Adding upstream version 2.1.2.

Signed-off-by: Daniel Baumann <daniel@debian.org>

timeutil.go

@@ -0,0 +1,150 @@
+package chart
+
+import "time"
+
+// SecondsPerXYZ
+const (
+	SecondsPerHour = 60 * 60
+	SecondsPerDay  = 60 * 60 * 24
+)
+
+// TimeMillis returns a duration as a float millis.
+func TimeMillis(d time.Duration) float64 {
+	return float64(d) / float64(time.Millisecond)
+}
+
+// DiffHours returns the difference in hours between two times.
+func DiffHours(t1, t2 time.Time) (hours int) {
+	t1n := t1.Unix()
+	t2n := t2.Unix()
+	var diff int64
+	if t1n > t2n {
+		diff = t1n - t2n
+	} else {
+		diff = t2n - t1n
+	}
+	return int(diff / (SecondsPerHour))
+}
+
+// TimeMin returns the minimum and maximum times in a given range.
+func TimeMin(times ...time.Time) (min time.Time) {
+	if len(times) == 0 {
+		return
+	}
+	min = times[0]
+	for index := 1; index < len(times); index++ {
+		if times[index].Before(min) {
+			min = times[index]
+		}
+
+	}
+	return
+}
+
+// TimeMax returns the minimum and maximum times in a given range.
+func TimeMax(times ...time.Time) (max time.Time) {
+	if len(times) == 0 {
+		return
+	}
+	max = times[0]
+
+	for index := 1; index < len(times); index++ {
+		if times[index].After(max) {
+			max = times[index]
+		}
+	}
+	return
+}
+
+// TimeMinMax returns the minimum and maximum times in a given range.
+func TimeMinMax(times ...time.Time) (min, max time.Time) {
+	if len(times) == 0 {
+		return
+	}
+	min = times[0]
+	max = times[0]
+
+	for index := 1; index < len(times); index++ {
+		if times[index].Before(min) {
+			min = times[index]
+		}
+		if times[index].After(max) {
+			max = times[index]
+		}
+	}
+	return
+}
+
+// TimeToFloat64 returns a float64 representation of a time.
+func TimeToFloat64(t time.Time) float64 {
+	return float64(t.UnixNano())
+}
+
+// TimeFromFloat64 returns a time from a float64.
+func TimeFromFloat64(tf float64) time.Time {
+	return time.Unix(0, int64(tf))
+}
+
+// TimeDescending sorts a given list of times ascending, or min to max.
+type TimeDescending []time.Time
+
+// Len implements sort.Sorter
+func (d TimeDescending) Len() int { return len(d) }
+
+// Swap implements sort.Sorter
+func (d TimeDescending) Swap(i, j int) { d[i], d[j] = d[j], d[i] }
+
+// Less implements sort.Sorter
+func (d TimeDescending) Less(i, j int) bool { return d[i].After(d[j]) }
+
+// TimeAscending sorts a given list of times ascending, or min to max.
+type TimeAscending []time.Time
+
+// Len implements sort.Sorter
+func (a TimeAscending) Len() int { return len(a) }
+
+// Swap implements sort.Sorter
+func (a TimeAscending) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
+
+// Less implements sort.Sorter
+func (a TimeAscending) Less(i, j int) bool { return a[i].Before(a[j]) }
+
+// Days generates a seq of timestamps by day, from -days to today.
+func Days(days int) []time.Time {
+	var values []time.Time
+	for day := days; day >= 0; day-- {
+		values = append(values, time.Now().AddDate(0, 0, -day))
+	}
+	return values
+}
+
+// Hours returns a sequence of times by the hour for a given number of hours
+// after a given start.
+func Hours(start time.Time, totalHours int) []time.Time {
+	times := make([]time.Time, totalHours)
+
+	last := start
+	for i := 0; i < totalHours; i++ {
+		times[i] = last
+		last = last.Add(time.Hour)
+	}
+
+	return times
+}
+
+// HoursFilled adds zero values for the data bounded by the start and end of the xdata array.
+func HoursFilled(xdata []time.Time, ydata []float64) ([]time.Time, []float64) {
+	start, end := TimeMinMax(xdata...)
+	totalHours := DiffHours(start, end)
+
+	finalTimes := Hours(start, totalHours+1)
+	finalValues := make([]float64, totalHours+1)
+
+	var hoursFromStart int
+	for i, xd := range xdata {
+		hoursFromStart = DiffHours(start, xd)
+		finalValues[hoursFromStart] = ydata[i]
+	}
+
+	return finalTimes, finalValues
+}