Add new prefixes, add some more interface functions

README.md

@@ -5,8 +5,10 @@ When working with metrics, the problem comes up that they may use different unit
 In order to enable unit comparison and conversion, the ccUnits package provides some helpers:
 There are basically two important functions:
 ```go
-NewUnit(unit string) Unit
+NewUnit(unit string) Unit // create a new unit from some string like 'GHz', 'Mbyte' or 'kevents/s'
-GetUnitPrefixFactor(in Unit, out Unit) (func(value float64) float64, error) // Get conversion function for the value
+func GetUnitUnitFactor(in Unit, out Unit) (func(value float64) float64, error) // Get conversion function between two units
+func GetPrefixFactor(in Prefix, out Prefix) func(value float64) float64 // Get conversion function between two prefixes
+func GetUnitPrefixFactor(in Unit, out Prefix) (func(value float64) float64, Unit) // Get conversion function for prefix changes and the new unit for further use
 
 type Unit interface {
 	Valid() bool
@@ -26,14 +28,35 @@ v := NewUnit("foo")
 fmt.Println(v.Valid())                   // false
 ```
 
-If you have two units and need the conversion function:
+If you have two units or other components and need the conversion function:
 ```go
+// Get conversion functions for 'kB' to 'MBytes'
 u1 := NewUnit("kB")
 u2 := NewUnit("MBytes")
-convFunc, err := GetUnitPrefixFactor(u1, u2) // Returns an error if the units have different measures
+convFunc, err := GetUnitUnitFactor(u1, u2) // Returns an error if the units have different measures
 if err == nil {
     v2 := convFunc(v1)
+	fmt.Printf("%f %s\n", v2, u2.Short())
 }
+// Get conversion function for 'kB' -> 'G' prefix.
+// Returns the function and the new unit 'GBytes'
+p1 := NewPrefix("G")
+convFunc, u_p1 := GetUnitPrefixFactor(u1, p1)
+// or
+// convFunc, u_p1 := GetUnitPrefixStringFactor(u1, "G")
+if convFunc != nil {
+	v2 := convFunc(v1)
+	fmt.Printf("%f %s\n", v2, u_p1.Short())
+}
+// Get conversion function for two prefixes: 'G' -> 'T'
+p2 := NewPrefix("T")
+convFunc = GetPrefixPrefixFactor(p1, p2)
+if convFunc != nil {
+	v2 := convFunc(v1)
+	fmt.Printf("%f %s -> %f %s\n", v1, p1.Prefix(), v2, p2.Prefix())
+}
+
+
 ```
 
 (In the ClusterCockpit ecosystem the separation between values and units if useful since they are commonly not stored as a single entity but the value is a field in the CCMetric while unit is a tag or a meta information).

ccUnitMeasure.go

@@ -5,7 +5,7 @@ import "regexp"
 type Measure int
 
 const (
-	None Measure = iota
+	InvalidMeasure Measure = iota
 	Bytes
 	Flops
 	Percentage
@@ -25,7 +25,7 @@ const (
 func (m *Measure) String() string {
 	switch *m {
 	case Bytes:
-		return "Bytes"
+		return "byte"
 	case Flops:
 		return "Flops"
 	case Percentage:
@@ -52,6 +52,8 @@ func (m *Measure) String() string {
 		return "Packets"
 	case Events:
 		return "Events"
+	case InvalidMeasure:
+		return "Invalid"
 	default:
 		return "Unknown"
 	}
@@ -60,7 +62,7 @@ func (m *Measure) String() string {
 func (m *Measure) Short() string {
 	switch *m {
 	case Bytes:
-		return "Bytes"
+		return "B"
 	case Flops:
 		return "Flops"
 	case Percentage:
@@ -87,6 +89,8 @@ func (m *Measure) Short() string {
 		return "packets"
 	case Events:
 		return "events"
+	case InvalidMeasure:
+		return "Invalid"
 	default:
 		return "Unknown"
 	}
@@ -180,5 +184,5 @@ func NewMeasure(unit string) Measure {
 	if match != nil {
 		return Events
 	}
-	return None
+	return InvalidMeasure
 }

