BUG-7033: Implement batchHint in ShardDataTree
[controller.git] / opendaylight / md-sal / sal-distributed-datastore / src / test / java / org / opendaylight / controller / cluster / datastore / ShardDataTreeTest.java
index 9ae74bb47c1b8dd17a2f3f8b8f7a51d9ecbd68b7..6f0b32b4506ebce3f3886fe227cfc5afbdf231a9 100644 (file)
@@ -11,17 +11,31 @@ package org.opendaylight.controller.cluster.datastore;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.fail;
+import static org.mockito.Matchers.any;
+import static org.mockito.Matchers.anyBoolean;
+import static org.mockito.Matchers.eq;
+import static org.mockito.Mockito.atLeastOnce;
+import static org.mockito.Mockito.doNothing;
 import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.inOrder;
 import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.atLeastOnce;
-import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.reset;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.verifyNoMoreInteractions;
+import static org.opendaylight.controller.cluster.datastore.ShardDataTreeMocking.coordinatedCanCommit;
+import static org.opendaylight.controller.cluster.datastore.ShardDataTreeMocking.coordinatedCommit;
+import static org.opendaylight.controller.cluster.datastore.ShardDataTreeMocking.coordinatedPreCommit;
+import static org.opendaylight.controller.cluster.datastore.ShardDataTreeMocking.immediate3PhaseCommit;
 import static org.opendaylight.controller.cluster.datastore.ShardDataTreeMocking.immediateCanCommit;
 import static org.opendaylight.controller.cluster.datastore.ShardDataTreeMocking.immediateCommit;
 import static org.opendaylight.controller.cluster.datastore.ShardDataTreeMocking.immediatePreCommit;
+
 import com.google.common.base.Optional;
 import com.google.common.base.Ticker;
 import com.google.common.collect.Maps;
+import com.google.common.primitives.UnsignedLong;
+import com.google.common.util.concurrent.FutureCallback;
 import java.math.BigInteger;
 import java.util.ArrayList;
 import java.util.Collection;
@@ -32,16 +46,18 @@ import java.util.function.Consumer;
 import org.junit.Before;
 import org.junit.Test;
 import org.mockito.ArgumentCaptor;
+import org.mockito.InOrder;
 import org.mockito.Mockito;
 import org.opendaylight.controller.cluster.datastore.jmx.mbeans.shard.ShardStats;
+import org.opendaylight.controller.cluster.datastore.persisted.CommitTransactionPayload;
 import org.opendaylight.controller.md.cluster.datastore.model.CarsModel;
 import org.opendaylight.controller.md.cluster.datastore.model.PeopleModel;
 import org.opendaylight.controller.md.cluster.datastore.model.SchemaContextHelper;
 import org.opendaylight.controller.md.sal.dom.api.DOMDataTreeChangeListener;
 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
+import org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode;
 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
-import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidateTip;
 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidates;
 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeModification;
 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeSnapshot;
@@ -52,8 +68,7 @@ import org.opendaylight.yangtools.yang.model.api.SchemaContext;
 public class ShardDataTreeTest extends AbstractTest {
 
     private final Shard mockShard = Mockito.mock(Shard.class);
-
-
+    private ShardDataTree shardDataTree;
     private SchemaContext fullSchema;
 
     @Before
@@ -63,30 +78,33 @@ public class ShardDataTreeTest extends AbstractTest {
         doReturn(Mockito.mock(ShardStats.class)).when(mockShard).getShardMBean();
 
         fullSchema = SchemaContextHelper.full();
+
+        shardDataTree = new ShardDataTree(mockShard, fullSchema, TreeType.OPERATIONAL);
     }
 
     @Test
     public void testWrite() throws ExecutionException, InterruptedException {
-        modify(new ShardDataTree(mockShard, fullSchema, TreeType.OPERATIONAL), false, true, true);
+        modify(false, true, true);
     }
 
     @Test
     public void testMerge() throws ExecutionException, InterruptedException {
-        modify(new ShardDataTree(mockShard, fullSchema, TreeType.OPERATIONAL), true, true, true);
+        modify(true, true, true);
     }
 
