Add support for label scan in the Kernel API implementation

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

@@ -0,0 +1,88 @@
+/*
+ * Copyright (c) 2002-2017 "Neo Technology,"
+ * Network Engine for Objects in Lund AB [http://neotechnology.com]
+ *
+ * This file is part of Neo4j.
+ *
+ * Neo4j is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.neo4j.internal.kernel.api;
+
+import org.junit.Test;
+
+import org.neo4j.collection.primitive.Primitive;
+import org.neo4j.collection.primitive.PrimitiveLongSet;
+import org.neo4j.graphdb.GraphDatabaseService;
+import org.neo4j.graphdb.Transaction;
+
+import static org.neo4j.graphdb.Label.label;
+import static org.neo4j.internal.kernel.api.NodeValueIndexCursorTestBase.assertFoundNodes;
+
+public abstract class NodeLabelIndexCursorTestBase<G extends KernelAPIReadTestSupport>
+        extends KernelAPIReadTestBase<G>
+{
+    @Override
+    void createTestGraph( GraphDatabaseService graphDb )
+    {
+        try ( Transaction tx = graphDb.beginTx() )
+        {
+            graphDb.createNode( label( "One" ), label( "First" ) );
+            graphDb.createNode( label( "Two" ), label( "First" ) );
+            graphDb.createNode( label( "Three" ), label( "First" ) );
+            graphDb.createNode( label( "Two" ) );
+            graphDb.createNode( label( "Three" ) );
+            graphDb.createNode( label( "Three" ) );
+
+            tx.success();
+        }
+    }
+
+    @Test
+    public void shouldFindNodesByLabel() throws Exception
+    {
+        // given
+        int one = read.nodeLabel( "One" );
+        int two = read.nodeLabel( "Two" );
+        int three = read.nodeLabel( "Three" );
+        int first = read.nodeLabel( "First" );
+        try ( NodeLabelIndexCursor cursor = cursors.allocateNodeLabelIndexCursor();
+              PrimitiveLongSet uniqueIds = Primitive.longSet() )
+        {
+            // when
+            read.nodeLabelScan( one, cursor );
+
+            // then
+            assertFoundNodes( cursor, 1, uniqueIds );
+
+            // when
+            read.nodeLabelScan( two, cursor );
+
+            // then
+            assertFoundNodes( cursor, 2, uniqueIds );
+
+            // when
+            read.nodeLabelScan( three, cursor );
+
+            // then
+            assertFoundNodes( cursor, 3, uniqueIds );
+
+            // when
+            uniqueIds.clear();
+            read.nodeLabelScan( first, cursor );
+
+            // then
+            assertFoundNodes( cursor, 3, uniqueIds );
+        }
+    }
+}

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

@@ -222,8 +222,7 @@ public void shouldPerformNumericRangeSearch() throws Exception
         int prop = read.propertyKey( "prop" );
         IndexReference index = read.index( label, prop );
         try ( NodeValueIndexCursor node = cursors.allocateNodeValueIndexCursor();
-              PrimitiveLongSet uniqueIds = Primitive.longSet();
-              NodeCursor n = cursors.allocateNodeCursor(); PropertyCursor p = cursors.allocatePropertyCursor() )
+              PrimitiveLongSet uniqueIds = Primitive.longSet() )
         {
             // when
             uniqueIds.clear();
@@ -273,7 +272,7 @@ public void shouldPerformIndexScan() throws Exception
         }
     }
 
-    private static void assertFoundNodes( NodeValueIndexCursor node, int nodes, PrimitiveLongSet uniqueIds )
+    static void assertFoundNodes( NodeIndexCursor node, int nodes, PrimitiveLongSet uniqueIds )
     {
         for ( int i = 0; i < nodes; i++ )
         {

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

@@ -19,6 +19,7 @@
  */
 package org.neo4j.kernel.impl.newapi;
 
