Merge b4995dee38 into 25aee26a57

model/histogram/float_histogram.go

@@ -294,6 +294,9 @@ func (h *FloatHistogram) Mul(factor float64) *FloatHistogram {
 	for i := range h.NegativeBuckets {
 		h.NegativeBuckets[i] *= factor
 	}
+	if factor < 0 {
+		h.CounterResetHint = GaugeType
+	}
 	return h
 }
 
@@ -317,6 +320,9 @@ func (h *FloatHistogram) Div(scalar float64) *FloatHistogram {
 	for i := range h.NegativeBuckets {
 		h.NegativeBuckets[i] /= scalar
 	}
+	if scalar < 0 {
+		h.CounterResetHint = GaugeType
+	}
 	return h
 }
 
@@ -410,53 +416,7 @@ func (h *FloatHistogram) Add(other *FloatHistogram) (*FloatHistogram, error) {
 
 // Sub works like Add but subtracts the other histogram.
 func (h *FloatHistogram) Sub(other *FloatHistogram) (*FloatHistogram, error) {
-	if h.UsesCustomBuckets() != other.UsesCustomBuckets() {
+	return h.Add(other.Copy().Mul(-1))
-		return nil, ErrHistogramsIncompatibleSchema
-	}
-	if h.UsesCustomBuckets() && !FloatBucketsMatch(h.CustomValues, other.CustomValues) {
-		return nil, ErrHistogramsIncompatibleBounds
-	}
-
-	if !h.UsesCustomBuckets() {
-		otherZeroCount := h.reconcileZeroBuckets(other)
-		h.ZeroCount -= otherZeroCount
-	}
-	h.Count -= other.Count
-	h.Sum -= other.Sum
-
-	var (
-		hPositiveSpans       = h.PositiveSpans
-		hPositiveBuckets     = h.PositiveBuckets
-		otherPositiveSpans   = other.PositiveSpans
-		otherPositiveBuckets = other.PositiveBuckets
-	)
-
-	if h.UsesCustomBuckets() {
-		h.PositiveSpans, h.PositiveBuckets = addBuckets(h.Schema, h.ZeroThreshold, true, hPositiveSpans, hPositiveBuckets, otherPositiveSpans, otherPositiveBuckets)
-		return h, nil
-	}
-
-	var (
-		hNegativeSpans       = h.NegativeSpans
-		hNegativeBuckets     = h.NegativeBuckets
-		otherNegativeSpans   = other.NegativeSpans
-		otherNegativeBuckets = other.NegativeBuckets
-	)
-
-	switch {
-	case other.Schema < h.Schema:
-		hPositiveSpans, hPositiveBuckets = reduceResolution(hPositiveSpans, hPositiveBuckets, h.Schema, other.Schema, false, true)
-		hNegativeSpans, hNegativeBuckets = reduceResolution(hNegativeSpans, hNegativeBuckets, h.Schema, other.Schema, false, true)
-		h.Schema = other.Schema
-	case other.Schema > h.Schema:
-		otherPositiveSpans, otherPositiveBuckets = reduceResolution(otherPositiveSpans, otherPositiveBuckets, other.Schema, h.Schema, false, false)
-		otherNegativeSpans, otherNegativeBuckets = reduceResolution(otherNegativeSpans, otherNegativeBuckets, other.Schema, h.Schema, false, false)
-	}
-
-	h.PositiveSpans, h.PositiveBuckets = addBuckets(h.Schema, h.ZeroThreshold, true, hPositiveSpans, hPositiveBuckets, otherPositiveSpans, otherPositiveBuckets)
-	h.NegativeSpans, h.NegativeBuckets = addBuckets(h.Schema, h.ZeroThreshold, true, hNegativeSpans, hNegativeBuckets, otherNegativeSpans, otherNegativeBuckets)
-
-	return h, nil
 }
 
 // Equals returns true if the given float histogram matches exactly.

