mirror of https://github.com/docker/cli.git
118 lines
2.2 KiB
Go
118 lines
2.2 KiB
Go
/*
|
|
Simple byte size formatting.
|
|
|
|
This package implements types that can be used in stdlib formatting functions
|
|
like `fmt.Printf` to control the output of the expected printed string.
|
|
|
|
|
|
Floating point flags %f and %g print the value in using the correct unit
|
|
suffix. Decimal units are default, # switches to binary units. If a value is
|
|
best represented as full bytes, integer bytes are printed instead.
|
|
|
|
Examples:
|
|
fmt.Printf("%.2f", 123 * B) => "123B"
|
|
fmt.Printf("%.2f", 1234 * B) => "1.23kB"
|
|
fmt.Printf("%g", 1200 * B) => "1.2kB"
|
|
fmt.Printf("%#g", 1024 * B) => "1KiB"
|
|
|
|
|
|
Integer flag %d always prints the value in bytes. # flag adds an unit prefix.
|
|
|
|
Examples:
|
|
fmt.Printf("%d", 1234 * B) => "1234"
|
|
fmt.Printf("%#d", 1234 * B) => "1234B"
|
|
|
|
%v is equal to %g
|
|
|
|
*/
|
|
package units
|
|
|
|
import (
|
|
"fmt"
|
|
"io"
|
|
"math"
|
|
"math/big"
|
|
)
|
|
|
|
type Bytes int64
|
|
|
|
const (
|
|
B Bytes = 1 << (10 * iota)
|
|
KiB
|
|
MiB
|
|
GiB
|
|
TiB
|
|
PiB
|
|
EiB
|
|
|
|
KB = 1e3 * B
|
|
MB = 1e3 * KB
|
|
GB = 1e3 * MB
|
|
TB = 1e3 * GB
|
|
PB = 1e3 * TB
|
|
EB = 1e3 * PB
|
|
)
|
|
|
|
var units = map[bool][]string{
|
|
false: []string{
|
|
"B", "kB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB",
|
|
},
|
|
true: []string{
|
|
"B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB", "ZiB", "YiB",
|
|
},
|
|
}
|
|
|
|
func (b Bytes) Format(f fmt.State, c rune) {
|
|
switch c {
|
|
case 'f', 'g':
|
|
fv, unit, ok := b.floatValue(f.Flag('#'))
|
|
if !ok {
|
|
b.formatInt(f, 'd', true)
|
|
return
|
|
}
|
|
big.NewFloat(fv).Format(f, c)
|
|
io.WriteString(f, unit)
|
|
case 'd':
|
|
b.formatInt(f, c, f.Flag('#'))
|
|
default:
|
|
if f.Flag('#') {
|
|
fmt.Fprintf(f, "bytes(%d)", int64(b))
|
|
} else {
|
|
fmt.Fprintf(f, "%g", b)
|
|
}
|
|
}
|
|
}
|
|
|
|
func (b Bytes) formatInt(f fmt.State, c rune, withUnit bool) {
|
|
big.NewInt(int64(b)).Format(f, c)
|
|
if withUnit {
|
|
io.WriteString(f, "B")
|
|
}
|
|
}
|
|
|
|
func (b Bytes) floatValue(binary bool) (float64, string, bool) {
|
|
i := 0
|
|
var baseUnit Bytes = 1
|
|
if b < 0 {
|
|
baseUnit *= -1
|
|
}
|
|
for {
|
|
next := baseUnit
|
|
if binary {
|
|
next *= 1 << 10
|
|
} else {
|
|
next *= 1e3
|
|
}
|
|
if (baseUnit > 0 && b >= next) || (baseUnit < 0 && b <= next) {
|
|
i++
|
|
baseUnit = next
|
|
continue
|
|
}
|
|
if i == 0 {
|
|
return 0, "", false
|
|
}
|
|
|
|
return float64(b) / math.Abs(float64(baseUnit)), units[binary][i], true
|
|
}
|
|
}
|