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 com.google.common.base.Preconditions.checkState;
  11 import static java.util.Objects.requireNonNull;
  12 import static org.opendaylight.netconf.sal.connect.netconf.util.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.Sets;
  17 import com.google.common.util.concurrent.FutureCallback;
  18 import com.google.common.util.concurrent.Futures;
  19 import com.google.common.util.concurrent.ListenableFuture;
  20 import com.google.common.util.concurrent.ListeningExecutorService;
  21 import com.google.common.util.concurrent.MoreExecutors;
  22 import com.google.common.util.concurrent.SettableFuture;
  23 import java.util.ArrayList;
  24 import java.util.Arrays;
  25 import java.util.Collection;
  26 import java.util.Collections;
  27 import java.util.List;
  28 import java.util.Objects;
  29 import java.util.Set;
  30 import java.util.concurrent.ExecutionException;
  31 import java.util.stream.Collectors;
  32 import org.checkerframework.checker.lock.qual.GuardedBy;
  33 import org.opendaylight.mdsal.dom.api.DOMRpcResult;
  34 import org.opendaylight.mdsal.dom.api.DOMRpcService;
  35 import org.opendaylight.netconf.api.NetconfMessage;
  36 import org.opendaylight.netconf.api.xml.XmlNetconfConstants;
  37 import org.opendaylight.netconf.sal.connect.api.DeviceActionFactory;
  38 import org.opendaylight.netconf.sal.connect.api.MessageTransformer;
  39 import org.opendaylight.netconf.sal.connect.api.NetconfDeviceSchemasResolver;
  40 import org.opendaylight.netconf.sal.connect.api.RemoteDevice;
  41 import org.opendaylight.netconf.sal.connect.api.RemoteDeviceCommunicator;
  42 import org.opendaylight.netconf.sal.connect.api.RemoteDeviceHandler;
  43 import org.opendaylight.netconf.sal.connect.netconf.listener.NetconfDeviceCapabilities;
  44 import org.opendaylight.netconf.sal.connect.netconf.listener.NetconfDeviceCommunicator;
  45 import org.opendaylight.netconf.sal.connect.netconf.listener.NetconfSessionPreferences;
  46 import org.opendaylight.netconf.sal.connect.netconf.sal.NetconfDeviceRpc;
  47 import org.opendaylight.netconf.sal.connect.netconf.schema.mapping.BaseNetconfSchemas;
  48 import org.opendaylight.netconf.sal.connect.netconf.schema.mapping.BaseSchema;
  49 import org.opendaylight.netconf.sal.connect.netconf.schema.mapping.NetconfMessageTransformer;
  50 import org.opendaylight.netconf.sal.connect.netconf.util.NetconfMessageTransformUtil;
  51 import org.opendaylight.netconf.sal.connect.util.RemoteDeviceId;
  52 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.netconf.notifications.rev120206.NetconfCapabilityChange;
  53 import org.opendaylight.yang.gen.v1.urn.opendaylight.netconf.node.topology.rev150114.netconf.node.connection.status.available.capabilities.AvailableCapabilityBuilder;
  54 import org.opendaylight.yang.gen.v1.urn.opendaylight.netconf.node.topology.rev150114.netconf.node.connection.status.unavailable.capabilities.UnavailableCapability;
  55 import org.opendaylight.yangtools.concepts.Registration;
  56 import org.opendaylight.yangtools.rfc8528.data.api.MountPointContext;
  57 import org.opendaylight.yangtools.rfc8528.data.util.EmptyMountPointContext;
  58 import org.opendaylight.yangtools.rfc8528.model.api.SchemaMountConstants;
  59 import org.opendaylight.yangtools.yang.common.QName;
  60 import org.opendaylight.yangtools.yang.common.RpcError;
  61 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  62 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifier;
  63 import org.opendaylight.yangtools.yang.data.api.schema.ContainerNode;
  64 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  65 import org.opendaylight.yangtools.yang.data.impl.schema.Builders;
  66 import org.opendaylight.yangtools.yang.model.api.EffectiveModelContext;
  67 import org.opendaylight.yangtools.yang.model.repo.api.EffectiveModelContextFactory;
  68 import org.opendaylight.yangtools.yang.model.repo.api.MissingSchemaSourceException;
  69 import org.opendaylight.yangtools.yang.model.repo.api.SchemaRepository;
  70 import org.opendaylight.yangtools.yang.model.repo.api.SchemaResolutionException;
  71 import org.opendaylight.yangtools.yang.model.repo.api.SourceIdentifier;
  72 import org.opendaylight.yangtools.yang.model.repo.api.YangTextSchemaSource;
