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.ArgumentMatchers.any;
  15 import static org.mockito.ArgumentMatchers.nullable;
  16 import static org.mockito.Mockito.doAnswer;
  17 import static org.mockito.Mockito.doReturn;
  18 import static org.mockito.Mockito.mock;
  19 import static org.opendaylight.controller.cluster.datastore.DataStoreVersions.CURRENT_VERSION;
  20 import static org.opendaylight.controller.cluster.datastore.ShardDataTreeMocking.successfulCanCommit;
  21 import static org.opendaylight.controller.cluster.datastore.ShardDataTreeMocking.successfulCommit;
  22 import static org.opendaylight.controller.cluster.datastore.ShardDataTreeMocking.successfulPreCommit;
  23
  24 import akka.actor.ActorRef;
  25 import akka.actor.PoisonPill;
  26 import akka.actor.Props;
  27 import akka.dispatch.Dispatchers;
  28 import akka.japi.Creator;
  29 import akka.pattern.Patterns;
  30 import akka.testkit.TestActorRef;
  31 import akka.util.Timeout;
  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.Optional;
  40 import java.util.Set;
  41 import java.util.SortedSet;
  42 import java.util.concurrent.CountDownLatch;
  43 import java.util.concurrent.ExecutionException;
  44 import java.util.concurrent.TimeUnit;
  45 import java.util.concurrent.TimeoutException;
  46 import java.util.concurrent.atomic.AtomicInteger;
  47 import org.junit.After;
  48 import org.junit.Assert;
  49 import org.junit.Before;
  50 import org.opendaylight.controller.cluster.access.concepts.MemberName;
  51 import org.opendaylight.controller.cluster.access.concepts.TransactionIdentifier;
  52 import org.opendaylight.controller.cluster.datastore.DatastoreContext.Builder;
  53 import org.opendaylight.controller.cluster.datastore.identifiers.ShardIdentifier;
  54 import org.opendaylight.controller.cluster.datastore.messages.BatchedModifications;
  55 import org.opendaylight.controller.cluster.datastore.messages.ForwardedReadyTransaction;
  56 import org.opendaylight.controller.cluster.datastore.modification.MergeModification;
  57 import org.opendaylight.controller.cluster.datastore.modification.MutableCompositeModification;
  58 import org.opendaylight.controller.cluster.datastore.modification.WriteModification;
  59 import org.opendaylight.controller.cluster.datastore.persisted.CommitTransactionPayload;
  60 import org.opendaylight.controller.cluster.datastore.persisted.MetadataShardDataTreeSnapshot;
  61 import org.opendaylight.controller.cluster.datastore.persisted.ShardSnapshotState;
  62 import org.opendaylight.controller.cluster.raft.ReplicatedLogEntry;
  63 import org.opendaylight.controller.cluster.raft.TestActorFactory;
  64 import org.opendaylight.controller.cluster.raft.persisted.Snapshot;
  65 import org.opendaylight.controller.cluster.raft.utils.InMemoryJournal;
  66 import org.opendaylight.controller.cluster.raft.utils.InMemorySnapshotStore;
  67 import org.opendaylight.controller.md.cluster.datastore.model.CarsModel;
  68 import org.opendaylight.controller.md.cluster.datastore.model.TestModel;
  69 import org.opendaylight.yangtools.yang.common.Empty;
  70 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  71 import org.opendaylight.yangtools.yang.data.api.schema.DataContainerChild;
  72 import org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode;
  73 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  74 import org.opendaylight.yangtools.yang.data.impl.schema.ImmutableNodes;
  75 import org.opendaylight.yangtools.yang.data.tree.api.DataTree;
  76 import org.opendaylight.yangtools.yang.data.tree.api.DataTreeCandidate;
  77 import org.opendaylight.yangtools.yang.data.tree.api.DataTreeCandidateNode;
  78 import org.opendaylight.yangtools.yang.data.tree.api.DataTreeCandidateTip;
  79 import org.opendaylight.yangtools.yang.data.tree.api.DataTreeConfiguration;
  80 import org.opendaylight.yangtools.yang.data.tree.api.DataTreeModification;
  81 import org.opendaylight.yangtools.yang.data.tree.api.DataValidationFailedException;
  82 import org.opendaylight.yangtools.yang.data.tree.api.ModificationType;
  83 import org.opendaylight.yangtools.yang.data.tree.impl.di.InMemoryDataTreeFactory;
  84 import org.opendaylight.yangtools.yang.model.api.EffectiveModelContext;
  85 import scala.concurrent.Await;
  86 import scala.concurrent.Future;
  87 import scala.concurrent.duration.FiniteDuration;
  88
  89 /**
  90  * Abstract base for shard unit tests.
