Happy path: add and delete nodes and labels

community/kernel-api/src/main/java/org/neo4j/internal/kernel/api/Write.java

@@ -35,8 +35,9 @@ public interface Write
     /**
      * Delete a node.
      * @param node the internal id of the node to delete
+     * @return returns true if it deleted a node or false if no node was found for this id
      */
-    void nodeDelete( long node );
+    boolean nodeDelete( long node );
 
     /**
      * Create a relationship between two nodes.

community/kernel-api/src/test/java/org/neo4j/internal/kernel/api/NodeWriteTestBase.java

@@ -27,6 +27,7 @@
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.equalTo;
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.fail;
 import static org.neo4j.graphdb.Label.label;
 
@@ -69,6 +70,53 @@ public void shouldRollbackOnFailure() throws Exception
         }
     }
 
+    @Test
+    public void shouldRemoveNode() throws Exception
+    {
+        long node;
+        try ( org.neo4j.graphdb.Transaction tx = graphDb.beginTx() )
+        {
+            node = graphDb.createNode().getId();
+            tx.success();
+        }
+
+        try ( Transaction tx = session.beginTransaction() )
+        {
+            tx.dataWrite().nodeDelete( node );
+            tx.success();
+        }
+        try ( org.neo4j.graphdb.Transaction tx = graphDb.beginTx() )
+        {
+            try
+            {
+                graphDb.getNodeById( node );
+                fail( "Did not remove node" );
+            }
+            catch ( NotFoundException e )
+            {
+                // expected
+            }
+        }
+    }
+
+    @Test
+    public void shouldNotRemoveNodeThatDoesNotExist() throws Exception
+    {
+        long node = 0;
+
+        try ( Transaction tx = session.beginTransaction() )
+        {
+            assertFalse( tx.dataWrite().nodeDelete( node ) );
+            tx.failure();
+        }
+        try ( Transaction tx = session.beginTransaction() )
+        {
+            assertFalse( tx.dataWrite().nodeDelete( node ) );
+            tx.success();
+        }
+        // should not crash
+    }
+
     @Test
     public void shouldAddLabelNode() throws Exception
     {
@@ -85,9 +133,7 @@ public void shouldAddLabelNode() throws Exception
 
         try ( org.neo4j.graphdb.Transaction ctx = graphDb.beginTx() )
         {
-            assertThat(
-                    graphDb.getNodeById( node ).getLabels(),
-                    equalTo( Iterables.iterable( label( labelName ) ) ) );
+            assertThat( graphDb.getNodeById( node ).getLabels(), equalTo( Iterables.iterable( label( labelName ) ) ) );
         }
     }
 
@@ -113,9 +159,9 @@ public void shouldRemoveLabel() throws Exception
 
         try ( org.neo4j.graphdb.Transaction ctx = graphDb.beginTx() )
         {
-            assertThat(
-                    graphDb.getNodeById( nodeId ).getLabels(),
-                    equalTo( Iterables.empty() ) );
+            assertThat( graphDb.getNodeById( nodeId ).getLabels(), equalTo( Iterables.empty() ) );
         }
     }
+
+
 }

community/kernel/src/main/java/org/neo4j/kernel/NeoStoreDataSource.java

@@ -83,6 +83,7 @@
 import org.neo4j.kernel.impl.locking.ReentrantLockService;
 import org.neo4j.kernel.impl.locking.StatementLocksFactory;
 import org.neo4j.kernel.impl.logging.LogService;
+import org.neo4j.kernel.impl.newapi.Cursors;
 import org.neo4j.kernel.impl.proc.Procedures;
 import org.neo4j.kernel.impl.storageengine.impl.recordstorage.RecordStorageEngine;
 import org.neo4j.kernel.impl.storageengine.impl.recordstorage.id.IdController;
@@ -688,7 +689,7 @@ private NeoStoreKernelModule buildKernel( LogFiles logFiles, TransactionAppender
                 constraintIndexCreator, statementOperationParts, schemaWriteGuard, transactionHeaderInformationFactory,
                 transactionCommitProcess, indexConfigStore, explicitIndexProviderLookup, hooks, transactionMonitor,
                 availabilityGuard, tracers, storageEngine, procedures, transactionIdStore, clock,
-                cpuClock, heapAllocation, accessCapability ) );
+                cpuClock, heapAllocation, accessCapability, new Cursors() ) );
 
         buildTransactionMonitor( kernelTransactions, clock, config );
 

community/kernel/src/main/java/org/neo4j/kernel/impl/api/KernelTransactionImplementation.java

