1
mirror of https://github.com/rclone/rclone synced 2024-12-24 15:43:45 +01:00
rclone/fs/sizesuffix.go
albertony 2925e1384c Use binary prefixes for size and rate units
Includes adding support for additional size input suffix Mi and MiB, treated equivalent to M.
Extends binary suffix output with letter i, e.g. Ki and Mi.
Centralizes creation of bit/byte unit strings.
2021-04-27 02:25:52 +03:00

257 lines
6.1 KiB
Go

package fs
// SizeSuffix is parsed by flag with K/M/G binary suffixes
import (
"encoding/json"
"fmt"
"math"
"sort"
"strconv"
"strings"
"github.com/pkg/errors"
)
// SizeSuffix is an int64 with a friendly way of printing setting
type SizeSuffix int64
// Common multipliers for SizeSuffix
const (
SizeSuffixBase SizeSuffix = 1 << (iota * 10)
Kibi
Mebi
Gibi
Tebi
Pebi
Exbi
)
const (
// SizeSuffixMax is the largest SizeSuffix multiplier
SizeSuffixMax = Exbi
// SizeSuffixMaxValue is the largest value that can be used to create SizeSuffix
SizeSuffixMaxValue = math.MaxInt64
// SizeSuffixMinValue is the smallest value that can be used to create SizeSuffix
SizeSuffixMinValue = math.MinInt64
)
// Turn SizeSuffix into a string and a suffix
func (x SizeSuffix) string() (string, string) {
scaled := float64(0)
suffix := ""
switch {
case x < 0:
return "off", ""
case x == 0:
return "0", ""
case x < Kibi:
scaled = float64(x)
suffix = ""
case x < Mebi:
scaled = float64(x) / float64(Kibi)
suffix = "Ki"
case x < Gibi:
scaled = float64(x) / float64(Mebi)
suffix = "Mi"
case x < Tebi:
scaled = float64(x) / float64(Gibi)
suffix = "Gi"
case x < Pebi:
scaled = float64(x) / float64(Tebi)
suffix = "Ti"
case x < Exbi:
scaled = float64(x) / float64(Pebi)
suffix = "Pi"
default:
scaled = float64(x) / float64(Exbi)
suffix = "Ei"
}
if math.Floor(scaled) == scaled {
return fmt.Sprintf("%.0f", scaled), suffix
}
return fmt.Sprintf("%.3f", scaled), suffix
}
// String turns SizeSuffix into a string
func (x SizeSuffix) String() string {
val, suffix := x.string()
return val + suffix
}
// Unit turns SizeSuffix into a string with a unit
func (x SizeSuffix) unit(unit string) string {
val, suffix := x.string()
if val == "off" {
return val
}
var suffixUnit string
if suffix != "" && unit != "" {
suffixUnit = suffix + unit
} else {
suffixUnit = suffix + unit
}
return val + " " + suffixUnit
}
// BitUnit turns SizeSuffix into a string with bit unit
func (x SizeSuffix) BitUnit() string {
return x.unit("bit")
}
// BitRateUnit turns SizeSuffix into a string with bit rate unit
func (x SizeSuffix) BitRateUnit() string {
return x.unit("bit/s")
}
// ByteUnit turns SizeSuffix into a string with byte unit
func (x SizeSuffix) ByteUnit() string {
return x.unit("Byte")
}
// ByteRateUnit turns SizeSuffix into a string with byte rate unit
func (x SizeSuffix) ByteRateUnit() string {
return x.unit("Byte/s")
}
// ByteShortUnit turns SizeSuffix into a string with byte unit short form
func (x SizeSuffix) ByteShortUnit() string {
return x.unit("B")
}
// ByteRateShortUnit turns SizeSuffix into a string with byte rate unit short form
func (x SizeSuffix) ByteRateShortUnit() string {
return x.unit("B/s")
}
func (x *SizeSuffix) multiplierFromSymbol(s byte) (found bool, multiplier float64) {