model/histogram/float_histogram_test.go

@@ -153,6 +153,7 @@ func TestFloatHistogramMul(t *testing.T) {
 				PositiveBuckets:  []float64{-1, 0, -3, -4, -7},
 				NegativeSpans:    []Span{{3, 2}, {3, 2}},
 				NegativeBuckets:  []float64{-3, -1, -5, -6},
+				CounterResetHint: GaugeType,
 			},
 		},
 		{
@@ -177,6 +178,7 @@ func TestFloatHistogramMul(t *testing.T) {
 				PositiveBuckets:  []float64{-2, 0, -6, -8, -14},
 				NegativeSpans:    []Span{{3, 2}, {3, 2}},
 				NegativeBuckets:  []float64{-6, -2, -10, -12},
+				CounterResetHint: GaugeType,
 			},
 		},
 		{
@@ -475,6 +477,7 @@ func TestFloatHistogramDiv(t *testing.T) {
 				PositiveBuckets:  []float64{-1, -3.3, -4.2, -0.1},
 				NegativeSpans:    []Span{{3, 2}, {3, 2}},
 				NegativeBuckets:  []float64{-3.1, -3, -1.234e5, -1000},
+				CounterResetHint: GaugeType,
 			},
 		},
 		{
@@ -499,6 +502,7 @@ func TestFloatHistogramDiv(t *testing.T) {
 				PositiveBuckets:  []float64{-0.5, 0, -1.5, -2, -3.5},
 				NegativeSpans:    []Span{{3, 2}, {3, 2}},
 				NegativeBuckets:  []float64{-1.5, -0.5, -2.5, -3},
+				CounterResetHint: GaugeType,
 			},
 		},
 		{
@@ -2387,6 +2391,7 @@ func TestFloatHistogramSub(t *testing.T) {
 				PositiveBuckets:  []float64{1, 0, 1, 1, 1},
 				NegativeSpans:    []Span{{3, 2}, {3, 2}},
 				NegativeBuckets:  []float64{2, 0, 1, 2},
+				CounterResetHint: GaugeType,
 			},
 			"",
 		},
@@ -2423,6 +2428,7 @@ func TestFloatHistogramSub(t *testing.T) {
 				PositiveBuckets:  []float64{1, 5, 4, 2, 2, 2, 0, 5},
 				NegativeSpans:    []Span{{3, 3}, {1, 3}},
 				NegativeBuckets:  []float64{1, 9, 1, 4, 9, 1},
+				CounterResetHint: GaugeType,
 			},
 			"",
 		},
@@ -2451,6 +2457,7 @@ func TestFloatHistogramSub(t *testing.T) {
 				PositiveSpans:    []Span{{0, 2}, {1, 3}},
 				PositiveBuckets:  []float64{1, 0, 1, 1, 1},
 				CustomValues:     []float64{1, 2, 3, 4},
+				CounterResetHint: GaugeType,
 			},
 			"",
 		},

promql/engine_test.go

@@ -4049,3 +4049,85 @@ func TestSubQueryHistogramsCopy(t *testing.T) {
 		queryable.Close()
 	}
 }
+
+func TestHistogram_CounterResetHint(t *testing.T) {
+	baseT := timestamp.Time(0)
+	load := `
+		load 2m
+		test_histogram {{count:0}}+{{count:1}}x4
+	`
+	testCases := []struct {
+		name  string
+		query string
+		want  histogram.CounterResetHint
+	}{
+		{
+			name:  "adding histograms",
+			query: `test_histogram + test_histogram`,
+			want:  histogram.NotCounterReset,
+		},
+		{
+			name:  "subtraction",
+			query: `test_histogram - test_histogram`,
+			want:  histogram.GaugeType,
+		},
+		{
+			name:  "negated addition",
+			query: `test_histogram + (-test_histogram)`,
+			want:  histogram.GaugeType,
+		},
+		{
+			name:  "negated subtraction",
+			query: `test_histogram - (-test_histogram)`,
+			want:  histogram.GaugeType,
+		},
+		{
+			name:  "unary negation",
+			query: `-test_histogram`,
+			want:  histogram.GaugeType,
+		},
+		{
+			name:  "repeated unary negation",
+			query: `-(-test_histogram)`,
+			want:  histogram.GaugeType,
+		},
+		{
+			name:  "multiplication",
+			query: `2 * test_histogram`,
+			want:  histogram.NotCounterReset,
+		},
+		{
+			name:  "negative multiplication",
+			query: `-1 * test_histogram`,
+			want:  histogram.GaugeType,
+		},
+		{
+			name:  "division",
+			query: `test_histogram / 2`,
+			want:  histogram.NotCounterReset,
+		},
+		{
+			name:  "negative division",
+			query: `test_histogram / -1`,
+			want:  histogram.GaugeType,
+		},
+	}
+	ctx := context.Background()
+	queryable := promqltest.LoadedStorage(t, load)
+	defer queryable.Close()
+	engine := promqltest.NewTestEngine(t, false, 0, promqltest.DefaultMaxSamplesPerQuery)
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			q, err := engine.NewInstantQuery(ctx, queryable, nil, tc.query, baseT.Add(2*time.Minute))
+			require.NoError(t, err)
+			defer q.Close()
+			res := q.Exec(ctx)
+			require.NoError(t, res.Err)
+			v, err := res.Vector()
+			require.NoError(t, err)
+			require.Len(t, v, 1)
+			require.NotNil(t, v[0].H)
+			require.Equal(t, tc.want, v[0].H.CounterResetHint)
+		})
+	}
+}

promql/parser/parse_test.go

@@ -5310,6 +5310,7 @@ func TestParseHistogramSeries(t *testing.T) {
 						Offset: 0,
 						Length: 3,
 					}},
+					CounterResetHint: histogram.GaugeType,
 				},
 				{
 					Schema:          1,
@@ -5318,6 +5319,7 @@ func TestParseHistogramSeries(t *testing.T) {
 						Offset: 0,
 						Length: 3,
 					}},
+					CounterResetHint: histogram.GaugeType,
 				},
 			},
 		},