diff options
Diffstat (limited to 'vendor/github.com/docker/go-units/size.go')
| -rw-r--r-- | vendor/github.com/docker/go-units/size.go | 154 |
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) +} |