@@ -63,6 +63,7 @@
 import org.neo4j.kernel.impl.locking.LockTracer;
 import org.neo4j.kernel.impl.locking.Locks;
 import org.neo4j.kernel.impl.locking.StatementLocks;
+import org.neo4j.kernel.impl.newapi.Cursors;
 import org.neo4j.kernel.impl.newapi.Operations;
 import org.neo4j.kernel.impl.proc.Procedures;
 import org.neo4j.kernel.impl.transaction.TransactionHeaderInformationFactory;
@@ -164,7 +165,7 @@ public KernelTransactionImplementation( StatementOperationParts statementOperati
             TransactionMonitor transactionMonitor, Supplier<ExplicitIndexTransactionState> explicitIndexTxStateSupplier,
             Pool<KernelTransactionImplementation> pool, Clock clock, CpuClock cpuClock, HeapAllocation heapAllocation,
             TransactionTracer transactionTracer, LockTracer lockTracer, PageCursorTracerSupplier cursorTracerSupplier,
-            StorageEngine storageEngine, AccessCapability accessCapability )
+            StorageEngine storageEngine, AccessCapability accessCapability, Cursors cursors )
     {
         this.statementOperations = statementOperations;
         this.schemaWriteGuard = schemaWriteGuard;
@@ -185,7 +186,7 @@ public KernelTransactionImplementation( StatementOperationParts statementOperati
                 procedures, accessCapability, lockTracer, statementOperations );
         this.statistics = new Statistics( this, cpuClock, heapAllocation );
         this.userMetaData = new HashMap<>();
-        this.operations = new Operations( storageEngine, storageStatement, this, explicitIndexTxStateSupplier );
+        this.operations = new Operations( storageEngine, storageStatement, this, explicitIndexTxStateSupplier, cursors );
     }
 
     /**
@@ -684,7 +685,7 @@ public Read dataRead()
     @Override
     public Write dataWrite()
     {
-        throw new UnsupportedOperationException( "not implemented" );
+        return operations;
     }
 
     @Override

community/kernel/src/main/java/org/neo4j/kernel/impl/api/KernelTransactions.java

@@ -42,6 +42,7 @@
 import org.neo4j.kernel.impl.index.IndexConfigStore;
 import org.neo4j.kernel.impl.locking.StatementLocks;
 import org.neo4j.kernel.impl.locking.StatementLocksFactory;
+import org.neo4j.kernel.impl.newapi.Cursors;
 import org.neo4j.kernel.impl.proc.Procedures;
 import org.neo4j.kernel.impl.store.TransactionId;
 import org.neo4j.kernel.impl.transaction.TransactionHeaderInformationFactory;
@@ -88,6 +89,7 @@ public class KernelTransactions extends LifecycleAdapter implements Supplier<Ker
     private final SystemNanoClock clock;
     private final ReentrantReadWriteLock newTransactionsLock = new ReentrantReadWriteLock();
     private final MonotonicCounter userTransactionIdCounter = MonotonicCounter.newAtomicMonotonicCounter();
+    private final Cursors cursors;
 
