netconf/sal-netconf-connector/src/main/java/org/opendaylight/netconf/sal/connect/netconf/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.sal.connect.netconf;
   9
  10 import static java.util.Objects.requireNonNull;
  11
  12 import com.google.common.base.Optional;
  13 import com.google.common.base.Preconditions;
  14 import com.google.common.base.Predicates;
  15 import com.google.common.collect.Collections2;
  16 import com.google.common.collect.Lists;
  17 import com.google.common.collect.Sets;
  18 import com.google.common.util.concurrent.CheckedFuture;
  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.ListeningExecutorService;
  23 import com.google.common.util.concurrent.MoreExecutors;
  24 import java.util.ArrayList;
  25 import java.util.Collection;
  26 import java.util.Collections;
  27 import java.util.LinkedList;
  28 import java.util.List;
  29 import java.util.Set;
  30 import java.util.concurrent.Callable;
  31 import java.util.concurrent.ExecutionException;
  32 import java.util.stream.Collectors;
  33 import javax.annotation.Nonnull;
  34 import javax.annotation.concurrent.GuardedBy;
  35 import org.opendaylight.controller.md.sal.dom.api.DOMNotification;
  36 import org.opendaylight.controller.md.sal.dom.api.DOMRpcException;
  37 import org.opendaylight.controller.md.sal.dom.api.DOMRpcResult;
  38 import org.opendaylight.controller.md.sal.dom.api.DOMRpcService;
  39 import org.opendaylight.netconf.api.NetconfMessage;
  40 import org.opendaylight.netconf.sal.connect.api.DeviceActionFactory;
  41 import org.opendaylight.netconf.sal.connect.api.MessageTransformer;
  42 import org.opendaylight.netconf.sal.connect.api.NetconfDeviceSchemas;
  43 import org.opendaylight.netconf.sal.connect.api.NetconfDeviceSchemasResolver;
  44 import org.opendaylight.netconf.sal.connect.api.RemoteDevice;
  45 import org.opendaylight.netconf.sal.connect.api.RemoteDeviceCommunicator;
  46 import org.opendaylight.netconf.sal.connect.api.RemoteDeviceHandler;
  47 import org.opendaylight.netconf.sal.connect.netconf.listener.NetconfDeviceCapabilities;
  48 import org.opendaylight.netconf.sal.connect.netconf.listener.NetconfDeviceCommunicator;
  49 import org.opendaylight.netconf.sal.connect.netconf.listener.NetconfSessionPreferences;
  50 import org.opendaylight.netconf.sal.connect.netconf.sal.NetconfDeviceRpc;
  51 import org.opendaylight.netconf.sal.connect.netconf.schema.NetconfRemoteSchemaYangSourceProvider;
  52 import org.opendaylight.netconf.sal.connect.netconf.schema.YangLibrarySchemaYangSourceProvider;
  53 import org.opendaylight.netconf.sal.connect.netconf.schema.mapping.BaseSchema;
  54 import org.opendaylight.netconf.sal.connect.netconf.schema.mapping.NetconfMessageTransformer;
  55 import org.opendaylight.netconf.sal.connect.netconf.util.NetconfMessageTransformUtil;
  56 import org.opendaylight.netconf.sal.connect.util.RemoteDeviceId;
  57 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.netconf.notifications.rev120206.NetconfCapabilityChange;
  58 import org.opendaylight.yang.gen.v1.urn.opendaylight.netconf.node.topology.rev150114.netconf.node.connection.status.available.capabilities.AvailableCapabilityBuilder;
  59 import org.opendaylight.yang.gen.v1.urn.opendaylight.netconf.node.topology.rev150114.netconf.node.connection.status.unavailable.capabilities.UnavailableCapability;
  60 import org.opendaylight.yangtools.yang.common.QName;
  61 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  62 import org.opendaylight.yangtools.yang.model.repo.api.MissingSchemaSourceException;
  63 import org.opendaylight.yangtools.yang.model.repo.api.RevisionSourceIdentifier;
  64 import org.opendaylight.yangtools.yang.model.repo.api.SchemaContextFactory;
  65 import org.opendaylight.yangtools.yang.model.repo.api.SchemaRepository;
  66 import org.opendaylight.yangtools.yang.model.repo.api.SchemaResolutionException;
  67 import org.opendaylight.yangtools.yang.model.repo.api.SchemaSourceRepresentation;
  68 import org.opendaylight.yangtools.yang.model.repo.api.SourceIdentifier;
  69 import org.opendaylight.yangtools.yang.model.repo.api.YangTextSchemaSource;
  70 import org.opendaylight.yangtools.yang.model.repo.spi.PotentialSchemaSource;
  71 import org.opendaylight.yangtools.yang.model.repo.spi.SchemaSourceProvider;
  72 import org.opendaylight.yangtools.yang.model.repo.spi.SchemaSourceRegistration;
  73 import org.opendaylight.yangtools.yang.model.repo.spi.SchemaSourceRegistry;
  74 import org.slf4j.Logger;
  75 import org.slf4j.LoggerFactory;
  76
  77 /**
  78  *  This is a mediator between NetconfDeviceCommunicator and NetconfDeviceSalFacade.
