1package humanize
2
3import (
4 "fmt"
5 "math"
6 "strconv"
7 "strings"
8 "unicode"
9)
10
11// IEC Sizes.
12// kibis of bits
13const (
14 Byte = 1 << (iota * 10)
15 KiByte
16 MiByte
17 GiByte
18 TiByte
19 PiByte
20 EiByte
21)
22
23// SI Sizes.
24const (
25 IByte = 1
26 KByte = IByte * 1000
27 MByte = KByte * 1000
28 GByte = MByte * 1000
29 TByte = GByte * 1000
30 PByte = TByte * 1000
31 EByte = PByte * 1000
32)
33
34var bytesSizeTable = map[string]uint64{
35 "b": Byte,
36 "kib": KiByte,
37 "kb": KByte,
38 "mib": MiByte,
39 "mb": MByte,
40 "gib": GiByte,
41 "gb": GByte,
42 "tib": TiByte,
43 "tb": TByte,
44 "pib": PiByte,
45 "pb": PByte,
46 "eib": EiByte,
47 "eb": EByte,
48 // Without suffix
49 "": Byte,
50 "ki": KiByte,
51 "k": KByte,
52 "mi": MiByte,
53 "m": MByte,
54 "gi": GiByte,
55 "g": GByte,
56 "ti": TiByte,
57 "t": TByte,
58 "pi": PiByte,
59 "p": PByte,
60 "ei": EiByte,
61 "e": EByte,
62}
63
64func logn(n, b float64) float64 {
65 return math.Log(n) / math.Log(b)
66}
67
68func humanateBytes(s uint64, base float64, sizes []string) string {
69 if s < 10 {
70 return fmt.Sprintf("%d B", s)
71 }
72 e := math.Floor(logn(float64(s), base))
73 suffix := sizes[int(e)]
74 val := math.Floor(float64(s)/math.Pow(base, e)*10+0.5) / 10
75 f := "%.0f %s"
76 if val < 10 {
77 f = "%.1f %s"
78 }
79
80 return fmt.Sprintf(f, val, suffix)
81}
82
83// Bytes produces a human readable representation of an SI size.
84//
85// See also: ParseBytes.
86//
87// Bytes(82854982) -> 83 MB
88func Bytes(s uint64) string {
89 sizes := []string{"B", "kB", "MB", "GB", "TB", "PB", "EB"}
90 return humanateBytes(s, 1000, sizes)
91}
92
93// IBytes produces a human readable representation of an IEC size.
94//
95// See also: ParseBytes.
96//
97// IBytes(82854982) -> 79 MiB
98func IBytes(s uint64) string {
99 sizes := []string{"B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB"}
100 return humanateBytes(s, 1024, sizes)
101}
102
103// ParseBytes parses a string representation of bytes into the number
104// of bytes it represents.
105//
106// See Also: Bytes, IBytes.
107//
108// ParseBytes("42 MB") -> 42000000, nil
109// ParseBytes("42 mib") -> 44040192, nil
110func ParseBytes(s string) (uint64, error) {
111 lastDigit := 0
112 hasComma := false
113 for _, r := range s {
114 if !(unicode.IsDigit(r) || r == '.' || r == ',') {
115 break
116 }
117 if r == ',' {
118 hasComma = true
119 }
120 lastDigit++
121 }
122
123 num := s[:lastDigit]
124 if hasComma {
125 num = strings.Replace(num, ",", "", -1)
126 }
127
128 f, err := strconv.ParseFloat(num, 64)
129 if err != nil {
130 return 0, err
131 }
132
133 extra := strings.ToLower(strings.TrimSpace(s[lastDigit:]))
134 if m, ok := bytesSizeTable[extra]; ok {
135 f *= float64(m)
136 if f >= math.MaxUint64 {
137 return 0, fmt.Errorf("too large: %v", s)
138 }
139 return uint64(f), nil
140 }
141
142 return 0, fmt.Errorf("unhandled size name: %v", extra)
143}