffectiveModelContext schemaContext, final BaseSchema baseSchema,
 281             final NetconfDeviceCommunicator listener) {
 282         final MountPointContext emptyContext = MountPointContext.of(schemaContext);
 283         if (schemaContext.findModule(SchemaMountConstants.RFC8528_MODULE).isEmpty()) {
 284             return Futures.immediateFuture(emptyContext);
 285         }
 286
 287         // Create a temporary RPC invoker and acquire the mount point tree
 288         LOG.debug("{}: Acquiring available mount points", id);
 289         final NetconfDeviceRpc deviceRpc = new NetconfDeviceRpc(schemaContext, listener,
 290             new NetconfMessageTransformer(emptyContext, false, baseSchema));
 291
 292         return Futures.transform(deviceRpc.domRpcService().invokeRpc(Get.QNAME, ImmutableNodes.newContainerBuilder()
 293             .withNodeIdentifier(NETCONF_GET_NODEID)
 294             .withChild(NetconfMessageTransformUtil.toFilterStructure(RFC8528_SCHEMA_MOUNTS, schemaContext))
 295             .build()), rpcResult -> processSchemaMounts(rpcResult, emptyContext), MoreExecutors.directExecutor());
 296     }
 297
 298     private MountPointContext processSchemaMounts(final DOMRpcResult rpcResult, final MountPointContext emptyContext) {
 299         final var errors = rpcResult.errors();
 300         if (!errors.isEmpty()) {
 301             LOG.warn("{}: Schema-mounts acquisition resulted in errors {}", id, errors);
 302         }
 303         final var schemaMounts = rpcResult.value();
 304         if (schemaMounts == null) {
 305             LOG.debug("{}: device does not define any schema mounts", id);
 306             return emptyContext;
 307         }
 308
 309         return DeviceMountPointContext.create(emptyContext, schemaMounts);
 310     }
 311
 312     @Override
 313     public void onRemoteSessionDown() {
 314         cleanupInitialization();
 315         salFacade.onDeviceDisconnected();
 316     }
 317
 318     @Override
 319     public void onNotification(final NetconfMessage notification) {
 320         notificationHandler.handleNotification(notification);
 321     }
 322
 323     private BaseSchema resolveBaseSchema(final boolean notificationSupport) {
 324         return notificationSupport ? baseSchemas.baseSchemaWithNotifications() : baseSchemas.baseSchema();
 325     }
 326
 327     protected NetconfDeviceRpc getDeviceSpecificRpc(final MountPointContext result,
 328             final RemoteDeviceCommunicator listener, final BaseSchema schema) {
 329         return new NetconfDeviceRpc(result.modelContext(), listener,
 330             new NetconfMessageTransformer(result, true, schema));
 331     }
 332
 333     /**
 334      * Just a transfer object containing schema related dependencies. Injected in constructor.
 335      */
 336     public static class SchemaResourcesDTO {
 337         private final SchemaSourceRegistry schemaRegistry;
 338         private final SchemaRepository schemaRepository;
 339         private final EffectiveModelContextFactory schemaContextFactory;
 340         private final NetconfDeviceSchemasResolver stateSchemasResolver;
 341
 342         public SchemaResourcesDTO(final SchemaSourceRegistry schemaRegistry,
 343                                   final SchemaRepository schemaRepository,
 344                                   final EffectiveModelContextFactory schemaContextFactory,
 345                                   final NetconfDeviceSchemasResolver deviceSchemasResolver) {
 346             this.schemaRegistry = requireNonNull(schemaRegistry);
 347             this.schemaRepository = requireNonNull(schemaRepository);
 348             this.schemaContextFactory = requireNonNull(schemaContextFactory);
 349             stateSchemasResolver = requireNonNull(deviceSchemasResolver);
 350         }
 351
 352         public SchemaSourceRegistry getSchemaRegistry() {
 353             return schemaRegistry;
 354         }
 355
 356         public SchemaRepository getSchemaRepository() {
 357             return schemaRepository;
 358         }
 359
 360         public EffectiveModelContextFactory getSchemaContextFactory() {
 361             return schemaContextFactory;
 362         }
 363
 364         public NetconfDeviceSchemasResolver getStateSchemasResolver() {
 365             return stateSchemasResolver;
 366         }
 367     }
 368
 369     /**
 370      * A dedicated exception to indicate when we fail to setup an {@link EffectiveModelContext}.
 371      */
 372     public static final class EmptySchemaContextException extends Exception {
 373         @Serial
 374         private static final long serialVersionUID = 1L;
 375
 376         public EmptySchemaContextException(final String message) {
 377             super(message);
 378         }
 379     }
 380
 381     /**
 382      * {@link NetconfDeviceCapabilities} and {@link EffectiveModelContext}.
 383      */
 384     private record SchemaResult(
 385         @NonNull NetconfDeviceCapabilities capabilities,
 386         @NonNull EffectiveModelContext modelContext) {
 387
 388         SchemaResult {
 389             requireNonNull(capabilities);
 390             requireNonNull(modelContext);
 391         }
 392     }
 393
 394     /**
 395      * Schema builder that tries to build schema context from provided sources or biggest subset of it.