  79  */
  80 public class NetconfDevice
  81         implements RemoteDevice<NetconfSessionPreferences, NetconfMessage, NetconfDeviceCommunicator> {
  82
  83     private static final Logger LOG = LoggerFactory.getLogger(NetconfDevice.class);
  84
  85     protected final RemoteDeviceId id;
  86     protected final SchemaContextFactory schemaContextFactory;
  87     protected final SchemaSourceRegistry schemaRegistry;
  88     protected final SchemaRepository schemaRepository;
  89
  90     protected final List<SchemaSourceRegistration<? extends SchemaSourceRepresentation>> sourceRegistrations =
  91             new ArrayList<>();
  92
  93     private final RemoteDeviceHandler<NetconfSessionPreferences> salFacade;
  94     private final ListeningExecutorService processingExecutor;
  95     private final DeviceActionFactory deviceActionFactory;
  96     private final NetconfDeviceSchemasResolver stateSchemasResolver;
  97     private final NotificationHandler notificationHandler;
  98     private final boolean reconnectOnSchemasChange;
  99
 100     @GuardedBy("this")
 101     private boolean connected = false;
 102
 103     // Message transformer is constructed once the schemas are available
 104     private MessageTransformer<NetconfMessage> messageTransformer;
 105
 106     /**
 107      * Create rpc implementation capable of handling RPC for monitoring and notifications
 108      * even before the schemas of remote device are downloaded.
 109      */
 110     static NetconfDeviceRpc getRpcForInitialization(final NetconfDeviceCommunicator listener,
 111                                                     final boolean notificationSupport) {
 112         final BaseSchema baseSchema = notificationSupport
 113                 ? BaseSchema.BASE_NETCONF_CTX_WITH_NOTIFICATIONS
 114                 : BaseSchema.BASE_NETCONF_CTX;
 115
 116         return new NetconfDeviceRpc(baseSchema.getSchemaContext(), listener,
 117                 new NetconfMessageTransformer(baseSchema.getSchemaContext(), false, baseSchema));
 118     }
 119
 120     public NetconfDevice(final SchemaResourcesDTO schemaResourcesDTO, final RemoteDeviceId id,
 121                          final RemoteDeviceHandler<NetconfSessionPreferences> salFacade,
 122                          final ListeningExecutorService globalProcessingExecutor,
 123                          final boolean reconnectOnSchemasChange) {
 124         this(schemaResourcesDTO, id, salFacade, globalProcessingExecutor, reconnectOnSchemasChange, null);
 125     }
 126
 127     public NetconfDevice(final SchemaResourcesDTO schemaResourcesDTO, final RemoteDeviceId id,
 128             final RemoteDeviceHandler<NetconfSessionPreferences> salFacade,
 129             final ListeningExecutorService globalProcessingExecutor, final boolean reconnectOnSchemasChange,
 130             final DeviceActionFactory deviceActionFactory) {
 131         this.id = id;
 132         this.reconnectOnSchemasChange = reconnectOnSchemasChange;
 133         this.deviceActionFactory = deviceActionFactory;
 134         this.schemaRegistry = schemaResourcesDTO.getSchemaRegistry();
 135         this.schemaRepository = schemaResourcesDTO.getSchemaRepository();
 136         this.schemaContextFactory = schemaResourcesDTO.getSchemaContextFactory();
 137         this.salFacade = salFacade;
 138         this.stateSchemasResolver = schemaResourcesDTO.getStateSchemasResolver();
 139         this.processingExecutor = requireNonNull(globalProcessingExecutor);
 140         this.notificationHandler = new NotificationHandler(salFacade, id);
 141     }
 142
 143     @Override
 144     public void onRemoteSessionUp(final NetconfSessionPreferences remoteSessionCapabilities,
 145                                   final NetconfDeviceCommunicator listener) {
 146         // SchemaContext setup has to be performed in a dedicated thread since
 147         // we are in a netty thread in this method
 148         // Yang models are being downloaded in this method and it would cause a
 149         // deadlock if we used the netty thread
 150         // http://netty.io/wiki/thread-model.html
 151         setConnected(true);
 152         LOG.debug("{}: Session to remote device established with {}", id, remoteSessionCapabilities);
 153
 154         final NetconfDeviceRpc initRpc =
 155                 getRpcForInitialization(listener, remoteSessionCapabilities.isNotificationsSupported());
 156         final DeviceSourcesResolver task =
