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
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
|
package mapstructure
import (
"encoding"
"errors"
"fmt"
"net"
"reflect"
"strconv"
"strings"
"time"
)
// typedDecodeHook takes a raw DecodeHookFunc (an interface{}) and turns
// it into the proper DecodeHookFunc type, such as DecodeHookFuncType.
func typedDecodeHook(h DecodeHookFunc) DecodeHookFunc {
// Create variables here so we can reference them with the reflect pkg
var f1 DecodeHookFuncType
var f2 DecodeHookFuncKind
var f3 DecodeHookFuncValue
// Fill in the variables into this interface and the rest is done
// automatically using the reflect package.
potential := []interface{}{f1, f2, f3}
v := reflect.ValueOf(h)
vt := v.Type()
for _, raw := range potential {
pt := reflect.ValueOf(raw).Type()
if vt.ConvertibleTo(pt) {
return v.Convert(pt).Interface()
}
}
return nil
}
// DecodeHookExec executes the given decode hook. This should be used
// since it'll naturally degrade to the older backwards compatible DecodeHookFunc
// that took reflect.Kind instead of reflect.Type.
func DecodeHookExec(
raw DecodeHookFunc,
from reflect.Value, to reflect.Value) (interface{}, error) {
switch f := typedDecodeHook(raw).(type) {
case DecodeHookFuncType:
return f(from.Type(), to.Type(), from.Interface())
case DecodeHookFuncKind:
return f(from.Kind(), to.Kind(), from.Interface())
case DecodeHookFuncValue:
return f(from, to)
default:
return nil, errors.New("invalid decode hook signature")
}
}
// ComposeDecodeHookFunc creates a single DecodeHookFunc that
// automatically composes multiple DecodeHookFuncs.
//
// The composed funcs are called in order, with the result of the
// previous transformation.
func ComposeDecodeHookFunc(fs ...DecodeHookFunc) DecodeHookFunc {
return func(f reflect.Value, t reflect.Value) (interface{}, error) {
var err error
var data interface{}
newFrom := f
for _, f1 := range fs {
data, err = DecodeHookExec(f1, newFrom, t)
if err != nil {
return nil, err
}
newFrom = reflect.ValueOf(data)
}
return data, nil
}
}
// StringToSliceHookFunc returns a DecodeHookFunc that converts
// string to []string by splitting on the given sep.
func StringToSliceHookFunc(sep string) DecodeHookFunc {
return func(
f reflect.Kind,
t reflect.Kind,
data interface{}) (interface{}, error) {
if f != reflect.String || t != reflect.Slice {
return data, nil
}
raw := data.(string)
if raw == "" {
return []string{}, nil
}
return strings.Split(raw, sep), nil
}
}
// StringToTimeDurationHookFunc returns a DecodeHookFunc that converts
// strings to time.Duration.
func StringToTimeDurationHookFunc() DecodeHookFunc {
return func(
f reflect.Type,
t reflect.Type,
data interface{}) (interface{}, error) {
if f.Kind() != reflect.String {
return data, nil
}
if t != reflect.TypeOf(time.Duration(5)) {
return data, nil
}
// Convert it by parsing
return time.ParseDuration(data.(string))
}
}
// StringToIPHookFunc returns a DecodeHookFunc that converts
// strings to net.IP
func StringToIPHookFunc() DecodeHookFunc {
return func(
f reflect.Type,
t reflect.Type,
data interface{}) (interface{}, error) {
if f.Kind() != reflect.String {
return data, nil
}
if t != reflect.TypeOf(net.IP{}) {
return data, nil
}
// Convert it by parsing
ip := net.ParseIP(data.(string))
if ip == nil {
return net.IP{}, fmt.Errorf("failed parsing ip %v", data)
}
return ip, nil
}
}
// StringToIPNetHookFunc returns a DecodeHookFunc that converts
// strings to net.IPNet
func StringToIPNetHookFunc() DecodeHookFunc {
return func(
f reflect.Type,
t reflect.Type,
data interface{}) (interface{}, error) {
if f.Kind() != reflect.String {
return data, nil
}
if t != reflect.TypeOf(net.IPNet{}) {
return data, nil
}
// Convert it by parsing
_, net, err := net.ParseCIDR(data.(string))
return net, err
}
}
// StringToTimeHookFunc returns a DecodeHookFunc that converts
// strings to time.Time.
func StringToTimeHookFunc(layout string) DecodeHookFunc {
return func(
f reflect.Type,
t reflect.Type,
data interface{}) (interface{}, error) {
if f.Kind() != reflect.String {
return data, nil
}
if t != reflect.TypeOf(time.Time{}) {
return data, nil
}
// Convert it by parsing
return time.Parse(layout, data.(string))
}
}
// WeaklyTypedHook is a DecodeHookFunc which adds support for weak typing to
// the decoder.
//
// Note that this is significantly different from the WeaklyTypedInput option
// of the DecoderConfig.
func WeaklyTypedHook(
f reflect.Kind,
t reflect.Kind,
data interface{}) (interface{}, error) {
dataVal := reflect.ValueOf(data)
switch t {
case reflect.String:
switch f {
case reflect.Bool:
if dataVal.Bool() {
return "1", nil
}
return "0", nil
case reflect.Float32:
return strconv.FormatFloat(dataVal.Float(), 'f', -1, 64), nil
case reflect.Int:
return strconv.FormatInt(dataVal.Int(), 10), nil
case reflect.Slice:
dataType := dataVal.Type()
elemKind := dataType.Elem().Kind()
if elemKind == reflect.Uint8 {
return string(dataVal.Interface().([]uint8)), nil
}
case reflect.Uint:
return strconv.FormatUint(dataVal.Uint(), 10), nil
}
}
return data, nil
}
func RecursiveStructToMapHookFunc() DecodeHookFunc {
return func(f reflect.Value, t reflect.Value) (interface{}, error) {
if f.Kind() != reflect.Struct {
return f.Interface(), nil
}
var i interface{} = struct{}{}
if t.Type() != reflect.TypeOf(&i).Elem() {
return f.Interface(), nil
}
m := make(map[string]interface{})
t.Set(reflect.ValueOf(m))
return f.Interface(), nil
}
}
// TextUnmarshallerHookFunc returns a DecodeHookFunc that applies
// strings to the UnmarshalText function, when the target type
// implements the encoding.TextUnmarshaler interface
func TextUnmarshallerHookFunc() DecodeHookFuncType {
return func(
f reflect.Type,
t reflect.Type,
data interface{}) (interface{}, error) {
if f.Kind() != reflect.String {
return data, nil
}
result := reflect.New(t).Interface()
unmarshaller, ok := result.(encoding.TextUnmarshaler)
if !ok {
return data, nil
}
if err := unmarshaller.UnmarshalText([]byte(data.(string))); err != nil {
return nil, err
}
return result, nil
}
}
|