+import org.neo4j.internal.kernel.api.LabelSet;
 import org.neo4j.values.storable.Value;
 
 public interface IndexCursorProgressor
@@ -35,4 +36,13 @@ interface NodeValueCursor
 
         boolean node( long reference, Value[] values );
     }
+
+    interface NodeLabelCursor
+    {
+        void initialize( IndexCursorProgressor progressor, boolean providesLabels );
+
+        void done();
+
+        boolean node( long reference, LabelSet labels );
+    }
 }

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

@@ -22,37 +22,63 @@
 import org.neo4j.internal.kernel.api.LabelSet;
 import org.neo4j.internal.kernel.api.NodeCursor;
 
-class NodeLabelIndexCursor implements org.neo4j.internal.kernel.api.NodeLabelIndexCursor
+import static org.neo4j.kernel.impl.store.record.AbstractBaseRecord.NO_ID;
+
+class NodeLabelIndexCursor implements org.neo4j.internal.kernel.api.NodeLabelIndexCursor,
+        IndexCursorProgressor.NodeLabelCursor
 {
     private final Read read;
+    private long node;
+    private LabelSet labels;
+    private IndexCursorProgressor progressor;
 
     NodeLabelIndexCursor( Read read )
     {
         this.read = read;
     }
 
+    @Override
+    public void initialize( IndexCursorProgressor progressor, boolean providesLabels )
+    {
+        this.progressor = progressor;
+    }
+
+    @Override
+    public boolean node( long reference, LabelSet labels )
+    {
+        this.node = reference;
+        this.labels = labels;
+        return true;
+    }
+
+    @Override
+    public void done()
+    {
+        close();
+    }
+
     @Override
     public void node( NodeCursor cursor )
     {
-        throw new UnsupportedOperationException( "not implemented" );
+        read.singleNode( node, cursor );
     }
 
     @Override
     public long nodeReference()
     {
-        throw new UnsupportedOperationException( "not implemented" );
+        return node;
     }
 
     @Override
     public LabelSet labels()
     {
-        throw new UnsupportedOperationException( "not implemented" );
+        return labels;
     }
 
     @Override
     public boolean next()
     {
-        throw new UnsupportedOperationException( "not implemented" );
+        return progressor != null && progressor.next();
     }
 
     @Override
@@ -64,6 +90,8 @@ public boolean shouldRetry()
     @Override
     public void close()
     {
-        throw new UnsupportedOperationException( "not implemented" );
+        progressor.close();
+        node = NO_ID;
+        labels = null;
     }
 }

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

@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) 2002-2017 "Neo Technology,"
+ * Network Engine for Objects in Lund AB [http://neotechnology.com]
+ *
+ * This file is part of Neo4j.
+ *
+ * Neo4j is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.neo4j.kernel.impl.newapi;
+
+import org.neo4j.collection.primitive.PrimitiveLongIterator;
+import org.neo4j.graphdb.Resource;
+
+class NodeLabelIndexProgressor implements IndexCursorProgressor
+{
+    private final PrimitiveLongIterator iterator;
+    private final NodeLabelCursor target;
+
+    NodeLabelIndexProgressor( PrimitiveLongIterator iterator, NodeLabelCursor target )
+    {
+        this.iterator = iterator;
+        this.target = target;
+    }
+
+    @Override
+    public boolean next()
+    {
+        while ( iterator.hasNext() )
+        {
+            if ( target.node( iterator.next(), null ) )
+            {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    @Override
+    public void close()
+    {
+        if ( iterator instanceof Resource )
+        {
+            ((Resource) iterator).close();
+        }
+    }
+}

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

@@ -21,6 +21,7 @@
 
 import java.util.Arrays;
 
+import org.neo4j.collection.primitive.PrimitiveLongIterator;
 import org.neo4j.internal.kernel.api.IndexQuery;
 import org.neo4j.internal.kernel.api.Scan;
 import org.neo4j.io.pagecache.PageCursor;
@@ -32,6 +33,7 @@
 import org.neo4j.kernel.impl.store.record.RelationshipGroupRecord;
 import org.neo4j.kernel.impl.store.record.RelationshipRecord;
 import org.neo4j.storageengine.api.schema.IndexReader;
+import org.neo4j.storageengine.api.schema.LabelScanReader;
 import org.neo4j.values.storable.ArrayValue;
 import org.neo4j.values.storable.TextValue;
 import org.neo4j.values.storable.Value;
@@ -95,12 +97,12 @@ public final void nodeIndexScan(
         indexReader( (IndexReference) index ).scan( (NodeValueIndexCursor) cursor );
     }
 
