Fix fields / remove target

Author: jjaderberg

algo/src/main/java/org/neo4j/gds/steiner/LinkCutNode.java

@@ -23,17 +23,14 @@ class LinkCutNode {
     private LinkCutNode up;
     private LinkCutNode left;
     private LinkCutNode right;
-    private long source;//from;
-    private long target;//to;
-
+    private final long source;//from;
     private boolean reverseBit;
 
-    LinkCutNode(long source, long target, LinkCutNode p) {
+    LinkCutNode(long source, LinkCutNode p) {
         up = p;
         left = null;
         right = null;
         this.source = source;
-        this.target = target;
         reverseBit = false;
     }
 
@@ -85,7 +82,7 @@ boolean isChildOf(LinkCutNode node) {
     }
 
     static LinkCutNode createSingle(long id) {
-        return new LinkCutNode(id, id, null);
+        return new LinkCutNode(id, null);
     }
 
 }

algo/src/main/java/org/neo4j/gds/steiner/LinkCutTree.java

@@ -23,8 +23,8 @@
 
 class LinkCutTree {
 //Look here: https://dl.acm.org/doi/pdf/10.1145/3828.3835
-        HugeObjectArray<LinkCutNode> nodes;
-        HugeObjectArray<LinkCutNode> edgeInTree;
+        private final HugeObjectArray<LinkCutNode> nodes;
+        private final HugeObjectArray<LinkCutNode> edgeInTree;
 
         public LinkCutTree(long nodeCount) {
             nodes = HugeObjectArray.newArray(LinkCutNode.class,nodeCount);
@@ -162,7 +162,7 @@ private void addChild(LinkCutNode a, LinkCutNode b,Direction direction) {
         public void link(long source, long target) {
             LinkCutNode nodeSource = nodes.get(source);
             LinkCutNode nodeTarget = nodes.get(target);
-            LinkCutNode nodeEdge = new LinkCutNode(source, target, null);
+            LinkCutNode nodeEdge = new LinkCutNode(source, null);
             edgeInTree.set(target,nodeEdge);
             nodeEdge.setParent(nodeSource);
             evert(target);

algo/src/main/java/org/neo4j/gds/steiner/SteinerBasedDeltaStepping.java

@@ -57,7 +57,7 @@
  */
 public final class SteinerBasedDeltaStepping extends Algorithm<DijkstraResult> {
 
-    public static final int NO_BIN = Integer.MAX_VALUE;
+    static final int NO_BIN = Integer.MAX_VALUE;
     private static final long NO_TERMINAL = -1;
     public static final int BIN_SIZE_THRESHOLD = 1000;
     private final Graph graph;
@@ -72,7 +72,7 @@ public final class SteinerBasedDeltaStepping extends Algorithm<DijkstraResult> {
     private final BitSet unvisitedTerminal;
     private final BitSet mergedWithSource;
     private final LongAdder metTerminals;
-    private int binSizeThreshold;
+    private final int binSizeThreshold;
 
     SteinerBasedDeltaStepping(
         Graph graph,

algo/src/main/java/org/neo4j/gds/steiner/SteinerBasedDeltaTask.java

@@ -49,7 +49,7 @@ class SteinerBasedDeltaTask implements Runnable {
     private final HugeLongPriorityQueue terminalQueue;
     private final ReentrantLock terminalQueueLock;
     private double smallestConsideredDistance;
-    private int binSizeThreshold;
+    private final int binSizeThreshold;
 
     SteinerBasedDeltaTask(
         Graph graph,