Make CountData and SumData struct (#669)

It makes it easier for the user to use these types,
because they don't have to do type casting to work
with the values.

exporter/prometheus/prometheus.go

@@ -224,7 +224,7 @@ func (c *collector) Collect(ch chan<- prometheus.Metric) {
 func (c *collector) toMetric(desc *prometheus.Desc, v *view.View, row *view.Row) (prometheus.Metric, error) {
 	switch data := row.Data.(type) {
 	case *view.CountData:
-		return prometheus.NewConstMetric(desc, prometheus.CounterValue, float64(*data), tagValues(row.Tags)...)
+		return prometheus.NewConstMetric(desc, prometheus.CounterValue, float64(data.Value), tagValues(row.Tags)...)
 
 	case *view.DistributionData:
 		points := make(map[float64]uint64)
@@ -254,7 +254,7 @@ func (c *collector) toMetric(desc *prometheus.Desc, v *view.View, row *view.Row)
 		return prometheus.NewConstHistogram(desc, uint64(data.Count), data.Sum(), points, tagValues(row.Tags)...)
 
 	case *view.SumData:
-		return prometheus.NewConstMetric(desc, prometheus.UntypedValue, float64(*data), tagValues(row.Tags)...)
+		return prometheus.NewConstMetric(desc, prometheus.UntypedValue, data.Value, tagValues(row.Tags)...)
 
 	case *view.LastValueData:
 		return prometheus.NewConstMetric(desc, prometheus.UntypedValue, data.Value, tagValues(row.Tags)...)

exporter/prometheus/prometheus_test.go

@@ -44,7 +44,7 @@ func newView(measureName string, agg *view.Aggregation) *view.View {
 
 func TestOnlyCumulativeWindowSupported(t *testing.T) {
 	// See Issue https://github.com/census-instrumentation/opencensus-go/issues/214.
-	count1 := view.CountData(1)
+	count1 := &view.CountData{Value: 1}
 	tests := []struct {
 		vds  *view.Data
 		want int
@@ -59,7 +59,7 @@ func TestOnlyCumulativeWindowSupported(t *testing.T) {
 			vds: &view.Data{
 				View: newView("TestOnlyCumulativeWindowSupported/m2", view.Count()),
 				Rows: []*view.Row{
-					{Data: &count1},
+					{Data: count1},
 				},
 			},
 			want: 1,
@@ -126,9 +126,9 @@ func TestCollectNonRacy(t *testing.T) {
 		}()
 
 		for i := 0; i < 1e3; i++ {
-			count1 := view.CountData(1)
+			count1 := &view.CountData{Value: 1}
 			vds := []*view.Data{
-				{View: newView(fmt.Sprintf("TestCollectNonRacy/m2-%d", i), view.Count()), Rows: []*view.Row{{Data: &count1}}},
+				{View: newView(fmt.Sprintf("TestCollectNonRacy/m2-%d", i), view.Count()), Rows: []*view.Row{{Data: count1}}},
 			}
 			for _, v := range vds {
 				exp.ExportView(v)

exporter/stackdriver/stats.go

@@ -316,17 +316,17 @@ func newTypedValue(vd *view.View, r *view.Row) *monitoringpb.TypedValue {
 	switch v := r.Data.(type) {
 	case *view.CountData:
 		return &monitoringpb.TypedValue{Value: &monitoringpb.TypedValue_Int64Value{
-			Int64Value: int64(*v),
+			Int64Value: v.Value,
 		}}
 	case *view.SumData:
 		switch vd.Measure.(type) {
 		case *stats.Int64Measure:
 			return &monitoringpb.TypedValue{Value: &monitoringpb.TypedValue_Int64Value{
-				Int64Value: int64(*v),
+				Int64Value: int64(v.Value),
 			}}
 		case *stats.Float64Measure:
 			return &monitoringpb.TypedValue{Value: &monitoringpb.TypedValue_DoubleValue{
-				DoubleValue: float64(*v),
+				DoubleValue: v.Value,
 			}}
 		}
 	case *view.DistributionData:

