docker api

vendor/github.com/docker/go-units/size.go

@@ -0,0 +1,108 @@
+package units
+
+import (
+	"fmt"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+// See: http://en.wikipedia.org/wiki/Binary_prefix
+const (
+	// Decimal
+
+	KB = 1000
+	MB = 1000 * KB
+	GB = 1000 * MB
+	TB = 1000 * GB
+	PB = 1000 * TB
+
+	// Binary
+
+	KiB = 1024
+	MiB = 1024 * KiB
+	GiB = 1024 * MiB
+	TiB = 1024 * GiB
+	PiB = 1024 * TiB
+)
+
+type unitMap map[string]int64
+
+var (
+	decimalMap = unitMap{"k": KB, "m": MB, "g": GB, "t": TB, "p": PB}
+	binaryMap  = unitMap{"k": KiB, "m": MiB, "g": GiB, "t": TiB, "p": PiB}
+	sizeRegex  = regexp.MustCompile(`^(\d+(\.\d+)*) ?([kKmMgGtTpP])?[iI]?[bB]?$`)
+)
+
+var decimapAbbrs = []string{"B", "kB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"}
+var binaryAbbrs = []string{"B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB", "ZiB", "YiB"}
+
+func getSizeAndUnit(size float64, base float64, _map []string) (float64, string) {
+	i := 0
+	unitsLimit := len(_map) - 1
+	for size >= base && i < unitsLimit {
+		size = size / base
+		i++
+	}
+	return size, _map[i]
+}
+
+// CustomSize returns a human-readable approximation of a size
+// using custom format.
+func CustomSize(format string, size float64, base float64, _map []string) string {
+	size, unit := getSizeAndUnit(size, base, _map)
+	return fmt.Sprintf(format, size, unit)
+}
+
+// HumanSizeWithPrecision allows the size to be in any precision,
+// instead of 4 digit precision used in units.HumanSize.
+func HumanSizeWithPrecision(size float64, precision int) string {
+	size, unit := getSizeAndUnit(size, 1000.0, decimapAbbrs)
+	return fmt.Sprintf("%.*g%s", precision, size, unit)
+}
+
+// HumanSize returns a human-readable approximation of a size
+// capped at 4 valid numbers (eg. "2.746 MB", "796 KB").
+func HumanSize(size float64) string {
+	return HumanSizeWithPrecision(size, 4)
+}
+
+// BytesSize returns a human-readable size in bytes, kibibytes,
+// mebibytes, gibibytes, or tebibytes (eg. "44kiB", "17MiB").
+func BytesSize(size float64) string {
+	return CustomSize("%.4g%s", size, 1024.0, binaryAbbrs)
+}
+
+// FromHumanSize returns an integer from a human-readable specification of a
+// size using SI standard (eg. "44kB", "17MB").
+func FromHumanSize(size string) (int64, error) {
+	return parseSize(size, decimalMap)
+}
+
+// RAMInBytes parses a human-readable string representing an amount of RAM
+// in bytes, kibibytes, mebibytes, gibibytes, or tebibytes and
+// returns the number of bytes, or -1 if the string is unparseable.
+// Units are case-insensitive, and the 'b' suffix is optional.
+func RAMInBytes(size string) (int64, error) {
+	return parseSize(size, binaryMap)
+}
+
+// Parses the human-readable size string into the amount it represents.
+func parseSize(sizeStr string, uMap unitMap) (int64, error) {
+	matches := sizeRegex.FindStringSubmatch(sizeStr)
+	if len(matches) != 4 {
+		return -1, fmt.Errorf("invalid size: '%s'", sizeStr)
+	}
+
+	size, err := strconv.ParseFloat(matches[1], 64)
+	if err != nil {
+		return -1, err
+	}
+
+	unitPrefix := strings.ToLower(matches[3])
+	if mul, ok := uMap[unitPrefix]; ok {
+		size *= float64(mul)
+	}
+
+	return int64(size), nil
+}