Fix style error

Signed-off-by: Vijayan B <[email protected]>

Author: VijayanB

src/main/java/org/opensearch/knn/index/mapper/CompressionLevel.java

@@ -108,14 +108,14 @@ public static boolean isConfigured(CompressionLevel compressionLevel) {
      *                  is invalid.
      */
     public RescoreContext getDefaultRescoreContext(Mode mode, int dimension, Version version) {
-        //TODO move this to separate class called resolver to resolve rescore context
+        // TODO move this to separate class called resolver to resolve rescore context
         if (modesForRescore.contains(mode)) {
-            if( this == x4 && version.before(Version.V_3_1_0)){
+            if (this == x4 && version.before(Version.V_3_1_0)) {
                 // For index created before 3.1, context was always null and mode is empty
                 return null;
             }
-            // Adjust RescoreContext based on dimension
-            if (dimension <= RescoreContext.DIMENSION_THRESHOLD) {
+            // Adjust RescoreContext based on dimension except for 4x compression
+            if (this != x4 && dimension <= RescoreContext.DIMENSION_THRESHOLD) {
                 // For dimensions <= 1000, return a RescoreContext with 5.0f oversample factor
                 return RescoreContext.builder()
                     .oversampleFactor(RescoreContext.OVERSAMPLE_FACTOR_BELOW_DIMENSION_THRESHOLD)
@@ -128,7 +128,7 @@ public RescoreContext getDefaultRescoreContext(Mode mode, int dimension, Version
     }
 
     @VisibleForTesting
-    RescoreContext getDefaultRescoreContext(Mode mode, int dimension){
+    RescoreContext getDefaultRescoreContext(Mode mode, int dimension) {
         return getDefaultRescoreContext(mode, dimension, Version.CURRENT);
     }
 

src/test/java/org/opensearch/knn/index/mapper/CompressionLevelTests.java

@@ -93,7 +93,7 @@ public void testGetDefaultRescoreContext() {
         // x4 with dimension <= 1000 should have an oversample factor of 5.0f
         rescoreContext = CompressionLevel.x4.getDefaultRescoreContext(mode, belowThresholdDimension);
         assertNotNull(rescoreContext);
-        assertEquals(5.0f, rescoreContext.getOversampleFactor(), 0.0f);
+        assertEquals(1.0f, rescoreContext.getOversampleFactor(), 0.0f);
         assertTrue(rescoreContext.isRescoreEnabled());
         assertFalse(rescoreContext.isUserProvided());
         // x4 with dimension > 1000 should have an oversample factor of 1.0f

src/test/java/org/opensearch/knn/integ/ModeAndCompressionIT.java

@@ -650,7 +650,7 @@ private void validateSearch(
         String exactSearchResponseBody = EntityUtils.toString(exactSearchResponse.getEntity());
         List<Float> exactSearchKnnResults = parseSearchResponseScore(exactSearchResponseBody, FIELD_NAME);
         assertEquals(NUM_DOCS, exactSearchKnnResults.size());
-        if(Mode.ON_DISK.getName().equals(mode)){
+        if (Mode.ON_DISK.getName().equals(mode)) {
             Assert.assertEquals(exactSearchKnnResults, knnResults);
         }