move implementation to internal/ directory (#828)

internal/util/datasizeunit/datasizeunit.go

@@ -0,0 +1,86 @@
+package datasizeunit
+
+import (
+	"errors"
+	"fmt"
+	"math"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+type Bits struct {
+	bits float64
+}
+
+func (b Bits) ToBits() float64    { return b.bits }
+func (b Bits) ToBytes() float64   { return b.bits / 8 }
+func FromBytesInt64(i int64) Bits { return Bits{float64(i) * 8} }
+
+var datarateRegex = regexp.MustCompile(`^([-0-9\.]*)\s*(bit|(|K|Ki|M|Mi|G|Gi|T|Ti)([bB]))$`)
+
+func (r *Bits) UnmarshalYAML(u func(interface{}, bool) error) (_ error) {
+
+	var s string
+	err := u(&s, false)
+	if err != nil {
+		return err
+	}
+
+	genericErr := func(err error) error {
+		var buf strings.Builder
+		fmt.Fprintf(&buf, "cannot parse %q using regex %s", s, datarateRegex)
+		if err != nil {
+			fmt.Fprintf(&buf, ": %s", err)
+		}
+		return errors.New(buf.String())
+	}
+
+	match := datarateRegex.FindStringSubmatch(s)
+	if match == nil {
+		return genericErr(nil)
+	}
+
+	bps, err := strconv.ParseFloat(match[1], 64)
+	if err != nil {
+		return genericErr(err)
+	}
+
+	if match[2] == "bit" {
+		if math.Round(bps) != bps {
+			return genericErr(fmt.Errorf("unit bit must be an integer value"))
+		}
+		r.bits = bps
+		return nil
+	}
+
+	factorMap := map[string]uint64{
+		"": 1,
+
+		"K": 1e3,
+		"M": 1e6,
+		"G": 1e9,
+		"T": 1e12,
+
+		"Ki": 1 << 10,
+		"Mi": 1 << 20,
+		"Gi": 1 << 30,
+		"Ti": 1 << 40,
+	}
+	factor, ok := factorMap[match[3]]
+	if !ok {
+		panic(match)
+	}
+
+	baseUnitFactorMap := map[string]uint64{
+		"b": 1,
+		"B": 8,
+	}
+	baseUnitFactor, ok := baseUnitFactorMap[match[4]]
+	if !ok {
+		panic(match)
+	}
+
+	r.bits = bps * float64(factor) * float64(baseUnitFactor)
+	return nil
+}