     /**
      * Used to enumerate all transactions in the system, active and idle ones.
@@ -124,7 +126,7 @@ public KernelTransactions( StatementLocksFactory statementLocksFactory,
             ExplicitIndexProviderLookup explicitIndexProviderLookup, TransactionHooks hooks,
             TransactionMonitor transactionMonitor, AvailabilityGuard availabilityGuard, Tracers tracers,
             StorageEngine storageEngine, Procedures procedures, TransactionIdStore transactionIdStore, SystemNanoClock clock,
-            CpuClock cpuClock, HeapAllocation heapAllocation, AccessCapability accessCapability )
+            CpuClock cpuClock, HeapAllocation heapAllocation, AccessCapability accessCapability, Cursors cursors )
     {
         this.statementLocksFactory = statementLocksFactory;
         this.constraintIndexCreator = constraintIndexCreator;
@@ -146,6 +148,7 @@ public KernelTransactions( StatementLocksFactory statementLocksFactory,
                 new ExplicitIndexTransactionStateImpl( indexConfigStore, explicitIndexProviderLookup ) );
         this.clock = clock;
         blockNewTransactions();
+        this.cursors = cursors;
     }
 
     public Supplier<ExplicitIndexTransactionState> explicitIndexTxStateSupplier()
@@ -332,7 +335,7 @@ public KernelTransactionImplementation newInstance()
                             constraintIndexCreator, procedures, transactionHeaderInformationFactory,
                             transactionCommitProcess, transactionMonitor, explicitIndexTxStateSupplier, localTxPool,
                             clock, cpuClock, heapAllocation, tracers.transactionTracer, tracers.lockTracer,
-                            tracers.pageCursorTracerSupplier, storageEngine, accessCapability );
+                            tracers.pageCursorTracerSupplier, storageEngine, accessCapability, cursors );
             this.transactions.add( tx );
             return tx;
         }

community/kernel/src/main/java/org/neo4j/kernel/impl/api/explicitindex/InternalAutoIndexOperations.java

@@ -312,4 +312,4 @@ private void ensureIndexExists( DataWriteOperations ops ) throws ExplicitIndexNo
             indexCreated = true;
         }
     }
-}
+}

community/kernel/src/main/java/org/neo4j/kernel/impl/newapi/AllStoreHolder.java

@@ -70,8 +70,10 @@ class AllStoreHolder extends Read implements Token
 
     AllStoreHolder( StorageEngine engine,
                     StorageStatement statement,
-                    Supplier<ExplicitIndexTransactionState> explicitIndexes )
+                    Supplier<ExplicitIndexTransactionState> explicitIndexes,
+                    Cursors cursors )
     {
+        super( cursors );
         this.read = engine.storeReadLayer();
         this.statement = statement; // use provided statement, to assert no leakage
         this.explicitIndexes = Suppliers.lazySingleton( explicitIndexes );
@@ -238,11 +240,6 @@ RecordCursor<DynamicRecord> labelCursor()
         return nodes.newLabelCursor();
     }
 
-    private static <R extends AbstractBaseRecord> RecordCursor<R> newCursor( RecordStore<R> store )
-    {
-        return store.newRecordCursor( store.newRecord() ).acquire( store.getNumberOfReservedLowIds(), NORMAL );
-    }
-
     @Override
     void node( NodeRecord record, long reference, PageCursor pageCursor )
     {
@@ -294,4 +291,9 @@ ArrayValue array( PropertyCursor cursor, long reference, PageCursor page )
         buffer.flip();
         return PropertyUtil.readArrayFromBuffer( buffer );
     }
+
+    public boolean nodeExists( long id )
+    {
+        return read.nodeExists( id );
+    }
 }

community/kernel/src/main/java/org/neo4j/kernel/impl/newapi/Cursors.java

@@ -19,66 +19,59 @@
  */
 package org.neo4j.kernel.impl.newapi;
 
-class Cursors implements org.neo4j.internal.kernel.api.CursorFactory
+public class Cursors implements org.neo4j.internal.kernel.api.CursorFactory
 {
-    private final Read read;
-
-    Cursors( Read read )
-    {
-        this.read = read;
-    }
-
     @Override
     public NodeCursor allocateNodeCursor()
     {
-        return new NodeCursor( read );
+        return new NodeCursor( );
     }
 
     @Override
     public RelationshipScanCursor allocateRelationshipScanCursor()
     {
-        return new RelationshipScanCursor( read );
+        return new RelationshipScanCursor( );
     }
 
