Remove unused construction batch member from OnHeapGraphIndex (#510)

* Remove unused construction batch member from OnHeapGraphIndex

* Remove batchSize argument from constructor

Author: marianotepper

jvector-base/src/main/java/io/github/jbellis/jvector/graph/GraphIndexBuilder.java

@@ -58,8 +58,6 @@
  * that spawning a new Thread per call is not advisable.  This includes virtual threads.
  */
 public class GraphIndexBuilder implements Closeable {
-    private static final int BUILD_BATCH_SIZE = 50;
-
     private static final Logger logger = LoggerFactory.getLogger(GraphIndexBuilder.class);
 
     private final int beamWidth;
@@ -327,7 +325,7 @@ public GraphIndexBuilder(BuildScoreProvider scoreProvider,
         this.simdExecutor = simdExecutor;
         this.parallelExecutor = parallelExecutor;
 
-        this.graph = new OnHeapGraphIndex(maxDegrees, neighborOverflow, new VamanaDiversityProvider(scoreProvider, alpha), BUILD_BATCH_SIZE);
+        this.graph = new OnHeapGraphIndex(maxDegrees, neighborOverflow, new VamanaDiversityProvider(scoreProvider, alpha));
         this.searchers = ExplicitThreadLocal.withInitial(() -> {
             var gs = new GraphSearcher(graph);
             gs.usePruning(false);

jvector-base/src/main/java/io/github/jbellis/jvector/graph/OnHeapGraphIndex.java

@@ -77,9 +77,7 @@ public class OnHeapGraphIndex implements GraphIndex {
     // ratio, i.e., the maximum allowable degree if maxDegree * overflowRatio, it should be higher than 1.
     private final double overflowRatio;
 
-    public final ConcurrentMap<NodeAtLevel, VectorFloat<?>> constructionBatch;
-
-    OnHeapGraphIndex(List<Integer> maxDegrees, double overflowRatio, DiversityProvider diversityProvider, int batchSize) {
+    OnHeapGraphIndex(List<Integer> maxDegrees, double overflowRatio, DiversityProvider diversityProvider) {
         this.overflowRatio = overflowRatio;
         this.maxDegrees = new IntArrayList();
         setDegrees(maxDegrees);
@@ -92,7 +90,6 @@ public class OnHeapGraphIndex implements GraphIndex {
                 getDegree(0),
                 (int) (getDegree(0) * overflowRatio))
         );
-        this.constructionBatch = new ConcurrentHashMap<>(batchSize);
     }
 
     /**