  91  *
  92  * @author Thomas Pantelis
  93  */
  94 public abstract class AbstractShardTest extends AbstractActorTest {
  95     protected static final EffectiveModelContext SCHEMA_CONTEXT = TestModel.createTestContext();
  96
  97     protected static final AtomicInteger SHARD_NUM = new AtomicInteger();
  98     protected static final int HEARTBEAT_MILLIS = 100;
  99
 100     protected final Builder dataStoreContextBuilder = DatastoreContext.newBuilder()
 101             .shardJournalRecoveryLogBatchSize(3).shardSnapshotBatchCount(5000)
 102             .shardHeartbeatIntervalInMillis(HEARTBEAT_MILLIS);
 103
 104     protected final TestActorFactory actorFactory = new TestActorFactory(getSystem());
 105     protected final int nextShardNum = SHARD_NUM.getAndIncrement();
 106     protected final ShardIdentifier shardID = ShardIdentifier.create("inventory", MemberName.forName("member-1"),
 107         "config" + nextShardNum);
 108
 109     @Before
 110     public void setUp() throws Exception {
 111         InMemorySnapshotStore.clear();
 112         InMemoryJournal.clear();
 113     }
 114
 115     @After
 116     public void tearDown() {
 117         InMemorySnapshotStore.clear();
 118         InMemoryJournal.clear();
 119         actorFactory.close();
 120     }
 121
 122     protected DatastoreContext newDatastoreContext() {
 123         return dataStoreContextBuilder.build();
 124     }
 125
 126     protected Props newShardProps() {
 127         return newShardBuilder().props();
 128     }
 129
 130     protected Shard.Builder newShardBuilder() {
 131         return Shard.builder().id(shardID).datastoreContext(newDatastoreContext())
 132             .schemaContextProvider(() -> SCHEMA_CONTEXT);
 133     }
 134
 135     protected void testRecovery(final Set<Integer> listEntryKeys, final boolean stopActorOnFinish) throws Exception {
 136         // Create the actor and wait for recovery complete.
 137
 138         final int nListEntries = listEntryKeys.size();
 139
 140         final CountDownLatch recoveryComplete = new CountDownLatch(1);
 141
 142         final Creator<Shard> creator = () -> new Shard(newShardBuilder()) {
 143             @Override
 144             protected void onRecoveryComplete() {
 145                 try {
 146                     super.onRecoveryComplete();
 147                 } finally {
 148                     recoveryComplete.countDown();
 149                 }
 150             }
 151         };
 152
 153         final TestActorRef<Shard> shard = TestActorRef.create(getSystem(), Props.create(Shard.class,
 154                 new DelegatingShardCreator(creator)).withDispatcher(Dispatchers.DefaultDispatcherId()), "testRecovery");
 155
 156         assertTrue("Recovery complete", recoveryComplete.await(5, TimeUnit.SECONDS));
 157
 158         // Verify data in the data store.