 157                 new DeviceSourcesResolver(remoteSessionCapabilities, id, stateSchemasResolver, initRpc);
 158         final ListenableFuture<DeviceSources> sourceResolverFuture = processingExecutor.submit(task);
 159
 160         if (shouldListenOnSchemaChange(remoteSessionCapabilities)) {
 161             registerToBaseNetconfStream(initRpc, listener);
 162         }
 163
 164         final FutureCallback<DeviceSources> resolvedSourceCallback = new FutureCallback<DeviceSources>() {
 165             @Override
 166             public void onSuccess(@Nonnull final DeviceSources result) {
 167                 addProvidedSourcesToSchemaRegistry(result);
 168                 setUpSchema(result);
 169             }
 170
 171             private void setUpSchema(final DeviceSources result) {
 172                 processingExecutor.submit(new SchemaSetup(result, remoteSessionCapabilities, listener));
 173             }
 174
 175             @Override
 176             public void onFailure(final Throwable throwable) {
 177                 LOG.warn("{}: Unexpected error resolving device sources", id, throwable);
 178                 handleSalInitializationFailure(throwable, listener);
 179             }
 180         };
 181
 182         Futures.addCallback(sourceResolverFuture, resolvedSourceCallback, MoreExecutors.directExecutor());
 183     }
 184
 185     private void registerToBaseNetconfStream(final NetconfDeviceRpc deviceRpc,
 186                                              final NetconfDeviceCommunicator listener) {
 187         // TODO check whether the model describing create subscription is present in schema
 188         // Perhaps add a default schema context to support create-subscription if the model was not provided
 189         // (same as what we do for base netconf operations in transformer)
 190         final CheckedFuture<DOMRpcResult, DOMRpcException> rpcResultListenableFuture = deviceRpc.invokeRpc(
 191                 NetconfMessageTransformUtil.toPath(NetconfMessageTransformUtil.CREATE_SUBSCRIPTION_RPC_QNAME),
 192                 NetconfMessageTransformUtil.CREATE_SUBSCRIPTION_RPC_CONTENT);
 193
 194         final NotificationHandler.NotificationFilter filter = new NotificationHandler.NotificationFilter() {
 195             @Override
 196             public Optional<DOMNotification> filterNotification(final DOMNotification notification) {
 197                 if (isCapabilityChanged(notification)) {
 198                     LOG.info("{}: Schemas change detected, reconnecting", id);
 199                     // Only disconnect is enough,
 200                     // the reconnecting nature of the connector will take care of reconnecting
 201                     listener.disconnect();
 202                     return Optional.absent();
 203                 }
 204                 return Optional.of(notification);
 205             }
 206
 207             private boolean isCapabilityChanged(final DOMNotification notification) {
 208                 return notification.getBody().getNodeType().equals(NetconfCapabilityChange.QNAME);
 209             }
 210         };
 211
 212         Futures.addCallback(rpcResultListenableFuture, new FutureCallback<DOMRpcResult>() {
 213             @Override
 214             public void onSuccess(final DOMRpcResult domRpcResult) {
 215                 notificationHandler.addNotificationFilter(filter);
 216             }
 217
 218             @Override
 219             public void onFailure(final Throwable throwable) {
 220                 LOG.warn("Unable to subscribe to base notification stream. Schemas will not be reloaded on the fly",
 221                         throwable);
 222             }
 223         }, MoreExecutors.directExecutor());
 224     }
 225
 226     private boolean shouldListenOnSchemaChange(final NetconfSessionPreferences remoteSessionCapabilities) {
 227         return remoteSessionCapabilities.isNotificationsSupported() && reconnectOnSchemasChange;
 228     }
 229
 230     private synchronized void handleSalInitializationSuccess(final SchemaContext result,
 231                                         final NetconfSessionPreferences remoteSessionCapabilities,
 232                                         final DOMRpcService deviceRpc,
 233                                         final RemoteDeviceCommunicator<NetconfMessage> listener) {
 234         //NetconfDevice.SchemaSetup can complete after NetconfDeviceCommunicator was closed. In that case do nothing,
 235         //since salFacade.onDeviceDisconnected was already called.
