Rename buckets operations

output/cloud/expv2/hdr.go

@@ -125,9 +125,9 @@ func (h *histogram) addToBucket(v float64) {
 	case len(h.Buckets) == 0:
 		h.init(index)
 	case index < h.FirstNotZeroBucket:
-		h.growLeft(index)
+		h.prependBuckets(index)
 	case index > h.LastNotZeroBucket:
-		h.growRight(index)
+		h.appendBuckets(index)
 	default:
 		h.Buckets[index-h.FirstNotZeroBucket]++
 	}
@@ -140,7 +140,9 @@ func (h *histogram) init(index uint32) {
 	h.Buckets[0] = 1
 }
 
-func (h *histogram) growLeft(index uint32) {
+// prependBuckets expands the buckets slice with zeros up to the required index,
+// then it increments the required bucket.
+func (h *histogram) prependBuckets(index uint32) {
 	if h.FirstNotZeroBucket <= index {
 		panic("buckets is already contains the requested index")
 	}
@@ -160,10 +162,10 @@ func (h *histogram) growLeft(index uint32) {
 	h.FirstNotZeroBucket = index
 }
 
-// growRight expands the buckets slice
-// with zeros up to the required index.
-// If it array has enough capacity then it reuses it without allocate.
-func (h *histogram) growRight(index uint32) {
+// appendBuckets expands the buckets slice with zeros buckets till the required index,
+// then it increments the required bucket.
+// If the slice has enough capacity then it reuses it without allocate.
+func (h *histogram) appendBuckets(index uint32) {
 	if h.LastNotZeroBucket >= index {
 		panic("buckets is already bigger than requested index")
 	}

output/cloud/expv2/hdr_test.go

@@ -233,28 +233,28 @@ func TestNewHistoramWithNoVals(t *testing.T) {
 	assert.Equal(t, exp, res)
 }
 
-func TestHistogramGrowRight(t *testing.T) {
+func TestHistogramAppendBuckets(t *testing.T) {
 	t.Parallel()
 	h := histogram{}
 
 	// the cap is smaller than requested index
 	// so it creates a new slice
-	h.growRight(3)
+	h.appendBuckets(3)
 	assert.Len(t, h.Buckets, 4)
 
 	// it must preserve already existing items
 	h.Buckets[2] = 101
 
 	// it appends to the same slice
-	h.growRight(5)
+	h.appendBuckets(5)
 	assert.Len(t, h.Buckets, 6)
 	assert.Equal(t, uint32(101), h.Buckets[2])
 	assert.Equal(t, uint32(1), h.Buckets[5])
 
 	// it is not possible to request an index smaller than
 	// the last already available index
 	h.LastNotZeroBucket = 5
-	assert.Panics(t, func() { h.growRight(4) })
+	assert.Panics(t, func() { h.appendBuckets(4) })
 }
 
 func TestHistogramAsProto(t *testing.T) {