Scale/offset

pkg/datasource/functions.go

@@ -2,6 +2,7 @@ package datasource
 
 import (
 	"fmt"
+	"strconv"
 
 	"github.com/alexanderzobnin/grafana-zabbix/pkg/gtime"
 	"github.com/alexanderzobnin/grafana-zabbix/pkg/timeseries"
@@ -18,6 +19,8 @@ var funcMap map[string]DataProcessingFunc
 func init() {
 	funcMap = map[string]DataProcessingFunc{
 		"groupBy": applyGroupBy,
+		"scale":   applyScale,
+		"offset":  applyOffset,
 	}
 
 }
@@ -53,6 +56,28 @@ func applyGroupBy(series timeseries.TimeSeries, params ...string) (timeseries.Ti
 	return s, nil
 }
 
+func applyScale(series timeseries.TimeSeries, params ...string) (timeseries.TimeSeries, error) {
+	pFactor := params[0]
+	factor, err := strconv.ParseFloat(pFactor, 64)
+	if err != nil {
+		return nil, err
+	}
+
+	transformFunc := timeseries.TransformScale(factor)
+	return series.Transform(transformFunc), nil
+}
+
+func applyOffset(series timeseries.TimeSeries, params ...string) (timeseries.TimeSeries, error) {
+	pOffset := params[0]
+	offset, err := strconv.ParseFloat(pOffset, 64)
+	if err != nil {
+		return nil, err
+	}
+
+	transformFunc := timeseries.TransformOffset(offset)
+	return series.Transform(transformFunc), nil
+}
+
 func getAggFunc(agg string) timeseries.AggFunc {
 	switch agg {
 	case "avg":

pkg/timeseries/agg_functions.go

@@ -0,0 +1,80 @@
+package timeseries
+
+import (
+	"math"
+	"sort"
+)
+
+func AggAvg(points []TimePoint) *float64 {
+	sum := AggSum(points)
+	avg := *sum / float64(len(points))
+	return &avg
+}
+
+func AggSum(points []TimePoint) *float64 {
+	var sum float64 = 0
+	for _, p := range points {
+		if p.Value != nil {
+			sum += *p.Value
+		}
+	}
+	return &sum
+}
+
+func AggMax(points []TimePoint) *float64 {
+	var max *float64 = nil
+	for _, p := range points {
+		if p.Value != nil {
+			if max == nil {
+				max = p.Value
+			} else if *p.Value > *max {
+				max = p.Value
+			}
+		}
+	}
+	return max
+}
+
+func AggMin(points []TimePoint) *float64 {
+	var min *float64 = nil
+	for _, p := range points {
+		if p.Value != nil {
+			if min == nil {
+				min = p.Value
+			} else if *p.Value < *min {
+				min = p.Value
+			}
+		}
+	}
+	return min
+}
+
+func AggCount(points []TimePoint) *float64 {
+	count := float64(len(points))
+	return &count
+}
+
+func AggFirst(points []TimePoint) *float64 {
+	return points[0].Value
+}
+
+func AggLast(points []TimePoint) *float64 {
+	return points[len(points)-1].Value
+}
+
+func AggMedian(points []TimePoint) *float64 {
+	values := make([]float64, 0)
+	for _, p := range points {
+		if p.Value != nil {
+			values = append(values, *p.Value)
+		}
+	}
+	if len(values) == 0 {
+		return nil
+	}
+
+	values = sort.Float64Slice(values)
+	medianIndex := int(math.Floor(float64(len(values)) / 2))
+	median := values[medianIndex]
+	return &median
+}

pkg/timeseries/models.go

@@ -31,3 +31,5 @@ type TimeSeriesMeta struct {
 }
 
 type AggFunc = func(points []TimePoint) *float64
+
+type TransformFunc = func(point TimePoint) TimePoint

pkg/timeseries/timeseries.go

@@ -74,78 +74,11 @@ func (ts TimeSeries) GroupBy(interval time.Duration, aggFunc AggFunc) TimeSeries
 	return groupedSeries
 }
 
-func AggAvg(points []TimePoint) *float64 {
+func (ts TimeSeries) Transform(transformFunc TransformFunc) TimeSeries {
-	sum := AggSum(points)
+	for i, p := range ts {
-	avg := *sum / float64(len(points))
+		ts[i] = transformFunc(p)
-	return &avg
-}
-
-func AggSum(points []TimePoint) *float64 {
-	var sum float64 = 0
-	for _, p := range points {
-		if p.Value != nil {
-			sum += *p.Value
-		}
 	}
-	return &sum
+	return ts
-}
-
-func AggMax(points []TimePoint) *float64 {
-	var max *float64 = nil
-	for _, p := range points {
-		if p.Value != nil {
-			if max == nil {
-				max = p.Value
-			} else if *p.Value > *max {
-				max = p.Value
-			}
-		}
-	}
-	return max
-}
-
-func AggMin(points []TimePoint) *float64 {
-	var min *float64 = nil
-	for _, p := range points {
-		if p.Value != nil {
-			if min == nil {
-				min = p.Value
-			} else if *p.Value < *min {
-				min = p.Value
-			}
-		}
-	}
-	return min
-}
-
-func AggCount(points []TimePoint) *float64 {
-	count := float64(len(points))
-	return &count
-}
-
-func AggFirst(points []TimePoint) *float64 {
-	return points[0].Value
-}
-
-func AggLast(points []TimePoint) *float64 {
-	return points[len(points)-1].Value
-}
-
-func AggMedian(points []TimePoint) *float64 {
-	values := make([]float64, 0)
-	for _, p := range points {
-		if p.Value != nil {
-			values = append(values, *p.Value)
-		}
-	}
-	if len(values) == 0 {
-		return nil
-	}
-
-	values = sort.Float64Slice(values)
-	medianIndex := int(math.Floor(float64(len(values)) / 2))
-	median := values[medianIndex]
-	return &median
 }
 
 // Aligns point's time stamps according to provided interval.

pkg/timeseries/transform_functions.go

@@ -0,0 +1,29 @@
+package timeseries
+
+func TransformScale(factor float64) TransformFunc {
+	return func(point TimePoint) TimePoint {
+		return transformScale(point, factor)
+	}
+}
+
+func TransformOffset(offset float64) TransformFunc {
+	return func(point TimePoint) TimePoint {
+		return transformOffset(point, offset)
+	}
+}
+
+func transformScale(point TimePoint, factor float64) TimePoint {
+	if point.Value != nil {
+		newValue := *point.Value * factor
+		point.Value = &newValue
+	}
+	return point
+}
+
+func transformOffset(point TimePoint, offset float64) TimePoint {
+	if point.Value != nil {
+		newValue := *point.Value + offset
+		point.Value = &newValue
+	}
+	return point
+}