From dafcffcc50a91273f228e4d5c8f5784fef551ac1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ha=CC=8Avard=20Ottestad?= <hmottestad@gmail.com>
Date: Wed, 11 Dec 2024 10:52:51 +0100
Subject: [PATCH] code cleanup

---
 .../core/compact/bitmap/Bitmap375Big.java     | 72 +++++++++----------
 1 file changed, 35 insertions(+), 37 deletions(-)

diff --git a/qendpoint-core/src/main/java/com/the_qa_company/qendpoint/core/compact/bitmap/Bitmap375Big.java b/qendpoint-core/src/main/java/com/the_qa_company/qendpoint/core/compact/bitmap/Bitmap375Big.java
index 48800499..01cb9c21 100644
--- a/qendpoint-core/src/main/java/com/the_qa_company/qendpoint/core/compact/bitmap/Bitmap375Big.java
+++ b/qendpoint-core/src/main/java/com/the_qa_company/qendpoint/core/compact/bitmap/Bitmap375Big.java
@@ -23,6 +23,8 @@
 import com.the_qa_company.qendpoint.core.util.io.CloseSuppressPath;
 import com.the_qa_company.qendpoint.core.util.io.Closer;
 import com.the_qa_company.qendpoint.core.util.io.IOUtil;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import java.io.Closeable;
 import java.io.IOException;
@@ -39,29 +41,31 @@
  * @author mario.arias
  */
 public class Bitmap375Big extends Bitmap64Big {
-	private final boolean oldBinarySearch;
 
-	/**
-	 * create disk version bitmap with in memory super index
-	 *
-	 * @param location location
-	 * @param nbits    number of bits
-	 * @return bitmap
-	 */
+	private static final Logger logger = LoggerFactory.getLogger(Bitmap375Big.class);
+
+	private static final boolean oldBinarySearch;
 
-	{
+	static {
 		// check if the system property "useOldBinarySeearch" is set to true
 		String useOldBinarySearch = System.getProperty("useOldBinarySearch");
 		if (useOldBinarySearch != null && useOldBinarySearch.equalsIgnoreCase("true")) {
-			this.oldBinarySearch = true;
-			System.out.println("Using old binary search");
+			oldBinarySearch = true;
+			logger.debug("Using old binary search");
 		} else {
-			System.out.println("Using new binary search");
-			this.oldBinarySearch = false;
+			logger.debug("Using new binary search");
+			oldBinarySearch = false;
 		}
 
 	}
 
+	/**
+	 * create disk version bitmap with in memory super index
+	 *
+	 * @param location location
+	 * @param nbits    number of bits
+	 * @return bitmap
+	 */
 	public static Bitmap375Big disk(Path location, long nbits) {
 		return disk(location, nbits, false);
 	}
@@ -483,39 +487,33 @@ public static long binarySearchNew(LongArray arr, long val) {
 		long max = arr.getEstimatedLocationUpperBound(val);
 		long mid = arr.getEstimatedLocation(val, min, max);
 
-//		System.out.println("Searching for: " + val);
-		int step = 0;
+		int i = 0;
 		while (min + 1 < max) {
-			step++;
-			// print min, max, mid
-//			System.out.println("min: " + min + " max: " + max + " mid: " + mid);
-
-			long l = arr.get(mid);
-
-			if (l >= val) {
-				max = mid;
-
-				if (min + 1 < max && step > 1 && step < 4) {
-					long l1 = arr.get(min + 1);
-					if (l1 >= val) {
-						max = min + 1;
-					} else {
-						// is this actually correct?
-						min = min + 1;
-					}
+			// After the first iteration, the value that we are looking for is
+			// typically very close to the min value. Using linear search for
+			// the next two iterations improves the chances that we find the
+			// value faster than with binary search.
+			if (i == 1 || i == 2) {
+				long v = arr.get(min + 1);
+				if (v >= val) {
+					max = min + 1;
+				} else {
+					min = min + 1;
 				}
-
 			} else {
-				min = mid;
+				long v = arr.get(mid);
+				if (v >= val) {
+					max = mid;
+				} else {
+					min = mid;
+				}
 			}
 			mid = (min + max) / 2;
+			i++;
 		}
-//		System.out.println("Found after: " + step + " steps");
 
 		arr.updateEstimatedValueLocation(val, min);
 
-		// prevFound[index] = min;
-
 		return min;
 	}