 236         if (connected) {
 237             final BaseSchema baseSchema =
 238                 remoteSessionCapabilities.isNotificationsSupported()
 239                         ? BaseSchema.BASE_NETCONF_CTX_WITH_NOTIFICATIONS : BaseSchema.BASE_NETCONF_CTX;
 240             this.messageTransformer = new NetconfMessageTransformer(result, true, baseSchema);
 241
 242             updateTransformer(this.messageTransformer);
 243             // salFacade.onDeviceConnected has to be called before the notification handler is initialized
 244             this.salFacade.onDeviceConnected(result, remoteSessionCapabilities, deviceRpc,
 245                     this.deviceActionFactory == null ? null : this.deviceActionFactory.createDeviceAction(
 246                             this.messageTransformer, listener, result));
 247             this.notificationHandler.onRemoteSchemaUp(this.messageTransformer);
 248
 249             LOG.info("{}: Netconf connector initialized successfully", id);
 250         } else {
 251             LOG.warn("{}: Device communicator was closed before schema setup finished.", id);
 252         }
 253     }
 254
 255     private void handleSalInitializationFailure(final Throwable throwable,
 256                                                 final RemoteDeviceCommunicator<NetconfMessage> listener) {
 257         LOG.error("{}: Initialization in sal failed, disconnecting from device", id, throwable);
 258         listener.close();
 259         onRemoteSessionDown();
 260         resetMessageTransformer();
 261     }
 262
 263     /**
 264      * Set the transformer to null as is in initial state.
 265      */
 266     private void resetMessageTransformer() {
 267         updateTransformer(null);
 268     }
 269
 270     private synchronized void updateTransformer(final MessageTransformer<NetconfMessage> transformer) {
 271         messageTransformer = transformer;
 272     }
 273
 274     private synchronized void setConnected(final boolean connected) {
 275         this.connected = connected;
 276     }
 277
 278     private void addProvidedSourcesToSchemaRegistry(final DeviceSources deviceSources) {
 279         final SchemaSourceProvider<YangTextSchemaSource> yangProvider = deviceSources.getSourceProvider();
 280         for (final SourceIdentifier sourceId : deviceSources.getProvidedSources()) {
 281             sourceRegistrations.add(schemaRegistry.registerSchemaSource(yangProvider,
 282                     PotentialSchemaSource.create(
 283                             sourceId, YangTextSchemaSource.class, PotentialSchemaSource.Costs.REMOTE_IO.getValue())));
 284         }
 285     }
 286
 287     @Override
 288     public void onRemoteSessionDown() {
 289         setConnected(false);
 290         notificationHandler.onRemoteSchemaDown();
 291
 292         salFacade.onDeviceDisconnected();
 293         for (final SchemaSourceRegistration<? extends SchemaSourceRepresentation> sourceRegistration
 294                 : sourceRegistrations) {
 295             sourceRegistration.close();
 296         }
 297         resetMessageTransformer();
 298     }
 299
 300     @Override
 301     public void onRemoteSessionFailed(final Throwable throwable) {
 302         setConnected(false);
 303         salFacade.onDeviceFailed(throwable);
 304     }
 305
 306     @Override
 307     public void onNotification(final NetconfMessage notification) {
 308         notificationHandler.handleNotification(notification);
 309     }
 310
 311     /**
 312      * Just a transfer object containing schema related dependencies. Injected in constructor.
