Avoid producing tons of state maps for single node cursor

Remember state of already defined nodes only for case of nodes iteration and do not do that if cursor created to go over single node.
neo4j · Jan 12, 2018 · 436902e · 436902e
1 parent 03b5247
commit 436902e
Showing 1 changed file with 14 additions and 5 deletions.
diff --git a/community/kernel/src/main/java/org/neo4j/kernel/impl/newapi/NodeCursor.java b/community/kernel/src/main/java/org/neo4j/kernel/impl/newapi/NodeCursor.java
@@ -34,6 +34,7 @@
 import org.neo4j.kernel.impl.store.record.DynamicRecord;
 import org.neo4j.kernel.impl.store.record.NodeRecord;
 
+import static java.util.Collections.emptySet;
 import static org.neo4j.kernel.impl.newapi.References.setDirectFlag;
 import static org.neo4j.kernel.impl.newapi.References.setGroupFlag;
 
@@ -73,7 +74,7 @@ void scan( Read read )
         this.highMark = read.nodeHighMark();
         this.read = read;
         this.hasChanges = HasChanges.MAYBE;
-        this.addedNodes = null;
+        this.addedNodes = emptySet();
     }
 
     void single( long reference, Read read )
@@ -91,7 +92,7 @@ void single( long reference, Read read )
         this.highMark = NO_ID;
         this.read = read;
         this.hasChanges = HasChanges.MAYBE;
-        this.addedNodes = null;
+        this.addedNodes = emptySet();
     }
 
     @Override
@@ -188,7 +189,7 @@ public boolean next()
         TransactionState txs = hasChanges ? read.txState() : null;
         do
         {
-            if ( hasChanges && addedNodes.contains( next ) )
+            if ( hasChanges && containsNode( txs ) )
             {
                 setId( next++ );
                 setInUse( true );
@@ -233,6 +234,11 @@ else if ( next < 0 )
         return true;
     }
 
+    private boolean containsNode( TransactionState txs )
+    {
+        return isSingle() ? txs.nodeIsAddedInThisTx( next ) : addedNodes.contains( next );
+    }
+
     @Override
     public boolean shouldRetry()
     {
@@ -255,7 +261,7 @@ public void close()
             labelCursor = null;
         }
         hasChanges = HasChanges.MAYBE;
-        addedNodes = null;
+        addedNodes = emptySet();
         reset();
     }
 
@@ -277,7 +283,10 @@ private boolean hasChanges()
             boolean changes = read.hasTxStateWithChanges();
             if ( changes )
             {
-                addedNodes = read.txState().addedAndRemovedNodes().getAddedSnapshot();
+                if ( !isSingle() )
+                {
+                    addedNodes = read.txState().addedAndRemovedNodes().getAddedSnapshot();
+                }
                 hasChanges = HasChanges.YES;
             }
             else