opendaylight/md-sal/sal-distributed-datastore/src/test/java/org/opendaylight/controller/cluster/datastore/AbstractShardTest.java

   1 /*
   2  * Copyright (c) 2015 Brocade Communications 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.controller.cluster.datastore;
   9
  10 import static org.junit.Assert.assertEquals;
  11 import static org.junit.Assert.assertNotNull;
  12 import static org.junit.Assert.assertTrue;
  13 import static org.junit.Assert.fail;
  14 import static org.mockito.Matchers.any;
  15 import static org.mockito.Mockito.doAnswer;
  16 import static org.mockito.Mockito.doReturn;
  17 import static org.mockito.Mockito.mock;
  18 import static org.opendaylight.controller.cluster.datastore.DataStoreVersions.CURRENT_VERSION;
  19 import static org.opendaylight.controller.cluster.datastore.ShardDataTreeMocking.successfulCanCommit;
  20 import static org.opendaylight.controller.cluster.datastore.ShardDataTreeMocking.successfulCommit;
  21 import static org.opendaylight.controller.cluster.datastore.ShardDataTreeMocking.successfulPreCommit;
  22
  23 import akka.actor.ActorRef;
  24 import akka.actor.PoisonPill;
  25 import akka.actor.Props;
  26 import akka.dispatch.Dispatchers;
  27 import akka.japi.Creator;
  28 import akka.pattern.Patterns;
  29 import akka.testkit.TestActorRef;
  30 import akka.util.Timeout;
  31 import com.google.common.base.Optional;
  32 import com.google.common.primitives.UnsignedLong;
  33 import com.google.common.util.concurrent.FutureCallback;
  34 import com.google.common.util.concurrent.Uninterruptibles;
  35 import java.io.IOException;
  36 import java.util.Collections;
  37 import java.util.HashMap;
  38 import java.util.Map;
  39 import java.util.Set;
  40 import java.util.concurrent.CountDownLatch;
  41 import java.util.concurrent.ExecutionException;
  42 import java.util.concurrent.TimeUnit;
  43 import java.util.concurrent.TimeoutException;
  44 import java.util.concurrent.atomic.AtomicInteger;
  45 import org.junit.After;
  46 import org.junit.Assert;
  47 import org.junit.Before;
  48 import org.opendaylight.controller.cluster.access.concepts.MemberName;
  49 import org.opendaylight.controller.cluster.access.concepts.TransactionIdentifier;
  50 import org.opendaylight.controller.cluster.datastore.DatastoreContext.Builder;
  51 import org.opendaylight.controller.cluster.datastore.identifiers.ShardIdentifier;
  52 import org.opendaylight.controller.cluster.datastore.messages.BatchedModifications;
  53 import org.opendaylight.controller.cluster.datastore.messages.ForwardedReadyTransaction;
  54 import org.opendaylight.controller.cluster.datastore.modification.MergeModification;
  55 import org.opendaylight.controller.cluster.datastore.modification.MutableCompositeModification;
  56 import org.opendaylight.controller.cluster.datastore.modification.WriteModification;
  57 import org.opendaylight.controller.cluster.datastore.persisted.CommitTransactionPayload;
  58 import org.opendaylight.controller.cluster.datastore.persisted.MetadataShardDataTreeSnapshot;
  59 import org.opendaylight.controller.cluster.datastore.persisted.ShardSnapshotState;
  60 import org.opendaylight.controller.cluster.raft.ReplicatedLogEntry;
  61 import org.opendaylight.controller.cluster.raft.TestActorFactory;
  62 import org.opendaylight.controller.cluster.raft.persisted.Snapshot;
  63 import org.opendaylight.controller.cluster.raft.utils.InMemoryJournal;
  64 import org.opendaylight.controller.cluster.raft.utils.InMemorySnapshotStore;
  65 import org.opendaylight.controller.md.cluster.datastore.model.CarsModel;
  66 import org.opendaylight.controller.md.cluster.datastore.model.TestModel;
  67 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  68 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
  69 import org.opendaylight.yangtools.yang.data.api.schema.DataContainerChild;
  70 import org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode;
  71 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  72 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTree;
  73 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  74 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidateNode;
  75 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidateTip;
  76 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeModification;
  77 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataValidationFailedException;
  78 import org.opendaylight.yangtools.yang.data.api.schema.tree.ModificationType;
  79 import org.opendaylight.yangtools.yang.data.api.schema.tree.TipProducingDataTree;
  80 import org.opendaylight.yangtools.yang.data.api.schema.tree.TreeType;
  81 import org.opendaylight.yangtools.yang.data.impl.schema.ImmutableNodes;
  82 import org.opendaylight.yangtools.yang.data.impl.schema.tree.InMemoryDataTreeFactory;
  83 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  84 import scala.concurrent.Await;
  85 import scala.concurrent.Future;
  86 import scala.concurrent.duration.Duration;
  87
  88 /**
  89  * Abstract base for shard unit tests.