  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 implements RemoteDevice<NetconfDeviceCommunicator> {
  81     private static final Logger LOG = LoggerFactory.getLogger(NetconfDevice.class);
  82
  83     private static final QName RFC8528_SCHEMA_MOUNTS_QNAME = QName.create(
  84         SchemaMountConstants.RFC8528_MODULE, "schema-mounts").intern();
  85     private static final YangInstanceIdentifier RFC8528_SCHEMA_MOUNTS = YangInstanceIdentifier.create(
  86         NodeIdentifier.create(RFC8528_SCHEMA_MOUNTS_QNAME));
  87
  88     protected final RemoteDeviceId id;
  89     protected final EffectiveModelContextFactory schemaContextFactory;
  90     protected final SchemaSourceRegistry schemaRegistry;
  91     protected final SchemaRepository schemaRepository;
  92
  93     protected final List<Registration> sourceRegistrations = new ArrayList<>();
  94
  95     private final RemoteDeviceHandler salFacade;
  96     private final ListeningExecutorService processingExecutor;
  97     private final DeviceActionFactory deviceActionFactory;
  98     private final NetconfDeviceSchemasResolver stateSchemasResolver;
  99     private final NotificationHandler notificationHandler;
 100     private final boolean reconnectOnSchemasChange;
 101     private final BaseNetconfSchemas baseSchemas;
 102
 103     @GuardedBy("this")
 104     private boolean connected = false;
 105
 106     // Message transformer is constructed once the schemas are available
 107     private MessageTransformer messageTransformer;
 108
 109     public NetconfDevice(final SchemaResourcesDTO schemaResourcesDTO, final BaseNetconfSchemas baseSchemas,
 110             final RemoteDeviceId id, final RemoteDeviceHandler salFacade,
 111             final ListeningExecutorService globalProcessingExecutor, final boolean reconnectOnSchemasChange) {
 112         this(schemaResourcesDTO, baseSchemas, id, salFacade, globalProcessingExecutor, reconnectOnSchemasChange, null);
 113     }
 114
 115     public NetconfDevice(final SchemaResourcesDTO schemaResourcesDTO, final BaseNetconfSchemas baseSchemas,
 116             final RemoteDeviceId id, final RemoteDeviceHandler salFacade,
 117             final ListeningExecutorService globalProcessingExecutor, final boolean reconnectOnSchemasChange,
 118             final DeviceActionFactory deviceActionFactory) {
 119         this.baseSchemas = requireNonNull(baseSchemas);
 120         this.id = id;
 121         this.reconnectOnSchemasChange = reconnectOnSchemasChange;
 122         this.deviceActionFactory = deviceActionFactory;
 123         schemaRegistry = schemaResourcesDTO.getSchemaRegistry();
 124         schemaRepository = schemaResourcesDTO.getSchemaRepository();
 125         schemaContextFactory = schemaResourcesDTO.getSchemaContextFactory();
 126         this.salFacade = salFacade;
 127         stateSchemasResolver = schemaResourcesDTO.getStateSchemasResolver();
 128         processingExecutor = requireNonNull(globalProcessingExecutor);
 129         notificationHandler = new NotificationHandler(salFacade, id);
 130     }
 131
 132     @Override
 133     public void onRemoteSessionUp(final NetconfSessionPreferences remoteSessionCapabilities,
 134                                   final NetconfDeviceCommunicator listener) {
 135         // SchemaContext setup has to be performed in a dedicated thread since
 136         // we are in a netty thread in this method
 137         // Yang models are being downloaded in this method and it would cause a
 138         // deadlock if we used the netty thread
 139         // http://netty.io/wiki/thread-model.html
 140         setConnected(true);
 141         LOG.debug("{}: Session to remote device established with {}", id, remoteSessionCapabilities);
 142
 143         final BaseSchema baseSchema = resolveBaseSchema(remoteSessionCapabilities.isNotificationsSupported());
 144         final NetconfDeviceRpc initRpc = new NetconfDeviceRpc(baseSchema.getEffectiveModelContext(), listener,
 145             new NetconfMessageTransformer(baseSchema.getMountPointContext(), false, baseSchema));
 146         final ListenableFuture<DeviceSources> sourceResolverFuture = processingExecutor.submit(
 147             new DeviceSourcesResolver(id, baseSchema, initRpc, remoteSessionCapabilities, stateSchemasResolver));
 148