 313      */
 314     public static class SchemaResourcesDTO {
 315         private final SchemaSourceRegistry schemaRegistry;
 316         private final SchemaRepository schemaRepository;
 317         private final SchemaContextFactory schemaContextFactory;
 318         private final NetconfDeviceSchemasResolver stateSchemasResolver;
 319
 320         public SchemaResourcesDTO(final SchemaSourceRegistry schemaRegistry,
 321                                   final SchemaRepository schemaRepository,
 322                                   final SchemaContextFactory schemaContextFactory,
 323                                   final NetconfDeviceSchemasResolver deviceSchemasResolver) {
 324             this.schemaRegistry = Preconditions.checkNotNull(schemaRegistry);
 325             this.schemaRepository = Preconditions.checkNotNull(schemaRepository);
 326             this.schemaContextFactory = Preconditions.checkNotNull(schemaContextFactory);
 327             this.stateSchemasResolver = Preconditions.checkNotNull(deviceSchemasResolver);
 328         }
 329
 330         public SchemaSourceRegistry getSchemaRegistry() {
 331             return schemaRegistry;
 332         }
 333
 334         public SchemaRepository getSchemaRepository() {
 335             return schemaRepository;
 336         }
 337
 338         public SchemaContextFactory getSchemaContextFactory() {
 339             return schemaContextFactory;
 340         }
 341
 342         public NetconfDeviceSchemasResolver getStateSchemasResolver() {
 343             return stateSchemasResolver;
 344         }
 345     }
 346
 347     /**
 348      * Schema building callable.
 349      */
 350     private static class DeviceSourcesResolver implements Callable<DeviceSources> {
 351
 352         private final NetconfDeviceRpc deviceRpc;
 353         private final NetconfSessionPreferences remoteSessionCapabilities;
 354         private final RemoteDeviceId id;
 355         private final NetconfDeviceSchemasResolver stateSchemasResolver;
 356
 357         DeviceSourcesResolver(final NetconfDeviceRpc deviceRpc,
 358                               final NetconfSessionPreferences remoteSessionCapabilities,
 359                               final RemoteDeviceId id, final NetconfDeviceSchemasResolver stateSchemasResolver) {
 360             this.deviceRpc = deviceRpc;
 361             this.remoteSessionCapabilities = remoteSessionCapabilities;
 362             this.id = id;
 363             this.stateSchemasResolver = stateSchemasResolver;
 364         }
 365
 366         DeviceSourcesResolver(final NetconfSessionPreferences remoteSessionCapabilities, final RemoteDeviceId id,
 367                                      final NetconfDeviceSchemasResolver stateSchemasResolver,
 368                                      final NetconfDeviceRpc rpcForMonitoring) {
 369             this(rpcForMonitoring, remoteSessionCapabilities, id, stateSchemasResolver);
 370         }
 371
 372         @Override
 373         public DeviceSources call() {
 374             final NetconfDeviceSchemas availableSchemas =
 375                     stateSchemasResolver.resolve(deviceRpc, remoteSessionCapabilities, id);
 376             LOG.debug("{}: Schemas exposed by ietf-netconf-monitoring: {}", id,
 377                     availableSchemas.getAvailableYangSchemasQNames());
 378
 379             final Set<QName> requiredSources = Sets.newHashSet(remoteSessionCapabilities.getModuleBasedCaps());
 380             final Set<QName> providedSources = availableSchemas.getAvailableYangSchemasQNames();
 381
 382             final Set<QName> requiredSourcesNotProvided = Sets.difference(requiredSources, providedSources);
 383             if (!requiredSourcesNotProvided.isEmpty()) {
 384                 LOG.warn("{}: Netconf device does not provide all yang models reported in hello message capabilities,"
 385                         + " required but not provided: {}", id, requiredSourcesNotProvided);
 386                 LOG.warn("{}: Attempting to build schema context from required sources", id);
 387             }
 388
 389             // Here all the sources reported in netconf monitoring are merged with those reported in hello.
 390             // It is necessary to perform this since submodules are not mentioned in hello but still required.
 391             // This clashes with the option of a user to specify supported yang models manually in configuration
 392             // for netconf-connector and as a result one is not able to fully override yang models of a device.
 393             // It is only possible to add additional models.