 396      */
 397     private final class SchemaSetup implements FutureCallback<EffectiveModelContext> {
 398         private final SettableFuture<SchemaResult> resultFuture = SettableFuture.create();
 399
 400         private final Set<AvailableCapability> nonModuleBasedCapabilities = new HashSet<>();
 401         private final Map<QName, FailureReason> unresolvedCapabilites = new HashMap<>();
 402         private final Set<AvailableCapability> resolvedCapabilities = new HashSet<>();
 403
 404         private final DeviceSources deviceSources;
 405         private final NetconfSessionPreferences remoteSessionCapabilities;
 406
 407         private Collection<SourceIdentifier> requiredSources;
 408
 409         SchemaSetup(final DeviceSources deviceSources, final NetconfSessionPreferences remoteSessionCapabilities) {
 410             this.deviceSources = deviceSources;
 411             this.remoteSessionCapabilities = remoteSessionCapabilities;
 412
 413             // If device supports notifications and does not contain necessary modules, add them automatically
 414             if (remoteSessionCapabilities.containsNonModuleCapability(CapabilityURN.NOTIFICATION)) {
 415                 // FIXME: mutable collection modification!
 416                 deviceSources.getRequiredSourcesQName().addAll(List.of(
 417                     org.opendaylight.yang.svc.v1.urn.ietf.params.xml.ns.netconf.notification._1._0.rev080714
 418                         .YangModuleInfoImpl.getInstance().getName(),
 419                     org.opendaylight.yang.svc.v1.urn.ietf.params.xml.ns.yang.ietf.yang.types.rev130715
 420                         .YangModuleInfoImpl.getInstance().getName())
 421                 );
 422             }
 423
 424             requiredSources = deviceSources.getRequiredSources();
 425             final Collection<SourceIdentifier> missingSources = filterMissingSources(requiredSources);
 426
 427             addUnresolvedCapabilities(getQNameFromSourceIdentifiers(missingSources),
 428                 UnavailableCapability.FailureReason.MissingSource);
 429             requiredSources.removeAll(missingSources);
 430         }
 431
 432         ListenableFuture<SchemaResult> startResolution() {
 433             trySetupSchema();
 434             return resultFuture;
 435         }
 436
 437         @Override
 438         public void onSuccess(final EffectiveModelContext result) {
 439             LOG.debug("{}: Schema context built successfully from {}", id, requiredSources);
 440
 441             final Collection<QName> filteredQNames = Sets.difference(deviceSources.getRequiredSourcesQName(),
 442                     unresolvedCapabilites.keySet());
 443             resolvedCapabilities.addAll(filteredQNames.stream()
 444                 .map(capability -> new AvailableCapabilityBuilder()
 445                     .setCapability(capability.toString())
 446                     .setCapabilityOrigin(remoteSessionCapabilities.capabilityOrigin(capability))
 447                     .build())
 448                 .collect(Collectors.toList()));
 449
 450             nonModuleBasedCapabilities.addAll(remoteSessionCapabilities.nonModuleCaps().keySet().stream()
 451                 .map(capability -> new AvailableCapabilityBuilder()
 452                     .setCapability(capability)
 453                     .setCapabilityOrigin(remoteSessionCapabilities.capabilityOrigin(capability))
 454                     .build())
 455                 .collect(Collectors.toList()));
 456
 457
 458             resultFuture.set(new SchemaResult(new NetconfDeviceCapabilities(ImmutableMap.copyOf(unresolvedCapabilites),
 459                 ImmutableSet.copyOf(resolvedCapabilities), ImmutableSet.copyOf(nonModuleBasedCapabilities)), result));
 460         }
 461
 462         @Override
 463         public void onFailure(final Throwable cause) {
 464             // schemaBuilderFuture.checkedGet() throws only SchemaResolutionException
 465             // that might be wrapping a MissingSchemaSourceException so we need to look
 466             // at the cause of the exception to make sure we don't misinterpret it.
 467             if (cause instanceof MissingSchemaSourceException) {
 468                 requiredSources = handleMissingSchemaSourceException((MissingSchemaSourceException) cause);
 469             } else if (cause instanceof SchemaResolutionException) {
 470                 requiredSources = handleSchemaResolutionException((SchemaResolutionException) cause);
 471             } else {
 472                 LOG.debug("Unhandled failure", cause);
 473                 resultFuture.setException(cause);
 474                 // No more trying...