 159
 160         final NormalizedNode outerList = readStore(shard, TestModel.OUTER_LIST_PATH);
 161         assertNotNull(TestModel.OUTER_LIST_QNAME.getLocalName() + " not found", outerList);
 162         assertTrue(TestModel.OUTER_LIST_QNAME.getLocalName() + " value is not Iterable",
 163                 outerList.body() instanceof Iterable);
 164         for (final Object entry: (Iterable<?>) outerList.body()) {
 165             assertTrue(TestModel.OUTER_LIST_QNAME.getLocalName() + " entry is not MapEntryNode",
 166                     entry instanceof MapEntryNode);
 167             final MapEntryNode mapEntry = (MapEntryNode)entry;
 168             final Optional<DataContainerChild> idLeaf =
 169                     mapEntry.findChildByArg(new YangInstanceIdentifier.NodeIdentifier(TestModel.ID_QNAME));
 170             assertTrue("Missing leaf " + TestModel.ID_QNAME.getLocalName(), idLeaf.isPresent());
 171             final Object value = idLeaf.orElseThrow().body();
 172             assertTrue("Unexpected value for leaf " + TestModel.ID_QNAME.getLocalName() + ": " + value,
 173                     listEntryKeys.remove(value));
 174         }
 175
 176         if (!listEntryKeys.isEmpty()) {
 177             fail("Missing " + TestModel.OUTER_LIST_QNAME.getLocalName() + " entries with keys: " + listEntryKeys);
 178         }
 179
 180         assertEquals("Last log index", nListEntries,
 181                 shard.underlyingActor().getShardMBean().getLastLogIndex());
 182         assertEquals("Commit index", nListEntries,
 183                 shard.underlyingActor().getShardMBean().getCommitIndex());
 184         assertEquals("Last applied", nListEntries,
 185                 shard.underlyingActor().getShardMBean().getLastApplied());
 186
 187         if (stopActorOnFinish) {
 188             shard.tell(PoisonPill.getInstance(), ActorRef.noSender());
 189         }
 190     }
 191
 192     protected void verifyLastApplied(final TestActorRef<Shard> shard, final long expectedValue) {
 193         long lastApplied = -1;
 194         for (int i = 0; i < 20 * 5; i++) {
 195             lastApplied = shard.underlyingActor().getShardMBean().getLastApplied();
 196             if (lastApplied == expectedValue) {
 197                 return;
 198             }
 199             Uninterruptibles.sleepUninterruptibly(50, TimeUnit.MILLISECONDS);
 200         }
 201
 202         Assert.fail(String.format("Expected last applied: %d, Actual: %d", expectedValue, lastApplied));
 203     }
 204
 205     protected DataTree createDelegatingMockDataTree() throws Exception {
 206         final DataTree actual = new InMemoryDataTreeFactory().create(DataTreeConfiguration.DEFAULT_CONFIGURATION);
 207         final DataTree mock = mock(DataTree.class);
 208
 209         doAnswer(invocation -> {
 210             actual.validate(invocation.getArgument(0));
 211             return null;
 212         }).when(mock).validate(any(DataTreeModification.class));
 213
 214         doAnswer(invocation -> actual.prepare(invocation.getArgument(0))).when(
 215                 mock).prepare(any(DataTreeModification.class));
 216
 217         doAnswer(invocation -> {
 218             actual.commit(invocation.getArgument(0));
 219             return null;
 220         }).when(mock).commit(any(DataTreeCandidate.class));
 221
 222         doAnswer(invocation -> {
 223             actual.setEffectiveModelContext(invocation.getArgument(0));
 224             return null;
 225         }).when(mock).setEffectiveModelContext(any(EffectiveModelContext.class));
 226
 227         doAnswer(invocation -> actual.takeSnapshot()).when(mock).takeSnapshot();
 228
 229         doAnswer(invocation -> actual.getRootPath()).when(mock).getRootPath();
 230
 231         return mock;
 232     }
 233
 234     protected ShardDataTreeCohort mockShardDataTreeCohort() {
 235         ShardDataTreeCohort cohort = mock(ShardDataTreeCohort.class);
 236         DataTreeCandidate candidate = mockCandidate("candidate");
 237         successfulCanCommit(cohort);
 238         successfulPreCommit(cohort, candidate);
 239         successfulCommit(cohort);
 240         doReturn(candidate).when(cohort).getCandidate();
 241         return cohort;
 242     }
 243
 244     protected Map<TransactionIdentifier, CapturingShardDataTreeCohort> setupCohortDecorator(final Shard shard,
 245             final TransactionIdentifier... transactionIDs) {
 246         final Map<TransactionIdentifier, CapturingShardDataTreeCohort> cohortMap = new HashMap<>();
 247         for (TransactionIdentifier id: transactionIDs) {
 248             cohortMap.put(id, new CapturingShardDataTreeCohort());
 249         }
 250
 251         shard.getCommitCoordinator().setCohortDecorator((transactionID, actual) -> {
 252             CapturingShardDataTreeCohort cohort = cohortMap.get(transactionID);