ccUnitPrefix.go

@@ -5,20 +5,27 @@ import "regexp"
 type Prefix float64
 
 const (
-	Base  Prefix = 1
+	InvalidPrefix Prefix = iota
-	Exa          = 1e18
+	Base                 = 1
-	Peta         = 1e15
+	Yotta                = 1e24
-	Tera         = 1e12
+	Zetta                = 1e21
-	Giga         = 1e9
+	Exa                  = 1e18
-	Mega         = 1e6
+	Peta                 = 1e15
-	Kilo         = 1e3
+	Tera                 = 1e12
-	Milli        = 1e-3
+	Giga                 = 1e9
-	Micro        = 1e-6
+	Mega                 = 1e6
-	Nano         = 1e-9
+	Kilo                 = 1e3
-	Kibi         = 1024
+	Milli                = 1e-3
-	Mebi         = 1024 * 1024
+	Micro                = 1e-6
-	Gibi         = 1024 * 1024 * 1024
+	Nano                 = 1e-9
-	Tebi         = 1024 * 1024 * 1024 * 1024
+	Kibi                 = 1024
+	Mebi                 = 1024 * 1024
+	Gibi                 = 1024 * 1024 * 1024
+	Tebi                 = 1024 * 1024 * 1024 * 1024
+	Pebi                 = 1024 * 1024 * 1024 * 1024 * 1024
+	Exbi                 = 1024 * 1024 * 1024 * 1024 * 1024 * 1024
+	Zebi                 = 1024 * 1024 * 1024 * 1024 * 1024 * 1024 * 1024
+	Yobi                 = 1024 * 1024 * 1024 * 1024 * 1024 * 1024 * 1024 * 1024
 )
 const prefixRegexStr = `^([kKmMgGtTpP]?[i]?)(.*)`
 
@@ -26,6 +33,8 @@ var prefixRegex = regexp.MustCompile(prefixRegexStr)
 
 func (s *Prefix) String() string {
 	switch *s {
+	case InvalidPrefix:
+		return "Inval"
 	case Base:
 		return ""
 	case Kilo:
@@ -40,6 +49,10 @@ func (s *Prefix) String() string {
 		return "Peta"
 	case Exa:
 		return "Exa"
+	case Zetta:
+		return "Zetta"
+	case Yotta:
+		return "Yotta"
 	case Milli:
 		return "Milli"
 	case Micro:
@@ -61,6 +74,8 @@ func (s *Prefix) String() string {
 
 func (s *Prefix) Prefix() string {
 	switch *s {
+	case InvalidPrefix:
+		return "<inval>"
 	case Base:
 		return ""
 	case Kilo:
@@ -75,6 +90,10 @@ func (s *Prefix) Prefix() string {
 		return "P"
 	case Exa:
 		return "E"
+	case Zetta:
+		return "Z"
+	case Yotta:
+		return "Y"
 	case Milli:
 		return "m"
 	case Micro:
@@ -120,6 +139,14 @@ func NewPrefix(prefix string) Prefix {
 		return Exa
 	case "E":
 		return Exa
+	case "z":
+		return Zetta
+	case "Z":
+		return Zetta
+	case "y":
+		return Yotta
+	case "Y":
+		return Yotta
 	case "u":
 		return Micro
 	case "n":
@@ -139,6 +166,6 @@ func NewPrefix(prefix string) Prefix {
 	case "":
 		return Base
 	default:
-		return Base
+		return InvalidPrefix
 	}
 }

ccUnits.go

@@ -19,14 +19,17 @@ type Unit interface {
 	getPrefix() Prefix
 	getMeasure() Measure
 	getDivMeasure() Measure
+	setPrefix(p Prefix)
 }
 
+var INVALID_UNIT = NewUnit("foobar")
+
 func (u *unit) Valid() bool {
-	return u.measure != None
+	return u.measure != InvalidMeasure
 }
 
 func (u *unit) String() string {
-	if u.divMeasure != None {
+	if u.divMeasure != InvalidMeasure {
 		return fmt.Sprintf("%s%s/%s", u.prefix.String(), u.measure.String(), u.divMeasure.String())
 	} else {
 		return fmt.Sprintf("%s%s", u.prefix.String(), u.measure.String())
@@ -34,7 +37,7 @@ func (u *unit) String() string {
 }
 
 func (u *unit) Short() string {
-	if u.divMeasure != None {
+	if u.divMeasure != InvalidMeasure {
 		return fmt.Sprintf("%s%s/%s", u.prefix.Prefix(), u.measure.Short(), u.divMeasure.Short())
 	} else {
 		return fmt.Sprintf("%s%s", u.prefix.Prefix(), u.measure.Short())
@@ -49,6 +52,10 @@ func (u *unit) getPrefix() Prefix {
 	return u.prefix
 }
 
+func (u *unit) setPrefix(p Prefix) {
+	u.prefix = p
+}
+
 func (u *unit) getMeasure() Measure {
 	return u.measure
 }
@@ -57,7 +64,7 @@ func (u *unit) getDivMeasure() Measure {
 	return u.divMeasure
 }
 