 149         if (shouldListenOnSchemaChange(remoteSessionCapabilities)) {
 150             registerToBaseNetconfStream(initRpc, listener);
 151         }
 152
 153         // Set up the SchemaContext for the device
 154         final ListenableFuture<EffectiveModelContext> futureSchema = Futures.transformAsync(sourceResolverFuture,
 155             deviceSources -> assembleSchemaContext(deviceSources, remoteSessionCapabilities), processingExecutor);
 156
 157         // Potentially acquire mount point list and interpret it
 158         final ListenableFuture<MountPointContext> futureContext = Futures.transformAsync(futureSchema,
 159             schemaContext -> createMountPointContext(schemaContext, baseSchema, listener), processingExecutor);
 160
 161         Futures.addCallback(futureContext, new FutureCallback<MountPointContext>() {
 162             @Override
 163             public void onSuccess(final MountPointContext result) {
 164                 handleSalInitializationSuccess(result, remoteSessionCapabilities,
 165                         getDeviceSpecificRpc(result, listener, baseSchema), listener);
 166             }
 167
 168             @Override
 169             public void onFailure(final Throwable cause) {
 170                 LOG.warn("{}: Unexpected error resolving device sources", id, cause);
 171                 // FIXME: this causes salFacade to see onDeviceDisconnected() and then onDeviceFailed(), which is quite
 172                 //        weird
 173                 handleSalInitializationFailure(cause, listener);
 174                 salFacade.onDeviceFailed(cause);
 175             }
 176         }, MoreExecutors.directExecutor());
 177     }
 178
 179     private void registerToBaseNetconfStream(final NetconfDeviceRpc deviceRpc,
 180                                              final NetconfDeviceCommunicator listener) {
 181         // TODO check whether the model describing create subscription is present in schema
 182         // Perhaps add a default schema context to support create-subscription if the model was not provided
 183         // (same as what we do for base netconf operations in transformer)
 184         final ListenableFuture<DOMRpcResult> rpcResultListenableFuture = deviceRpc.invokeRpc(
 185                 NetconfMessageTransformUtil.CREATE_SUBSCRIPTION_RPC_QNAME,
 186                 NetconfMessageTransformUtil.CREATE_SUBSCRIPTION_RPC_CONTENT);
 187
 188         Futures.addCallback(rpcResultListenableFuture, new FutureCallback<DOMRpcResult>() {
 189             @Override
 190             public void onSuccess(final DOMRpcResult domRpcResult) {
 191                 notificationHandler.addNotificationFilter(notification -> {
 192                     if (NetconfCapabilityChange.QNAME.equals(notification.getBody().getIdentifier().getNodeType())) {
 193                         LOG.info("{}: Schemas change detected, reconnecting", id);
 194                         // Only disconnect is enough,
 195                         // the reconnecting nature of the connector will take care of reconnecting
 196                         listener.disconnect();
 197                         return false;
 198                     }
 199                     return true;
 200                 });
 201             }
 202
 203             @Override
 204             public void onFailure(final Throwable throwable) {
 205                 LOG.warn("Unable to subscribe to base notification stream. Schemas will not be reloaded on the fly",
 206                         throwable);
 207             }
 208         }, MoreExecutors.directExecutor());
 209     }
 210
 211     private boolean shouldListenOnSchemaChange(final NetconfSessionPreferences remoteSessionCapabilities) {
 212         return remoteSessionCapabilities.isNotificationsSupported() && reconnectOnSchemasChange;
 213     }
 214
 215     private synchronized void handleSalInitializationSuccess(final MountPointContext result,
 216             final NetconfSessionPreferences remoteSessionCapabilities, final DOMRpcService deviceRpc,
 217             final RemoteDeviceCommunicator listener) {
 218         //NetconfDevice.SchemaSetup can complete after NetconfDeviceCommunicator was closed. In that case do nothing,
 219         //since salFacade.onDeviceDisconnected was already called.