 394             final Set<QName> providedSourcesNotRequired = Sets.difference(providedSources, requiredSources);
 395             if (!providedSourcesNotRequired.isEmpty()) {
 396                 LOG.warn("{}: Netconf device provides additional yang models not reported in "
 397                         + "hello message capabilities: {}", id, providedSourcesNotRequired);
 398                 LOG.warn("{}: Adding provided but not required sources as required to prevent failures", id);
 399                 LOG.debug("{}: Netconf device reported in hello: {}", id, requiredSources);
 400                 requiredSources.addAll(providedSourcesNotRequired);
 401             }
 402
 403             final SchemaSourceProvider<YangTextSchemaSource> sourceProvider;
 404             if (availableSchemas instanceof LibraryModulesSchemas) {
 405                 sourceProvider = new YangLibrarySchemaYangSourceProvider(id,
 406                         ((LibraryModulesSchemas) availableSchemas).getAvailableModels());
 407             } else {
 408                 sourceProvider = new NetconfRemoteSchemaYangSourceProvider(id, deviceRpc);
 409             }
 410
 411             return new DeviceSources(requiredSources, providedSources, sourceProvider);
 412         }
 413     }
 414
 415     /**
 416      * Contains RequiredSources - sources from capabilities.
 417      */
 418     private static final class DeviceSources {
 419         private final Set<QName> requiredSources;
 420         private final Set<QName> providedSources;
 421         private final SchemaSourceProvider<YangTextSchemaSource> sourceProvider;
 422
 423         DeviceSources(final Set<QName> requiredSources, final Set<QName> providedSources,
 424                              final SchemaSourceProvider<YangTextSchemaSource> sourceProvider) {
 425             this.requiredSources = requiredSources;
 426             this.providedSources = providedSources;
 427             this.sourceProvider = sourceProvider;
 428         }
 429
 430         public Set<QName> getRequiredSourcesQName() {
 431             return requiredSources;
 432         }
 433
 434         public Set<QName> getProvidedSourcesQName() {
 435             return providedSources;
 436         }
 437
 438         public Collection<SourceIdentifier> getRequiredSources() {
 439             return Collections2.transform(requiredSources, DeviceSources::toSourceId);
 440         }
 441
 442         public Collection<SourceIdentifier> getProvidedSources() {
 443             return Collections2.transform(providedSources, DeviceSources::toSourceId);
 444         }
 445
 446         public SchemaSourceProvider<YangTextSchemaSource> getSourceProvider() {
 447             return sourceProvider;
 448         }
 449
 450         private static SourceIdentifier toSourceId(final QName input) {
 451             return RevisionSourceIdentifier.create(input.getLocalName(), input.getRevision());
 452         }
 453     }
 454
 455     /**
 456      * Schema builder that tries to build schema context from provided sources or biggest subset of it.
 457      */
 458     private final class SchemaSetup implements Runnable {
 459         private final DeviceSources deviceSources;
 460         private final NetconfSessionPreferences remoteSessionCapabilities;
 461         private final RemoteDeviceCommunicator<NetconfMessage> listener;
 462         private final NetconfDeviceCapabilities capabilities;
 463
 464         SchemaSetup(final DeviceSources deviceSources, final NetconfSessionPreferences remoteSessionCapabilities,
 465                            final RemoteDeviceCommunicator<NetconfMessage> listener) {
 466             this.deviceSources = deviceSources;
 467             this.remoteSessionCapabilities = remoteSessionCapabilities;
 468             this.listener = listener;
 469             this.capabilities = remoteSessionCapabilities.getNetconfDeviceCapabilities();
 470         }
 471
 472         @Override
 473         public void run() {
 474
 475             final Collection<SourceIdentifier> requiredSources = deviceSources.getRequiredSources();
 476             final Collection<SourceIdentifier> missingSources = filterMissingSources(requiredSources);
 477
 478             capabilities.addUnresolvedCapabilities(getQNameFromSourceIdentifiers(missingSources),
 479                     UnavailableCapability.FailureReason.MissingSource);
 480
 481             requiredSources.removeAll(missingSources);
 482             setUpSchema(requiredSources);
 483         }
 484
 485         private Collection<SourceIdentifier> filterMissingSources(final Collection<SourceIdentifier> requiredSources) {
 486             return requiredSources.parallelStream().filter(sourceIdentifier -> {
 487                 try {
 488                     schemaRepository.getSchemaSource(sourceIdentifier, YangTextSchemaSource.class).get();
 489                     return false;
 490                 } catch (InterruptedException | ExecutionException e) {
 491                     return true;
 492                 }
 493             }).collect(Collectors.toList());
 494         }
 495
 496         /**
 497          * Build schema context, in case of success or final failure notify device.
