change origin schema in `ReduceResolution` method of histogram and float histogram (#13116)

* change origin schema in ReduceResolution method of histogram and float histogram

Signed-off-by: Ziqi Zhao <zhaoziqi9146@gmail.com>

---------

Signed-off-by: Ziqi Zhao <zhaoziqi9146@gmail.com>

model/histogram/float_histogram.go

@@ -1112,6 +1112,6 @@ func floatBucketsMatch(b1, b2 []float64) bool {
 func (h *FloatHistogram) ReduceResolution(targetSchema int32) *FloatHistogram {
 	h.PositiveSpans, h.PositiveBuckets = reduceResolution(h.PositiveSpans, h.PositiveBuckets, h.Schema, targetSchema, false)
 	h.NegativeSpans, h.NegativeBuckets = reduceResolution(h.NegativeSpans, h.NegativeBuckets, h.Schema, targetSchema, false)
-
+	h.Schema = targetSchema
 	return h
 }

model/histogram/float_histogram_test.go

@@ -2442,3 +2442,46 @@ func createRandomSpans(rng *rand.Rand, spanNum int32) ([]Span, []float64) {
 	}
 	return Spans, Buckets
 }
+
+func TestFloatHistogramReduceResolution(t *testing.T) {
+	tcs := map[string]struct {
+		origin *FloatHistogram
+		target *FloatHistogram
+	}{
+		"valid float histogram": {
+			origin: &FloatHistogram{
+				Schema: 0,
+				PositiveSpans: []Span{
+					{Offset: 0, Length: 4},
+					{Offset: 0, Length: 0},
+					{Offset: 3, Length: 2},
+				},
+				PositiveBuckets: []float64{1, 3, 1, 2, 1, 1},
+				NegativeSpans: []Span{
+					{Offset: 0, Length: 4},
+					{Offset: 0, Length: 0},
+					{Offset: 3, Length: 2},
+				},
+				NegativeBuckets: []float64{1, 3, 1, 2, 1, 1},
+			},
+			target: &FloatHistogram{
+				Schema: -1,
+				PositiveSpans: []Span{
+					{Offset: 0, Length: 3},
+					{Offset: 1, Length: 1},
+				},
+				PositiveBuckets: []float64{1, 4, 2, 2},
+				NegativeSpans: []Span{
+					{Offset: 0, Length: 3},
+					{Offset: 1, Length: 1},
+				},
+				NegativeBuckets: []float64{1, 4, 2, 2},
+			},
+		},
+	}
+
+	for _, tc := range tcs {
+		target := tc.origin.ReduceResolution(tc.target.Schema)
+		require.Equal(t, tc.target, target)
+	}
+}

model/histogram/histogram.go

@@ -503,5 +503,6 @@ func (h *Histogram) ReduceResolution(targetSchema int32) *Histogram {
 	h.NegativeSpans, h.NegativeBuckets = reduceResolution(
 		h.NegativeSpans, h.NegativeBuckets, h.Schema, targetSchema, true,
 	)
+	h.Schema = targetSchema
 	return h
 }

model/histogram/histogram_test.go

@@ -967,3 +967,46 @@ func BenchmarkHistogramValidation(b *testing.B) {
 		require.NoError(b, h.Validate())
 	}
 }
+
+func TestHistogramReduceResolution(t *testing.T) {
+	tcs := map[string]struct {
+		origin *Histogram
+		target *Histogram
+	}{
+		"valid histogram": {
+			origin: &Histogram{
+				Schema: 0,
+				PositiveSpans: []Span{
+					{Offset: 0, Length: 4},
+					{Offset: 0, Length: 0},
+					{Offset: 3, Length: 2},
+				},
+				PositiveBuckets: []int64{1, 2, -2, 1, -1, 0},
+				NegativeSpans: []Span{
+					{Offset: 0, Length: 4},
+					{Offset: 0, Length: 0},
+					{Offset: 3, Length: 2},
+				},
+				NegativeBuckets: []int64{1, 2, -2, 1, -1, 0},
+			},
+			target: &Histogram{
+				Schema: -1,
+				PositiveSpans: []Span{
+					{Offset: 0, Length: 3},
+					{Offset: 1, Length: 1},
+				},
+				PositiveBuckets: []int64{1, 3, -2, 0},
+				NegativeSpans: []Span{
+					{Offset: 0, Length: 3},
+					{Offset: 1, Length: 1},
+				},
+				NegativeBuckets: []int64{1, 3, -2, 0},
+			},
+		},
+	}
+
+	for _, tc := range tcs {
+		target := tc.origin.ReduceResolution(tc.target.Schema)
+		require.Equal(t, tc.target, target)
+	}
+}