-    abstract IndexReader indexReader( IndexReference index );
-
     @Override
     public final void nodeLabelScan( int label, org.neo4j.internal.kernel.api.NodeLabelIndexCursor cursor )
     {
-        throw new UnsupportedOperationException( "not implemented" );
+        LabelScanReader reader = labelScanReader();
+        IndexCursorProgressor.NodeLabelCursor target = (NodeLabelIndexCursor) cursor;
+        target.initialize( new NodeLabelIndexProgressor( reader.nodesWithLabel( label ), target ), false );
     }
 
     @Override
@@ -256,6 +258,10 @@ public final void futureRelationshipPropertyReferenceRead( long reference )
     {
     }
 
+    abstract IndexReader indexReader( IndexReference index );
+
+    abstract LabelScanReader labelScanReader();
+
     @Override
     public abstract IndexReference index( int label, int... properties );
 

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

@@ -22,6 +22,7 @@
 import java.nio.ByteBuffer;
 import java.nio.ByteOrder;
 
+import org.neo4j.collection.primitive.PrimitiveLongIterator;
 import org.neo4j.io.pagecache.PageCursor;
 import org.neo4j.kernel.api.exceptions.index.IndexNotFoundKernelException;
 import org.neo4j.kernel.api.schema.LabelSchemaDescriptor;
@@ -47,6 +48,7 @@
 import org.neo4j.storageengine.api.StorageStatement;
 import org.neo4j.storageengine.api.StoreReadLayer;
 import org.neo4j.storageengine.api.schema.IndexReader;
+import org.neo4j.storageengine.api.schema.LabelScanReader;
 import org.neo4j.string.UTF8;
 import org.neo4j.values.storable.ArrayValue;
 import org.neo4j.values.storable.TextValue;
@@ -90,6 +92,12 @@ IndexReader indexReader( IndexReference index )
         }
     }
 
+    @Override
+    LabelScanReader labelScanReader()
+    {
+        return statement.getLabelScanReader();
+    }
+
     @Override
     public IndexReference index( int label, int... properties )
     {

community/kernel/src/test/java/org/neo4j/kernel/impl/newapi/MockStore.java

@@ -38,6 +38,7 @@
 import org.neo4j.kernel.impl.store.record.RelationshipGroupRecord;
 import org.neo4j.kernel.impl.store.record.RelationshipRecord;
 import org.neo4j.storageengine.api.schema.IndexReader;
+import org.neo4j.storageengine.api.schema.LabelScanReader;
 import org.neo4j.values.storable.ArrayValue;
 import org.neo4j.values.storable.TextValue;
 import org.neo4j.values.storable.Value;
@@ -65,6 +66,12 @@ IndexReader indexReader( IndexReference index )
         throw new UnsupportedOperationException( "not implemented" );
     }
 
+    @Override
+    LabelScanReader labelScanReader()
+    {
+        throw new UnsupportedOperationException( "not implemented" );
+    }
+
     @Override
     PageCursor nodePage( long reference )
     {

community/kernel/src/test/java/org/neo4j/kernel/impl/newapi/NodeLabelIndexCursorTest.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) 2002-2017 "Neo Technology,"
+ * Network Engine for Objects in Lund AB [http://neotechnology.com]
+ *
+ * This file is part of Neo4j.
+ *
+ * Neo4j is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.neo4j.kernel.impl.newapi;
+
+import org.neo4j.internal.kernel.api.NodeLabelIndexCursorTestBase;
+
+public class NodeLabelIndexCursorTest extends NodeLabelIndexCursorTestBase<ReadTestSupport>
+{
+    @Override
+    public ReadTestSupport newTestSupport()
+    {
+        return new ReadTestSupport();
+    }
+}