 220         if (connected) {
 221             messageTransformer = new NetconfMessageTransformer(result, true,
 222                 resolveBaseSchema(remoteSessionCapabilities.isNotificationsSupported()));
 223
 224             // salFacade.onDeviceConnected has to be called before the notification handler is initialized
 225             salFacade.onDeviceConnected(result, remoteSessionCapabilities, deviceRpc,
 226                     deviceActionFactory == null ? null : deviceActionFactory.createDeviceAction(
 227                             messageTransformer, listener, result.getEffectiveModelContext()));
 228             notificationHandler.onRemoteSchemaUp(messageTransformer);
 229
 230             LOG.info("{}: Netconf connector initialized successfully", id);
 231         } else {
 232             LOG.warn("{}: Device communicator was closed before schema setup finished.", id);
 233         }
 234     }
 235
 236     private void handleSalInitializationFailure(final Throwable throwable, final RemoteDeviceCommunicator listener) {
 237         LOG.error("{}: Initialization in sal failed, disconnecting from device", id, throwable);
 238         listener.close();
 239         onRemoteSessionDown();
 240         resetMessageTransformer();
 241     }
 242
 243     /**
 244      * Set the transformer to null as is in initial state.
 245      */
 246     private void resetMessageTransformer() {
 247         updateTransformer(null);
 248     }
 249
 250     private synchronized void updateTransformer(final MessageTransformer transformer) {
 251         messageTransformer = transformer;
 252     }
 253
 254     private synchronized void setConnected(final boolean connected) {
 255         this.connected = connected;
 256     }
 257
 258     private ListenableFuture<EffectiveModelContext> assembleSchemaContext(final DeviceSources deviceSources,
 259             final NetconfSessionPreferences remoteSessionCapabilities) {
 260         LOG.debug("{}: Resolved device sources to {}", id, deviceSources);
 261
 262         sourceRegistrations.addAll(deviceSources.register(schemaRegistry));
 263
 264         return new SchemaSetup(deviceSources, remoteSessionCapabilities).startResolution();
 265     }
 266
 267     private ListenableFuture<MountPointContext> createMountPointContext(final EffectiveModelContext schemaContext,
 268             final BaseSchema baseSchema, final NetconfDeviceCommunicator listener) {
 269         final MountPointContext emptyContext = new EmptyMountPointContext(schemaContext);
 270         if (schemaContext.findModule(SchemaMountConstants.RFC8528_MODULE).isEmpty()) {
 271             return Futures.immediateFuture(emptyContext);
 272         }
 273
 274         // Create a temporary RPC invoker and acquire the mount point tree
 275         LOG.debug("{}: Acquiring available mount points", id);
 276         final NetconfDeviceRpc deviceRpc = new NetconfDeviceRpc(schemaContext, listener,
 277             new NetconfMessageTransformer(emptyContext, false, baseSchema));
 278
 279         return Futures.transform(deviceRpc.invokeRpc(NetconfMessageTransformUtil.NETCONF_GET_QNAME,
 280             Builders.containerBuilder().withNodeIdentifier(NETCONF_GET_NODEID)
 281                 .withChild(NetconfMessageTransformUtil.toFilterStructure(RFC8528_SCHEMA_MOUNTS, schemaContext))
 282                 .build()), rpcResult -> processSchemaMounts(rpcResult, emptyContext), MoreExecutors.directExecutor());
 283     }
 284
 285     private MountPointContext processSchemaMounts(final DOMRpcResult rpcResult, final MountPointContext emptyContext) {
 286         final Collection<? extends RpcError> errors = rpcResult.getErrors();
 287         if (!errors.isEmpty()) {
 288             LOG.warn("{}: Schema-mounts acquisition resulted in errors {}", id, errors);
 289         }
 290         final NormalizedNode schemaMounts = rpcResult.getResult();
 291         if (schemaMounts == null) {