-func GetPrefixFactor(in Prefix, out Prefix) func(value float64) float64 {
+func GetPrefixPrefixFactor(in Prefix, out Prefix) func(value float64) float64 {
 	var factor = 1.0
 	var in_prefix = float64(in)
 	var out_prefix = float64(out)
@@ -65,7 +72,33 @@ func GetPrefixFactor(in Prefix, out Prefix) func(value float64) float64 {
 	return func(value float64) float64 { return factor }
 }
 
-func GetUnitPrefixFactor(in Unit, out Unit) (func(value float64) float64, error) {
+func GetPrefixStringPrefixStringFactor(in string, out string) func(value float64) float64 {
+	var i Prefix = NewPrefix(in)
+	var o Prefix = NewPrefix(out)
+	return GetPrefixPrefixFactor(i, o)
+}
+
+func GetUnitPrefixFactor(in Unit, out Prefix) (func(value float64) float64, Unit) {
+	outUnit := NewUnit(in.Short())
+	if outUnit.Valid() {
+		outUnit.setPrefix(out)
+		conv := GetPrefixPrefixFactor(in.getPrefix(), out)
+		return conv, outUnit
+	}
+	return nil, INVALID_UNIT
+}
+
+func GetUnitPrefixStringFactor(in Unit, out string) (func(value float64) float64, Unit) {
+	var o Prefix = NewPrefix(out)
+	return GetUnitPrefixFactor(in, o)
+}
+
+func GetUnitStringPrefixStringFactor(in string, out string) (func(value float64) float64, Unit) {
+	var i = NewUnit(in)
+	return GetUnitPrefixStringFactor(i, out)
+}
+
+func GetUnitUnitFactor(in Unit, out Unit) (func(value float64) float64, error) {
 	if in.getMeasure() == TemperatureC && out.getMeasure() == TemperatureF {
 		return func(value float64) float64 { return (value * 1.8) + 32 }, nil
 	} else if in.getMeasure() == TemperatureF && out.getMeasure() == TemperatureC {
@@ -73,14 +106,14 @@ func GetUnitPrefixFactor(in Unit, out Unit) (func(value float64) float64, error)
 	} else if in.getMeasure() != out.getMeasure() || in.getDivMeasure() != out.getDivMeasure() {
 		return func(value float64) float64 { return 1.0 }, fmt.Errorf("invalid measures in in and out Unit")
 	}
-	return GetPrefixFactor(in.getPrefix(), out.getPrefix()), nil
+	return GetPrefixPrefixFactor(in.getPrefix(), out.getPrefix()), nil
 }
 
 func NewUnit(unitStr string) Unit {
 	u := &unit{
-		prefix:     Base,
+		prefix:     InvalidPrefix,
-		measure:    None,
+		measure:    InvalidMeasure,
-		divMeasure: None,
+		divMeasure: InvalidMeasure,
 	}
 	matches := prefixRegex.FindStringSubmatch(unitStr)
 	if len(matches) > 2 {
@@ -90,17 +123,17 @@ func NewUnit(unitStr string) Unit {
 		// Special case for prefix 'p' or 'P' (Peta) and measures starting with 'p' or 'P'
 		// like 'packets' or 'percent'. Same for 'e' or 'E' (Exa) for measures starting with
 		// 'e' or 'E' like 'events'
-		if m == None {
+		if m == InvalidMeasure {
 			switch pre {
 			case Peta, Exa:
 				t := NewMeasure(matches[1] + measures[0])
-				if t != None {
+				if t != InvalidMeasure {
 					m = t
 					pre = Base
 				}
 			}
 		}
-		div := None
+		div := InvalidMeasure
 		if len(measures) > 1 {
 			div = NewMeasure(measures[1])
 		}
@@ -115,9 +148,13 @@ func NewUnit(unitStr string) Unit {
 		case Percentage:
 			pre = Base
 		}
-		u.prefix = pre
+		if pre != InvalidPrefix && m != InvalidMeasure {
-		u.measure = m
+			u.prefix = pre
-		u.divMeasure = div
+			u.measure = m
+			if div != InvalidMeasure {
+				u.divMeasure = div
+			}
+		}
 	}
 	return u
 }

ccUnits_test.go

@@ -24,7 +24,7 @@ func TestUnitsExact(t *testing.T) {
 		{"GB", NewUnit("GBytes")},
 		{"Hz", NewUnit("Hertz")},
 		{"MHz", NewUnit("MHertz")},
-		{"GHertz", NewUnit("GHertz")},
+		{"GHz", NewUnit("GHertz")},
 		{"pkts", NewUnit("Packets")},
 		{"packets", NewUnit("Packets")},
 		{"packet", NewUnit("Packets")},
@@ -44,7 +44,7 @@ func TestUnitsExact(t *testing.T) {
 		{"event", NewUnit("events")},
 		{"EveNts", NewUnit("events")},
 		{"reqs", NewUnit("requests")},
-		{"requests", NewUnit("requests")},
+		{"reQuEsTs", NewUnit("requests")},
 		{"Requests", NewUnit("requests")},
 		{"cyc", NewUnit("cycles")},
 		{"cy", NewUnit("cycles")},
@@ -79,7 +79,7 @@ func TestUnitsExact(t *testing.T) {
 	}
 }
 