 253             cohort.setDelegate(actual);
 254             return cohort;
 255         });
 256
 257         return cohortMap;
 258     }
 259
 260     protected BatchedModifications prepareBatchedModifications(final TransactionIdentifier transactionID,
 261                                                                final MutableCompositeModification modification) {
 262         return prepareBatchedModifications(transactionID, modification, false);
 263     }
 264
 265     protected static BatchedModifications prepareBatchedModifications(final TransactionIdentifier transactionID,
 266                                                              final MutableCompositeModification modification,
 267                                                              final boolean doCommitOnReady) {
 268         final BatchedModifications batchedModifications = new BatchedModifications(transactionID, CURRENT_VERSION);
 269         batchedModifications.addModification(modification);
 270         batchedModifications.setReady();
 271         batchedModifications.setDoCommitOnReady(doCommitOnReady);
 272         batchedModifications.setTotalMessagesSent(1);
 273         return batchedModifications;
 274     }
 275
 276     protected static BatchedModifications prepareBatchedModifications(final TransactionIdentifier transactionID,
 277             final YangInstanceIdentifier path, final NormalizedNode data, final boolean doCommitOnReady) {
 278         final MutableCompositeModification modification = new MutableCompositeModification();
 279         modification.addModification(new WriteModification(path, data));
 280         return prepareBatchedModifications(transactionID, modification, doCommitOnReady);
 281     }
 282
 283     protected static ForwardedReadyTransaction prepareForwardedReadyTransaction(final TestActorRef<Shard> shard,
 284             final TransactionIdentifier transactionID, final YangInstanceIdentifier path,
 285             final NormalizedNode data, final boolean doCommitOnReady) {
 286         ReadWriteShardDataTreeTransaction rwTx = shard.underlyingActor().getDataStore()
 287                 .newReadWriteTransaction(transactionID);
 288         rwTx.getSnapshot().write(path, data);
 289         return new ForwardedReadyTransaction(transactionID, CURRENT_VERSION, rwTx, doCommitOnReady, Optional.empty());
 290     }
 291
 292     public static NormalizedNode readStore(final TestActorRef<? extends Shard> shard,
 293             final YangInstanceIdentifier id) {
 294         return shard.underlyingActor().getDataStore().readNode(id).orElse(null);
 295     }
 296
 297     public static NormalizedNode readStore(final DataTree store, final YangInstanceIdentifier id) {
 298         return store.takeSnapshot().readNode(id).orElse(null);
 299     }
 300
 301     public void writeToStore(final TestActorRef<Shard> shard, final YangInstanceIdentifier id,
 302             final NormalizedNode node) throws InterruptedException, ExecutionException {
 303         Future<Object> future = Patterns.ask(shard, newBatchedModifications(nextTransactionId(),
 304                 id, node, true, true, 1), new Timeout(5, TimeUnit.SECONDS));
 305         try {
 306             Await.ready(future, FiniteDuration.create(5, TimeUnit.SECONDS));
 307         } catch (TimeoutException e) {
 308             throw new ExecutionException(e);
 309         }
 310     }
 311
 312     public static void writeToStore(final ShardDataTree store, final YangInstanceIdentifier id,
 313             final NormalizedNode node) throws DataValidationFailedException {
 314         BatchedModifications batched = newBatchedModifications(nextTransactionId(), id, node, true, true, 1);
 315         DataTreeModification modification = store.getDataTree().takeSnapshot().newModification();
 316         batched.apply(modification);
 317         store.notifyListeners(commitTransaction(store.getDataTree(), modification));
 318     }
 319
 320     public static void writeToStore(final DataTree store, final YangInstanceIdentifier id, final NormalizedNode node)
 321             throws DataValidationFailedException {
 322         final DataTreeModification transaction = store.takeSnapshot().newModification();
 323
 324         transaction.write(id, node);
 325         transaction.ready();
 326         store.validate(transaction);
 327         final DataTreeCandidate candidate = store.prepare(transaction);
 328         store.commit(candidate);
 329     }
 330
 331     public void mergeToStore(final ShardDataTree store, final YangInstanceIdentifier id, final NormalizedNode node)
 332         throws DataValidationFailedException {
 333         final BatchedModifications batched = new BatchedModifications(nextTransactionId(), CURRENT_VERSION);
 334         batched.addModification(new MergeModification(id, node));