-
-    private void modify(final ShardDataTree shardDataTree, final boolean merge, final boolean expectedCarsPresent, final boolean expectedPeoplePresent) throws ExecutionException, InterruptedException {
+    private void modify(final boolean merge, final boolean expectedCarsPresent, final boolean expectedPeoplePresent)
+            throws ExecutionException, InterruptedException {
 
         assertEquals(fullSchema, shardDataTree.getSchemaContext());
 
-        final ReadWriteShardDataTreeTransaction transaction = shardDataTree.newReadWriteTransaction(nextTransactionId());
+        final ReadWriteShardDataTreeTransaction transaction =
+                shardDataTree.newReadWriteTransaction(nextTransactionId());
 
         final DataTreeModification snapshot = transaction.getSnapshot();
 
         assertNotNull(snapshot);
 
-        if(merge){
+        if (merge) {
             snapshot.merge(CarsModel.BASE_PATH, CarsModel.create());
             snapshot.merge(PeopleModel.BASE_PATH, PeopleModel.create());
         } else {
@@ -100,7 +118,8 @@ public class ShardDataTreeTest extends AbstractTest {
         immediatePreCommit(cohort);
         immediateCommit(cohort);
 
-        final ReadOnlyShardDataTreeTransaction readOnlyShardDataTreeTransaction = shardDataTree.newReadOnlyTransaction(nextTransactionId());
+        final ReadOnlyShardDataTreeTransaction readOnlyShardDataTreeTransaction =
+                shardDataTree.newReadOnlyTransaction(nextTransactionId());
 
         final DataTreeSnapshot snapshot1 = readOnlyShardDataTreeTransaction.getSnapshot();
 
@@ -111,14 +130,11 @@ public class ShardDataTreeTest extends AbstractTest {
         final Optional<NormalizedNode<?, ?>> optional1 = snapshot1.readNode(PeopleModel.BASE_PATH);
 
         assertEquals(expectedPeoplePresent, optional1.isPresent());
-
     }
 
     @Test
     public void bug4359AddRemoveCarOnce() throws ExecutionException, InterruptedException {
-        final ShardDataTree shardDataTree = new ShardDataTree(mockShard, fullSchema, TreeType.OPERATIONAL);
-
-        final List<DataTreeCandidateTip> candidates = new ArrayList<>();
+        final List<DataTreeCandidate> candidates = new ArrayList<>();
         candidates.add(addCar(shardDataTree));
         candidates.add(removeCar(shardDataTree));
 
@@ -133,9 +149,7 @@ public class ShardDataTreeTest extends AbstractTest {
 
     @Test
     public void bug4359AddRemoveCarTwice() throws ExecutionException, InterruptedException {
-        final ShardDataTree shardDataTree = new ShardDataTree(mockShard, fullSchema, TreeType.OPERATIONAL);
-
-        final List<DataTreeCandidateTip> candidates = new ArrayList<>();
+        final List<DataTreeCandidate> candidates = new ArrayList<>();
         candidates.add(addCar(shardDataTree));
         candidates.add(removeCar(shardDataTree));
         candidates.add(addCar(shardDataTree));
@@ -152,8 +166,6 @@ public class ShardDataTreeTest extends AbstractTest {
 
     @Test
     public void testListenerNotifiedOnApplySnapshot() throws Exception {
-        final ShardDataTree shardDataTree = new ShardDataTree(mockShard, fullSchema, TreeType.OPERATIONAL);
-
         DOMDataTreeChangeListener listener = mock(DOMDataTreeChangeListener.class);
         shardDataTree.registerTreeChangeListener(CarsModel.CAR_LIST_PATH.node(CarsModel.CAR_QNAME), listener);
 
@@ -187,17 +199,265 @@ public class ShardDataTreeTest extends AbstractTest {
             assertEquals("getModificationType", expType, dtc.getRootNode().getModificationType());
         });
 
-        if(!expChanges.isEmpty()) {
+        if (!expChanges.isEmpty()) {
             fail("Missing change notifications: " + expChanges);
         }
     }
 
