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.PreBoronShardDataTreeSnapshot;
  59 import org.opendaylight.controller.cluster.raft.ReplicatedLogEntry;
  60 import org.opendaylight.controller.cluster.raft.Snapshot;
  61 import org.opendaylight.controller.cluster.raft.TestActorFactory;
  62 import org.opendaylight.controller.cluster.raft.utils.InMemoryJournal;
  63 import org.opendaylight.controller.cluster.raft.utils.InMemorySnapshotStore;
  64 import org.opendaylight.controller.md.cluster.datastore.model.CarsModel;
  65 import org.opendaylight.controller.md.cluster.datastore.model.TestModel;
  66 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  67 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
  68 import org.opendaylight.yangtools.yang.data.api.schema.DataContainerChild;
  69 import org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode;
  70 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  71 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTree;
  72 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  73 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidateNode;
  74 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidateTip;
  75 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeModification;
  76 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataValidationFailedException;
  77 import org.opendaylight.yangtools.yang.data.api.schema.tree.ModificationType;
  78 import org.opendaylight.yangtools.yang.data.api.schema.tree.TipProducingDataTree;
  79 import org.opendaylight.yangtools.yang.data.api.schema.tree.TreeType;
  80 import org.opendaylight.yangtools.yang.data.impl.schema.ImmutableNodes;
  81 import org.opendaylight.yangtools.yang.data.impl.schema.tree.InMemoryDataTreeFactory;
  82 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  83 import scala.concurrent.Await;
  84 import scala.concurrent.Future;
  85 import scala.concurrent.duration.Duration;
  86
  87 /**
  88  * Abstract base for shard unit tests.
  89  *
  90  * @author Thomas Pantelis
  91  */
  92 public abstract class AbstractShardTest extends AbstractActorTest {
  93     protected static final SchemaContext SCHEMA_CONTEXT = TestModel.createTestContext();
  94
  95     private static final AtomicInteger NEXT_SHARD_NUM = new AtomicInteger();
  96
  97     protected final ShardIdentifier shardID = ShardIdentifier.create("inventory", MemberName.forName("member-1"),
  98         "config" + NEXT_SHARD_NUM.getAndIncrement());
  99
 100     protected final Builder dataStoreContextBuilder = DatastoreContext.newBuilder()
 101             .shardJournalRecoveryLogBatchSize(3).shardSnapshotBatchCount(5000).shardHeartbeatIntervalInMillis(100);
 102
 103     protected final TestActorFactory actorFactory = new TestActorFactory(getSystem());
 104
 105     @Before
 106     public void setUp() {
 107         InMemorySnapshotStore.clear();
 108         InMemoryJournal.clear();
 109     }
 110
 111     @After
 112     public void tearDown() {
 113         InMemorySnapshotStore.clear();
 114         InMemoryJournal.clear();
 115         actorFactory.close();
 116     }
 117
 118     protected DatastoreContext newDatastoreContext() {
 119         return dataStoreContextBuilder.build();
 120     }
 121
 122     protected Props newShardProps() {
 123         return newShardBuilder().props();
 124     }
 125
 126     protected Shard.Builder newShardBuilder() {
 127         return Shard.builder().id(shardID).datastoreContext(newDatastoreContext()).schemaContext(SCHEMA_CONTEXT);
 128     }
 129
 130     protected void testRecovery(final Set<Integer> listEntryKeys) throws Exception {
 131         // Create the actor and wait for recovery complete.
 132
 133         final int nListEntries = listEntryKeys.size();
 134
 135         final CountDownLatch recoveryComplete = new CountDownLatch(1);
 136
 137         final Creator<Shard> creator = () -> new Shard(newShardBuilder()) {
 138             @Override
 139             protected void onRecoveryComplete() {
 140                 try {
 141                     super.onRecoveryComplete();
 142                 } finally {
 143                     recoveryComplete.countDown();
 144                 }
 145             }
 146         };
 147
 148         final TestActorRef<Shard> shard = TestActorRef.create(getSystem(),
 149                 Props.create(new DelegatingShardCreator(creator)).withDispatcher(Dispatchers.DefaultDispatcherId()),
 150                 "testRecovery");
 151
 152         assertEquals("Recovery complete", true, recoveryComplete.await(5, TimeUnit.SECONDS));
 153
 154         // Verify data in the data store.