-func TestUnitsDifferentPrefix(t *testing.T) {
+func TestUnitUnitConversion(t *testing.T) {
 	testCases := []struct {
 		in           string
 		want         Unit
@@ -97,7 +97,7 @@ func TestUnitsDifferentPrefix(t *testing.T) {
 	}
 	compareUnitWithPrefix := func(in, out Unit, factor float64) bool {
 		if in.getMeasure() == out.getMeasure() && in.getDivMeasure() == out.getDivMeasure() {
-			if f := GetPrefixFactor(in.getPrefix(), out.getPrefix()); f(1.0) == factor {
+			if f := GetPrefixPrefixFactor(in.getPrefix(), out.getPrefix()); f(1.0) == factor {
 				return true
 			} else {
 				fmt.Println(f(1.0))
@@ -108,7 +108,73 @@ func TestUnitsDifferentPrefix(t *testing.T) {
 	for _, c := range testCases {
 		u := NewUnit(c.in)
 		if (!u.Valid()) || (!compareUnitWithPrefix(u, c.want, c.prefixFactor)) {
-			t.Errorf("func NewUnit(%q) == %q, want %q with factor %f", c.in, u.String(), c.want.String(), c.prefixFactor)
+			t.Errorf("GetPrefixPrefixFactor(%q, %q) invalid, want %q with factor %f", c.in, u.String(), c.want.String(), c.prefixFactor)
+		}
+	}
+}
+
+func TestUnitPrefixConversion(t *testing.T) {
+	testCases := []struct {
+		in           string
+		want         string
+		prefixFactor float64
+		wantUnit     Unit
+	}{
+		{"KBytes", "", 1000, NewUnit("Bytes")},
+		{"MBytes", "", 1e6, NewUnit("Bytes")},
+		{"MBytes", "G", 1e-3, NewUnit("GBytes")},
+		{"mb", "M", 1, NewUnit("MBytes")},
+	}
+	compareUnitPrefix := func(in Unit, out Prefix, factor float64, outUnit Unit) bool {
+		if in.Valid() {
+			conv, unit := GetUnitPrefixFactor(in, out)
+			value := conv(1.0)
+			if value == factor && unit.String() == outUnit.String() {
+				return true
+			}
+		}
+		return false
+	}
+	for _, c := range testCases {
+		u := NewUnit(c.in)
+		p := NewPrefix(c.want)
+		if (!u.Valid()) || (!compareUnitPrefix(u, p, c.prefixFactor, c.wantUnit)) {
+			t.Errorf("GetUnitPrefixFactor(%q, %q) invalid, want %q with factor %f", c.in, p.Prefix(), c.wantUnit.String(), c.prefixFactor)
+		}
+
+	}
+}
+
+func TestPrefixPrefixConversion(t *testing.T) {
+	testCases := []struct {
+		in           string
+		want         string
+		prefixFactor float64
+	}{
+		{"K", "", 1000},
+		{"M", "", 1e6},
+		{"M", "G", 1e-3},
+		{"", "M", 1e-6},
+		{"", "m", 1e3},
+		{"m", "n", 1e6},
+		//{"", "n", 1e9} does not work because of IEEE rounding problems
+	}
+	comparePrefixPrefix := func(in Prefix, out Prefix, factor float64) bool {
+		if in != InvalidPrefix && out != InvalidPrefix {
+			conv := GetPrefixPrefixFactor(in, out)
+			value := conv(1.0)
+			fmt.Println("1.0 -> ", value, ", want ", factor)
+			if value == factor {
+				return true
+			}
+		}
+		return false
+	}
+	for _, c := range testCases {
+		i := NewPrefix(c.in)
+		o := NewPrefix(c.want)
+		if !comparePrefixPrefix(i, o, c.prefixFactor) {
+			t.Errorf("GetPrefixPrefixFactor(%q, %q) invalid, want %q with factor %f", c.in, c.want, o.Prefix(), c.prefixFactor)
 		}
 	}
 }