byteformats: add k-based byte formatters

Author: nekohasekai

common/byteformats/formats.go

@@ -6,8 +6,10 @@ import (
 )
 
 var (
-	unitNames  = []string{"B", "kB", "MB", "GB", "TB", "PB", "EB"}
-	iUnitNames = []string{"B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB"}
+	unitNames   = []string{"B", "kB", "MB", "GB", "TB", "PB", "EB"}
+	iUnitNames  = []string{"B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB"}
+	kUnitNames  = []string{"kB", "MB", "GB", "TB", "PB", "EB"}
+	kiUnitNames = []string{"KiB", "MiB", "GiB", "TiB", "PiB", "EiB"}
 )
 
 func formatBytes(s uint64, base float64, sizes []string) string {
@@ -25,6 +27,24 @@ func formatBytes(s uint64, base float64, sizes []string) string {
 	return fmt.Sprintf(f, val, suffix)
 }
 
+func formatKBytes(s uint64, base float64, sizes []string) string {
+	if s == 0 {
+		return fmt.Sprintf("0 %s", sizes[0])
+	}
+	e := math.Floor(logn(float64(s), base))
+	if e < 1 {
+		e = 1
+	}
+	suffix := sizes[int(e)-1]
+	val := math.Floor(float64(s)/math.Pow(base, e)*10+0.5) / 10
+	f := "%.0f %s"
+	if val < 10 {
+		f = "%.1f %s"
+	}
+
+	return fmt.Sprintf(f, val, suffix)
+}
+
 func logn(n, b float64) float64 {
 	return math.Log(n) / math.Log(b)
 }
@@ -40,3 +60,15 @@ func FormatMemoryBytes(s uint64) string {
 func FormatIBytes(s uint64) string {
 	return formatBytes(s, 1024, iUnitNames)
 }
+
+func FormatKBytes(s uint64) string {
+	return formatKBytes(s, 1000, kUnitNames)
+}
+
+func FormatMemoryKBytes(s uint64) string {
+	return formatKBytes(s, 1024, kUnitNames)
+}
+
+func FormatKIBytes(s uint64) string {
+	return formatKBytes(s, 1024, kiUnitNames)
+}