158 lines
3.4 KiB
Go
158 lines
3.4 KiB
Go
package util
|
|
|
|
import (
|
|
"encoding/json"
|
|
"errors"
|
|
"strconv"
|
|
"strings"
|
|
)
|
|
|
|
const (
|
|
precision = 8
|
|
decimals = 100000000
|
|
)
|
|
|
|
var errInvalidString = errors.New("Fixed8 must satisfy following regex \\d+(\\.\\d{1,8})?")
|
|
|
|
// Fixed8 represents a fixed-point number with precision 10^-8.
|
|
type Fixed8 int64
|
|
|
|
// String implements the Stringer interface.
|
|
func (f Fixed8) String() string {
|
|
buf := new(strings.Builder)
|
|
val := int64(f)
|
|
if val < 0 {
|
|
buf.WriteRune('-')
|
|
val = -val
|
|
}
|
|
str := strconv.FormatInt(val/decimals, 10)
|
|
buf.WriteString(str)
|
|
val %= decimals
|
|
if val > 0 {
|
|
buf.WriteRune('.')
|
|
str = strconv.FormatInt(val, 10)
|
|
for i := len(str); i < 8; i++ {
|
|
buf.WriteRune('0')
|
|
}
|
|
buf.WriteString(strings.TrimRight(str, "0"))
|
|
}
|
|
return buf.String()
|
|
}
|
|
|
|
// FloatValue returns the original value representing Fixed8 as float64.
|
|
func (f Fixed8) FloatValue() float64 {
|
|
return float64(f) / decimals
|
|
}
|
|
|
|
// Int64Value returns the original value representing Fixed8 as int64.
|
|
func (f Fixed8) Int64Value() int64 {
|
|
return int64(f) / decimals
|
|
}
|
|
|
|
// Fixed8FromInt64 returns a new Fixed8 type multiplied by decimals.
|
|
func Fixed8FromInt64(val int64) Fixed8 {
|
|
return Fixed8(decimals * val)
|
|
}
|
|
|
|
// Fixed8FromFloat returns a new Fixed8 type multiplied by decimals.
|
|
func Fixed8FromFloat(val float64) Fixed8 {
|
|
return Fixed8(int64(decimals * val))
|
|
}
|
|
|
|
// Fixed8FromString parses s which must be a fixed point number
|
|
// with precision up to 10^-8
|
|
func Fixed8FromString(s string) (Fixed8, error) {
|
|
parts := strings.SplitN(s, ".", 2)
|
|
ip, err := strconv.ParseInt(parts[0], 10, 64)
|
|
if err != nil {
|
|
return 0, errInvalidString
|
|
} else if len(parts) == 1 {
|
|
return Fixed8(ip * decimals), nil
|
|
}
|
|
|
|
fp, err := strconv.ParseInt(parts[1], 10, 64)
|
|
if err != nil || fp >= decimals {
|
|
return 0, errInvalidString
|
|
}
|
|
for i := len(parts[1]); i < precision; i++ {
|
|
fp *= 10
|
|
}
|
|
if ip < 0 {
|
|
return Fixed8(ip*decimals - fp), nil
|
|
}
|
|
return Fixed8(ip*decimals + fp), nil
|
|
}
|
|
|
|
// UnmarshalJSON implements the json unmarshaller interface.
|
|
func (f *Fixed8) UnmarshalJSON(data []byte) error {
|
|
var s string
|
|
if err := json.Unmarshal(data, &s); err == nil {
|
|
p, err := Fixed8FromString(s)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
*f = p
|
|
return nil
|
|
}
|
|
|
|
var fl float64
|
|
if err := json.Unmarshal(data, &fl); err != nil {
|
|
return err
|
|
}
|
|
|
|
*f = Fixed8(decimals * fl)
|
|
return nil
|
|
}
|
|
|
|
// Size returns the size in number of bytes of Fixed8.
|
|
func (f *Fixed8) Size() int {
|
|
return 8
|
|
}
|
|
|
|
// MarshalJSON implements the json marshaller interface.
|
|
func (f Fixed8) MarshalJSON() ([]byte, error) {
|
|
return []byte(`"` + f.String() + `"`), nil
|
|
}
|
|
|
|
// Satoshi defines the value of a 'Satoshi'.
|
|
func Satoshi() Fixed8 {
|
|
return Fixed8(1)
|
|
}
|
|
|
|
// Div implements Fixd8 division operator.
|
|
func (f Fixed8) Div(i int64) Fixed8 {
|
|
return f / Fixed8FromInt64(i)
|
|
}
|
|
|
|
// Add implements Fixd8 addition operator.
|
|
func (f Fixed8) Add(g Fixed8) Fixed8 {
|
|
return f + g
|
|
}
|
|
|
|
// Sub implements Fixd8 subtraction operator.
|
|
func (f Fixed8) Sub(g Fixed8) Fixed8 {
|
|
return f - g
|
|
}
|
|
|
|
// LessThan implements Fixd8 < operator.
|
|
func (f Fixed8) LessThan(g Fixed8) bool {
|
|
return f < g
|
|
}
|
|
|
|
// GreaterThan implements Fixd8 < operator.
|
|
func (f Fixed8) GreaterThan(g Fixed8) bool {
|
|
return f > g
|
|
}
|
|
|
|
// Equal implements Fixd8 == operator.
|
|
func (f Fixed8) Equal(g Fixed8) bool {
|
|
return f == g
|
|
}
|
|
|
|
// CompareTo returns the difference between the f and g.
|
|
// difference < 0 implies f < g.
|
|
// difference = 0 implies f = g.
|
|
// difference > 0 implies f > g.
|
|
func (f Fixed8) CompareTo(g Fixed8) int {
|
|
return int(f - g)
|
|
}
|