Wrap target nodes in a predicate type

Author: jjaderberg

algo/src/main/java/org/neo4j/gds/similarity/filteredknn/FilteredKnn.java

@@ -58,7 +58,7 @@ public class FilteredKnn extends Algorithm<FilteredKnnResult> {
     private final double sampleRate;
     private final double similarityCutoff;
     private final List<Long> sourceNodes;
-    private final List<Long> targetNodes;
+    private final TargetNodePredicate targetNodePredicate;
     private final int topK;
 
     private long nodePairsConsidered;
@@ -79,6 +79,7 @@ public static FilteredKnn create(
         var splittableRandom = getSplittableRandom(config.randomSeed());
         var sourceNodes = config.sourceNodeFilter().stream().map(graph::toMappedNodeId).collect(Collectors.toList());
         var targetNodes = config.targetNodeFilter().stream().map(graph::toMappedNodeId).collect(Collectors.toList());
+        var targetNodePredicate = new TargetNodePredicate(targetNodes);
         var samplerSupplier = samplerSupplier(graph, config);
         return new FilteredKnn(
             context.progressTracker(),
@@ -98,7 +99,7 @@ public static FilteredKnn create(
             config.sampleRate(),
             config.similarityCutoff(),
             sourceNodes,
-            targetNodes,
+            targetNodePredicate,
             config.topK()
         );
     }
@@ -142,7 +143,7 @@ private FilteredKnn(
         double sampleRate,
         double similarityCutoff,
         List<Long> sourceNodes,
-        List<Long> targetNodes,
+        TargetNodePredicate targetNodePredicate,
         int topK
 
     ) {
@@ -163,7 +164,7 @@ private FilteredKnn(
         this.sampleRate = sampleRate;
         this.similarityCutoff = similarityCutoff;
         this.sourceNodes = sourceNodes;
-        this.targetNodes = targetNodes;
+        this.targetNodePredicate = targetNodePredicate;
         this.topK = topK;
     }
 

algo/src/main/java/org/neo4j/gds/similarity/filteredknn/TargetNodePredicate.java

@@ -0,0 +1,32 @@
+/*
+ * 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.similarity.filteredknn;
+
+import java.util.List;
+
+public class TargetNodePredicate {
+    private final List<Long> nodeIds;
+
+    public TargetNodePredicate(List<Long> nodeIds) {this.nodeIds = nodeIds;}
+
+    public boolean test(long nodeId) {
+        return nodeIds.contains(nodeId);
+    }
+}