Reorganize, add aggregation

cmd/ursrv/formatting.go

@@ -0,0 +1,71 @@
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"strings"
+)
+
+func number(isBinary bool, v float64) string {
+	if isBinary {
+		return binary(v)
+	} else {
+		return metric(v)
+	}
+}
+
+type prefix struct {
+	Prefix     string
+	Multiplier float64
+}
+
+var metricPrefixes = []prefix{
+	{"G", 1e9},
+	{"M", 1e6},
+	{"k", 1e3},
+}
+
+var binaryPrefixes = []prefix{
+	{"Gi", 1 << 30},
+	{"Mi", 1 << 20},
+	{"Ki", 1 << 10},
+}
+
+func metric(v float64) string {
+	return withPrefix(v, metricPrefixes)
+}
+
+func binary(v float64) string {
+	return withPrefix(v, binaryPrefixes)
+}
+
+func withPrefix(v float64, ps []prefix) string {
+	for _, p := range ps {
+		if v >= p.Multiplier {
+			return fmt.Sprintf("%.1f %s", v/p.Multiplier, p.Prefix)
+		}
+	}
+	return fmt.Sprint(v)
+}
+
+// commatize returns a number with sep as thousands separators. Handles
+// integers and plain floats.
+func commatize(sep, s string) string {
+	var b bytes.Buffer
+	fs := strings.SplitN(s, ".", 2)
+
+	l := len(fs[0])
+	for i := range fs[0] {
+		b.Write([]byte{s[i]})
+		if i < l-1 && (l-i)%3 == 1 {
+			b.WriteString(sep)
+		}
+	}
+
+	if len(fs) > 1 && len(fs[1]) > 0 {
+		b.WriteString(".")
+		b.WriteString(fs[1])
+	}
+
+	return b.String()
+}