 498          *
 499          * @param requiredSources required sources
 500          */
 501         @SuppressWarnings("checkstyle:IllegalCatch")
 502         private void setUpSchema(Collection<SourceIdentifier> requiredSources) {
 503             while (!requiredSources.isEmpty()) {
 504                 LOG.trace("{}: Trying to build schema context from {}", id, requiredSources);
 505                 try {
 506                     final ListenableFuture<SchemaContext> schemaBuilderFuture = schemaContextFactory
 507                             .createSchemaContext(requiredSources);
 508                     final SchemaContext result = schemaBuilderFuture.get();
 509                     LOG.debug("{}: Schema context built successfully from {}", id, requiredSources);
 510                     final Collection<QName> filteredQNames = Sets.difference(deviceSources.getRequiredSourcesQName(),
 511                             capabilities.getUnresolvedCapabilites().keySet());
 512                     capabilities.addCapabilities(filteredQNames.stream().map(entry -> new AvailableCapabilityBuilder()
 513                             .setCapability(entry.toString()).setCapabilityOrigin(
 514                                     remoteSessionCapabilities.getModuleBasedCapsOrigin().get(entry)).build())
 515                             .collect(Collectors.toList()));
 516
 517                     capabilities.addNonModuleBasedCapabilities(remoteSessionCapabilities
 518                             .getNonModuleCaps().stream().map(entry -> new AvailableCapabilityBuilder()
 519                                     .setCapability(entry).setCapabilityOrigin(
 520                                             remoteSessionCapabilities.getNonModuleBasedCapsOrigin().get(entry)).build())
 521                             .collect(Collectors.toList()));
 522
 523                     handleSalInitializationSuccess(result, remoteSessionCapabilities, getDeviceSpecificRpc(result),
 524                             listener);
 525                     return;
 526                 } catch (final ExecutionException e) {
 527                     // schemaBuilderFuture.checkedGet() throws only SchemaResolutionException
 528                     // that might be wrapping a MissingSchemaSourceException so we need to look
 529                     // at the cause of the exception to make sure we don't misinterpret it.
 530                     final Throwable cause = e.getCause();
 531
 532                     if (cause instanceof MissingSchemaSourceException) {
 533                         requiredSources = handleMissingSchemaSourceException(
 534                                 requiredSources, (MissingSchemaSourceException) cause);
 535                         continue;
 536                     }
 537                     if (cause instanceof SchemaResolutionException) {
 538                         requiredSources = handleSchemaResolutionException(requiredSources,
 539                             (SchemaResolutionException) cause);
 540                     } else {
 541                         handleSalInitializationFailure(e, listener);
 542                         return;
 543                     }
 544                 } catch (final Exception e) {
 545                     // unknown error, fail
 546                     handleSalInitializationFailure(e, listener);
 547                     return;
 548                 }
 549             }
 550             // No more sources, fail
 551             final IllegalStateException cause = new IllegalStateException(id + ": No more sources for schema context");
 552             handleSalInitializationFailure(cause, listener);
 553             salFacade.onDeviceFailed(cause);
 554         }
 555
 556         private Collection<SourceIdentifier> handleMissingSchemaSourceException(
 557                 final Collection<SourceIdentifier> requiredSources, final MissingSchemaSourceException exception) {
 558             // In case source missing, try without it
 559             final SourceIdentifier missingSource = exception.getSourceId();
 560             LOG.warn("{}: Unable to build schema context, missing source {}, will reattempt without it",
 561                 id, missingSource);
 562             LOG.debug("{}: Unable to build schema context, missing source {}, will reattempt without it",
 563                 id, missingSource, exception);
 564             final Collection<QName> qNameOfMissingSource =
 565                 getQNameFromSourceIdentifiers(Sets.newHashSet(missingSource));
 566             if (!qNameOfMissingSource.isEmpty()) {
 567                 capabilities.addUnresolvedCapabilities(
 568                         qNameOfMissingSource, UnavailableCapability.FailureReason.MissingSource);
 569             }
 570             return stripUnavailableSource(requiredSources, missingSource);
 571         }
 572
 573         private Collection<SourceIdentifier> handleSchemaResolutionException(
 574             final Collection<SourceIdentifier> requiredSources, final SchemaResolutionException resolutionException) {
 575             // In case resolution error, try only with resolved sources
 576             // There are two options why schema resolution exception occurred : unsatisfied imports or flawed model
 577             // FIXME Do we really have assurance that these two cases cannot happen at once?
