| package units |
| |
| import ( |
| "fmt" |
| "regexp" |
| "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[string]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} |
| sizeRegex = regexp.MustCompile(`^(\d+(\.\d+)*) ?([kKmMgGtTpP])?[bB]?$`) |
| ) |
| |
| var decimapAbbrs = []string{"B", "kB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"} |
| var 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) { |
| matches := sizeRegex.FindStringSubmatch(sizeStr) |
| if len(matches) != 4 { |
| return -1, fmt.Errorf("invalid size: '%s'", sizeStr) |
| } |
| |
| size, err := strconv.ParseFloat(matches[1], 64) |
| if err != nil { |
| return -1, err |
| } |
| |
| unitPrefix := strings.ToLower(matches[3]) |
| if mul, ok := uMap[unitPrefix]; ok { |
| size *= float64(mul) |
| } |
| |
| return int64(size), nil |
| } |