+    @Test
+    public void testPipelinedTransactionsWithCoordinatedCommits() throws Exception {
+        doReturn(false).when(mockShard).canSkipPayload();
+
+        final ShardDataTreeCohort cohort1 = newShardDataTreeCohort(snapshot ->
+            snapshot.write(CarsModel.BASE_PATH, CarsModel.emptyContainer()));
+
+        final ShardDataTreeCohort cohort2 = newShardDataTreeCohort(snapshot ->
+            snapshot.write(CarsModel.CAR_LIST_PATH, CarsModel.newCarMapNode()));
+
+        NormalizedNode<?, ?> peopleNode = PeopleModel.create();
+        final ShardDataTreeCohort cohort3 = newShardDataTreeCohort(snapshot ->
+            snapshot.write(PeopleModel.BASE_PATH, peopleNode));
+
+        YangInstanceIdentifier carPath = CarsModel.newCarPath("optima");
+        MapEntryNode carNode = CarsModel.newCarEntry("optima", new BigInteger("100"));
+        final ShardDataTreeCohort cohort4 = newShardDataTreeCohort(snapshot -> snapshot.write(carPath, carNode));
+
+        immediateCanCommit(cohort1);
+        final FutureCallback<Void> canCommitCallback2 = coordinatedCanCommit(cohort2);
+        final FutureCallback<Void> canCommitCallback3 = coordinatedCanCommit(cohort3);
+        final FutureCallback<Void> canCommitCallback4 = coordinatedCanCommit(cohort4);
+
+        final FutureCallback<DataTreeCandidate> preCommitCallback1 = coordinatedPreCommit(cohort1);
+        verify(preCommitCallback1).onSuccess(cohort1.getCandidate());
+        verify(canCommitCallback2).onSuccess(null);
+
+        final FutureCallback<DataTreeCandidate> preCommitCallback2 = coordinatedPreCommit(cohort2);
+        verify(preCommitCallback2).onSuccess(cohort2.getCandidate());
+        verify(canCommitCallback3).onSuccess(null);
+
+        final FutureCallback<DataTreeCandidate> preCommitCallback3 = coordinatedPreCommit(cohort3);
+        verify(preCommitCallback3).onSuccess(cohort3.getCandidate());
+        verify(canCommitCallback4).onSuccess(null);
+
+        final FutureCallback<DataTreeCandidate> preCommitCallback4 = coordinatedPreCommit(cohort4);
+        verify(preCommitCallback4).onSuccess(cohort4.getCandidate());
+
+        final FutureCallback<UnsignedLong> commitCallback2 = coordinatedCommit(cohort2);
+        verify(mockShard, never()).persistPayload(eq(cohort1.getIdentifier()), any(CommitTransactionPayload.class),
+                anyBoolean());
+        verifyNoMoreInteractions(commitCallback2);
+
+        final FutureCallback<UnsignedLong> commitCallback4 = coordinatedCommit(cohort4);
+        verify(mockShard, never()).persistPayload(eq(cohort4.getIdentifier()), any(CommitTransactionPayload.class),
+                anyBoolean());
+        verifyNoMoreInteractions(commitCallback4);
+
+        final FutureCallback<UnsignedLong> commitCallback1 = coordinatedCommit(cohort1);
+        InOrder inOrder = inOrder(mockShard);
+        inOrder.verify(mockShard).persistPayload(eq(cohort1.getIdentifier()), any(CommitTransactionPayload.class),
+                eq(true));
+        inOrder.verify(mockShard).persistPayload(eq(cohort2.getIdentifier()), any(CommitTransactionPayload.class),
+                eq(false));
+        verifyNoMoreInteractions(commitCallback1);
+        verifyNoMoreInteractions(commitCallback2);
+
+        final FutureCallback<UnsignedLong> commitCallback3 = coordinatedCommit(cohort3);
+        inOrder = inOrder(mockShard);
+        inOrder.verify(mockShard).persistPayload(eq(cohort3.getIdentifier()), any(CommitTransactionPayload.class),
+                eq(true));