  90  *
  91  * @author Thomas Pantelis
  92  */
  93 public abstract class AbstractShardTest extends AbstractActorTest {
  94     protected static final SchemaContext SCHEMA_CONTEXT = TestModel.createTestContext();
  95
  96     private static final AtomicInteger NEXT_SHARD_NUM = new AtomicInteger();
  97
  98     protected final ShardIdentifier shardID = ShardIdentifier.create("inventory", MemberName.forName("member-1"),
  99         "config" + NEXT_SHARD_NUM.getAndIncrement());
 100
 101     protected final Builder dataStoreContextBuilder = DatastoreContext.newBuilder()
 102             .shardJournalRecoveryLogBatchSize(3).shardSnapshotBatchCount(5000).shardHeartbeatIntervalInMillis(100);
 103
 104     protected final TestActorFactory actorFactory = new TestActorFactory(getSystem());
 105
 106     @Before
 107     public void setUp() {
 108         InMemorySnapshotStore.clear();
 109         InMemoryJournal.clear();
 110     }
 111
 112     @After
 113     public void tearDown() {
 114         InMemorySnapshotStore.clear();
 115         InMemoryJournal.clear();
 116         actorFactory.close();
 117     }
 118
 119     protected DatastoreContext newDatastoreContext() {
 120         return dataStoreContextBuilder.build();
 121     }
 122
 123     protected Props newShardProps() {
 124         return newShardBuilder().props();
 125     }
 126
 127     protected Shard.Builder newShardBuilder() {
 128         return Shard.builder().id(shardID).datastoreContext(newDatastoreContext())
 129             .schemaContextProvider(() -> SCHEMA_CONTEXT);
 130     }
 131
 132     protected void testRecovery(final Set<Integer> listEntryKeys) throws Exception {
 133         // Create the actor and wait for recovery complete.
 134
 135         final int nListEntries = listEntryKeys.size();
 136
 137         final CountDownLatch recoveryComplete = new CountDownLatch(1);
 138
 139         final Creator<Shard> creator = () -> new Shard(newShardBuilder()) {
 140             @Override
 141             protected void onRecoveryComplete() {
 142                 try {
 143                     super.onRecoveryComplete();
 144                 } finally {
 145                     recoveryComplete.countDown();
 146                 }
 147             }
 148         };
 149
 150         final TestActorRef<Shard> shard = TestActorRef.create(getSystem(),
 151                 Props.create(new DelegatingShardCreator(creator)).withDispatcher(Dispatchers.DefaultDispatcherId()),
 152                 "testRecovery");
 153
 154         assertEquals("Recovery complete", true, recoveryComplete.await(5, TimeUnit.SECONDS));
 155
 156         // Verify data in the data store.