 578             if (resolutionException.getFailedSource() != null) {
 579                 // flawed model - exclude it
 580                 final SourceIdentifier failedSourceId = resolutionException.getFailedSource();
 581                 LOG.warn("{}: Unable to build schema context, failed to resolve source {}, will reattempt without it",
 582                     id, failedSourceId);
 583                 LOG.warn("{}: Unable to build schema context, failed to resolve source {}, will reattempt without it",
 584                     id, failedSourceId, resolutionException);
 585                 capabilities.addUnresolvedCapabilities(
 586                         getQNameFromSourceIdentifiers(Collections.singleton(failedSourceId)),
 587                         UnavailableCapability.FailureReason.UnableToResolve);
 588                 return stripUnavailableSource(requiredSources, resolutionException.getFailedSource());
 589             }
 590             // unsatisfied imports
 591             final Set<SourceIdentifier> unresolvedSources = resolutionException.getUnsatisfiedImports().keySet();
 592             capabilities.addUnresolvedCapabilities(getQNameFromSourceIdentifiers(unresolvedSources),
 593                 UnavailableCapability.FailureReason.UnableToResolve);
 594             LOG.warn("{}: Unable to build schema context, unsatisfied imports {}, will reattempt with resolved only",
 595                 id, resolutionException.getUnsatisfiedImports());
 596             LOG.debug("{}: Unable to build schema context, unsatisfied imports {}, will reattempt with resolved only",
 597                 id, resolutionException.getUnsatisfiedImports(), resolutionException);
 598             return resolutionException.getResolvedSources();
 599         }
 600
 601         protected NetconfDeviceRpc getDeviceSpecificRpc(final SchemaContext result) {
 602             return new NetconfDeviceRpc(result, listener, new NetconfMessageTransformer(result, true));
 603         }
 604
 605         private Collection<SourceIdentifier> stripUnavailableSource(final Collection<SourceIdentifier> requiredSources,
 606                                                                     final SourceIdentifier sourceIdToRemove) {
 607             final LinkedList<SourceIdentifier> sourceIdentifiers = Lists.newLinkedList(requiredSources);
 608             final boolean removed = sourceIdentifiers.remove(sourceIdToRemove);
 609             Preconditions.checkState(
 610                     removed, "{}: Trying to remove {} from {} failed", id, sourceIdToRemove, requiredSources);
 611             return sourceIdentifiers;
 612         }
 613
 614         private Collection<QName> getQNameFromSourceIdentifiers(final Collection<SourceIdentifier> identifiers) {
 615             final Collection<QName> qNames = Collections2.transform(identifiers, this::getQNameFromSourceIdentifier);
 616
 617             if (qNames.isEmpty()) {
 618                 LOG.debug("{}: Unable to map any source identifiers to a capability reported by device : {}", id,
 619                         identifiers);
 620             }
 621             return Collections2.filter(qNames, Predicates.notNull());
 622         }
 623
 624         private QName getQNameFromSourceIdentifier(final SourceIdentifier identifier) {
 625             // Required sources are all required and provided merged in DeviceSourcesResolver
 626             for (final QName qname : deviceSources.getRequiredSourcesQName()) {
 627                 if (!qname.getLocalName().equals(identifier.getName())) {
 628                     continue;
 629                 }
 630
 631                 if (identifier.getRevision().equals(qname.getRevision())) {
 632                     return qname;
 633                 }
 634             }
 635             LOG.warn("Unable to map identifier to a devices reported capability: {} Available: {}",identifier,
 636                     deviceSources.getRequiredSourcesQName());
 637             // return null since we cannot find the QName,
 638             // this capability will be removed from required sources and not reported as unresolved-capability
 639             return null;
 640         }
 641     }
 642 }