+        inOrder.verify(mockShard).persistPayload(eq(cohort4.getIdentifier()), any(CommitTransactionPayload.class),
+                eq(false));
+        verifyNoMoreInteractions(commitCallback3);
+        verifyNoMoreInteractions(commitCallback4);
+
+        final ShardDataTreeCohort cohort5 = newShardDataTreeCohort(snapshot ->
+            snapshot.merge(CarsModel.BASE_PATH, CarsModel.emptyContainer()));
+        final FutureCallback<Void> canCommitCallback5 = coordinatedCanCommit(cohort5);
+
+        // The payload instance doesn't matter - it just needs to be of type CommitTransactionPayload.
+        CommitTransactionPayload mockPayload = CommitTransactionPayload.create(nextTransactionId(),
+                cohort1.getCandidate());
+        shardDataTree.applyReplicatedPayload(cohort1.getIdentifier(), mockPayload);
+        shardDataTree.applyReplicatedPayload(cohort2.getIdentifier(), mockPayload);
+        shardDataTree.applyReplicatedPayload(cohort3.getIdentifier(), mockPayload);
+        shardDataTree.applyReplicatedPayload(cohort4.getIdentifier(), mockPayload);
+
+        inOrder = inOrder(commitCallback1, commitCallback2, commitCallback3, commitCallback4);
+        inOrder.verify(commitCallback1).onSuccess(any(UnsignedLong.class));
+        inOrder.verify(commitCallback2).onSuccess(any(UnsignedLong.class));
+        inOrder.verify(commitCallback3).onSuccess(any(UnsignedLong.class));
+        inOrder.verify(commitCallback4).onSuccess(any(UnsignedLong.class));
+
+        verify(canCommitCallback5).onSuccess(null);
+
+        final DataTreeSnapshot snapshot =
+                shardDataTree.newReadOnlyTransaction(nextTransactionId()).getSnapshot();
+        Optional<NormalizedNode<?, ?>> optional = snapshot.readNode(carPath);
+        assertEquals("Car node present", true, optional.isPresent());
+        assertEquals("Car node", carNode, optional.get());
+
+        optional = snapshot.readNode(PeopleModel.BASE_PATH);
+        assertEquals("People node present", true, optional.isPresent());
+        assertEquals("People node", peopleNode, optional.get());
+    }
+
+    @Test
+    public void testPipelinedTransactionsWithImmediateCommits() throws Exception {
+        doReturn(false).when(mockShard).canSkipPayload();
+
+        final ShardDataTreeCohort cohort1 = newShardDataTreeCohort(snapshot ->
+            snapshot.write(CarsModel.BASE_PATH, CarsModel.emptyContainer()));
+
+        final ShardDataTreeCohort cohort2 = newShardDataTreeCohort(snapshot ->
+            snapshot.write(CarsModel.CAR_LIST_PATH, CarsModel.newCarMapNode()));
+
+        YangInstanceIdentifier carPath = CarsModel.newCarPath("optima");
+        MapEntryNode carNode = CarsModel.newCarEntry("optima", new BigInteger("100"));
+        final ShardDataTreeCohort cohort3 = newShardDataTreeCohort(snapshot -> snapshot.write(carPath, carNode));
+
+        final FutureCallback<UnsignedLong> commitCallback2 = immediate3PhaseCommit(cohort2);
+        final FutureCallback<UnsignedLong> commitCallback3 = immediate3PhaseCommit(cohort3);
+        final FutureCallback<UnsignedLong> commitCallback1 = immediate3PhaseCommit(cohort1);
+
+        InOrder inOrder = inOrder(mockShard);
+        inOrder.verify(mockShard).persistPayload(eq(cohort1.getIdentifier()), any(CommitTransactionPayload.class),
+                eq(true));
+        inOrder.verify(mockShard).persistPayload(eq(cohort2.getIdentifier()), any(CommitTransactionPayload.class),
+                eq(true));
+        inOrder.verify(mockShard).persistPayload(eq(cohort3.getIdentifier()), any(CommitTransactionPayload.class),
+                eq(false));
