From 1a57267a17c2fc17fb6e104846fabc3e363c326c Mon Sep 17 00:00:00 2001 From: Emile Date: Fri, 16 Aug 2024 19:50:26 +0200 Subject: initial commit --- vendor/github.com/dustin/go-humanize/si.go | 127 +++++++++++++++++++++++++++++ 1 file changed, 127 insertions(+) create mode 100644 vendor/github.com/dustin/go-humanize/si.go (limited to 'vendor/github.com/dustin/go-humanize/si.go') diff --git a/vendor/github.com/dustin/go-humanize/si.go b/vendor/github.com/dustin/go-humanize/si.go new file mode 100644 index 0000000..8b85019 --- /dev/null +++ b/vendor/github.com/dustin/go-humanize/si.go @@ -0,0 +1,127 @@ +package humanize + +import ( + "errors" + "math" + "regexp" + "strconv" +) + +var siPrefixTable = map[float64]string{ + -30: "q", // quecto + -27: "r", // ronto + -24: "y", // yocto + -21: "z", // zepto + -18: "a", // atto + -15: "f", // femto + -12: "p", // pico + -9: "n", // nano + -6: "ยต", // micro + -3: "m", // milli + 0: "", + 3: "k", // kilo + 6: "M", // mega + 9: "G", // giga + 12: "T", // tera + 15: "P", // peta + 18: "E", // exa + 21: "Z", // zetta + 24: "Y", // yotta + 27: "R", // ronna + 30: "Q", // quetta +} + +var revSIPrefixTable = revfmap(siPrefixTable) + +// revfmap reverses the map and precomputes the power multiplier +func revfmap(in map[float64]string) map[string]float64 { + rv := map[string]float64{} + for k, v := range in { + rv[v] = math.Pow(10, k) + } + return rv +} + +var riParseRegex *regexp.Regexp + +func init() { + ri := `^([\-0-9.]+)\s?([` + for _, v := range siPrefixTable { + ri += v + } + ri += `]?)(.*)` + + riParseRegex = regexp.MustCompile(ri) +} + +// ComputeSI finds the most appropriate SI prefix for the given number +// and returns the prefix along with the value adjusted to be within +// that prefix. +// +// See also: SI, ParseSI. +// +// e.g. ComputeSI(2.2345e-12) -> (2.2345, "p") +func ComputeSI(input float64) (float64, string) { + if input == 0 { + return 0, "" + } + mag := math.Abs(input) + exponent := math.Floor(logn(mag, 10)) + exponent = math.Floor(exponent/3) * 3 + + value := mag / math.Pow(10, exponent) + + // Handle special case where value is exactly 1000.0 + // Should return 1 M instead of 1000 k + if value == 1000.0 { + exponent += 3 + value = mag / math.Pow(10, exponent) + } + + value = math.Copysign(value, input) + + prefix := siPrefixTable[exponent] + return value, prefix +} + +// SI returns a string with default formatting. +// +// SI uses Ftoa to format float value, removing trailing zeros. +// +// See also: ComputeSI, ParseSI. +// +// e.g. SI(1000000, "B") -> 1 MB +// e.g. SI(2.2345e-12, "F") -> 2.2345 pF +func SI(input float64, unit string) string { + value, prefix := ComputeSI(input) + return Ftoa(value) + " " + prefix + unit +} + +// SIWithDigits works like SI but limits the resulting string to the +// given number of decimal places. +// +// e.g. SIWithDigits(1000000, 0, "B") -> 1 MB +// e.g. SIWithDigits(2.2345e-12, 2, "F") -> 2.23 pF +func SIWithDigits(input float64, decimals int, unit string) string { + value, prefix := ComputeSI(input) + return FtoaWithDigits(value, decimals) + " " + prefix + unit +} + +var errInvalid = errors.New("invalid input") + +// ParseSI parses an SI string back into the number and unit. +// +// See also: SI, ComputeSI. +// +// e.g. ParseSI("2.2345 pF") -> (2.2345e-12, "F", nil) +func ParseSI(input string) (float64, string, error) { + found := riParseRegex.FindStringSubmatch(input) + if len(found) != 4 { + return 0, "", errInvalid + } + mag := revSIPrefixTable[found[2]] + unit := found[3] + + base, err := strconv.ParseFloat(found[1], 64) + return base * mag, unit, err +} -- cgit 1.4.1