forked from qri-io/starlib
-
Notifications
You must be signed in to change notification settings - Fork 0
/
base64.go
97 lines (84 loc) · 2.9 KB
/
base64.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
package base64
import (
gobase64 "encoding/base64"
"fmt"
"sync"
"go.starlark.net/starlark"
"go.starlark.net/starlarkstruct"
)
// ModuleName defines the expected name for this Module when used
// in starlark's load() function, eg: load('encoding/base64.star', 'base64')
const ModuleName = "encoding/base64.star"
var (
once sync.Once
base64Module starlark.StringDict
)
// Encodings is a map of strings to encoding formats
var Encodings = map[string]*gobase64.Encoding{
// StdEncoding is the standard base64 encoding, as defined in RFC 4648.
"standard": gobase64.StdEncoding,
// RawStdEncoding is the standard raw, unpadded base64 encoding,
// as defined in RFC 4648 section 3.2.
// This is the same as StdEncoding but omits padding characters.
"standard_raw": gobase64.RawStdEncoding,
// URLEncoding is the alternate base64 encoding defined in RFC 4648.
// It is typically used in URLs and file names.
"url": gobase64.URLEncoding,
// RawURLEncoding is the unpadded alternate base64 encoding defined in RFC 4648.
// It is typically used in URLs and file names.
// This is the same as URLEncoding but omits padding characters.
"url_raw": gobase64.RawURLEncoding,
}
// LoadModule loads the base64 module.
// It is concurrency-safe and idempotent.
func LoadModule() (starlark.StringDict, error) {
once.Do(func() {
base64Module = starlark.StringDict{
"base64": &starlarkstruct.Module{
Name: "base64",
Members: starlark.StringDict{
"encode": starlark.NewBuiltin("encode", encodeString),
"decode": starlark.NewBuiltin("decode", decodeString),
},
},
}
})
return base64Module, nil
}
func selectEncoder(encoding starlark.String) (encoder *gobase64.Encoding, err error) {
if encoding == "" {
encoding = starlark.String("standard")
}
encoder = Encodings[string(encoding)]
if encoder == nil {
err = fmt.Errorf("unsupported encoding format: %s", encoding)
}
return
}
func encodeString(thread *starlark.Thread, _ *starlark.Builtin, args starlark.Tuple, kwargs []starlark.Tuple) (starlark.Value, error) {
var data, encoding starlark.String
if err := starlark.UnpackArgs("encode", args, kwargs, "data", &data, "encoding?", &encoding); err != nil {
return starlark.None, err
}
encoder, err := selectEncoder(encoding)
if err != nil {
return starlark.None, err
}
enc := encoder.EncodeToString([]byte(string(data)))
return starlark.String(enc), nil
}
func decodeString(thread *starlark.Thread, _ *starlark.Builtin, args starlark.Tuple, kwargs []starlark.Tuple) (starlark.Value, error) {
var data, encoding starlark.String
if err := starlark.UnpackArgs("decode", args, kwargs, "data", &data, "encoding?", &encoding); err != nil {
return starlark.None, err
}
encoder, err := selectEncoder(encoding)
if err != nil {
return starlark.None, err
}
dec, err := encoder.DecodeString(string(data))
if err != nil {
return starlark.None, err
}
return starlark.String(string(dec)), nil
}