Function FormatOpenMetricsFloat

model/labels/float.go:35–60

FormatOpenMetricsFloat works like the usual Go string formatting of a float but appends ".0" if the resulting number would otherwise contain neither a "." nor an "e".

(f float64)

// but appends ".0" if the resulting number would otherwise contain neither a
// "." nor an "e".
func FormatOpenMetricsFloat(f float64) string {
	// A few common cases hardcoded.
	switch {
	case f == 1:
		return "1.0"
	case f == 0:
		return "0.0"
	case f == -1:
		return "-1.0"
	case math.IsNaN(f):
		return "NaN"
	case math.IsInf(f, +1):
		return "+Inf"
	case math.IsInf(f, -1):
		return "-Inf"
	}
	bp := floatFormatBufPool.Get().(*[]byte)
	defer floatFormatBufPool.Put(bp)

	*bp = strconv.AppendFloat((*bp)[:0], f, 'g', -1, 64)
	if bytes.ContainsAny(*bp, "e.") {
		return string(*bp)
	}
	*bp = append(*bp, '.', '0')
	return string(*bp)
}