 157
 158         final NormalizedNode<?, ?> outerList = readStore(shard, TestModel.OUTER_LIST_PATH);
 159         assertNotNull(TestModel.OUTER_LIST_QNAME.getLocalName() + " not found", outerList);
 160         assertTrue(TestModel.OUTER_LIST_QNAME.getLocalName() + " value is not Iterable",
 161                 outerList.getValue() instanceof Iterable);
 162         for (final Object entry: (Iterable<?>) outerList.getValue()) {
 163             assertTrue(TestModel.OUTER_LIST_QNAME.getLocalName() + " entry is not MapEntryNode",
 164                     entry instanceof MapEntryNode);
 165             final MapEntryNode mapEntry = (MapEntryNode)entry;
 166             final Optional<DataContainerChild<? extends PathArgument, ?>> idLeaf =
 167                     mapEntry.getChild(new YangInstanceIdentifier.NodeIdentifier(TestModel.ID_QNAME));
 168             assertTrue("Missing leaf " + TestModel.ID_QNAME.getLocalName(), idLeaf.isPresent());
 169             final Object value = idLeaf.get().getValue();
 170             assertTrue("Unexpected value for leaf " + TestModel.ID_QNAME.getLocalName() + ": " + value,
 171                     listEntryKeys.remove(value));
 172         }
 173
 174         if (!listEntryKeys.isEmpty()) {
 175             fail("Missing " + TestModel.OUTER_LIST_QNAME.getLocalName() + " entries with keys: " + listEntryKeys);
 176         }
 177
 178         assertEquals("Last log index", nListEntries,
 179                 shard.underlyingActor().getShardMBean().getLastLogIndex());
 180         assertEquals("Commit index", nListEntries,
 181                 shard.underlyingActor().getShardMBean().getCommitIndex());
 182         assertEquals("Last applied", nListEntries,
 183                 shard.underlyingActor().getShardMBean().getLastApplied());
 184
 185         shard.tell(PoisonPill.getInstance(), ActorRef.noSender());
 186     }
 187
 188     protected void verifyLastApplied(final TestActorRef<Shard> shard, final long expectedValue) {
 189         long lastApplied = -1;
 190         for (int i = 0; i < 20 * 5; i++) {
 191             lastApplied = shard.underlyingActor().getShardMBean().getLastApplied();
 192             if (lastApplied == expectedValue) {
 193                 return;
 194             }
 195             Uninterruptibles.sleepUninterruptibly(50, TimeUnit.MILLISECONDS);
 196         }
 197
 198         Assert.fail(String.format("Expected last applied: %d, Actual: %d", expectedValue, lastApplied));
 199     }
 200
 201     protected TipProducingDataTree createDelegatingMockDataTree() throws Exception {
 202         TipProducingDataTree actual = InMemoryDataTreeFactory.getInstance().create(TreeType.CONFIGURATION);
 203         final TipProducingDataTree mock = mock(TipProducingDataTree.class);
 204
 205         doAnswer(invocation -> {
 206             actual.validate(invocation.getArgumentAt(0, DataTreeModification.class));
 207             return null;
 208         }).when(mock).validate(any(DataTreeModification.class));
 209
 210         doAnswer(invocation -> actual.prepare(invocation.getArgumentAt(0, DataTreeModification.class))).when(
 211                 mock).prepare(any(DataTreeModification.class));
 212
 213         doAnswer(invocation -> {
 214             actual.commit(invocation.getArgumentAt(0, DataTreeCandidate.class));
 215             return null;
 216         }).when(mock).commit(any(DataTreeCandidate.class));
 217
 218         doAnswer(invocation -> {
 219             actual.setSchemaContext(invocation.getArgumentAt(0, SchemaContext.class));
 220             return null;
 221         }).when(mock).setSchemaContext(any(SchemaContext.class));
 222
 223         doAnswer(invocation -> actual.takeSnapshot()).when(mock).takeSnapshot();
 224
 225         doAnswer(invocation -> actual.getRootPath()).when(mock).getRootPath();
 226
 227         return mock;
 228     }
 229
 230     protected ShardDataTreeCohort mockShardDataTreeCohort() {
 231         ShardDataTreeCohort cohort = mock(ShardDataTreeCohort.class);
 232         DataTreeCandidate candidate = mockCandidate("candidate");
 233         successfulCanCommit(cohort);
 234         successfulPreCommit(cohort, candidate);
 235         successfulCommit(cohort);
 236         doReturn(candidate).when(cohort).getCandidate();
 237         return cohort;
 238     }
 239
 240     protected Map<TransactionIdentifier, CapturingShardDataTreeCohort> setupCohortDecorator(final Shard shard,
 241             final TransactionIdentifier... transactionIDs) {
 242         final Map<TransactionIdentifier, CapturingShardDataTreeCohort> cohortMap = new HashMap<>();
 243         for (TransactionIdentifier id: transactionIDs) {