exporter/stackdriver/stats_test.go

@@ -93,10 +93,10 @@ func TestExporter_makeReq(t *testing.T) {
 
 	start := time.Now()
 	end := start.Add(time.Minute)
-	count1 := view.CountData(10)
-	count2 := view.CountData(16)
-	sum1 := view.SumData(5.5)
-	sum2 := view.SumData(-11.1)
+	count1 := &view.CountData{Value: 10}
+	count2 := &view.CountData{Value: 16}
+	sum1 := &view.SumData{Value: 5.5}
+	sum2 := &view.SumData{Value: -11.1}
 	last1 := view.LastValueData{Value: 100}
 	last2 := view.LastValueData{Value: 200}
 	taskValue := getTaskValue()
@@ -110,7 +110,7 @@ func TestExporter_makeReq(t *testing.T) {
 		{
 			name:   "count agg + timeline",
 			projID: "proj-id",
-			vd:     newTestViewData(v, start, end, &count1, &count2),
+			vd:     newTestViewData(v, start, end, count1, count2),
 			want: []*monitoringpb.CreateTimeSeriesRequest{{
 				Name: monitoring.MetricProjectPath("proj-id"),
 				TimeSeries: []*monitoringpb.TimeSeries{
@@ -178,7 +178,7 @@ func TestExporter_makeReq(t *testing.T) {
 		{
 			name:   "sum agg + timeline",
 			projID: "proj-id",
-			vd:     newTestViewData(v, start, end, &sum1, &sum2),
+			vd:     newTestViewData(v, start, end, sum1, sum2),
 			want: []*monitoringpb.CreateTimeSeriesRequest{{
 				Name: monitoring.MetricProjectPath("proj-id"),
 				TimeSeries: []*monitoringpb.TimeSeries{
@@ -387,13 +387,13 @@ func TestExporter_makeReq_batching(t *testing.T) {
 		},
 	}
 
-	count1 := view.CountData(10)
-	count2 := view.CountData(16)
+	count1 := &view.CountData{Value: 10}
+	count2 := &view.CountData{Value: 16}
 
 	for _, tt := range tests {
 		var vds []*view.Data
 		for i := 0; i < tt.iter; i++ {
-			vds = append(vds, newTestViewData(v, time.Now(), time.Now(), &count1, &count2))
+			vds = append(vds, newTestViewData(v, time.Now(), time.Now(), count1, count2))
 		}
 
 		e := &statsExporter{}
@@ -540,8 +540,8 @@ func TestExporter_createMeasure(t *testing.T) {
 		Aggregation: view.Sum(),
 	}
 
-	data := view.CountData(0)
-	vd := newTestViewData(v, time.Now(), time.Now(), &data, &data)
+	data := &view.CountData{Value: 0}
+	vd := newTestViewData(v, time.Now(), time.Now(), data, data)
 
 	e := &statsExporter{
 		createdViews: make(map[string]*metricpb.MetricDescriptor),
@@ -616,8 +616,8 @@ func TestExporter_createMeasure_CountAggregation(t *testing.T) {
 		Aggregation: view.Count(),
 	}
 
-	data := view.CountData(0)
-	vd := newTestViewData(v, time.Now(), time.Now(), &data, &data)
+	data := &view.CountData{Value: 0}
+	vd := newTestViewData(v, time.Now(), time.Now(), data, data)
 
 	e := &statsExporter{
 		createdViews: make(map[string]*metricpb.MetricDescriptor),
@@ -684,8 +684,8 @@ func TestExporter_makeReq_withCustomMonitoredResource(t *testing.T) {
 
 	start := time.Now()
 	end := start.Add(time.Minute)
-	count1 := view.CountData(10)
-	count2 := view.CountData(16)
+	count1 := &view.CountData{Value: 10}
+	count2 := &view.CountData{Value: 16}
 	taskValue := getTaskValue()
 