 475                 return;
 476             }
 477
 478             trySetupSchema();
 479         }
 480
 481         private void trySetupSchema() {
 482             if (!requiredSources.isEmpty()) {
 483                 // Initiate async resolution, drive it back based on the result
 484                 LOG.trace("{}: Trying to build schema context from {}", id, requiredSources);
 485                 Futures.addCallback(schemaContextFactory.createEffectiveModelContext(requiredSources), this,
 486                     MoreExecutors.directExecutor());
 487             } else {
 488                 LOG.debug("{}: no more sources for schema context", id);
 489                 resultFuture.setException(new EmptySchemaContextException(id + ": No more sources for schema context"));
 490             }
 491         }
 492
 493         private List<SourceIdentifier> filterMissingSources(final Collection<SourceIdentifier> origSources) {
 494             return origSources.parallelStream().filter(sourceIdentifier -> {
 495                 try {
 496                     schemaRepository.getSchemaSource(sourceIdentifier, YangTextSource.class).get();
 497                     return false;
 498                 } catch (InterruptedException | ExecutionException e) {
 499                     return true;
 500                 }
 501             }).collect(Collectors.toList());
 502         }
 503
 504         private void addUnresolvedCapabilities(final Collection<QName> capabilities, final FailureReason reason) {
 505             for (QName s : capabilities) {
 506                 unresolvedCapabilites.put(s, reason);
 507             }
 508         }
 509
 510         private List<SourceIdentifier> handleMissingSchemaSourceException(
 511                 final MissingSchemaSourceException exception) {
 512             // In case source missing, try without it
 513             final SourceIdentifier missingSource = exception.sourceId();
 514             LOG.warn("{}: Unable to build schema context, missing source {}, will reattempt without it",
 515                 id, missingSource);
 516             LOG.debug("{}: Unable to build schema context, missing source {}, will reattempt without it",
 517                 id, missingSource, exception);
 518             final var qNameOfMissingSource = getQNameFromSourceIdentifiers(Sets.newHashSet(missingSource));
 519             if (!qNameOfMissingSource.isEmpty()) {
 520                 addUnresolvedCapabilities(qNameOfMissingSource, UnavailableCapability.FailureReason.MissingSource);
 521             }
 522             return stripUnavailableSource(missingSource);
 523         }
 524
 525         private Collection<SourceIdentifier> handleSchemaResolutionException(
 526                 final SchemaResolutionException resolutionException) {
 527             // In case resolution error, try only with resolved sources
 528             // There are two options why schema resolution exception occurred : unsatisfied imports or flawed model
 529             // FIXME Do we really have assurance that these two cases cannot happen at once?
 530             final var failedSourceId = resolutionException.sourceId();
 531             if (failedSourceId != null) {
 532                 // flawed model - exclude it
 533                 LOG.warn("{}: Unable to build schema context, failed to resolve source {}, will reattempt without it",
 534                     id, failedSourceId);
 535                 LOG.warn("{}: Unable to build schema context, failed to resolve source {}, will reattempt without it",
 536                     id, failedSourceId, resolutionException);
 537                 addUnresolvedCapabilities(getQNameFromSourceIdentifiers(List.of(failedSourceId)),
 538                         UnavailableCapability.FailureReason.UnableToResolve);
 539                 return stripUnavailableSource(failedSourceId);
 540             }
 541             // unsatisfied imports
 542             addUnresolvedCapabilities(
 543                 getQNameFromSourceIdentifiers(resolutionException.getUnsatisfiedImports().keySet()),
 544                 UnavailableCapability.FailureReason.UnableToResolve);
 545             LOG.warn("{}: Unable to build schema context, unsatisfied imports {}, will reattempt with resolved only",
 546                 id, resolutionException.getUnsatisfiedImports());
 547             LOG.debug("{}: Unable to build schema context, unsatisfied imports {}, will reattempt with resolved only",
 548                 id, resolutionException.getUnsatisfiedImports(), resolutionException);
 549             return resolutionException.getResolvedSources();
 550         }
 551
 552         private List<SourceIdentifier> stripUnavailableSource(final SourceIdentifier sourceIdToRemove) {
 553             final var tmp = new ArrayList<>(requiredSources);
 554             checkState(tmp.remove(sourceIdToRemove), "%s: Trying to remove %s from %s failed", id, sourceIdToRemove,
 555                 requiredSources);
 556             return tmp;
 557         }
 558
 559         private Collection<QName> getQNameFromSourceIdentifiers(final Collection<SourceIdentifier> identifiers) {
 560             final Collection<QName> qNames = Collections2.transform(identifiers, this::getQNameFromSourceIdentifier);
 561
 562             if (qNames.isEmpty()) {
 563                 LOG.debug("{}: Unable to map any source identifiers to a capability reported by device : {}", id,
 564                         identifiers);
 565             }
 566             return Collections2.filter(qNames, Predicates.notNull());
 567         }
 568
 569         private QName getQNameFromSourceIdentifier(final SourceIdentifier identifier) {
 570             // Required sources are all required and provided merged in DeviceSourcesResolver
 571             for (final QName qname : deviceSources.getRequiredSourcesQName()) {
 572                 if (!qname.getLocalName().equals(identifier.name().getLocalName())) {
 573                     continue;
 574                 }
 575
 576                 if (Objects.equals(identifier.revision(), qname.getRevision().orElse(null))) {
 577                     return qname;
 578                 }
 579             }
 580             LOG.warn("Unable to map identifier to a devices reported capability: {} Available: {}",identifier,
 581                     deviceSources.getRequiredSourcesQName());
 582             // return null since we cannot find the QName,
 583             // this capability will be removed from required sources and not reported as unresolved-capability
 584             return null;
 585         }
 586     }
 587 }