 244             cohortMap.put(id, new CapturingShardDataTreeCohort());
 245         }
 246
 247         shard.getCommitCoordinator().setCohortDecorator((transactionID, actual) -> {
 248             CapturingShardDataTreeCohort cohort = cohortMap.get(transactionID);
 249             cohort.setDelegate(actual);
 250             return cohort;
 251         });
 252
 253         return cohortMap;
 254     }
 255
 256     protected BatchedModifications prepareBatchedModifications(final TransactionIdentifier transactionID,
 257                                                                final MutableCompositeModification modification) {
 258         return prepareBatchedModifications(transactionID, modification, false);
 259     }
 260
 261     protected static BatchedModifications prepareBatchedModifications(final TransactionIdentifier transactionID,
 262                                                              final MutableCompositeModification modification,
 263                                                              final boolean doCommitOnReady) {
 264         final BatchedModifications batchedModifications = new BatchedModifications(transactionID, CURRENT_VERSION);
 265         batchedModifications.addModification(modification);
 266         batchedModifications.setReady(true);
 267         batchedModifications.setDoCommitOnReady(doCommitOnReady);
 268         batchedModifications.setTotalMessagesSent(1);
 269         return batchedModifications;
 270     }
 271
 272     protected static BatchedModifications prepareBatchedModifications(final TransactionIdentifier transactionID,
 273             final YangInstanceIdentifier path, final NormalizedNode<?, ?> data, final boolean doCommitOnReady) {
 274         final MutableCompositeModification modification = new MutableCompositeModification();
 275         modification.addModification(new WriteModification(path, data));
 276         return prepareBatchedModifications(transactionID, modification, doCommitOnReady);
 277     }
 278
 279     protected static ForwardedReadyTransaction prepareForwardedReadyTransaction(final TestActorRef<Shard> shard,
 280             final TransactionIdentifier transactionID, final YangInstanceIdentifier path,
 281             final NormalizedNode<?, ?> data, final boolean doCommitOnReady) {
 282         ReadWriteShardDataTreeTransaction rwTx = shard.underlyingActor().getDataStore()
 283                 .newReadWriteTransaction(transactionID);
 284         rwTx.getSnapshot().write(path, data);
 285         return new ForwardedReadyTransaction(transactionID, CURRENT_VERSION, rwTx, doCommitOnReady);
 286     }
 287
 288     public static NormalizedNode<?,?> readStore(final TestActorRef<? extends Shard> shard,
 289             final YangInstanceIdentifier id) throws ExecutionException, InterruptedException {
 290         return shard.underlyingActor().getDataStore().readNode(id).orNull();
 291     }
 292
 293     public static NormalizedNode<?,?> readStore(final DataTree store, final YangInstanceIdentifier id) {
 294         return store.takeSnapshot().readNode(id).orNull();
 295     }
 296
 297     public void writeToStore(final TestActorRef<Shard> shard, final YangInstanceIdentifier id,
 298             final NormalizedNode<?,?> node) throws InterruptedException, ExecutionException {
 299         Future<Object> future = Patterns.ask(shard, newBatchedModifications(nextTransactionId(),
 300                 id, node, true, true, 1), new Timeout(5, TimeUnit.SECONDS));
 301         try {
 302             Await.ready(future, Duration.create(5, TimeUnit.SECONDS));
 303         } catch (TimeoutException e) {
 304             throw new ExecutionException(e);
 305         }
 306     }
 307
 308     public static void writeToStore(final ShardDataTree store, final YangInstanceIdentifier id,
 309             final NormalizedNode<?,?> node) throws Exception {
 310         BatchedModifications batched = newBatchedModifications(nextTransactionId(), id, node, true, true, 1);
 311         DataTreeModification modification = store.getDataTree().takeSnapshot().newModification();
 312         batched.apply(modification);
 313         store.notifyListeners(store.commit(modification));
 314     }
 315
 316     public static void writeToStore(final DataTree store, final YangInstanceIdentifier id,
 317             final NormalizedNode<?,?> node) throws DataValidationFailedException {
 318         final DataTreeModification transaction = store.takeSnapshot().newModification();
 319
 320         transaction.write(id, node);
 321         transaction.ready();
 322         store.validate(transaction);
 323         final DataTreeCandidate candidate = store.prepare(transaction);
