Merge pull request #53 from imakhlin/replace-nan-with-infinity

Replace nan with infinity

Author: Igor Makhlin

pkg/aggregate/aggregate.go

@@ -148,13 +148,13 @@ func NewAggregatorList(aggrType AggrType) *AggregatorList {
 		list = append(list, &SqrAggregator{FloatAggregator{attr: "sqr"}})
 	}
 	if (aggrType & aggrTypeMin) != 0 {
-		list = append(list, &MinAggregator{FloatAggregator{attr: "min", val: math.MaxFloat64}}) // TODO: use math.Inf(1)
+		list = append(list, &MinAggregator{FloatAggregator{attr: "min", val: math.Inf(1)}})
 	}
 	if (aggrType & aggrTypeMax) != 0 {
-		list = append(list, &MaxAggregator{FloatAggregator{attr: "max", val: -math.MaxFloat64}}) // TODO: use math.Inf(-1)
+		list = append(list, &MaxAggregator{FloatAggregator{attr: "max", val: math.Inf(-1)}})
 	}
 	if (aggrType & aggrTypeLast) != 0 {
-		list = append(list, &LastAggregator{FloatAggregator{attr: "last"}, 0})
+		list = append(list, &LastAggregator{FloatAggregator{attr: "last", val: math.Inf(-1)}, 0})
 	}
 	return &list
 }

pkg/aggregate/functions.go

@@ -75,14 +75,14 @@ func (a *FloatAggregator) UpdateExpr(col string, bucket int) string {
 }
 
 func (a *FloatAggregator) InitExpr(col string, buckets int) string {
-	return fmt.Sprintf("_%s_%s=init_array(%d,'double');", col, a.attr, buckets)
+	return fmt.Sprintf("_%s_%s=init_array(%d,'double',%f);", col, a.attr, buckets, a.val)
 }
 
 // Sum Aggregator
 type SumAggregator struct{ FloatAggregator }
 
 func (a *SumAggregator) Aggregate(t int64, v float64) {
-	if !math.IsNaN(v) {
+	if utils.IsDefined(v) {
 		a.val += v
 	}
 }
@@ -91,18 +91,18 @@ func (a *SumAggregator) Aggregate(t int64, v float64) {
 type SqrAggregator struct{ FloatAggregator }
 
 func (a *SqrAggregator) Aggregate(t int64, v float64) {
-	if !math.IsNaN(v) {
+	if utils.IsDefined(v) {
 		a.val += v * v
 	}
 }
 
 // Minimum Aggregator
 type MinAggregator struct{ FloatAggregator }
 
-func (a *MinAggregator) Clear() { a.val = math.MaxFloat64 } // TODO: use math.Inf(1)
+func (a *MinAggregator) Clear() { a.val = math.Inf(1) }
 
 func (a *MinAggregator) Aggregate(t int64, v float64) {
-	if !math.IsNaN(v) && (math.IsNaN(a.val) || v < a.val) {
+	if v < a.val {
 		a.val = v
 	}
 }
@@ -114,10 +114,10 @@ func (a *MinAggregator) UpdateExpr(col string, bucket int) string {
 // Maximum Aggregator
 type MaxAggregator struct{ FloatAggregator }
 
-func (a *MaxAggregator) Clear() { a.val = -math.MaxFloat64 } // TODO: use math.Inf(-1)
+func (a *MaxAggregator) Clear() { a.val = math.Inf(-1) }
 
 func (a *MaxAggregator) Aggregate(t int64, v float64) {
-	if !math.IsNaN(v) && (math.IsNaN(a.val) || v > a.val) {
+	if v > a.val {
 		a.val = v
 	}
 }
@@ -132,7 +132,7 @@ type LastAggregator struct {
 	lastT int64
 }
 
-func (a *LastAggregator) Clear() { a.val = -math.MaxFloat64 } // TODO: use math.Inf(1)
+func (a *LastAggregator) Clear() { a.val = math.Inf(-1) }
 
 func (a *LastAggregator) Aggregate(t int64, v float64) {
 	if t > a.lastT {
@@ -142,7 +142,7 @@ func (a *LastAggregator) Aggregate(t int64, v float64) {
 }
 
 func (a *LastAggregator) UpdateExpr(col string, bucket int) string {
-	if math.IsNaN(a.val) {
+	if utils.IsUndefined(a.val) {
 		return ""
 	}
 

pkg/tsdb/tsdbtest/tsdbtest.go

@@ -143,7 +143,7 @@ func ValidateCountOfSamples(t testing.TB, adapter *V3ioAdapter, metricName strin
 	}
 
 	if expected != actual {
-		t.Fatalf("Check failed: actual result is not as expected (%d != %d)", expected, actual)
+		t.Fatalf("Check failed: actual result is not as expected [%d(actual) != %d(expected)]", actual, expected)
 	}
 }
 

pkg/utils/misc.go

@@ -2,9 +2,21 @@ package utils
 
 import (
 	"fmt"
+	"math"
 	"strings"
 )
 
+func IsUndefined(value float64) bool {
+	return math.IsNaN(value) || math.IsInf(value, -1) || math.IsInf(value, 1)
+}
+
+func IsDefined(value float64) bool {
+	return !IsUndefined(value)
+}
+
 func FloatToNormalizedScientificStr(val float64) string {
+	if IsUndefined(val) {
+		return fmt.Sprintf("%f", val)
+	}
 	return strings.Replace(fmt.Sprintf("%e", val), "+", "", 1)
 }