switch s {
case 'k', 'K':
return true, float64(Kibi)
case 'm', 'M':
return true, float64(Mebi)
case 'g', 'G':
return true, float64(Gibi)
case 't', 'T':
return true, float64(Tebi)
case 'p', 'P':
return true, float64(Pebi)
case 'e', 'E':
return true, float64(Exbi)
default:
return false, float64(SizeSuffixBase)
}
}
// Set a SizeSuffix
func (x *SizeSuffix) Set(s string) error {
if len(s) == 0 {
return errors.New("empty string")
}
if strings.ToLower(s) == "off" {
*x = -1
return nil
}
suffix := s[len(s)-1]
suffixLen := 1
multiplierFound := false
var multiplier float64
switch suffix {
case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '.':
suffixLen = 0
multiplier = float64(Kibi)
case 'b', 'B':
if len(s) > 2 && s[len(s)-2] == 'i' {
suffix = s[len(s)-3]
suffixLen = 3
if multiplierFound, multiplier = x.multiplierFromSymbol(suffix); !multiplierFound {
return errors.Errorf("bad suffix %q", suffix)
}
// Could also support SI form MB, and treat it equivalent to MiB, but perhaps better to reserve it for CountSuffix?
//} else if len(s) > 1 {
// suffix = s[len(s)-2]
// if multiplierFound, multiplier = x.multiplierFromSymbol(suffix); multiplierFound {
// suffixLen = 2
// }
//}
} else {
multiplier = float64(SizeSuffixBase)
}
case 'i', 'I':
if len(s) > 1 {
suffix = s[len(s)-2]
suffixLen = 2
multiplierFound, multiplier = x.multiplierFromSymbol(suffix)
}
if !multiplierFound {
return errors.Errorf("bad suffix %q", suffix)
}
default:
if multiplierFound, multiplier = x.multiplierFromSymbol(suffix); !multiplierFound {
return errors.Errorf("bad suffix %q", suffix)
}
}
s = s[:len(s)-suffixLen]
value, err := strconv.ParseFloat(s, 64)
if err != nil {
return err
}
if value < 0 {
return errors.Errorf("size can't be negative %q", s)
}
value *= multiplier
*x = SizeSuffix(value)
return nil
}
// Type of the value
func (x *SizeSuffix) Type() string {
return "SizeSuffix"
}
// Scan implements the fmt.Scanner interface
func (x *SizeSuffix) Scan(s fmt.ScanState, ch rune) error {
token, err := s.Token(true, nil)
if err != nil {
return err
}
return x.Set(string(token))
}
// SizeSuffixList is a slice SizeSuffix values
type SizeSuffixList []SizeSuffix
func (l SizeSuffixList) Len() int { return len(l) }
func (l SizeSuffixList) Swap(i, j int) { l[i], l[j] = l[j], l[i] }
func (l SizeSuffixList) Less(i, j int) bool { return l[i] < l[j] }
// Sort sorts the list
func (l SizeSuffixList) Sort() {
sort.Sort(l)
}
// UnmarshalJSONFlag unmarshals a JSON input for a flag. If the input
// is a string then it calls the Set method on the flag otherwise it
// calls the setInt function with a parsed int64.
func UnmarshalJSONFlag(in []byte, x interface{ Set(string) error }, setInt func(int64) error) error {
// Try to parse as string first
var s string
err := json.Unmarshal(in, &s)
if err == nil {
return x.Set(s)
}
// If that fails parse as integer
var i int64
err = json.Unmarshal(in, &i)
if err != nil {
return err
}
return setInt(i)
}
// UnmarshalJSON makes sure the value can be parsed as a string or integer in JSON
func (x *SizeSuffix) UnmarshalJSON(in []byte) error {
return UnmarshalJSONFlag(in, x, func(i int64) error {
*x = SizeSuffix(i)
return nil
})
}