 155
 156         final NormalizedNode<?, ?> outerList = readStore(shard, TestModel.OUTER_LIST_PATH);
 157         assertNotNull(TestModel.OUTER_LIST_QNAME.getLocalName() + " not found", outerList);
 158         assertTrue(TestModel.OUTER_LIST_QNAME.getLocalName() + " value is not Iterable",
 159                 outerList.getValue() instanceof Iterable);
 160         for (final Object entry: (Iterable<?>) outerList.getValue()) {
 161             assertTrue(TestModel.OUTER_LIST_QNAME.getLocalName() + " entry is not MapEntryNode",
 162                     entry instanceof MapEntryNode);
 163             final MapEntryNode mapEntry = (MapEntryNode)entry;
 164             final Optional<DataContainerChild<? extends PathArgument, ?>> idLeaf =
 165                     mapEntry.getChild(new YangInstanceIdentifier.NodeIdentifier(TestModel.ID_QNAME));
 166             assertTrue("Missing leaf " + TestModel.ID_QNAME.getLocalName(), idLeaf.isPresent());
 167             final Object value = idLeaf.get().getValue();
 168             assertTrue("Unexpected value for leaf " + TestModel.ID_QNAME.getLocalName() + ": " + value,
 169                     listEntryKeys.remove(value));
 170         }
 171
 172         if (!listEntryKeys.isEmpty()) {
 173             fail("Missing " + TestModel.OUTER_LIST_QNAME.getLocalName() + " entries with keys: " + listEntryKeys);
 174         }
 175
 176         assertEquals("Last log index", nListEntries,
 177                 shard.underlyingActor().getShardMBean().getLastLogIndex());
 178         assertEquals("Commit index", nListEntries,
 179                 shard.underlyingActor().getShardMBean().getCommitIndex());
 180         assertEquals("Last applied", nListEntries,
 181                 shard.underlyingActor().getShardMBean().getLastApplied());
 182
 183         shard.tell(PoisonPill.getInstance(), ActorRef.noSender());
 184     }
 185
 186     protected void verifyLastApplied(final TestActorRef<Shard> shard, final long expectedValue) {
 187         long lastApplied = -1;
 188         for (int i = 0; i < 20 * 5; i++) {
 189             lastApplied = shard.underlyingActor().getShardMBean().getLastApplied();
 190             if (lastApplied == expectedValue) {
 191                 return;
 192             }
 193             Uninterruptibles.sleepUninterruptibly(50, TimeUnit.MILLISECONDS);
 194         }
 195
 196         Assert.fail(String.format("Expected last applied: %d, Actual: %d", expectedValue, lastApplied));
 197     }
 198
 199     protected TipProducingDataTree createDelegatingMockDataTree() throws Exception {
 200         TipProducingDataTree actual = InMemoryDataTreeFactory.getInstance().create(TreeType.CONFIGURATION);
 201         final TipProducingDataTree mock = mock(TipProducingDataTree.class);
 202
 203         doAnswer(invocation -> {
 204             actual.validate(invocation.getArgumentAt(0, DataTreeModification.class));
 205             return null;
 206         }).when(mock).validate(any(DataTreeModification.class));
 207
 208         doAnswer(invocation -> {
 209             return actual.prepare(invocation.getArgumentAt(0, DataTreeModification.class));
 210         }).when(mock).prepare(any(DataTreeModification.class));
 211
 212         doAnswer(invocation -> {
 213             actual.commit(invocation.getArgumentAt(0, DataTreeCandidate.class));
 214             return null;
 215         }).when(mock).commit(any(DataTreeCandidate.class));
 216
 217         doAnswer(invocation -> {
 218             actual.setSchemaContext(invocation.getArgumentAt(0, SchemaContext.class));
 219             return null;
 220         }).when(mock).setSchemaContext(any(SchemaContext.class));
 221
 222         doAnswer(invocation -> {
 223             return actual.takeSnapshot();
 224         }).when(mock).takeSnapshot();
 225
 226         doAnswer(invocation -> {
 227             return actual.getRootPath();
 228         }).when(mock).getRootPath();
 229
 230         return mock;
 231     }
 232
 233     protected ShardDataTreeCohort mockShardDataTreeCohort() {
 234         ShardDataTreeCohort cohort = mock(ShardDataTreeCohort.class);
 235         DataTreeCandidate candidate = mockCandidate("candidate");
 236         successfulCanCommit(cohort);
 237         successfulPreCommit(cohort, candidate);
 238         successfulCommit(cohort);
 239         doReturn(candidate).when(cohort).getCandidate();
 240         return cohort;
 241     }
 242
 243     protected Map<TransactionIdentifier, CapturingShardDataTreeCohort> setupCohortDecorator(final Shard shard,
 244             final TransactionIdentifier... transactionIDs) {
 245         final Map<TransactionIdentifier, CapturingShardDataTreeCohort> cohortMap = new HashMap<>();
