cloudflare/cfssl_trust
Publicmirrored from https://github.com/cloudflare/cfssl_trustAvailable
vendor/github.com/mitchellh/mapstructure/decode_hooks.go
154lines · modecode
| 1 | package mapstructure |
| 2 | |
| 3 | import ( |
| 4 | "errors" |
| 5 | "reflect" |
| 6 | "strconv" |
| 7 | "strings" |
| 8 | "time" |
| 9 | ) |
| 10 | |
| 11 | // typedDecodeHook takes a raw DecodeHookFunc (an interface{}) and turns |
| 12 | // it into the proper DecodeHookFunc type, such as DecodeHookFuncType. |
| 13 | func typedDecodeHook(h DecodeHookFunc) DecodeHookFunc { |
| 14 | // Create variables here so we can reference them with the reflect pkg |
| 15 | var f1 DecodeHookFuncType |
| 16 | var f2 DecodeHookFuncKind |
| 17 | |
| 18 | // Fill in the variables into this interface and the rest is done |
| 19 | // automatically using the reflect package. |
| 20 | potential := []interface{}{f1, f2} |
| 21 | |
| 22 | v := reflect.ValueOf(h) |
| 23 | vt := v.Type() |
| 24 | for _, raw := range potential { |
| 25 | pt := reflect.ValueOf(raw).Type() |
| 26 | if vt.ConvertibleTo(pt) { |
| 27 | return v.Convert(pt).Interface() |
| 28 | } |
| 29 | } |
| 30 | |
| 31 | return nil |
| 32 | } |
| 33 | |
| 34 | // DecodeHookExec executes the given decode hook. This should be used |
| 35 | // since it'll naturally degrade to the older backwards compatible DecodeHookFunc |
| 36 | // that took reflect.Kind instead of reflect.Type. |
| 37 | func DecodeHookExec( |
| 38 | raw DecodeHookFunc, |
| 39 | from reflect.Type, to reflect.Type, |
| 40 | data interface{}) (interface{}, error) { |
| 41 | // Build our arguments that reflect expects |
| 42 | argVals := make([]reflect.Value, 3) |
| 43 | argVals[0] = reflect.ValueOf(from) |
| 44 | argVals[1] = reflect.ValueOf(to) |
| 45 | argVals[2] = reflect.ValueOf(data) |
| 46 | |
| 47 | switch f := typedDecodeHook(raw).(type) { |
| 48 | case DecodeHookFuncType: |
| 49 | return f(from, to, data) |
| 50 | case DecodeHookFuncKind: |
| 51 | return f(from.Kind(), to.Kind(), data) |
| 52 | default: |
| 53 | return nil, errors.New("invalid decode hook signature") |
| 54 | } |
| 55 | } |
| 56 | |
| 57 | // ComposeDecodeHookFunc creates a single DecodeHookFunc that |
| 58 | // automatically composes multiple DecodeHookFuncs. |
| 59 | // |
| 60 | // The composed funcs are called in order, with the result of the |
| 61 | // previous transformation. |
| 62 | func ComposeDecodeHookFunc(fs ...DecodeHookFunc) DecodeHookFunc { |
| 63 | return func( |
| 64 | f reflect.Type, |
| 65 | t reflect.Type, |
| 66 | data interface{}) (interface{}, error) { |
| 67 | var err error |
| 68 | for _, f1 := range fs { |
| 69 | data, err = DecodeHookExec(f1, f, t, data) |
| 70 | if err != nil { |
| 71 | return nil, err |
| 72 | } |
| 73 | |
| 74 | // Modify the from kind to be correct with the new data |
| 75 | f = nil |
| 76 | if val := reflect.ValueOf(data); val.IsValid() { |
| 77 | f = val.Type() |
| 78 | } |
| 79 | } |
| 80 | |
| 81 | return data, nil |
| 82 | } |
| 83 | } |
| 84 | |
| 85 | // StringToSliceHookFunc returns a DecodeHookFunc that converts |
| 86 | // string to []string by splitting on the given sep. |
| 87 | func StringToSliceHookFunc(sep string) DecodeHookFunc { |
| 88 | return func( |
| 89 | f reflect.Kind, |
| 90 | t reflect.Kind, |
| 91 | data interface{}) (interface{}, error) { |
| 92 | if f != reflect.String || t != reflect.Slice { |
| 93 | return data, nil |
| 94 | } |
| 95 | |
| 96 | raw := data.(string) |
| 97 | if raw == "" { |
| 98 | return []string{}, nil |
| 99 | } |
| 100 | |
| 101 | return strings.Split(raw, sep), nil |
| 102 | } |
| 103 | } |
| 104 | |
| 105 | // StringToTimeDurationHookFunc returns a DecodeHookFunc that converts |
| 106 | // strings to time.Duration. |
| 107 | func StringToTimeDurationHookFunc() DecodeHookFunc { |
| 108 | return func( |
| 109 | f reflect.Type, |
| 110 | t reflect.Type, |
| 111 | data interface{}) (interface{}, error) { |
| 112 | if f.Kind() != reflect.String { |
| 113 | return data, nil |
| 114 | } |
| 115 | if t != reflect.TypeOf(time.Duration(5)) { |
| 116 | return data, nil |
| 117 | } |
| 118 | |
| 119 | // Convert it by parsing |
| 120 | return time.ParseDuration(data.(string)) |
| 121 | } |
| 122 | } |
| 123 | |
| 124 | func WeaklyTypedHook( |
| 125 | f reflect.Kind, |
| 126 | t reflect.Kind, |
| 127 | data interface{}) (interface{}, error) { |
| 128 | dataVal := reflect.ValueOf(data) |
| 129 | switch t { |
| 130 | case reflect.String: |
| 131 | switch f { |
| 132 | case reflect.Bool: |
| 133 | if dataVal.Bool() { |
| 134 | return "1", nil |
| 135 | } else { |
| 136 | return "0", nil |
| 137 | } |
| 138 | case reflect.Float32: |
| 139 | return strconv.FormatFloat(dataVal.Float(), 'f', -1, 64), nil |
| 140 | case reflect.Int: |
| 141 | return strconv.FormatInt(dataVal.Int(), 10), nil |
| 142 | case reflect.Slice: |
| 143 | dataType := dataVal.Type() |
| 144 | elemKind := dataType.Elem().Kind() |
| 145 | if elemKind == reflect.Uint8 { |
| 146 | return string(dataVal.Interface().([]uint8)), nil |
| 147 | } |
| 148 | case reflect.Uint: |
| 149 | return strconv.FormatUint(dataVal.Uint(), 10), nil |
| 150 | } |
| 151 | } |
| 152 | |
| 153 | return data, nil |
| 154 | } |