+
+        // The payload instance doesn't matter - it just needs to be of type CommitTransactionPayload.
+        CommitTransactionPayload mockPayload = CommitTransactionPayload.create(nextTransactionId(),
+                cohort1.getCandidate());
+        shardDataTree.applyReplicatedPayload(cohort1.getIdentifier(), mockPayload);
+        shardDataTree.applyReplicatedPayload(cohort2.getIdentifier(), mockPayload);
+        shardDataTree.applyReplicatedPayload(cohort3.getIdentifier(), mockPayload);
+
+        inOrder = inOrder(commitCallback1, commitCallback2, commitCallback3);
+        inOrder.verify(commitCallback1).onSuccess(any(UnsignedLong.class));
+        inOrder.verify(commitCallback2).onSuccess(any(UnsignedLong.class));
+        inOrder.verify(commitCallback3).onSuccess(any(UnsignedLong.class));
+
+        final DataTreeSnapshot snapshot =
+                shardDataTree.newReadOnlyTransaction(nextTransactionId()).getSnapshot();
+        Optional<NormalizedNode<?, ?>> optional = snapshot.readNode(carPath);
+        assertEquals("Car node present", true, optional.isPresent());
+        assertEquals("Car node", carNode, optional.get());
+    }
+
+    @SuppressWarnings("unchecked")
+    @Test
+    public void testAbortWithPendingCommits() throws Exception {
+        doReturn(false).when(mockShard).canSkipPayload();
+
+        final ShardDataTreeCohort cohort1 = newShardDataTreeCohort(snapshot ->
+            snapshot.write(CarsModel.BASE_PATH, CarsModel.emptyContainer()));
+
+        final ShardDataTreeCohort cohort2 = newShardDataTreeCohort(snapshot ->
+            snapshot.write(PeopleModel.BASE_PATH, PeopleModel.create()));
+
+        final ShardDataTreeCohort cohort3 = newShardDataTreeCohort(snapshot ->
+            snapshot.write(CarsModel.CAR_LIST_PATH, CarsModel.newCarMapNode()));
+
+        YangInstanceIdentifier carPath = CarsModel.newCarPath("optima");
+        MapEntryNode carNode = CarsModel.newCarEntry("optima", new BigInteger("100"));
+        final ShardDataTreeCohort cohort4 = newShardDataTreeCohort(snapshot -> snapshot.write(carPath, carNode));
+
+        coordinatedCanCommit(cohort2);
+        immediateCanCommit(cohort1);
+        coordinatedCanCommit(cohort3);
+        coordinatedCanCommit(cohort4);
+
+        coordinatedPreCommit(cohort1);
+        coordinatedPreCommit(cohort2);
+        coordinatedPreCommit(cohort3);
+
+        FutureCallback<Void> mockAbortCallback = mock(FutureCallback.class);
+        doNothing().when(mockAbortCallback).onSuccess(null);
+        cohort2.abort(mockAbortCallback);
+        verify(mockAbortCallback).onSuccess(null);
+
+        coordinatedPreCommit(cohort4);
+        coordinatedCommit(cohort1);
+        coordinatedCommit(cohort3);
+        coordinatedCommit(cohort4);
+
+        InOrder inOrder = inOrder(mockShard);
+        inOrder.verify(mockShard).persistPayload(eq(cohort1.getIdentifier()), any(CommitTransactionPayload.class),
+                eq(false));
+        inOrder.verify(mockShard).persistPayload(eq(cohort3.getIdentifier()), any(CommitTransactionPayload.class),
+                eq(false));
+        inOrder.verify(mockShard).persistPayload(eq(cohort4.getIdentifier()), any(CommitTransactionPayload.class),
+                eq(false));
+
+        // The payload instance doesn't matter - it just needs to be of type CommitTransactionPayload.
+        CommitTransactionPayload mockPayload = CommitTransactionPayload.create(nextTransactionId(),
+                cohort1.getCandidate());
+        shardDataTree.applyReplicatedPayload(cohort1.getIdentifier(), mockPayload);
