summaryrefslogtreecommitdiff
path: root/vendor/github.com/docker/go-units/size.go
diff options
context:
space:
mode:
Diffstat (limited to 'vendor/github.com/docker/go-units/size.go')
-rw-r--r--vendor/github.com/docker/go-units/size.go154
1 files changed, 154 insertions, 0 deletions
diff --git a/vendor/github.com/docker/go-units/size.go b/vendor/github.com/docker/go-units/size.go
new file mode 100644
index 0000000..c245a89
--- /dev/null
+++ b/vendor/github.com/docker/go-units/size.go
@@ -0,0 +1,154 @@
+package units
+
+import (
+ "fmt"
+ "strconv"
+ "strings"
+)
+
+// See: http://en.wikipedia.org/wiki/Binary_prefix
+const (
+ // Decimal
+
+ KB = 1000
+ MB = 1000 * KB
+ GB = 1000 * MB
+ TB = 1000 * GB
+ PB = 1000 * TB
+
+ // Binary
+
+ KiB = 1024
+ MiB = 1024 * KiB
+ GiB = 1024 * MiB
+ TiB = 1024 * GiB
+ PiB = 1024 * TiB
+)
+
+type unitMap map[byte]int64
+
+var (
+ decimalMap = unitMap{'k': KB, 'm': MB, 'g': GB, 't': TB, 'p': PB}
+ binaryMap = unitMap{'k': KiB, 'm': MiB, 'g': GiB, 't': TiB, 'p': PiB}
+)
+
+var (
+ decimapAbbrs = []string{"B", "kB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"}
+ binaryAbbrs = []string{"B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB", "ZiB", "YiB"}
+)
+
+func getSizeAndUnit(size float64, base float64, _map []string) (float64, string) {
+ i := 0
+ unitsLimit := len(_map) - 1
+ for size >= base && i < unitsLimit {
+ size = size / base
+ i++
+ }
+ return size, _map[i]
+}
+
+// CustomSize returns a human-readable approximation of a size
+// using custom format.
+func CustomSize(format string, size float64, base float64, _map []string) string {
+ size, unit := getSizeAndUnit(size, base, _map)
+ return fmt.Sprintf(format, size, unit)
+}
+
+// HumanSizeWithPrecision allows the size to be in any precision,
+// instead of 4 digit precision used in units.HumanSize.
+func HumanSizeWithPrecision(size float64, precision int) string {
+ size, unit := getSizeAndUnit(size, 1000.0, decimapAbbrs)
+ return fmt.Sprintf("%.*g%s", precision, size, unit)
+}
+
+// HumanSize returns a human-readable approximation of a size
+// capped at 4 valid numbers (eg. "2.746 MB", "796 KB").
+func HumanSize(size float64) string {
+ return HumanSizeWithPrecision(size, 4)
+}
+
+// BytesSize returns a human-readable size in bytes, kibibytes,
+// mebibytes, gibibytes, or tebibytes (eg. "44kiB", "17MiB").
+func BytesSize(size float64) string {
+ return CustomSize("%.4g%s", size, 1024.0, binaryAbbrs)
+}
+
+// FromHumanSize returns an integer from a human-readable specification of a
+// size using SI standard (eg. "44kB", "17MB").
+func FromHumanSize(size string) (int64, error) {
+ return parseSize(size, decimalMap)
+}
+
+// RAMInBytes parses a human-readable string representing an amount of RAM
+// in bytes, kibibytes, mebibytes, gibibytes, or tebibytes and
+// returns the number of bytes, or -1 if the string is unparseable.
+// Units are case-insensitive, and the 'b' suffix is optional.
+func RAMInBytes(size string) (int64, error) {
+ return parseSize(size, binaryMap)
+}
+
+// Parses the human-readable size string into the amount it represents.
+func parseSize(sizeStr string, uMap unitMap) (int64, error) {
+ // TODO: rewrite to use strings.Cut if there's a space
+ // once Go < 1.18 is deprecated.
+ sep := strings.LastIndexAny(sizeStr, "01234567890. ")
+ if sep == -1 {
+ // There should be at least a digit.
+ return -1, fmt.Errorf("invalid size: '%s'", sizeStr)
+ }
+ var num, sfx string
+ if sizeStr[sep] != ' ' {
+ num = sizeStr[:sep+1]
+ sfx = sizeStr[sep+1:]
+ } else {
+ // Omit the space separator.
+ num = sizeStr[:sep]
+ sfx = sizeStr[sep+1:]
+ }
+
+ size, err := strconv.ParseFloat(num, 64)
+ if err != nil {
+ return -1, err
+ }
+ // Backward compatibility: reject negative sizes.
+ if size < 0 {
+ return -1, fmt.Errorf("invalid size: '%s'", sizeStr)
+ }
+
+ if len(sfx) == 0 {
+ return int64(size), nil
+ }
+
+ // Process the suffix.
+
+ if len(sfx) > 3 { // Too long.
+ goto badSuffix
+ }
+ sfx = strings.ToLower(sfx)
+ // Trivial case: b suffix.
+ if sfx[0] == 'b' {
+ if len(sfx) > 1 { // no extra characters allowed after b.
+ goto badSuffix
+ }
+ return int64(size), nil
+ }
+ // A suffix from the map.
+ if mul, ok := uMap[sfx[0]]; ok {
+ size *= float64(mul)
+ } else {
+ goto badSuffix
+ }
+
+ // The suffix may have extra "b" or "ib" (e.g. KiB or MB).
+ switch {
+ case len(sfx) == 2 && sfx[1] != 'b':
+ goto badSuffix
+ case len(sfx) == 3 && sfx[1:] != "ib":
+ goto badSuffix
+ }
+
+ return int64(size), nil
+
+badSuffix:
+ return -1, fmt.Errorf("invalid suffix: '%s'", sfx)
+}