     @Override
     public RelationshipTraversalCursor allocateRelationshipTraversalCursor()
     {
-        return new RelationshipTraversalCursor( read );
+        return new RelationshipTraversalCursor( allocateRelationshipGroupCursor() );
     }
 
     @Override
     public PropertyCursor allocatePropertyCursor()
     {
-        return new PropertyCursor( read );
+        return new PropertyCursor( );
     }
 
     @Override
     public RelationshipGroupCursor allocateRelationshipGroupCursor()
     {
-        return new RelationshipGroupCursor( read );
+        return new RelationshipGroupCursor( );
     }
 
     @Override
     public NodeValueIndexCursor allocateNodeValueIndexCursor()
     {
-        return new NodeValueIndexCursor( read );
+        return new NodeValueIndexCursor( );
     }
 
     @Override
     public NodeLabelIndexCursor allocateNodeLabelIndexCursor()
     {
-        return new NodeLabelIndexCursor( read );
+        return new NodeLabelIndexCursor( );
     }
 
     @Override
     public NodeExplicitIndexCursor allocateNodeManualIndexCursor()
     {
-        return new NodeExplicitIndexCursor( read );
+        return new NodeExplicitIndexCursor( );
     }
 
     @Override
     public RelationshipExplicitIndexCursor allocateRelationshipManualIndexCursor()
     {
-        return new RelationshipExplicitIndexCursor( read );
+        return new RelationshipExplicitIndexCursor( );
     }
 }

community/kernel/src/main/java/org/neo4j/kernel/impl/newapi/KernelToken.java

@@ -26,17 +26,17 @@
 
 class KernelToken implements Token
 {
-    private final StoreReadLayer read;
+    private final StoreReadLayer store;
 
     KernelToken( StorageEngine engine )
     {
-        read = engine.storeReadLayer();
+        store = engine.storeReadLayer();
     }
 
     @Override
     public int labelGetOrCreateForName( String labelName ) throws KernelException
     {
-        throw new UnsupportedOperationException( "not implemented" );
+        return store.labelGetOrCreateForName( labelName );
     }
 
     @Override
@@ -72,18 +72,18 @@ public void relationshipTypeCreateForName( String relationshipTypeName, int id )
     @Override
     public int nodeLabel( String name )
     {
-        return read.labelGetForName( name );
+        return store.labelGetForName( name );
     }
 
     @Override
     public int relationshipType( String name )
     {
-        return read.relationshipTypeGetForName( name );
+        return store.relationshipTypeGetForName( name );
     }
 
     @Override
     public int propertyKey( String name )
     {
-        return read.propertyKeyGetForName( name );
+        return store.propertyKeyGetForName( name );
     }
 }

community/kernel/src/main/java/org/neo4j/kernel/impl/newapi/NewKernel.java

@@ -51,6 +51,11 @@ public NewKernel( StorageEngine engine, Supplier<ExplicitIndexTransactionState>
         this.explicitIndexes = explicitIndexes;
         this.kernel = kernel;
         this.isRunning = false;
+        this.cursors = new Cursors(  );
+        // This extra statement will be remove once we start adding tx-state. That is because
+        // by then we cannot use a global Read in the CursorFactory, but need to use transaction
+        // specific Read instances which are given to the Cursors on initialization.
+        this.read = new AllStoreHolder( engine, engine.storeReadLayer().newStatement(), explicitIndexes, cursors );
     }
 
     @Override
@@ -69,14 +74,9 @@ public KernelSession beginSession( SecurityContext securityContext )
 
     public void start()
     {
-        // This extra statement will be remove once we start adding tx-state. That is because
-        // by then we cannot use a global Read in the CursorFactory, but need to use transaction
-        // specific Read instances which are given to the Cursors on initialization.
         statement = engine.storeReadLayer().newStatement();
-        this.read = new AllStoreHolder( engine, statement, explicitIndexes );
-        this.cursors = new Cursors( read );
+        this.cursors = new Cursors();
         isRunning = true;
-
     }
 
     public void stop()