+        shardDataTree.applyReplicatedPayload(cohort3.getIdentifier(), mockPayload);
+        shardDataTree.applyReplicatedPayload(cohort4.getIdentifier(), mockPayload);
+
+        final DataTreeSnapshot snapshot =
+                shardDataTree.newReadOnlyTransaction(nextTransactionId()).getSnapshot();
+        Optional<NormalizedNode<?, ?>> optional = snapshot.readNode(carPath);
+        assertEquals("Car node present", true, optional.isPresent());
+        assertEquals("Car node", carNode, optional.get());
+    }
+
+    @SuppressWarnings("unchecked")
+    @Test
+    public void testAbortWithFailedRebase() throws Exception {
+        final ShardDataTreeCohort cohort1 = newShardDataTreeCohort(snapshot ->
+            snapshot.write(CarsModel.BASE_PATH, CarsModel.emptyContainer()));
+
+        final ShardDataTreeCohort cohort2 = newShardDataTreeCohort(snapshot ->
+            snapshot.write(CarsModel.CAR_LIST_PATH, CarsModel.newCarMapNode()));
+
+        NormalizedNode<?, ?> peopleNode = PeopleModel.create();
+        final ShardDataTreeCohort cohort3 = newShardDataTreeCohort(snapshot ->
+            snapshot.write(PeopleModel.BASE_PATH, peopleNode));
+
+        immediateCanCommit(cohort1);
+        FutureCallback<Void> canCommitCallback2 = coordinatedCanCommit(cohort2);
+
+        coordinatedPreCommit(cohort1);
+        verify(canCommitCallback2).onSuccess(null);
+
+        FutureCallback<Void> mockAbortCallback = mock(FutureCallback.class);
+        doNothing().when(mockAbortCallback).onSuccess(null);
+        cohort1.abort(mockAbortCallback);
+        verify(mockAbortCallback).onSuccess(null);
+
+        FutureCallback<DataTreeCandidate> preCommitCallback2 = coordinatedPreCommit(cohort2);
+        verify(preCommitCallback2).onFailure(any(Throwable.class));
+
+        immediateCanCommit(cohort3);
+        immediatePreCommit(cohort3);
+        immediateCommit(cohort3);
+
+        final DataTreeSnapshot snapshot =
+                shardDataTree.newReadOnlyTransaction(nextTransactionId()).getSnapshot();
+        Optional<NormalizedNode<?, ?>> optional = snapshot.readNode(PeopleModel.BASE_PATH);
+        assertEquals("People node present", true, optional.isPresent());
+        assertEquals("People node", peopleNode, optional.get());
+    }
+
+    private ShardDataTreeCohort newShardDataTreeCohort(final DataTreeOperation operation) {
+        final ReadWriteShardDataTreeTransaction transaction =
+                shardDataTree.newReadWriteTransaction(nextTransactionId());
+        final DataTreeModification snapshot = transaction.getSnapshot();
+        operation.execute(snapshot);
+        return shardDataTree.finishTransaction(transaction);
+    }
+
     @SuppressWarnings({ "rawtypes", "unchecked" })
-    private static void verifyOnDataTreeChanged(DOMDataTreeChangeListener listener, Consumer<DataTreeCandidate> callback) {
+    private static void verifyOnDataTreeChanged(final DOMDataTreeChangeListener listener,
+            final Consumer<DataTreeCandidate> callback) {
         ArgumentCaptor<Collection> changes = ArgumentCaptor.forClass(Collection.class);
         verify(listener, atLeastOnce()).onDataTreeChanged(changes.capture());
-        for(Collection list: changes.getAllValues()) {
-            for(Object dtc: list) {
+        for (Collection list : changes.getAllValues()) {
+            for (Object dtc : list) {
                 callback.accept((DataTreeCandidate)dtc);
             }
         }
@@ -206,7 +466,8 @@ public class ShardDataTreeTest extends AbstractTest {
     }
 
