Write array properties as an inner list with a single type

Co-Authored-By: Sören Reichardt <soren.reichardt@neotechnology.com>

Author: knutwalker

algo/src/main/java/org/neo4j/gds/louvain/Louvain.java

@@ -25,7 +25,6 @@
 import org.neo4j.gds.api.Graph;
 import org.neo4j.gds.api.IdMap;
 import org.neo4j.gds.api.RelationshipIterator;
-import org.neo4j.gds.api.properties.nodes.LongNodePropertyValues;
 import org.neo4j.gds.api.properties.nodes.NodePropertyValues;
 import org.neo4j.gds.beta.modularity.ImmutableModularityOptimizationStreamConfig;
 import org.neo4j.gds.beta.modularity.ModularityOptimization;
@@ -35,12 +34,11 @@
 import org.neo4j.gds.core.concurrency.ParallelUtil;
 import org.neo4j.gds.core.loading.construction.GraphFactory;
 import org.neo4j.gds.core.loading.construction.RelationshipsBuilder;
+import org.neo4j.gds.core.utils.OriginalIdNodePropertyValues;
 import org.neo4j.gds.core.utils.paged.HugeLongArray;
 import org.neo4j.gds.core.utils.partition.Partition;
 import org.neo4j.gds.core.utils.partition.PartitionUtils;
 import org.neo4j.gds.core.utils.progress.tasks.ProgressTracker;
-import org.neo4j.values.storable.Value;
-import org.neo4j.values.storable.Values;
 
 import java.util.Optional;
 import java.util.OptionalLong;
@@ -98,7 +96,13 @@ public Louvain compute() {
             long maxCommunityId = buildDendrogram(workingGraph, ranLevels, modularityOptimization);
 
             workingGraph = summarizeGraph(workingGraph, modularityOptimization, maxCommunityId);
-            nextSeedingValues = new OriginalIdNodePropertyValues(workingGraph);
+            nextSeedingValues = new OriginalIdNodePropertyValues(workingGraph) {
+                @Override
+                public OptionalLong getMaxLongPropertyValue() {
+                    // We want to use the maxSeedCommunity with value 0 in all subsequent iterations
+                    return OptionalLong.empty();
+                }
+            };
 
             if (workingGraph.nodeCount() == oldNodeCount
                 || workingGraph.nodeCount() == 1
@@ -269,34 +273,6 @@ public void release() {
         this.rootGraph.releaseTopology();
     }
 
-    static class OriginalIdNodePropertyValues implements LongNodePropertyValues {
-        private final Graph graph;
-
-        public OriginalIdNodePropertyValues(Graph graph) {
-            this.graph = graph;
-        }
-
-        @Override
-        public long longValue(long nodeId) {
-            return graph.toOriginalNodeId(nodeId);
-        }
-
-        @Override
-        public Value value(long nodeId) {
-            return Values.longValue(longValue(nodeId));
-        }
-
-        @Override
-        public OptionalLong getMaxLongPropertyValue() {
-            return OptionalLong.empty();
-        }
-
-        @Override
-        public long size() {
-            return graph.nodeCount();
-        }
-    }
-
     static final class RelationshipCreator implements Runnable {
 
         private final RelationshipsBuilder relationshipsBuilder;

core/src/main/java/org/neo4j/gds/core/utils/OriginalIdNodePropertyValues.java

@@ -0,0 +1,48 @@
+/*
+ * Copyright (c) "Neo4j"
+ * Neo4j Sweden AB [http://neo4j.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.gds.core.utils;
+
+import org.neo4j.gds.api.IdMap;
+import org.neo4j.gds.api.properties.nodes.LongNodePropertyValues;
+
+import java.util.OptionalLong;
+
+public class OriginalIdNodePropertyValues implements LongNodePropertyValues {
+    private final IdMap idMap;
+
+    public OriginalIdNodePropertyValues(IdMap idMap) {
+        this.idMap = idMap;
+    }
+
+    @Override
+    public long longValue(long nodeId) {
+        return idMap.toOriginalNodeId(nodeId);
+    }
+
+    @Override
+    public OptionalLong getMaxLongPropertyValue() {
+        return OptionalLong.of(idMap.highestNeoId());
+    }
+
+    @Override
+    public long size() {
+        return idMap.nodeCount();
+    }
+}