minFreeSpace argument allows size like 10GiB

weed/util/bytes.go

@@ -5,8 +5,13 @@ import (
 	"crypto/md5"
 	"crypto/rand"
 	"encoding/base64"
+	"errors"
 	"fmt"
 	"io"
+	"math"
+	"strconv"
+	"strings"
+	"unicode"
 )
 
 // BytesToHumanReadable returns the converted human readable representation of the bytes.
@@ -161,3 +166,105 @@ func NewBytesReader(b []byte) *BytesReader {
 		Reader: bytes.NewReader(b),
 	}
 }
+
+// EmptyTo returns to if s is empty.
+func EmptyTo(s, to string) string {
+	if s == "" {
+		return to
+	}
+
+	return s
+}
+
+var ErrMinFreeSpaceBadValue = errors.New("minFreeSpace is invalid")
+
+// ParseMinFreeSpace parses min free space expression s as percentage like 1,10 or human readable size like 10G
+func ParseMinFreeSpace(s string) (float32, error) {
+	if value, e := strconv.ParseFloat(s, 32); e == nil {
+		if value < 0 || value > 100 {
+			return 0, ErrMinFreeSpaceBadValue
+		}
+		return float32(value), nil
+	} else if directSize, e2 := ParseBytes(s); e2 == nil {
+		if directSize <= 100 {
+			return 0, ErrMinFreeSpaceBadValue
+		}
+		return float32(directSize), nil
+	}
+
+	return 0, ErrMinFreeSpaceBadValue
+}
+
+// ParseBytes parses a string representation of bytes into the number
+// of bytes it represents.
+//
+// See Also: Bytes, IBytes.
+//
+// ParseBytes("42MB") -> 42000000, nil
+// ParseBytes("42 MB") -> 42000000, nil
+// ParseBytes("42 mib") -> 44040192, nil
+func ParseBytes(s string) (uint64, error) {
+	lastDigit := 0
+	hasComma := false
+	for _, r := range s {
+		if !(unicode.IsDigit(r) || r == '.' || r == ',') {
+			break
+		}
+		if r == ',' {
+			hasComma = true
+		}
+		lastDigit++
+	}
+
+	num := s[:lastDigit]
+	if hasComma {
+		num = strings.Replace(num, ",", "", -1)
+	}
+
+	f, err := strconv.ParseFloat(num, 64)
+	if err != nil {
+		return 0, err
+	}
+
+	extra := strings.ToLower(strings.TrimSpace(s[lastDigit:]))
+	if m, ok := bytesSizeTable[extra]; ok {
+		f *= float64(m)
+		if f >= math.MaxUint64 {
+			return 0, fmt.Errorf("too large: %v", s)
+		}
+		return uint64(f), nil
+	}
+
+	return 0, fmt.Errorf("unhandled size name: %v", extra)
+}
+
+var bytesSizeTable = map[string]uint64{
+	"b": Byte, "kib": KiByte, "kb": KByte, "mib": MiByte, "mb": MByte, "gib": GiByte, "gb": GByte,
+	"tib": TiByte, "tb": TByte, "pib": PiByte, "pb": PByte, "eib": EiByte, "eb": EByte,
+	// Without suffix
+	"": Byte, "ki": KiByte, "k": KByte, "mi": MiByte, "m": MByte, "gi": GiByte, "g": GByte,
+	"ti": TiByte, "t": TByte, "pi": PiByte, "p": PByte, "ei": EiByte, "e": EByte,
+}
+
+// IEC Sizes.
+// kibis of bits
+const (
+	Byte = 1 << (iota * 10)
+	KiByte
+	MiByte
+	GiByte
+	TiByte
+	PiByte
+	EiByte
+)
+
+// SI Sizes.
+const (
+	IByte = 1
+	KByte = IByte * 1000
+	MByte = KByte * 1000
+	GByte = MByte * 1000
+	TByte = GByte * 1000
+	PByte = TByte * 1000
+	EByte = PByte * 1000
+)