 335         batched.setReady();
 336         batched.setDoCommitOnReady(true);
 337         batched.setTotalMessagesSent(1);
 338
 339         DataTreeModification modification = store.getDataTree().takeSnapshot().newModification();
 340         batched.apply(modification);
 341         store.notifyListeners(commitTransaction(store.getDataTree(), modification));
 342     }
 343
 344     DataTree setupInMemorySnapshotStore() throws DataValidationFailedException {
 345         final DataTree testStore = new InMemoryDataTreeFactory().create(
 346             DataTreeConfiguration.DEFAULT_OPERATIONAL, SCHEMA_CONTEXT);
 347
 348         writeToStore(testStore, TestModel.TEST_PATH, ImmutableNodes.containerNode(TestModel.TEST_QNAME));
 349
 350         final NormalizedNode root = readStore(testStore, YangInstanceIdentifier.of());
 351
 352         InMemorySnapshotStore.addSnapshot(shardID.toString(), Snapshot.create(
 353                 new ShardSnapshotState(new MetadataShardDataTreeSnapshot(root)),
 354                 Collections.<ReplicatedLogEntry>emptyList(), 0, 1, -1, -1, 1, null, null));
 355         return testStore;
 356     }
 357
 358     static CommitTransactionPayload payloadForModification(final DataTree source, final DataTreeModification mod,
 359             final TransactionIdentifier transactionId) throws DataValidationFailedException, IOException {
 360         source.validate(mod);
 361         final DataTreeCandidate candidate = source.prepare(mod);
 362         source.commit(candidate);
 363         return CommitTransactionPayload.create(transactionId, candidate);
 364     }
 365
 366     static BatchedModifications newBatchedModifications(final TransactionIdentifier transactionID,
 367             final YangInstanceIdentifier path, final NormalizedNode data, final boolean ready,
 368             final boolean doCommitOnReady, final int messagesSent) {
 369         final BatchedModifications batched = new BatchedModifications(transactionID, CURRENT_VERSION);
 370         batched.addModification(new WriteModification(path, data));
 371         if (ready) {
 372             batched.setReady();
 373         }
 374         batched.setDoCommitOnReady(doCommitOnReady);
 375         batched.setTotalMessagesSent(messagesSent);
 376         return batched;
 377     }
 378
 379     static BatchedModifications newReadyBatchedModifications(final TransactionIdentifier transactionID,
 380             final YangInstanceIdentifier path, final NormalizedNode data,
 381             final SortedSet<String> participatingShardNames) {
 382         final BatchedModifications batched = new BatchedModifications(transactionID, CURRENT_VERSION);
 383         batched.addModification(new WriteModification(path, data));
 384         batched.setReady(Optional.of(participatingShardNames));
 385         batched.setTotalMessagesSent(1);
 386         return batched;
 387     }
 388
 389     @SuppressWarnings("unchecked")
 390     static void verifyOuterListEntry(final TestActorRef<Shard> shard, final Object expIDValue) {
 391         final NormalizedNode outerList = readStore(shard, TestModel.OUTER_LIST_PATH);
 392         assertNotNull(TestModel.OUTER_LIST_QNAME.getLocalName() + " not found", outerList);
 393         assertTrue(TestModel.OUTER_LIST_QNAME.getLocalName() + " value is not Iterable",
 394                 outerList.body() instanceof Iterable);
 395         final Object entry = ((Iterable<Object>)outerList.body()).iterator().next();
 396         assertTrue(TestModel.OUTER_LIST_QNAME.getLocalName() + " entry is not MapEntryNode",
 397                 entry instanceof MapEntryNode);
 398         final MapEntryNode mapEntry = (MapEntryNode)entry;
 399         final Optional<DataContainerChild> idLeaf =
 400                 mapEntry.findChildByArg(new YangInstanceIdentifier.NodeIdentifier(TestModel.ID_QNAME));
 401         assertTrue("Missing leaf " + TestModel.ID_QNAME.getLocalName(), idLeaf.isPresent());
 402         assertEquals(TestModel.ID_QNAME.getLocalName() + " value", expIDValue, idLeaf.orElseThrow().body());
 403     }
 404
 405     public static DataTreeCandidateTip mockCandidate(final String name) {
 406         final DataTreeCandidateTip mockCandidate = mock(DataTreeCandidateTip.class, name);
 407         final DataTreeCandidateNode mockCandidateNode = mock(DataTreeCandidateNode.class, name + "-node");
 408         doReturn(ModificationType.WRITE).when(mockCandidateNode).modificationType();
 409         doReturn(ImmutableNodes.containerNode(CarsModel.CARS_QNAME)).when(mockCandidateNode).dataAfter();
 410         doReturn(CarsModel.BASE_PATH).when(mockCandidate).getRootPath();
 411         doReturn(mockCandidateNode).when(mockCandidate).getRootNode();
 412         return mockCandidate;
 413     }
 414
 415     static DataTreeCandidateTip mockUnmodifiedCandidate(final String name) {