     private static NormalizedNode<?, ?> getCars(final ShardDataTree shardDataTree) {
-        final ReadOnlyShardDataTreeTransaction readOnlyShardDataTreeTransaction = shardDataTree.newReadOnlyTransaction(nextTransactionId());
+        final ReadOnlyShardDataTreeTransaction readOnlyShardDataTreeTransaction =
+                shardDataTree.newReadOnlyTransaction(nextTransactionId());
         final DataTreeSnapshot snapshot1 = readOnlyShardDataTreeTransaction.getSnapshot();
 
         final Optional<NormalizedNode<?, ?>> optional = snapshot1.readNode(CarsModel.BASE_PATH);
@@ -216,57 +477,61 @@ public class ShardDataTreeTest extends AbstractTest {
         return optional.get();
     }
 
-    private static DataTreeCandidateTip addCar(final ShardDataTree shardDataTree) throws ExecutionException, InterruptedException {
+    private static DataTreeCandidate addCar(final ShardDataTree shardDataTree)
+            throws ExecutionException, InterruptedException {
         return addCar(shardDataTree, "altima");
     }
 
-    private static DataTreeCandidateTip addCar(final ShardDataTree shardDataTree, String name) throws ExecutionException, InterruptedException {
+    private static DataTreeCandidate addCar(final ShardDataTree shardDataTree, final String name)
+            throws ExecutionException, InterruptedException {
         return doTransaction(shardDataTree, snapshot -> {
-                snapshot.merge(CarsModel.BASE_PATH, CarsModel.emptyContainer());
-                snapshot.merge(CarsModel.CAR_LIST_PATH, CarsModel.newCarMapNode());
-                snapshot.write(CarsModel.newCarPath(name), CarsModel.newCarEntry(name, new BigInteger("100")));
-            });
+            snapshot.merge(CarsModel.BASE_PATH, CarsModel.emptyContainer());
+            snapshot.merge(CarsModel.CAR_LIST_PATH, CarsModel.newCarMapNode());
+            snapshot.write(CarsModel.newCarPath(name), CarsModel.newCarEntry(name, new BigInteger("100")));
+        });
     }
 
-    private static DataTreeCandidateTip removeCar(final ShardDataTree shardDataTree) throws ExecutionException, InterruptedException {
+    private static DataTreeCandidate removeCar(final ShardDataTree shardDataTree)
+            throws ExecutionException, InterruptedException {
         return doTransaction(shardDataTree, snapshot -> snapshot.delete(CarsModel.newCarPath("altima")));
     }
 
     @FunctionalInterface
-    private static interface DataTreeOperation {
+    private interface DataTreeOperation {
         void execute(DataTreeModification snapshot);
     }
 
-    private static DataTreeCandidateTip doTransaction(final ShardDataTree shardDataTree, final DataTreeOperation operation)
-            throws ExecutionException, InterruptedException {
-        final ReadWriteShardDataTreeTransaction transaction = shardDataTree.newReadWriteTransaction(nextTransactionId());
+    private static DataTreeCandidate doTransaction(final ShardDataTree shardDataTree,
+            final DataTreeOperation operation) throws ExecutionException, InterruptedException {
+        final ReadWriteShardDataTreeTransaction transaction =
+                shardDataTree.newReadWriteTransaction(nextTransactionId());
         final DataTreeModification snapshot = transaction.getSnapshot();
         operation.execute(snapshot);
         final ShardDataTreeCohort cohort = shardDataTree.finishTransaction(transaction);
 
         immediateCanCommit(cohort);
         immediatePreCommit(cohort);
-        final DataTreeCandidateTip candidate = cohort.getCandidate();
+        final DataTreeCandidate candidate = cohort.getCandidate();
         immediateCommit(cohort);
 
         return candidate;
     }
 
-    private static DataTreeCandidateTip applyCandidates(final ShardDataTree shardDataTree, final List<DataTreeCandidateTip> candidates)
-            throws ExecutionException, InterruptedException {
-        final ReadWriteShardDataTreeTransaction transaction = shardDataTree.newReadWriteTransaction(nextTransactionId());
+    private static DataTreeCandidate applyCandidates(final ShardDataTree shardDataTree,
+            final List<DataTreeCandidate> candidates) throws ExecutionException, InterruptedException {
+        final ReadWriteShardDataTreeTransaction transaction =
+                shardDataTree.newReadWriteTransaction(nextTransactionId());
         final DataTreeModification snapshot = transaction.getSnapshot();
-        for(final DataTreeCandidateTip candidateTip : candidates){
+        for (final DataTreeCandidate candidateTip : candidates) {
             DataTreeCandidates.applyToModification(snapshot, candidateTip);
         }
         final ShardDataTreeCohort cohort = shardDataTree.finishTransaction(transaction);
 
         immediateCanCommit(cohort);
         immediatePreCommit(cohort);
-        final DataTreeCandidateTip candidate = cohort.getCandidate();
+        final DataTreeCandidate candidate = cohort.getCandidate();
         immediateCommit(cohort);
 
         return candidate;
     }
-
 }