 	resource := &monitoredrespb.MonitoredResource{
@@ -702,7 +702,7 @@ func TestExporter_makeReq_withCustomMonitoredResource(t *testing.T) {
 		{
 			name:   "count agg timeline",
 			projID: "proj-id",
-			vd:     newTestViewData(v, start, end, &count1, &count2),
+			vd:     newTestViewData(v, start, end, count1, count2),
 			want: []*monitoringpb.CreateTimeSeriesRequest{{
 				Name: monitoring.MetricProjectPath("proj-id"),
 				TimeSeries: []*monitoringpb.TimeSeries{

plugin/ocgrpc/server_stats_handler_test.go

@@ -354,8 +354,7 @@ func TestServerDefaultCollections(t *testing.T) {
 }
 
 func newCountData(v int) *view.CountData {
-	cav := view.CountData(v)
-	return &cav
+	return &view.CountData{Value: int64(v)}
 }
 
 func newDistributionData(countPerBucket []int64, count int64, min, max, mean, sumOfSquaredDev float64) *view.DistributionData {

plugin/ochttp/client_test.go

@@ -110,7 +110,7 @@ func TestClient(t *testing.T) {
 		var count int64
 		switch data := data.(type) {
 		case *view.CountData:
-			count = *(*int64)(data)
+			count = data.Value
 		case *view.DistributionData:
 			count = data.Count
 		default:

plugin/ochttp/server_test.go

@@ -98,7 +98,7 @@ func TestHandlerStatsCollection(t *testing.T) {
 		var sum float64
 		switch data := data.(type) {
 		case *view.CountData:
-			count = int(*data)
+			count = int(data.Value)
 		case *view.DistributionData:
 			count = int(data.Count)
 			sum = data.Sum()

stats/view/aggregation.go

@@ -52,13 +52,13 @@ var (
 	aggCount = &Aggregation{
 		Type: AggTypeCount,
 		newData: func() AggregationData {
-			return newCountData(0)
+			return &CountData{}
 		},
 	}
 	aggSum = &Aggregation{
 		Type: AggTypeSum,
 		newData: func() AggregationData {
-			return newSumData(0)
+			return &SumData{}
 		},
 	}
 )

stats/view/aggregation_data.go

@@ -35,21 +35,18 @@ const epsilon = 1e-9
 // A count aggregation processes data and counts the recordings.
 //
 // Most users won't directly access count data.
-type CountData int64
-
-func newCountData(v int64) *CountData {
-	tmp := CountData(v)
-	return &tmp
+type CountData struct {
+	Value int64
 }
 
 func (a *CountData) isAggregationData() bool { return true }
 
 func (a *CountData) addSample(v float64) {
-	*a = *a + 1
+	a.Value = a.Value + 1
 }
 
 func (a *CountData) clone() AggregationData {
-	return newCountData(int64(*a))
+	return &CountData{Value: a.Value}
 }
 
 func (a *CountData) equal(other AggregationData) bool {
@@ -58,36 +55,33 @@ func (a *CountData) equal(other AggregationData) bool {
 		return false
 	}
 
-	return int64(*a) == int64(*a2)
+	return a.Value == a2.Value
 }
 
 // SumData is the aggregated data for the Sum aggregation.
 // A sum aggregation processes data and sums up the recordings.
 //
 // Most users won't directly access sum data.
-type SumData float64
-
-func newSumData(v float64) *SumData {
-	tmp := SumData(v)
-	return &tmp
+type SumData struct {
+	Value float64
 }
 
 func (a *SumData) isAggregationData() bool { return true }
 
 func (a *SumData) addSample(f float64) {
-	*a += SumData(f)
+	a.Value += f
 }
 
 func (a *SumData) clone() AggregationData {
-	return newSumData(float64(*a))
+	return &SumData{Value: a.Value}
 }
 
 func (a *SumData) equal(other AggregationData) bool {
 	a2, ok := other.(*SumData)
 	if !ok {
 		return false
 	}
-	return math.Pow(float64(*a)-float64(*a2), 2) < epsilon
+	return math.Pow(a.Value-a2.Value, 2) < epsilon
 }
 