 292             LOG.debug("{}: device does not define any schema mounts", id);
 293             return emptyContext;
 294         }
 295         if (!(schemaMounts instanceof ContainerNode)) {
 296             LOG.warn("{}: ignoring non-container schema mounts {}", id, schemaMounts);
 297             return emptyContext;
 298         }
 299
 300         return DeviceMountPointContext.create(emptyContext, (ContainerNode) schemaMounts);
 301     }
 302
 303     @Override
 304     public void onRemoteSessionDown() {
 305         setConnected(false);
 306         notificationHandler.onRemoteSchemaDown();
 307
 308         salFacade.onDeviceDisconnected();
 309         sourceRegistrations.forEach(Registration::close);
 310         sourceRegistrations.clear();
 311         resetMessageTransformer();
 312     }
 313
 314     @Override
 315     public void onRemoteSessionFailed(final Throwable throwable) {
 316         setConnected(false);
 317         salFacade.onDeviceFailed(throwable);
 318     }
 319
 320     @Override
 321     public void onNotification(final NetconfMessage notification) {
 322         notificationHandler.handleNotification(notification);
 323     }
 324
 325     private BaseSchema resolveBaseSchema(final boolean notificationSupport) {
 326         return notificationSupport ? baseSchemas.getBaseSchemaWithNotifications() : baseSchemas.getBaseSchema();
 327     }
 328
 329     protected NetconfDeviceRpc getDeviceSpecificRpc(final MountPointContext result,
 330             final RemoteDeviceCommunicator listener, final BaseSchema schema) {
 331         return new NetconfDeviceRpc(result.getEffectiveModelContext(), listener,
 332             new NetconfMessageTransformer(result, true, schema));
 333     }
 334
 335     /**
 336      * Just a transfer object containing schema related dependencies. Injected in constructor.
 337      */
 338     public static class SchemaResourcesDTO {
 339         private final SchemaSourceRegistry schemaRegistry;
 340         private final SchemaRepository schemaRepository;
 341         private final EffectiveModelContextFactory schemaContextFactory;
 342         private final NetconfDeviceSchemasResolver stateSchemasResolver;
 343
 344         public SchemaResourcesDTO(final SchemaSourceRegistry schemaRegistry,
 345                                   final SchemaRepository schemaRepository,
 346                                   final EffectiveModelContextFactory schemaContextFactory,
 347                                   final NetconfDeviceSchemasResolver deviceSchemasResolver) {
 348             this.schemaRegistry = requireNonNull(schemaRegistry);
 349             this.schemaRepository = requireNonNull(schemaRepository);
 350             this.schemaContextFactory = requireNonNull(schemaContextFactory);
 351             stateSchemasResolver = requireNonNull(deviceSchemasResolver);
 352         }
 353
 354         public SchemaSourceRegistry getSchemaRegistry() {
 355             return schemaRegistry;
 356         }
 357
 358         public SchemaRepository getSchemaRepository() {
 359             return schemaRepository;
 360         }
 361
 362         public EffectiveModelContextFactory getSchemaContextFactory() {
 363             return schemaContextFactory;
 364         }
 365
 366         public NetconfDeviceSchemasResolver getStateSchemasResolver() {
 367             return stateSchemasResolver;
 368         }
 369     }
 370
 371     /**
 372      * A dedicated exception to indicate when we fail to setup an {@link EffectiveModelContext}.
 373      */
 374     public static final class EmptySchemaContextException extends Exception {
 375         private static final long serialVersionUID = 1L;
 376
 377         public EmptySchemaContextException(final String message) {
 378             super(message);
 379         }
 380     }
 381
 382     /**
 383      * Schema builder that tries to build schema context from provided sources or biggest subset of it.
