Rework the panel onto SI figures, labelled chips and one spacing scale

render.go

@@ -57,11 +57,6 @@ func pad(s string, w int, right bool) string {
 	return s + strings.Repeat(" ", gap)
 }
 
-func uptime(d time.Duration) string {
-	total := int(d.Seconds())
-	return fmt.Sprintf("%d:%02d:%02d", total/3600, (total/60)%60, total%60)
-}
-
 func commas(v uint64) string {
 	s := fmt.Sprintf("%d", v)
 	if len(s) <= 3 {
@@ -94,6 +89,37 @@ func humanBytes(b uint64) string {
 	return fmt.Sprintf("%.1f PB", v)
 }
 
+// A figure with the letter for its magnitude, so the unit itself can stay a
+// fixed word on the label and only the letter moves with the value. Below a
+// thousand there is no letter and none is left dangling, since a trailing space
+// would push the figure off centre.
+func scaleSI(v float64) string {
+	for _, mag := range []string{"", "k", "M", "G", "T"} {
+		if v < 1000 {
+			if mag == "" {
+				return fmt.Sprintf("%.2f", v)
+			}
+			return fmt.Sprintf("%.2f %s", v, mag)
+		}
+		v /= 1000
+	}
+	return fmt.Sprintf("%.2f P", v)
+}
+
+// The same shape for time, whose magnitudes are sixties and twenty-fours rather
+// than thousands. The letter changes with the value; the label does not.
+func scaleTime(d time.Duration) string {
+	switch {
+	case d < time.Minute:
+		return fmt.Sprintf("%.2f s", d.Seconds())
+	case d < time.Hour:
+		return fmt.Sprintf("%.2f m", d.Minutes())
+	case d < 24*time.Hour:
+		return fmt.Sprintf("%.2f h", d.Hours())
+	}
+	return fmt.Sprintf("%.2f d", d.Hours()/24)
+}
+
 type colSpec struct {
 	title string
 	width int
@@ -216,6 +242,9 @@ func renderBox(title string, headers []string, rights []bool, rows [][]string) s
 	return b.String()
 }
 
+// Counted exactly rather than scaled: these are whole frames, and the figure
+// that matters most is the small one. Scaled, a single lost frame and a
+// thousand of them both read as 1.00, separated only by a letter.
 func statusCell(v uint64) string {
 	s := commas(v)
 	if v == 0 {
@@ -231,12 +260,12 @@ const (
 	rateYellowFrac = 0.80
 )
 
-func rateCell(gb float64, target float64) string {
-	s := fmt.Sprintf("%.2f", gb)
+func rateCell(bits float64, target float64) string {
+	s := scaleSI(bits)
 	switch {
-	case gb >= target*rateGreenFrac:
+	case bits >= target*rateGreenFrac:
 		return paint(s, cGreen)
-	case gb >= target*rateYellowFrac:
+	case bits >= target*rateYellowFrac:
 		return paint(s, cYellow)
 	default:
 		return paint(s, cRed)