Updated how NH are counted to samples, update testing to check NaN's …

…and NH's

pkg/streamingpromql/engine_test.go

@@ -2824,6 +2824,8 @@ func TestQueryStats(t *testing.T) {
 			start_series  0 1 _ _ _ _ _ _ _ _ _
 			end_series    _ _ _ _ _ 5 6 7 8 9 10
 			sparse_series 0 _ _ _ _ _ _ 7 _ _ _
+			nan_series    NaN NaN NaN NaN NaN NaN NaN NaN NaN NaN NaN
+			native_histogram_series {{schema:0 sum:2 count:4 buckets:[1 2 1]}} {{sum:2 count:4 buckets:[1 2 1]}}
 	`)
 
 	runQueryAndGetTotalSamples := func(t *testing.T, engine promql.QueryEngine, expr string, isInstantQuery bool) int64 {
@@ -2904,6 +2906,23 @@ func TestQueryStats(t *testing.T) {
 			expr:                 `dense_series{} + end_series{}`,
 			expectedTotalSamples: 11 + 6,
 		},
+		"instant vector selector with NaNs": {
+			expr:                 `nan_series{}`,
+			isInstantQuery:       true,
+			expectedTotalSamples: 1,
+		},
+		"range vector selector with NaNs": {
+			expr:                 `sum_over_time(nan_series{}[1m])`,
+			expectedTotalSamples: 11,
+		},
+		"instant vector selector with native histograms": {
+			expr:                 `native_histogram_series{}`,
+			expectedTotalSamples: 78,
+		},
+		"range vector selector with native histograms": {
+			expr:                 `sum_over_time(native_histogram_series{}[1m])`,
+			expectedTotalSamples: 26,
+		},
 	}
 
 	for name, testCase := range testCases {

pkg/streamingpromql/operators/selectors/instant_vector_selector.go

@@ -120,8 +120,6 @@ func (v *InstantVectorSelector) NextSeries(ctx context.Context) (types.InstantVe
 			continue
 		}
 
-		v.Stats.TotalSamples++
-
 		// if (f, h) have been set by PeekPrev, we do not know if f is 0 because that's the actual value, or because
 		// the previous value had a histogram.
 		// PeekPrev will set the histogram to nil, or the value to 0 if the other type exists.
@@ -146,6 +144,12 @@ func (v *InstantVectorSelector) NextSeries(ctx context.Context) (types.InstantVe
 			data.Histograms = append(data.Histograms, promql.HPoint{T: stepT, H: h})
 			lastHistogramT = t
 			lastHistogram = h
+
+			// For consistency with PromQL engine:
+			// h.Size() returns the size of the histogram in bytes,
+			// add 8 bytes to account for the timestamp,
+			// and divide by 16 to get the number of samples.
+			v.Stats.TotalSamples += int64((h.Size() + 8) / 16)
 		} else {
 			// Only create the slice once we know the series is a histogram or not.
 			if len(data.Floats) == 0 {
@@ -157,6 +161,7 @@ func (v *InstantVectorSelector) NextSeries(ctx context.Context) (types.InstantVe
 				}
 			}
 			data.Floats = append(data.Floats, promql.FPoint{T: stepT, F: f})
+			v.Stats.TotalSamples++
 		}
 	}
 

pkg/streamingpromql/operators/selectors/range_vector_selector.go

@@ -104,7 +104,7 @@ func (m *RangeVectorSelector) NextStepSamples() (*types.RangeVectorStepData, err
 	m.stepData.RangeStart = rangeStart
 	m.stepData.RangeEnd = rangeEnd
 
-	m.Stats.TotalSamples += int64(m.stepData.Floats.Count() + m.stepData.Histograms.Count())
+	m.Stats.TotalSamples += int64(m.stepData.Floats.Count() + m.stepData.Histograms.CountSamples())
 
 	return m.stepData, nil
 }

pkg/streamingpromql/types/hpoint_ring_buffer.go

@@ -301,6 +301,21 @@ func (v HPointRingBufferView) Count() int {
 	return v.size
 }
 
+// CountSamples returns the size of the HPointRingBufferView compared to the size of an FPointRingBufferView.
+// For consistency with PromQL engine:
+// H.Size() returns the size of the histogram in bytes,
+// add 8 bytes to account for the timestamp,
+// and divide by 16 to get the number of samples.
+func (v HPointRingBufferView) CountSamples() int {
+	var totalSize int
+	for i := 0; i < v.size; i++ {
+		totalSize += v.buffer.pointAt(i).H.Size() + 8
+	}
+	totalSize = totalSize / 16
+
+	return totalSize
+}
+
 // Any returns true if this ring buffer view contains any points.
 func (v HPointRingBufferView) Any() bool {
 	return v.size != 0