 324         store.commit(candidate);
 325     }
 326
 327     public void mergeToStore(final ShardDataTree store, final YangInstanceIdentifier id,
 328             final NormalizedNode<?,?> node) throws Exception {
 329         final BatchedModifications batched = new BatchedModifications(nextTransactionId(), CURRENT_VERSION);
 330         batched.addModification(new MergeModification(id, node));
 331         batched.setReady(true);
 332         batched.setDoCommitOnReady(true);
 333         batched.setTotalMessagesSent(1);
 334
 335         DataTreeModification modification = store.getDataTree().takeSnapshot().newModification();
 336         batched.apply(modification);
 337         store.notifyListeners(store.commit(modification));
 338     }
 339
 340     DataTree setupInMemorySnapshotStore() throws DataValidationFailedException {
 341         final DataTree testStore = InMemoryDataTreeFactory.getInstance().create(TreeType.OPERATIONAL);
 342         testStore.setSchemaContext(SCHEMA_CONTEXT);
 343
 344         writeToStore(testStore, TestModel.TEST_PATH, ImmutableNodes.containerNode(TestModel.TEST_QNAME));
 345
 346         final NormalizedNode<?, ?> root = readStore(testStore, YangInstanceIdentifier.EMPTY);
 347
 348         InMemorySnapshotStore.addSnapshot(shardID.toString(), Snapshot.create(
 349                 new ShardSnapshotState(new MetadataShardDataTreeSnapshot(root)),
 350                 Collections.<ReplicatedLogEntry>emptyList(), 0, 1, -1, -1, 1, null, null));
 351         return testStore;
 352     }
 353
 354     static CommitTransactionPayload payloadForModification(final DataTree source, final DataTreeModification mod,
 355             final TransactionIdentifier transactionId) throws DataValidationFailedException, IOException {
 356         source.validate(mod);
 357         final DataTreeCandidate candidate = source.prepare(mod);
 358         source.commit(candidate);
 359         return CommitTransactionPayload.create(transactionId, candidate);
 360     }
 361
 362     static BatchedModifications newBatchedModifications(final TransactionIdentifier transactionID,
 363             final YangInstanceIdentifier path, final NormalizedNode<?, ?> data, final boolean ready,
 364             final boolean doCommitOnReady, final int messagesSent) {
 365         final BatchedModifications batched = new BatchedModifications(transactionID, CURRENT_VERSION);
 366         batched.addModification(new WriteModification(path, data));
 367         batched.setReady(ready);
 368         batched.setDoCommitOnReady(doCommitOnReady);
 369         batched.setTotalMessagesSent(messagesSent);
 370         return batched;
 371     }
 372
 373     @SuppressWarnings("unchecked")
 374     static void verifyOuterListEntry(final TestActorRef<Shard> shard, final Object expIDValue) throws Exception {
 375         final NormalizedNode<?, ?> outerList = readStore(shard, TestModel.OUTER_LIST_PATH);
 376         assertNotNull(TestModel.OUTER_LIST_QNAME.getLocalName() + " not found", outerList);
 377         assertTrue(TestModel.OUTER_LIST_QNAME.getLocalName() + " value is not Iterable",
 378                 outerList.getValue() instanceof Iterable);
 379         final Object entry = ((Iterable<Object>)outerList.getValue()).iterator().next();
 380         assertTrue(TestModel.OUTER_LIST_QNAME.getLocalName() + " entry is not MapEntryNode",
 381                 entry instanceof MapEntryNode);
 382         final MapEntryNode mapEntry = (MapEntryNode)entry;
 383         final Optional<DataContainerChild<? extends PathArgument, ?>> idLeaf =
 384                 mapEntry.getChild(new YangInstanceIdentifier.NodeIdentifier(TestModel.ID_QNAME));
 385         assertTrue("Missing leaf " + TestModel.ID_QNAME.getLocalName(), idLeaf.isPresent());
 386         assertEquals(TestModel.ID_QNAME.getLocalName() + " value", expIDValue, idLeaf.get().getValue());
 387     }
 388
 389     public static DataTreeCandidateTip mockCandidate(final String name) {
 390         final DataTreeCandidateTip mockCandidate = mock(DataTreeCandidateTip.class, name);
 391         final DataTreeCandidateNode mockCandidateNode = mock(DataTreeCandidateNode.class, name + "-node");
 392         doReturn(ModificationType.WRITE).when(mockCandidateNode).getModificationType();
 393         doReturn(Optional.of(ImmutableNodes.containerNode(CarsModel.CARS_QNAME)))
 394                 .when(mockCandidateNode).getDataAfter();
 395         doReturn(CarsModel.BASE_PATH).when(mockCandidate).getRootPath();
 396         doReturn(mockCandidateNode).when(mockCandidate).getRootNode();
 397         return mockCandidate;
 398     }
 399
