Add support for inverse index in NodeFilteredGraph

Author: s1ck

core/src/main/java/org/neo4j/gds/core/huge/NodeFilteredGraph.java

@@ -20,6 +20,7 @@
 package org.neo4j.gds.core.huge;
 
 import org.apache.commons.lang3.mutable.MutableInt;
+import org.jetbrains.annotations.Nullable;
 import org.neo4j.gds.NodeLabel;
 import org.neo4j.gds.api.CSRGraph;
 import org.neo4j.gds.api.CSRGraphAdapter;
@@ -32,10 +33,10 @@
 import org.neo4j.gds.api.RelationshipWithPropertyConsumer;
 import org.neo4j.gds.api.properties.nodes.NodePropertyValues;
 import org.neo4j.gds.api.schema.GraphSchema;
+import org.neo4j.gds.collections.ha.HugeIntArray;
 import org.neo4j.gds.collections.primitive.PrimitiveLongIterable;
 import org.neo4j.gds.config.ConcurrencyConfig;
 import org.neo4j.gds.core.concurrency.RunWithConcurrency;
-import org.neo4j.gds.collections.ha.HugeIntArray;
 import org.neo4j.gds.core.utils.partition.Partition;
 import org.neo4j.gds.core.utils.partition.PartitionUtils;
 import org.neo4j.gds.utils.CloseableThreadLocal;
@@ -56,16 +57,30 @@ public class NodeFilteredGraph extends CSRGraphAdapter implements FilteredIdMap
     private final FilteredIdMap filteredIdMap;
     private long relationshipCount;
     private final HugeIntArray degreeCache;
+    private final HugeIntArray degreeInverseCache;
     private final CloseableThreadLocal<Graph> threadLocalGraph;
 
     public NodeFilteredGraph(CSRGraph originalGraph, FilteredIdMap filteredIdMap) {
-        this(originalGraph, filteredIdMap, emptyDegreeCache(filteredIdMap), -1);
+        this(
+            originalGraph,
+            filteredIdMap,
+            emptyDegreeCache(filteredIdMap),
+            originalGraph.characteristics().isInverseIndexed() ? emptyDegreeCache(filteredIdMap) : null,
+            -1
+        );
     }
 
-    private NodeFilteredGraph(CSRGraph originalGraph, FilteredIdMap filteredIdMap, HugeIntArray degreeCache, long relationshipCount) {
+    private NodeFilteredGraph(
+        CSRGraph originalGraph,
+        FilteredIdMap filteredIdMap,
+        HugeIntArray degreeCache,
+        @Nullable HugeIntArray degreeInverseCache,
+        long relationshipCount
+    ) {
         super(originalGraph);
 
         this.degreeCache = degreeCache;
+        this.degreeInverseCache = degreeInverseCache;
         this.filteredIdMap = filteredIdMap;
         this.relationshipCount = relationshipCount;
         this.threadLocalGraph = CloseableThreadLocal.withInitial(this::concurrentCopy);
@@ -104,18 +119,18 @@ public void forEachNode(LongPredicate consumer) {
 
     @Override
     public int degree(long nodeId) {
-        int cachedDegree = degreeCache.get(nodeId);
+        int cachedDegree = this.degreeCache.get(nodeId);
         if (cachedDegree != NO_DEGREE) {
             return cachedDegree;
         }
 
         var degree = new MutableInt();
 
-        threadLocalGraph.get().forEachRelationship(nodeId, (s, t) -> {
+        this.threadLocalGraph.get().forEachRelationship(nodeId, (s, t) -> {
             degree.increment();
             return true;
         });
-        degreeCache.set(nodeId, degree.intValue());
+        this.degreeCache.set(nodeId, degree.intValue());
 
         return degree.intValue();
     }
@@ -130,6 +145,24 @@ public int degreeWithoutParallelRelationships(long nodeId) {
         return degreeCounter.degree;
     }
 
+    @Override
+    public int degreeInverse(long nodeId) {
+        int cachedDegree = this.degreeInverseCache.get(nodeId);
+        if (cachedDegree != NO_DEGREE) {
+            return cachedDegree;
+        }
+
+        var degree = new MutableInt();
+
+        this.threadLocalGraph.get().forEachInverseRelationship(nodeId, (s, t) -> {
+            degree.increment();
+            return true;
+        });
+        this.degreeInverseCache.set(nodeId, degree.intValue());
+
+        return degree.intValue();
+    }
+
     @Override
     public long nodeCount() {
         return filteredIdMap.nodeCount();
@@ -218,9 +251,30 @@ public void forEachRelationship(long nodeId, double fallbackValue, RelationshipW
         );
     }
 
