Revert changes to NeighborArray and OnHeapHnswGraph

Author: Stefan Vodita

lucene/CHANGES.txt

@@ -299,7 +299,7 @@ Optimizations
 * GITHUB#12782: Use group-varint encoding for the tail of postings. (Adrien Grand, Zhang Chao)
 
 * GITHUB#12839: Introduce method to grow arrays up to a given upper limit and use it to reduce overallocation for
-  DirectoryTaxonomyReader and NeighborArray. (Stefan Vodita)
+  DirectoryTaxonomyReader#getBulkOrdinals. (Stefan Vodita)
 
 Changes in runtime behavior
 ---------------------

lucene/core/src/java/org/apache/lucene/util/hnsw/NeighborArray.java

@@ -32,20 +32,17 @@
  * @lucene.internal
  */
 public class NeighborArray {
-  private static final int INITIAL_CAPACITY = 10;
   private final boolean scoresDescOrder;
-  private final int maxSize;
   private int size;
   float[] score;
   int[] node;
   private int sortedNodeSize;
   public final ReadWriteLock rwlock = new ReentrantReadWriteLock(true);
 
   public NeighborArray(int maxSize, boolean descOrder) {
-    node = new int[INITIAL_CAPACITY];
-    score = new float[INITIAL_CAPACITY];
+    node = new int[maxSize];
+    score = new float[maxSize];
     this.scoresDescOrder = descOrder;
-    this.maxSize = maxSize;
   }
 
   /**
@@ -55,7 +52,7 @@ public NeighborArray(int maxSize, boolean descOrder) {
   public void addInOrder(int newNode, float newScore) {
     assert size == sortedNodeSize : "cannot call addInOrder after addOutOfOrder";
     if (size == node.length) {
-      node = ArrayUtil.growInRange(node, size + 1, maxSize);
+      node = ArrayUtil.grow(node);
       score = ArrayUtil.growExact(score, node.length);
     }
     if (size > 0) {
@@ -76,7 +73,7 @@ public void addInOrder(int newNode, float newScore) {
   /** Add node and newScore but do not insert as sorted */
   public void addOutOfOrder(int newNode, float newScore) {
     if (size == node.length) {
-      node = ArrayUtil.growInRange(node, size + 1, maxSize);
+      node = ArrayUtil.grow(node);
       score = ArrayUtil.growExact(score, node.length);
     }
 

lucene/core/src/java/org/apache/lucene/util/hnsw/OnHeapHnswGraph.java

@@ -279,12 +279,12 @@ public long ramBytesUsed() {
         (long) nsize0 * (Integer.BYTES + Float.BYTES)
             + RamUsageEstimator.NUM_BYTES_ARRAY_HEADER * 2L
             + RamUsageEstimator.NUM_BYTES_OBJECT_REF * 2L
-            + Integer.BYTES * 5;
+            + Integer.BYTES * 3;
     long neighborArrayBytes =
         (long) nsize * (Integer.BYTES + Float.BYTES)
             + RamUsageEstimator.NUM_BYTES_ARRAY_HEADER * 2L
             + RamUsageEstimator.NUM_BYTES_OBJECT_REF * 2L
-            + Integer.BYTES * 5;
+            + Integer.BYTES * 3;
     long total = 0;
     total +=
         size() * (neighborArrayBytes0 + RamUsageEstimator.NUM_BYTES_ARRAY_HEADER)