 400     static DataTreeCandidateTip mockUnmodifiedCandidate(final String name) {
 401         final DataTreeCandidateTip mockCandidate = mock(DataTreeCandidateTip.class, name);
 402         final DataTreeCandidateNode mockCandidateNode = mock(DataTreeCandidateNode.class, name + "-node");
 403         doReturn(ModificationType.UNMODIFIED).when(mockCandidateNode).getModificationType();
 404         doReturn(YangInstanceIdentifier.EMPTY).when(mockCandidate).getRootPath();
 405         doReturn(mockCandidateNode).when(mockCandidate).getRootNode();
 406         return mockCandidate;
 407     }
 408
 409     static void commitTransaction(final DataTree store, final DataTreeModification modification)
 410             throws DataValidationFailedException {
 411         modification.ready();
 412         store.validate(modification);
 413         store.commit(store.prepare(modification));
 414     }
 415
 416     @SuppressWarnings("serial")
 417     public static final class DelegatingShardCreator implements Creator<Shard> {
 418         private final Creator<Shard> delegate;
 419
 420         DelegatingShardCreator(final Creator<Shard> delegate) {
 421             this.delegate = delegate;
 422         }
 423
 424         @Override
 425         public Shard create() throws Exception {
 426             return delegate.create();
 427         }
 428     }
 429
 430     public static class CapturingShardDataTreeCohort extends ShardDataTreeCohort {
 431         private volatile ShardDataTreeCohort delegate;
 432         private FutureCallback<Void> canCommit;
 433         private FutureCallback<DataTreeCandidate> preCommit;
 434         private FutureCallback<UnsignedLong> commit;
 435
 436         public void setDelegate(final ShardDataTreeCohort delegate) {
 437             this.delegate = delegate;
 438         }
 439
 440         public FutureCallback<Void> getCanCommit() {
 441             assertNotNull("canCommit was not invoked", canCommit);
 442             return canCommit;
 443         }
 444
 445         public FutureCallback<DataTreeCandidate> getPreCommit() {
 446             assertNotNull("preCommit was not invoked", preCommit);
 447             return preCommit;
 448         }
 449
 450         public FutureCallback<UnsignedLong> getCommit() {
 451             assertNotNull("commit was not invoked", commit);
 452             return commit;
 453         }
 454
 455         @Override
 456         public TransactionIdentifier getIdentifier() {
 457             return delegate.getIdentifier();
 458         }
 459
 460         @Override
 461         DataTreeCandidateTip getCandidate() {
 462             return delegate.getCandidate();
 463         }
 464
 465         @Override
 466         DataTreeModification getDataTreeModification() {
 467             return delegate.getDataTreeModification();
 468         }
 469
 470         @Override
 471         public void canCommit(final FutureCallback<Void> callback) {
 472             canCommit = mockFutureCallback(callback);
 473             delegate.canCommit(canCommit);
 474         }
 475
 476         @Override
 477         public void preCommit(final FutureCallback<DataTreeCandidate> callback) {
 478             preCommit = mockFutureCallback(callback);
 479             delegate.preCommit(preCommit);
 480         }
 481
 482         @Override
 483         public void commit(final FutureCallback<UnsignedLong> callback) {
 484             commit = mockFutureCallback(callback);
 485             delegate.commit(commit);
 486         }
 487
 488         @SuppressWarnings("unchecked")
 489         private static <T> FutureCallback<T> mockFutureCallback(final FutureCallback<T> actual) {
 490             FutureCallback<T> mock = mock(FutureCallback.class);
 491             doAnswer(invocation -> {
 492                 actual.onFailure(invocation.getArgumentAt(0, Throwable.class));
 493                 return null;
 494             }).when(mock).onFailure(any(Throwable.class));
 495
 496             doAnswer(invocation -> {
 497                 actual.onSuccess((T) invocation.getArgumentAt(0, Throwable.class));
 498                 return null;
 499             }).when(mock).onSuccess((T) any(Object.class));
 500
 501             return mock;
 502         }
 503
 504         @Override
 505         public void abort(final FutureCallback<Void> callback) {
 506             delegate.abort(callback);
 507         }
 508
 509         @Override
 510         public boolean isFailed() {
 511             return delegate.isFailed();
 512         }
 513
 514         @Override
 515         public State getState() {
 516             return delegate.getState();
 517         }
 518     }
 519 }