+    @Override
+    public void forEachInverseRelationship(long nodeId, RelationshipConsumer consumer) {
+        super.forEachInverseRelationship(
+            filteredIdMap.toRootNodeId(nodeId),
+            (s, t) -> filterAndConsume(s, t, consumer)
+        );
+    }
+
+    @Override
+    public void forEachInverseRelationship(
+        long nodeId,
+        double fallbackValue,
+        RelationshipWithPropertyConsumer consumer
+    ) {
+        super.forEachInverseRelationship(
+            filteredIdMap.toRootNodeId(nodeId),
+            fallbackValue,
+            (s, t, p) -> filterAndConsume(s, t, p, consumer)
+        );
+    }
+
     @Override
     public Stream<RelationshipCursor> streamRelationships(long nodeId, double fallbackValue) {
-        if (! filteredIdMap.containsRootNodeId(filteredIdMap.toRootNodeId(nodeId))) {
+        if (!filteredIdMap.containsRootNodeId(filteredIdMap.toRootNodeId(nodeId))) {
             return Stream.empty();
         }
 
@@ -266,7 +320,13 @@ public double relationshipProperty(long sourceNodeId, long targetNodeId) {
 
     @Override
     public CSRGraph concurrentCopy() {
-        return new NodeFilteredGraph(csrGraph.concurrentCopy(), filteredIdMap, degreeCache, relationshipCount);
+        return new NodeFilteredGraph(
+            csrGraph.concurrentCopy(),
+            filteredIdMap,
+            degreeCache,
+            degreeInverseCache,
+            relationshipCount
+        );
     }
 
     @Override
@@ -312,7 +372,12 @@ private boolean filterAndConsume(long source, long target, RelationshipConsumer
         return true;
     }
 
-    private boolean filterAndConsume(long source, long target, double propertyValue, RelationshipWithPropertyConsumer consumer) {
+    private boolean filterAndConsume(
+        long source,
+        long target,
+        double propertyValue,
+        RelationshipWithPropertyConsumer consumer
+    ) {
         if (filteredIdMap.containsRootNodeId(source) && filteredIdMap.containsRootNodeId(target)) {
             long internalSourceId = filteredIdMap.toFilteredNodeId(source);
             long internalTargetId = filteredIdMap.toFilteredNodeId(target);

core/src/test/java/org/neo4j/gds/core/huge/NodeFilteredGraphTest.java

@@ -44,16 +44,18 @@
 @GdlExtension
 class NodeFilteredGraphTest {
 
-    @GdlGraph(idOffset = 1337)
+    @GdlGraph(idOffset = 1337, indexInverse = true)
     static String GDL = " (x:Ignore)," +
                         " (a:Person)," +
                         " (b:Ignore:Person)," +
                         " (c:Ignore:Person)," +
                         " (d:Person)," +
                         " (e:Ignore)," +
+                        " (x)-->(d)," + // ignored for index inverse
                         " (a)-->(b)," +
                         " (a)-->(e)," +
                         " (b)-->(c)," +
+                        " (x)-->(c)," + // ignored for index inverse
                         " (b)-->(d)," +
                         " (c)-->(e)";
 
@@ -122,6 +124,32 @@ void filterDegreeWithoutParallelRelationships() {
         assertThat(graph.degreeWithoutParallelRelationships(filteredIdFunction(graph).apply("a"))).isEqualTo(1L);
     }
 
+    @Test
+    void filterDegreeInverse() {
+        var graph = graphStore.getGraph(
+            NodeLabel.of("Person"),
+            RelationshipType.ALL_RELATIONSHIPS,
+            Optional.empty()
+        );
+
+        assertThat(graph.degreeInverse(filteredIdFunction(graph).apply("d"))).isEqualTo(1L);
+    }
+
+    @Test
+    void foreachInverseRelationship() {
+        var graph = graphStore.getGraph(
+            NodeLabel.of("Person"),
+            RelationshipType.ALL_RELATIONSHIPS,
+            Optional.empty()
+        );
+
+        graph.forEachInverseRelationship(filteredIdFunction(graph).apply("d"), (source, target) -> {
+            assertThat(source).isEqualTo(filteredIdFunction(graph).apply("d"));
+            assertThat(target).isEqualTo(filteredIdFunction(graph).apply("b"));
+            return true;
+        });
+    }
+
     @Test
     void filterStreamRelationships() {
         var graph = graphStore.getGraph(