small refactoring.

Author: lrhodes

src/main/java/com/yahoo/sketches/hll/AbstractCoupons.java

@@ -160,11 +160,11 @@ static final int find(final int[] array, final int lgArrInts, final int coupon)
     int probe = coupon & arrMask;
     final int loopIndex = probe;
     do {
-      final int arrVal = array[probe];
-      if (arrVal == EMPTY) { //Compares on entire coupon
+      final int couponAtIdx = array[probe];
+      if (couponAtIdx == EMPTY) {
         return ~probe; //empty
       }
-      else if (coupon == arrVal) { //Compares on entire coupon
+      else if (coupon == couponAtIdx) {
         return probe; //duplicate
       }
       final int stride = ((coupon & KEY_MASK_26) >>> lgArrInts) | 1;

src/main/java/com/yahoo/sketches/hll/CouponHashSet.java

@@ -105,9 +105,10 @@ HllSketchImpl couponUpdate(final int coupon) {
     }
     couponIntArr[~index] = coupon; //found empty
     couponCount++;
-    final boolean promote = checkGrowOrPromote();
-    if (!promote) { return this; }
-    return promoteHeapListOrSetToHll(this);
+    if (checkGrowOrPromote()) {
+      return promoteHeapListOrSetToHll(this);
+    }
+    return this;
   }
 
   @Override
@@ -122,17 +123,16 @@ int getPreInts() {
 
   private boolean checkGrowOrPromote() {
     if ((RESIZE_DENOM * couponCount) > (RESIZE_NUMER * (1 << lgCouponArrInts))) {
-      if (lgCouponArrInts == (lgConfigK - 3)) {
-        return true; // promote
+      if (lgCouponArrInts == (lgConfigK - 3)) { //at max size
+        return true; // promote to HLL
       }
       couponIntArr = growHashSet(couponIntArr, ++lgCouponArrInts);
     }
     return false;
   }
 
   private static final int[] growHashSet(final int[] coupIntArr, final int tgtLgCoupArrSize) {
-    final int tgtArrSize = 1 << tgtLgCoupArrSize;
-    final int[] tgtCouponIntArr = new int[tgtArrSize]; //create tgt
+    final int[] tgtCouponIntArr = new int[1 << tgtLgCoupArrSize]; //create tgt
     final int len = coupIntArr.length;
     for (int i = 0; i < len; i++) { //scan input arr for non-zero values
       final int fetched = coupIntArr[i];

src/main/java/com/yahoo/sketches/hll/CouponList.java

@@ -108,7 +108,7 @@ HllSketchImpl couponUpdate(final int coupon) {
         couponCount++;
         if (couponCount >= len) { //array full
           if (lgConfigK < 8) {
-            return promoteHeapListOrSetToHll(this);//oooFlag = false
+            return promoteHeapListOrSetToHll(this); //oooFlag = false
           }
           return promoteHeapListToSet(this); //oooFlag = true
         }

src/main/java/com/yahoo/sketches/hll/CubicInterpolation.java

@@ -16,6 +16,7 @@ final class CubicInterpolation {
    * @param x x
    * @return cubic interpolation
    */
+  //Used by AbstractCoupons
   //In C: again-two-registers cubic_interpolate_using_table L1377
   static double usingXAndYTables(final double[] xArr, final double[] yArr,
       final double x) {
@@ -56,6 +57,7 @@ private static double interpolateUsingXAndYTables(final double[] xArr, final dou
    * @return cubic interpolation
    */
   //In C: again-two-registers cubic_interpolate_with_x_arr_and_y_stride L1411
+  // Used by HllEstimators
   static double usingXArrAndYStride(
       final double[] xArr, final double yStride, final double x) {
     final int xArrLen = xArr.length;

src/main/java/com/yahoo/sketches/hll/Hll6Array.java

@@ -51,25 +51,6 @@ Hll6Array copy() {
     return new Hll6Array(this);
   }
 
-  @Override
-  HllSketchImpl couponUpdate(final int coupon) {
-    final int configKmask = (1 << getLgConfigK()) - 1;
-    final int slotNo = HllUtil.getLow26(coupon) & configKmask;
-    final int newVal = HllUtil.getValue(coupon);
-    assert newVal > 0;
-
-    final int curVal = getSlot(slotNo);
-    if (newVal > curVal) {
-      putSlot(slotNo, newVal);
-      hipAndKxQIncrementalUpdate(this, curVal, newVal);
-      if (curVal == 0) {
-        decNumAtCurMin(); //overloaded as num zeros
-        assert getNumAtCurMin() >= 0;
-      }
-    }
-    return this;
-  }
-
   @Override
   PairIterator getIterator() {
     return new HeapHll6Iterator(1 << lgConfigK);

src/main/java/com/yahoo/sketches/hll/Hll8Array.java

@@ -48,25 +48,6 @@ Hll8Array copy() {
     return new Hll8Array(this);
   }
 
-  @Override
-  HllSketchImpl couponUpdate(final int coupon) {
-    final int configKmask = (1 << getLgConfigK()) - 1;
-    final int slotNo = HllUtil.getLow26(coupon) & configKmask;
-    final int newVal = HllUtil.getValue(coupon);
-    assert newVal > 0;
-
-    final int curVal = getSlot(slotNo);
-    if (newVal > curVal) {
-      putSlot(slotNo, newVal);
-      hipAndKxQIncrementalUpdate(this, curVal, newVal);
-      if (curVal == 0) {
-        decNumAtCurMin(); //overloaded as num zeros
-        assert getNumAtCurMin() >= 0;
-      }
-    }
-    return this;
-  }
-
   @Override
   PairIterator getIterator() {
     return new HeapHll8Iterator(1 << lgConfigK);

src/main/java/com/yahoo/sketches/hll/HllArray.java

@@ -78,6 +78,25 @@ void addToHipAccum(final double delta) {
     hipAccum += delta;
   }
 
+  @Override //used by HLL6 and HLL8, overridden by HLL4
+  HllSketchImpl couponUpdate(final int coupon) {
+    final int configKmask = (1 << getLgConfigK()) - 1;
+    final int slotNo = HllUtil.getLow26(coupon) & configKmask;
+    final int newVal = HllUtil.getValue(coupon);
+    assert newVal > 0;
+
+    final int curVal = getSlot(slotNo);
+    if (newVal > curVal) {
+      putSlot(slotNo, newVal);
+      hipAndKxQIncrementalUpdate(this, curVal, newVal);
+      if (curVal == 0) {
+        decNumAtCurMin(); //overloaded as num zeros
+        assert getNumAtCurMin() >= 0;
+      }
+    }
+    return this;
+  }
+
   @Override
   void decNumAtCurMin() {
     numAtCurMin--;

src/main/java/com/yahoo/sketches/quantiles/DoublesSketch.java

@@ -12,7 +12,6 @@
 
 import com.yahoo.memory.Memory;
 import com.yahoo.memory.WritableMemory;
-
 import com.yahoo.sketches.Family;
 import com.yahoo.sketches.SketchesArgumentException;
 
@@ -561,7 +560,7 @@ public void putMemory(final WritableMemory dstMem) {
    *                performance at the cost of slightly increased serialization time.
    */
   public void putMemory(final WritableMemory dstMem, final boolean compact) {
-    if (isDirect() && isCompact() == compact) {
+    if (isDirect() && (isCompact() == compact)) {
       final Memory srcMem = getMemory();
       srcMem.copyTo(0, dstMem, 0, getStorageBytes());
     } else {