forked from filecoin-project/lotus
/
percent.go
39 lines (33 loc) · 829 Bytes
/
percent.go
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package types
import (
"fmt"
"math"
"strconv"
"golang.org/x/xerrors"
)
// Percent stores a signed percentage as an int64. When converted to a string (or json), it's stored
// as a decimal with two places (e.g., 100% -> 1.00).
type Percent int64
func (p Percent) String() string {
abs := p
sign := ""
if abs < 0 {
abs = -abs
sign = "-"
}
return fmt.Sprintf(`%s%d.%d`, sign, abs/100, abs%100)
}
func (p Percent) MarshalJSON() ([]byte, error) {
return []byte(p.String()), nil
}
func (p *Percent) UnmarshalJSON(b []byte) error {
flt, err := strconv.ParseFloat(string(b)+"e2", 64)
if err != nil {
return xerrors.Errorf("unable to parse ratio %s: %w", string(b), err)
}
if math.Trunc(flt) != flt {
return xerrors.Errorf("ratio may only have two decimals: %s", string(b))
}
*p = Percent(flt)
return nil
}