 246         for (TransactionIdentifier id: transactionIDs) {
 247             cohortMap.put(id, new CapturingShardDataTreeCohort());
 248         }
 249
 250         shard.getCommitCoordinator().setCohortDecorator((transactionID, actual) -> {
 251             CapturingShardDataTreeCohort cohort = cohortMap.get(transactionID);
 252             cohort.setDelegate(actual);
 253             return cohort;
 254         });
 255
 256         return cohortMap;
 257     }
 258
 259     protected BatchedModifications prepareBatchedModifications(final TransactionIdentifier transactionID,
 260                                                                final MutableCompositeModification modification) {
 261         return prepareBatchedModifications(transactionID, modification, false);
 262     }
 263
 264     protected static BatchedModifications prepareBatchedModifications(final TransactionIdentifier transactionID,
 265                                                              final MutableCompositeModification modification,
 266                                                              final boolean doCommitOnReady) {
 267         final BatchedModifications batchedModifications = new BatchedModifications(transactionID, CURRENT_VERSION);
 268         batchedModifications.addModification(modification);
 269         batchedModifications.setReady(true);
 270         batchedModifications.setDoCommitOnReady(doCommitOnReady);
 271         batchedModifications.setTotalMessagesSent(1);
 272         return batchedModifications;
 273     }
 274
 275     protected static BatchedModifications prepareBatchedModifications(final TransactionIdentifier transactionID,
 276             final YangInstanceIdentifier path, final NormalizedNode<?, ?> data, final boolean doCommitOnReady) {
 277         final MutableCompositeModification modification = new MutableCompositeModification();
 278         modification.addModification(new WriteModification(path, data));
 279         return prepareBatchedModifications(transactionID, modification, doCommitOnReady);
 280     }
 281
 282     protected static ForwardedReadyTransaction prepareForwardedReadyTransaction(final TestActorRef<Shard> shard,
 283             final TransactionIdentifier transactionID, final YangInstanceIdentifier path,
 284             final NormalizedNode<?, ?> data, final boolean doCommitOnReady) {
 285         ReadWriteShardDataTreeTransaction rwTx = shard.underlyingActor().getDataStore()
 286                 .newReadWriteTransaction(transactionID);
 287         rwTx.getSnapshot().write(path, data);
 288         return new ForwardedReadyTransaction(transactionID, CURRENT_VERSION, rwTx, doCommitOnReady);
 289     }
 290
 291     public static NormalizedNode<?,?> readStore(final TestActorRef<? extends Shard> shard,
 292             final YangInstanceIdentifier id) throws ExecutionException, InterruptedException {
 293         return shard.underlyingActor().getDataStore().readNode(id).orNull();
 294     }
 295
 296     public static NormalizedNode<?,?> readStore(final DataTree store, final YangInstanceIdentifier id) {
 297         return store.takeSnapshot().readNode(id).orNull();
 298     }
 299
 300     public void writeToStore(final TestActorRef<Shard> shard, final YangInstanceIdentifier id,
 301             final NormalizedNode<?,?> node) throws InterruptedException, ExecutionException {
 302         Future<Object> future = Patterns.ask(shard, newBatchedModifications(nextTransactionId(),
 303                 id, node, true, true, 1), new Timeout(5, TimeUnit.SECONDS));
 304         try {
 305             Await.ready(future, Duration.create(5, TimeUnit.SECONDS));
 306         } catch (TimeoutException e) {
 307             throw new ExecutionException(e);
 308         }
 309     }
 310
 311     public static void writeToStore(final ShardDataTree store, final YangInstanceIdentifier id,
 312             final NormalizedNode<?,?> node) throws Exception {
 313         BatchedModifications batched = newBatchedModifications(nextTransactionId(), id, node, true, true, 1);
 314         DataTreeModification modification = store.getDataTree().takeSnapshot().newModification();
 315         batched.apply(modification);
 316         store.notifyListeners(store.commit(modification));
 317     }
 318
 319     public static void writeToStore(final DataTree store, final YangInstanceIdentifier id,
 320             final NormalizedNode<?,?> node) throws DataValidationFailedException {
 321         final DataTreeModification transaction = store.takeSnapshot().newModification();
 322
 323         transaction.write(id, node);
 324         transaction.ready();
