Remove dead code

Author: JonasKunz

libs/exponential-histogram/src/main/java/org/elasticsearch/exponentialhistogram/ExponentialHistogram.java

@@ -40,7 +40,7 @@ public interface ExponentialHistogram {
     // One option would be to use "Quadruple": https://github.com/m-vokhm/Quadruple
     int MAX_SCALE = 38;
 
-    // Add this scale all double values already fall into a single bucket
+    // At this scale all double values already fall into a single bucket
     int MIN_SCALE = -11;
 
     // Only use 62 bit at max to allow to compute the difference between the smallest and largest index without causing overflow
@@ -122,8 +122,6 @@ interface BucketIterator {
          * @return the scale, which is guaranteed to be constant over the lifetime of this iterator.
          */
         int scale();
-
-        BucketIterator copy();
     }
 
     /**

libs/exponential-histogram/src/main/java/org/elasticsearch/exponentialhistogram/ExponentialHistogramMerger.java

@@ -62,26 +62,16 @@ public ExponentialHistogram get() {
         return result;
     }
 
-    public static ExponentialHistogram merge(int bucketCount, ExponentialHistogram... histograms) {
-        return merge(bucketCount, Arrays.stream(histograms));
-    }
-
-    public static ExponentialHistogram merge(int bucketCount, Stream<ExponentialHistogram> histograms) {
-        ExponentialHistogramMerger merger = new ExponentialHistogramMerger(bucketCount);
-        histograms.forEach(merger::add);
-        return merger.get();
-    }
-
     // TODO: this algorithm is very efficient if b has roughly as many buckets as a
     // However, if b is much smaller we still have to iterate over all buckets of a which is very wasteful
     // This can be optimized by buffering multiple histograms to accumulate first, then in O(log(b)) turn them into a single, merged histogram
     // (b is the number of buffered buckets)
 
     private void merge(FixedCapacityExponentialHistogram output, ExponentialHistogram a, ExponentialHistogram b) {
-        ExponentialHistogram.BucketIterator posBucketsA = a.positiveBuckets();
-        ExponentialHistogram.BucketIterator negBucketsA = a.negativeBuckets();
-        ExponentialHistogram.BucketIterator posBucketsB = b.positiveBuckets();
-        ExponentialHistogram.BucketIterator negBucketsB = b.negativeBuckets();
+        ExponentialHistogram.CopyableBucketIterator posBucketsA = a.positiveBuckets();
+        ExponentialHistogram.CopyableBucketIterator negBucketsA = a.negativeBuckets();
+        ExponentialHistogram.CopyableBucketIterator posBucketsB = b.positiveBuckets();
+        ExponentialHistogram.CopyableBucketIterator negBucketsB = b.negativeBuckets();
 
         ZeroBucket zeroBucket = a.zeroBucket().merge(b.zeroBucket());
         zeroBucket = zeroBucket.collapseOverlappingBuckets(posBucketsA, negBucketsA, posBucketsB, negBucketsB);

libs/exponential-histogram/src/main/java/org/elasticsearch/exponentialhistogram/MergingBucketIterator.java

@@ -79,11 +79,6 @@ public int scale() {
         return itA.scale();
     }
 
-    @Override
-    public ExponentialHistogram.BucketIterator copy() {
-        throw new UnsupportedOperationException();
-    }
-
     private void assertEndNotReached() {
         if (endReached) {
             throw new IllegalStateException("No more buckets");

libs/exponential-histogram/src/main/java/org/elasticsearch/exponentialhistogram/ScaleAdjustingBucketIterator.java

@@ -70,9 +70,4 @@ private void assertEndNotReached() {
     public int scale() {
         return delegate.scale() + scaleAdjustment;
     }
-
-    @Override
-    public ExponentialHistogram.BucketIterator copy() {
-        throw new UnsupportedOperationException();
-    }
 }