 384      */
 385     private final class SchemaSetup implements FutureCallback<EffectiveModelContext> {
 386         private final SettableFuture<EffectiveModelContext> resultFuture = SettableFuture.create();
 387
 388         private final DeviceSources deviceSources;
 389         private final NetconfSessionPreferences remoteSessionCapabilities;
 390         private final NetconfDeviceCapabilities capabilities;
 391
 392         private Collection<SourceIdentifier> requiredSources;
 393
 394         SchemaSetup(final DeviceSources deviceSources, final NetconfSessionPreferences remoteSessionCapabilities) {
 395             this.deviceSources = deviceSources;
 396             this.remoteSessionCapabilities = remoteSessionCapabilities;
 397             capabilities = remoteSessionCapabilities.getNetconfDeviceCapabilities();
 398
 399             // If device supports notifications and does not contain necessary modules, add them automatically
 400             if (remoteSessionCapabilities.containsNonModuleCapability(
 401                     XmlNetconfConstants.URN_IETF_PARAMS_NETCONF_CAPABILITY_NOTIFICATION_1_0)) {
 402                 deviceSources.getRequiredSourcesQName().addAll(
 403                         Arrays.asList(
 404                                 org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.netconf.notification._1._0.rev080714
 405                                         .$YangModuleInfoImpl.getInstance().getName(),
 406                                 org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.yang.types.rev130715
 407                                         .$YangModuleInfoImpl.getInstance().getName()
 408                         )
 409                 );
 410             }
 411
 412             requiredSources = deviceSources.getRequiredSources();
 413             final Collection<SourceIdentifier> missingSources = filterMissingSources(requiredSources);
 414
 415             capabilities.addUnresolvedCapabilities(getQNameFromSourceIdentifiers(missingSources),
 416                     UnavailableCapability.FailureReason.MissingSource);
 417             requiredSources.removeAll(missingSources);
 418         }
 419
 420         ListenableFuture<EffectiveModelContext> startResolution() {
 421             trySetupSchema();
 422             return resultFuture;
 423         }
 424
 425         @Override
 426         public void onSuccess(final EffectiveModelContext result) {
 427             LOG.debug("{}: Schema context built successfully from {}", id, requiredSources);
 428
 429             final Collection<QName> filteredQNames = Sets.difference(deviceSources.getRequiredSourcesQName(),
 430                     capabilities.getUnresolvedCapabilites().keySet());
 431             capabilities.addCapabilities(filteredQNames.stream().map(entry -> new AvailableCapabilityBuilder()
 432                     .setCapability(entry.toString()).setCapabilityOrigin(
 433                             remoteSessionCapabilities.getModuleBasedCapsOrigin().get(entry)).build())
 434                     .collect(Collectors.toList()));
 435
 436             capabilities.addNonModuleBasedCapabilities(remoteSessionCapabilities
 437                     .getNonModuleCaps().stream().map(entry -> new AvailableCapabilityBuilder()
 438                             .setCapability(entry).setCapabilityOrigin(
 439                                     remoteSessionCapabilities.getNonModuleBasedCapsOrigin().get(entry)).build())
 440                     .collect(Collectors.toList()));
 441
 442             resultFuture.set(result);
 443         }
 444
 445         @Override
 446         public void onFailure(final Throwable cause) {
 447             // schemaBuilderFuture.checkedGet() throws only SchemaResolutionException
 448             // that might be wrapping a MissingSchemaSourceException so we need to look
 449             // at the cause of the exception to make sure we don't misinterpret it.
 450             if (cause instanceof MissingSchemaSourceException) {
 451                 requiredSources = handleMissingSchemaSourceException((MissingSchemaSourceException) cause);
 452             } else if (cause instanceof SchemaResolutionException) {
 453                 requiredSources = handleSchemaResolutionException((SchemaResolutionException) cause);
 454             } else {
 455                 LOG.debug("Unhandled failure", cause);
 456                 resultFuture.setException(cause);
 457                 // No more trying...
 458                 return;
 459             }
 460
 461             trySetupSchema();
 462         }
 463
 464         private void trySetupSchema() {
 465             if (!requiredSources.isEmpty()) {
 466                 // Initiate async resolution, drive it back based on the result
 467                 LOG.trace("{}: Trying to build schema context from {}", id, requiredSources);
 468                 Futures.addCallback(schemaContextFactory.createEffectiveModelContext(requiredSources), this,
 469                     MoreExecutors.directExecutor());
 470             } else {
 471                 LOG.debug("{}: no more sources for schema context", id);
 472                 resultFuture.setException(new EmptySchemaContextException(id + ": No more sources for schema context"));
 473             }
 474         }
 475
 476         private List<SourceIdentifier> filterMissingSources(final Collection<SourceIdentifier> origSources) {
 477             return origSources.parallelStream().filter(sourceIdentifier -> {
 478                 try {
 479                     schemaRepository.getSchemaSource(sourceIdentifier, YangTextSchemaSource.class).get();
 480                     return false;
 481                 } catch (InterruptedException | ExecutionException e) {
 482                     return true;
 483                 }
 484             }).collect(Collectors.toList());
 485         }
 486
 487         private List<SourceIdentifier> handleMissingSchemaSourceException(
 488                 final MissingSchemaSourceException exception) {
 489             // In case source missing, try without it
 490             final SourceIdentifier missingSource = exception.getSourceId();
 491             LOG.warn("{}: Unable to build schema context, missing source {}, will reattempt without it",
 492                 id, missingSource);
 493             LOG.debug("{}: Unable to build schema context, missing source {}, will reattempt without it",
 494                 id, missingSource, exception);
 495             final Collection<QName> qNameOfMissingSource =
 496                 getQNameFromSourceIdentifiers(Sets.newHashSet(missingSource));
 497             if (!qNameOfMissingSource.isEmpty()) {
 498                 capabilities.addUnresolvedCapabilities(
 499                         qNameOfMissingSource, UnavailableCapability.FailureReason.MissingSource);
 500             }
 501             return stripUnavailableSource(missingSource);
 502         }
 503
 504         private Collection<SourceIdentifier> handleSchemaResolutionException(
 505                 final SchemaResolutionException resolutionException) {
 506             // In case resolution error, try only with resolved sources
 507             // There are two options why schema resolution exception occurred : unsatisfied imports or flawed model
 508             // FIXME Do we really have assurance that these two cases cannot happen at once?