 325         store.validate(transaction);
 326         final DataTreeCandidate candidate = store.prepare(transaction);
 327         store.commit(candidate);
 328     }
 329
 330     public void mergeToStore(final ShardDataTree store, final YangInstanceIdentifier id,
 331             final NormalizedNode<?,?> node) throws Exception {
 332         final BatchedModifications batched = new BatchedModifications(nextTransactionId(), CURRENT_VERSION);
 333         batched.addModification(new MergeModification(id, node));
 334         batched.setReady(true);
 335         batched.setDoCommitOnReady(true);
 336         batched.setTotalMessagesSent(1);
 337
 338         DataTreeModification modification = store.getDataTree().takeSnapshot().newModification();
 339         batched.apply(modification);
 340         store.notifyListeners(store.commit(modification));
 341     }
 342
 343     DataTree setupInMemorySnapshotStore() throws DataValidationFailedException {
 344         final DataTree testStore = InMemoryDataTreeFactory.getInstance().create(TreeType.OPERATIONAL);
 345         testStore.setSchemaContext(SCHEMA_CONTEXT);
 346
 347         writeToStore(testStore, TestModel.TEST_PATH, ImmutableNodes.containerNode(TestModel.TEST_QNAME));
 348
 349         final NormalizedNode<?, ?> root = readStore(testStore, YangInstanceIdentifier.EMPTY);
 350
 351         InMemorySnapshotStore.addSnapshot(shardID.toString(), Snapshot.create(
 352                 new PreBoronShardDataTreeSnapshot(root).serialize(),
 353                 Collections.<ReplicatedLogEntry>emptyList(), 0, 1, -1, -1));
 354         return testStore;
 355     }
 356
 357     static CommitTransactionPayload payloadForModification(final DataTree source, final DataTreeModification mod,
 358             final TransactionIdentifier transactionId) throws DataValidationFailedException, IOException {
 359         source.validate(mod);
 360         final DataTreeCandidate candidate = source.prepare(mod);
 361         source.commit(candidate);
 362         return CommitTransactionPayload.create(transactionId, candidate);
 363     }
 364
 365     static BatchedModifications newBatchedModifications(final TransactionIdentifier transactionID,
 366             final YangInstanceIdentifier path, final NormalizedNode<?, ?> data, final boolean ready,
 367             final boolean doCommitOnReady, final int messagesSent) {
 368         final BatchedModifications batched = new BatchedModifications(transactionID, CURRENT_VERSION);
 369         batched.addModification(new WriteModification(path, data));
 370         batched.setReady(ready);
 371         batched.setDoCommitOnReady(doCommitOnReady);
 372         batched.setTotalMessagesSent(messagesSent);
 373         return batched;
 374     }
 375
 376     @SuppressWarnings("unchecked")
 377     static void verifyOuterListEntry(final TestActorRef<Shard> shard, final Object expIDValue) throws Exception {
 378         final NormalizedNode<?, ?> outerList = readStore(shard, TestModel.OUTER_LIST_PATH);
 379         assertNotNull(TestModel.OUTER_LIST_QNAME.getLocalName() + " not found", outerList);
 380         assertTrue(TestModel.OUTER_LIST_QNAME.getLocalName() + " value is not Iterable",
 381                 outerList.getValue() instanceof Iterable);
 382         final Object entry = ((Iterable<Object>)outerList.getValue()).iterator().next();
 383         assertTrue(TestModel.OUTER_LIST_QNAME.getLocalName() + " entry is not MapEntryNode",
 384                 entry instanceof MapEntryNode);
 385         final MapEntryNode mapEntry = (MapEntryNode)entry;
 386         final Optional<DataContainerChild<? extends PathArgument, ?>> idLeaf =
 387                 mapEntry.getChild(new YangInstanceIdentifier.NodeIdentifier(TestModel.ID_QNAME));
 388         assertTrue("Missing leaf " + TestModel.ID_QNAME.getLocalName(), idLeaf.isPresent());
 389         assertEquals(TestModel.ID_QNAME.getLocalName() + " value", expIDValue, idLeaf.get().getValue());
 390     }
 391
 392     public static DataTreeCandidateTip mockCandidate(final String name) {
 393         final DataTreeCandidateTip mockCandidate = mock(DataTreeCandidateTip.class, name);
 394         final DataTreeCandidateNode mockCandidateNode = mock(DataTreeCandidateNode.class, name + "-node");
 395         doReturn(ModificationType.WRITE).when(mockCandidateNode).getModificationType();
 396         doReturn(Optional.of(ImmutableNodes.containerNode(CarsModel.CARS_QNAME)))
 397                 .when(mockCandidateNode).getDataAfter();
 398         doReturn(CarsModel.BASE_PATH).when(mockCandidate).getRootPath();
 399         doReturn(mockCandidateNode).when(mockCandidate).getRootNode();
 400         return mockCandidate;