 // DistributionData is the aggregated data for the

stats/view/aggregation_data_test.go

@@ -35,15 +35,15 @@ func TestDataClone(t *testing.T) {
 	}{
 		{
 			name: "count data",
-			src:  newCountData(5),
+			src:  &CountData{Value: 5},
 		},
 		{
 			name: "distribution data",
 			src:  dist,
 		},
 		{
 			name: "sum data",
-			src:  newSumData(65.7),
+			src:  &SumData{Value: 65.7},
 		},
 	}
 	for _, tt := range tests {

stats/view/view_measure_test.go

@@ -41,10 +41,10 @@ func TestMeasureFloat64AndInt64(t *testing.T) {
 
 	// We expect both views to return 7.2, as though we recorded on a single measure.
 
-	if got, want := float64(*sum1), 7.2; got != want {
+	if got, want := sum1.Value, 7.2; got != want {
 		t.Errorf("sum1 = %v; want %v", got, want)
 	}
-	if got, want := float64(*sum2), 7.2; got != want {
+	if got, want := sum2.Value, 7.2; got != want {
 		t.Errorf("sum2 = %v; want %v", got, want)
 	}
 }

stats/view/view_test.go

@@ -226,7 +226,7 @@ func Test_View_MeasureFloat64_AggregationSum(t *testing.T) {
 			[]*Row{
 				{
 					[]tag.Tag{{Key: k1, Value: "v1"}},
-					newSumData(6),
+					&SumData{Value: 6},
 				},
 			},
 		},
@@ -239,11 +239,11 @@ func Test_View_MeasureFloat64_AggregationSum(t *testing.T) {
 			[]*Row{
 				{
 					[]tag.Tag{{Key: k1, Value: "v1"}},
-					newSumData(1),
+					&SumData{Value: 1},
 				},
 				{
 					[]tag.Tag{{Key: k2, Value: "v2"}},
-					newSumData(5),
+					&SumData{Value: 5},
 				},
 			},
 		},
@@ -259,19 +259,19 @@ func Test_View_MeasureFloat64_AggregationSum(t *testing.T) {
 			[]*Row{
 				{
 					[]tag.Tag{{Key: k1, Value: "v1"}},
-					newSumData(6),
+					&SumData{Value: 6},
 				},
 				{
 					[]tag.Tag{{Key: k1, Value: "v1 other"}},
-					newSumData(1),
+					&SumData{Value: 1},
 				},
 				{
 					[]tag.Tag{{Key: k2, Value: "v2"}},
-					newSumData(5),
+					&SumData{Value: 5},
 				},
 				{
 					[]tag.Tag{{Key: k1, Value: "v1"}, {Key: k2, Value: "v2"}},
-					newSumData(5),
+					&SumData{Value: 5},
 				},
 			},
 		},

stats/view/worker_test.go

@@ -164,7 +164,7 @@ func Test_Worker_RecordFloat64(t *testing.T) {
 					[]*Row{
 						{
 							[]tag.Tag{{Key: k1, Value: "v1"}, {Key: k2, Value: "v2"}},
-							newCountData(2),
+							&CountData{Value: 2},
 						},
 					},
 					nil,
@@ -182,7 +182,7 @@ func Test_Worker_RecordFloat64(t *testing.T) {
 					[]*Row{
 						{
 							[]tag.Tag{{Key: k1, Value: "v1"}, {Key: k2, Value: "v2"}},
-							newCountData(2),
+							&CountData{Value: 2},
 						},
 					},
 					nil,
@@ -192,7 +192,7 @@ func Test_Worker_RecordFloat64(t *testing.T) {
 					[]*Row{
 						{
 							[]tag.Tag{{Key: k1, Value: "v1"}, {Key: k2, Value: "v2"}},
-							newCountData(2),
+							&CountData{Value: 2},
 						},
 					},
 					nil,
@@ -375,7 +375,7 @@ func (e *countExporter) ExportView(vd *Data) {
 
 	e.Lock()
 	defer e.Unlock()
-	e.count = int64(*d)
+	e.count = d.Value
 }
 
 type vdExporter struct {