 416         final DataTreeCandidateTip mockCandidate = mock(DataTreeCandidateTip.class, name);
 417         final DataTreeCandidateNode mockCandidateNode = mock(DataTreeCandidateNode.class, name + "-node");
 418         doReturn(ModificationType.UNMODIFIED).when(mockCandidateNode).modificationType();
 419         doReturn(YangInstanceIdentifier.of()).when(mockCandidate).getRootPath();
 420         doReturn(mockCandidateNode).when(mockCandidate).getRootNode();
 421         return mockCandidate;
 422     }
 423
 424     static DataTreeCandidate commitTransaction(final DataTree store, final DataTreeModification modification)
 425             throws DataValidationFailedException {
 426         modification.ready();
 427         store.validate(modification);
 428         final DataTreeCandidate candidate = store.prepare(modification);
 429         store.commit(candidate);
 430         return candidate;
 431     }
 432
 433     @SuppressWarnings("serial")
 434     public static final class DelegatingShardCreator implements Creator<Shard> {
 435         private final Creator<Shard> delegate;
 436
 437         DelegatingShardCreator(final Creator<Shard> delegate) {
 438             this.delegate = delegate;
 439         }
 440
 441         @Override
 442         public Shard create() throws Exception {
 443             return delegate.create();
 444         }
 445     }
 446
 447     public static class CapturingShardDataTreeCohort extends ShardDataTreeCohort {
 448         private volatile ShardDataTreeCohort delegate;
 449         private FutureCallback<Empty> canCommit;
 450         private FutureCallback<DataTreeCandidate> preCommit;
 451         private FutureCallback<UnsignedLong> commit;
 452
 453         public void setDelegate(final ShardDataTreeCohort delegate) {
 454             this.delegate = delegate;
 455         }
 456
 457         public FutureCallback<Empty> getCanCommit() {
 458             assertNotNull("canCommit was not invoked", canCommit);
 459             return canCommit;
 460         }
 461
 462         public FutureCallback<DataTreeCandidate> getPreCommit() {
 463             assertNotNull("preCommit was not invoked", preCommit);
 464             return preCommit;
 465         }
 466
 467         public FutureCallback<UnsignedLong> getCommit() {
 468             assertNotNull("commit was not invoked", commit);
 469             return commit;
 470         }
 471
 472         @Override
 473         TransactionIdentifier transactionId() {
 474             return delegate.transactionId();
 475         }
 476
 477         @Override
 478         DataTreeCandidateTip getCandidate() {
 479             return delegate.getCandidate();
 480         }
 481
 482         @Override
 483         DataTreeModification getDataTreeModification() {
 484             return delegate.getDataTreeModification();
 485         }
 486
 487         @Override
 488         public void canCommit(final FutureCallback<Empty> callback) {
 489             canCommit = mockFutureCallback(callback);
 490             delegate.canCommit(canCommit);
 491         }
 492
 493         @Override
 494         public void preCommit(final FutureCallback<DataTreeCandidate> callback) {
 495             preCommit = mockFutureCallback(callback);
 496             delegate.preCommit(preCommit);
 497         }
 498
 499         @Override
 500         public void commit(final FutureCallback<UnsignedLong> callback) {
 501             commit = mockFutureCallback(callback);
 502             delegate.commit(commit);
 503         }
 504
 505         @SuppressWarnings("unchecked")
 506         private static <T> FutureCallback<T> mockFutureCallback(final FutureCallback<T> actual) {
 507             FutureCallback<T> mock = mock(FutureCallback.class);
 508             doAnswer(invocation -> {
 509                 actual.onFailure(invocation.getArgument(0));
 510                 return null;
 511             }).when(mock).onFailure(any(Throwable.class));
 512
 513             doAnswer(invocation -> {
 514                 actual.onSuccess(invocation.getArgument(0));
 515                 return null;
 516             }).when(mock).onSuccess((T) nullable(Object.class));
 517
 518             return mock;
 519         }
 520
 521         @Override
 522         public void abort(final FutureCallback<Empty> callback) {
 523             delegate.abort(callback);
 524         }
 525
 526         @Override
 527         public boolean isFailed() {
 528             return delegate.isFailed();
 529         }
 530
 531         @Override
 532         public State getState() {
 533             return delegate.getState();
 534         }
 535
 536         @Override
 537         Optional<SortedSet<String>> getParticipatingShardNames() {
 538             return delegate.getParticipatingShardNames();
 539         }
 540     }
 541 }