 401     }
 402
 403     static DataTreeCandidateTip mockUnmodifiedCandidate(final String name) {
 404         final DataTreeCandidateTip mockCandidate = mock(DataTreeCandidateTip.class, name);
 405         final DataTreeCandidateNode mockCandidateNode = mock(DataTreeCandidateNode.class, name + "-node");
 406         doReturn(ModificationType.UNMODIFIED).when(mockCandidateNode).getModificationType();
 407         doReturn(YangInstanceIdentifier.EMPTY).when(mockCandidate).getRootPath();
 408         doReturn(mockCandidateNode).when(mockCandidate).getRootNode();
 409         return mockCandidate;
 410     }
 411
 412     static void commitTransaction(final DataTree store, final DataTreeModification modification)
 413             throws DataValidationFailedException {
 414         modification.ready();
 415         store.validate(modification);
 416         store.commit(store.prepare(modification));
 417     }
 418
 419     @SuppressWarnings("serial")
 420     public static final class DelegatingShardCreator implements Creator<Shard> {
 421         private final Creator<Shard> delegate;
 422
 423         DelegatingShardCreator(final Creator<Shard> delegate) {
 424             this.delegate = delegate;
 425         }
 426
 427         @Override
 428         public Shard create() throws Exception {
 429             return delegate.create();
 430         }
 431     }
 432
 433     public static class CapturingShardDataTreeCohort extends ShardDataTreeCohort {
 434         private volatile ShardDataTreeCohort delegate;
 435         private FutureCallback<Void> canCommit;
 436         private FutureCallback<DataTreeCandidate> preCommit;
 437         private FutureCallback<UnsignedLong> commit;
 438
 439         public void setDelegate(final ShardDataTreeCohort delegate) {
 440             this.delegate = delegate;
 441         }
 442
 443         public FutureCallback<Void> getCanCommit() {
 444             assertNotNull("canCommit was not invoked", canCommit);
 445             return canCommit;
 446         }
 447
 448         public FutureCallback<DataTreeCandidate> getPreCommit() {
 449             assertNotNull("preCommit was not invoked", preCommit);
 450             return preCommit;
 451         }
 452
 453         public FutureCallback<UnsignedLong> getCommit() {
 454             assertNotNull("commit was not invoked", commit);
 455             return commit;
 456         }
 457
 458         @Override
 459         public TransactionIdentifier getIdentifier() {
 460             return delegate.getIdentifier();
 461         }
 462
 463         @Override
 464         DataTreeCandidateTip getCandidate() {
 465             return delegate.getCandidate();
 466         }
 467
 468         @Override
 469         DataTreeModification getDataTreeModification() {
 470             return delegate.getDataTreeModification();
 471         }
 472
 473         @Override
 474         public void canCommit(final FutureCallback<Void> callback) {
 475             canCommit = mockFutureCallback(callback);
 476             delegate.canCommit(canCommit);
 477         }
 478
 479         @Override
 480         public void preCommit(final FutureCallback<DataTreeCandidate> callback) {
 481             preCommit = mockFutureCallback(callback);
 482             delegate.preCommit(preCommit);
 483         }
 484
 485         @Override
 486         public void commit(final FutureCallback<UnsignedLong> callback) {
 487             commit = mockFutureCallback(callback);
 488             delegate.commit(commit);
 489         }
 490
 491         @SuppressWarnings("unchecked")
 492         private <T> FutureCallback<T> mockFutureCallback(final FutureCallback<T> actual ) {
 493             FutureCallback<T> mock = mock(FutureCallback.class);
 494             doAnswer(invocation -> {
 495                 actual.onFailure(invocation.getArgumentAt(0, Throwable.class));
 496                 return null;
 497             }).when(mock).onFailure(any(Throwable.class));
 498
 499             doAnswer(invocation -> {
 500                 actual.onSuccess((T) invocation.getArgumentAt(0, Throwable.class));
 501                 return null;
 502             }).when(mock).onSuccess((T) any(Object.class));
 503
 504             return mock;
 505         }
 506
 507         @Override
 508         public void abort(final FutureCallback<Void> callback) {
 509             delegate.abort(callback);
 510         }
 511
 512         @Override
 513         public boolean isFailed() {
 514             return delegate.isFailed();
 515         }
 516
 517         @Override
 518         public State getState() {
 519             return delegate.getState();
 520         }
 521     }
 522 }