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
|
// Copyright 2018 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package defval marshals and unmarshals textual forms of default values.
//
// This package handles both the form historically used in Go struct field tags
// and also the form used by google.protobuf.FieldDescriptorProto.default_value
// since they differ in superficial ways.
package defval
import (
"fmt"
"math"
"strconv"
ptext "google.golang.org/protobuf/internal/encoding/text"
errors "google.golang.org/protobuf/internal/errors"
pref "google.golang.org/protobuf/reflect/protoreflect"
)
// Format is the serialization format used to represent the default value.
type Format int
const (
_ Format = iota
// Descriptor uses the serialization format that protoc uses with the
// google.protobuf.FieldDescriptorProto.default_value field.
Descriptor
// GoTag uses the historical serialization format in Go struct field tags.
GoTag
)
// Unmarshal deserializes the default string s according to the given kind k.
// When k is an enum, a list of enum value descriptors must be provided.
func Unmarshal(s string, k pref.Kind, evs pref.EnumValueDescriptors, f Format) (pref.Value, pref.EnumValueDescriptor, error) {
switch k {
case pref.BoolKind:
if f == GoTag {
switch s {
case "1":
return pref.ValueOfBool(true), nil, nil
case "0":
return pref.ValueOfBool(false), nil, nil
}
} else {
switch s {
case "true":
return pref.ValueOfBool(true), nil, nil
case "false":
return pref.ValueOfBool(false), nil, nil
}
}
case pref.EnumKind:
if f == GoTag {
// Go tags use the numeric form of the enum value.
if n, err := strconv.ParseInt(s, 10, 32); err == nil {
if ev := evs.ByNumber(pref.EnumNumber(n)); ev != nil {
return pref.ValueOfEnum(ev.Number()), ev, nil
}
}
} else {
// Descriptor default_value use the enum identifier.
ev := evs.ByName(pref.Name(s))
if ev != nil {
return pref.ValueOfEnum(ev.Number()), ev, nil
}
}
case pref.Int32Kind, pref.Sint32Kind, pref.Sfixed32Kind:
if v, err := strconv.ParseInt(s, 10, 32); err == nil {
return pref.ValueOfInt32(int32(v)), nil, nil
}
case pref.Int64Kind, pref.Sint64Kind, pref.Sfixed64Kind:
if v, err := strconv.ParseInt(s, 10, 64); err == nil {
return pref.ValueOfInt64(int64(v)), nil, nil
}
case pref.Uint32Kind, pref.Fixed32Kind:
if v, err := strconv.ParseUint(s, 10, 32); err == nil {
return pref.ValueOfUint32(uint32(v)), nil, nil
}
case pref.Uint64Kind, pref.Fixed64Kind:
if v, err := strconv.ParseUint(s, 10, 64); err == nil {
return pref.ValueOfUint64(uint64(v)), nil, nil
}
case pref.FloatKind, pref.DoubleKind:
var v float64
var err error
switch s {
case "-inf":
v = math.Inf(-1)
case "inf":
v = math.Inf(+1)
case "nan":
v = math.NaN()
default:
v, err = strconv.ParseFloat(s, 64)
}
if err == nil {
if k == pref.FloatKind {
return pref.ValueOfFloat32(float32(v)), nil, nil
} else {
return pref.ValueOfFloat64(float64(v)), nil, nil
}
}
case pref.StringKind:
// String values are already unescaped and can be used as is.
return pref.ValueOfString(s), nil, nil
case pref.BytesKind:
if b, ok := unmarshalBytes(s); ok {
return pref.ValueOfBytes(b), nil, nil
}
}
return pref.Value{}, nil, errors.New("could not parse value for %v: %q", k, s)
}
// Marshal serializes v as the default string according to the given kind k.
// When specifying the Descriptor format for an enum kind, the associated
// enum value descriptor must be provided.
func Marshal(v pref.Value, ev pref.EnumValueDescriptor, k pref.Kind, f Format) (string, error) {
switch k {
case pref.BoolKind:
if f == GoTag {
if v.Bool() {
return "1", nil
} else {
return "0", nil
}
} else {
if v.Bool() {
return "true", nil
} else {
return "false", nil
}
}
case pref.EnumKind:
if f == GoTag {
return strconv.FormatInt(int64(v.Enum()), 10), nil
} else {
return string(ev.Name()), nil
}
case pref.Int32Kind, pref.Sint32Kind, pref.Sfixed32Kind, pref.Int64Kind, pref.Sint64Kind, pref.Sfixed64Kind:
return strconv.FormatInt(v.Int(), 10), nil
case pref.Uint32Kind, pref.Fixed32Kind, pref.Uint64Kind, pref.Fixed64Kind:
return strconv.FormatUint(v.Uint(), 10), nil
case pref.FloatKind, pref.DoubleKind:
f := v.Float()
switch {
case math.IsInf(f, -1):
return "-inf", nil
case math.IsInf(f, +1):
return "inf", nil
case math.IsNaN(f):
return "nan", nil
default:
if k == pref.FloatKind {
return strconv.FormatFloat(f, 'g', -1, 32), nil
} else {
return strconv.FormatFloat(f, 'g', -1, 64), nil
}
}
case pref.StringKind:
// String values are serialized as is without any escaping.
return v.String(), nil
case pref.BytesKind:
if s, ok := marshalBytes(v.Bytes()); ok {
return s, nil
}
}
return "", errors.New("could not format value for %v: %v", k, v)
}
// unmarshalBytes deserializes bytes by applying C unescaping.
func unmarshalBytes(s string) ([]byte, bool) {
// Bytes values use the same escaping as the text format,
// however they lack the surrounding double quotes.
v, err := ptext.UnmarshalString(`"` + s + `"`)
if err != nil {
return nil, false
}
return []byte(v), true
}
// marshalBytes serializes bytes by using C escaping.
// To match the exact output of protoc, this is identical to the
// CEscape function in strutil.cc of the protoc source code.
func marshalBytes(b []byte) (string, bool) {
var s []byte
for _, c := range b {
switch c {
case '\n':
s = append(s, `\n`...)
case '\r':
s = append(s, `\r`...)
case '\t':
s = append(s, `\t`...)
case '"':
s = append(s, `\"`...)
case '\'':
s = append(s, `\'`...)
case '\\':
s = append(s, `\\`...)
default:
if printableASCII := c >= 0x20 && c <= 0x7e; printableASCII {
s = append(s, c)
} else {
s = append(s, fmt.Sprintf(`\%03o`, c)...)
}
}
}
return string(s), true
}
|