 509             if (resolutionException.getFailedSource() != null) {
 510                 // flawed model - exclude it
 511                 final SourceIdentifier failedSourceId = resolutionException.getFailedSource();
 512                 LOG.warn("{}: Unable to build schema context, failed to resolve source {}, will reattempt without it",
 513                     id, failedSourceId);
 514                 LOG.warn("{}: Unable to build schema context, failed to resolve source {}, will reattempt without it",
 515                     id, failedSourceId, resolutionException);
 516                 capabilities.addUnresolvedCapabilities(
 517                         getQNameFromSourceIdentifiers(Collections.singleton(failedSourceId)),
 518                         UnavailableCapability.FailureReason.UnableToResolve);
 519                 return stripUnavailableSource(resolutionException.getFailedSource());
 520             }
 521             // unsatisfied imports
 522             final Set<SourceIdentifier> unresolvedSources = resolutionException.getUnsatisfiedImports().keySet();
 523             capabilities.addUnresolvedCapabilities(getQNameFromSourceIdentifiers(unresolvedSources),
 524                 UnavailableCapability.FailureReason.UnableToResolve);
 525             LOG.warn("{}: Unable to build schema context, unsatisfied imports {}, will reattempt with resolved only",
 526                 id, resolutionException.getUnsatisfiedImports());
 527             LOG.debug("{}: Unable to build schema context, unsatisfied imports {}, will reattempt with resolved only",
 528                 id, resolutionException.getUnsatisfiedImports(), resolutionException);
 529             return resolutionException.getResolvedSources();
 530         }
 531
 532         private List<SourceIdentifier> stripUnavailableSource(final SourceIdentifier sourceIdToRemove) {
 533             final var tmp = new ArrayList<>(requiredSources);
 534             checkState(tmp.remove(sourceIdToRemove), "%s: Trying to remove %s from %s failed", id, sourceIdToRemove,
 535                 requiredSources);
 536             return tmp;
 537         }
 538
 539         private Collection<QName> getQNameFromSourceIdentifiers(final Collection<SourceIdentifier> identifiers) {
 540             final Collection<QName> qNames = Collections2.transform(identifiers, this::getQNameFromSourceIdentifier);
 541
 542             if (qNames.isEmpty()) {
 543                 LOG.debug("{}: Unable to map any source identifiers to a capability reported by device : {}", id,
 544                         identifiers);
 545             }
 546             return Collections2.filter(qNames, Predicates.notNull());
 547         }
 548
 549         private QName getQNameFromSourceIdentifier(final SourceIdentifier identifier) {
 550             // Required sources are all required and provided merged in DeviceSourcesResolver
 551             for (final QName qname : deviceSources.getRequiredSourcesQName()) {
 552                 if (!qname.getLocalName().equals(identifier.name().getLocalName())) {
 553                     continue;
 554                 }
 555
 556                 if (Objects.equals(identifier.revision(), qname.getRevision().orElse(null))) {
 557                     return qname;
 558                 }
 559             }
 560             LOG.warn("Unable to map identifier to a devices reported capability: {} Available: {}",identifier,
 561                     deviceSources.getRequiredSourcesQName());
 562             // return null since we cannot find the QName,
 563             // this capability will be removed from required sources and not reported as unresolved-capability
 564             return null;
 565         }
 566     }
 567 }