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
|
// Copyright 2019 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 proto
import (
"google.golang.org/protobuf/reflect/protoreflect"
)
// HasExtension reports whether an extension field is populated.
// It returns false if m is invalid or if xt does not extend m.
func HasExtension(m Message, xt protoreflect.ExtensionType) bool {
// Treat nil message interface or descriptor as an empty message; no populated
// fields.
if m == nil || xt == nil {
return false
}
// As a special-case, we reports invalid or mismatching descriptors
// as always not being populated (since they aren't).
mr := m.ProtoReflect()
xd := xt.TypeDescriptor()
if mr.Descriptor() != xd.ContainingMessage() {
return false
}
return mr.Has(xd)
}
// ClearExtension clears an extension field such that subsequent
// [HasExtension] calls return false.
// It panics if m is invalid or if xt does not extend m.
func ClearExtension(m Message, xt protoreflect.ExtensionType) {
m.ProtoReflect().Clear(xt.TypeDescriptor())
}
// GetExtension retrieves the value for an extension field.
// If the field is unpopulated, it returns the default value for
// scalars and an immutable, empty value for lists or messages.
// It panics if xt does not extend m.
//
// The type of the value is dependent on the field type of the extension.
// For extensions generated by protoc-gen-go, the Go type is as follows:
//
// ╔═══════════════════╤═════════════════════════╗
// ║ Go type │ Protobuf kind ║
// ╠═══════════════════╪═════════════════════════╣
// ║ bool │ bool ║
// ║ int32 │ int32, sint32, sfixed32 ║
// ║ int64 │ int64, sint64, sfixed64 ║
// ║ uint32 │ uint32, fixed32 ║
// ║ uint64 │ uint64, fixed64 ║
// ║ float32 │ float ║
// ║ float64 │ double ║
// ║ string │ string ║
// ║ []byte │ bytes ║
// ║ protoreflect.Enum │ enum ║
// ║ proto.Message │ message, group ║
// ╚═══════════════════╧═════════════════════════╝
//
// The protoreflect.Enum and proto.Message types are the concrete Go type
// associated with the named enum or message. Repeated fields are represented
// using a Go slice of the base element type.
//
// If a generated extension descriptor variable is directly passed to
// GetExtension, then the call should be followed immediately by a
// type assertion to the expected output value. For example:
//
// mm := proto.GetExtension(m, foopb.E_MyExtension).(*foopb.MyMessage)
//
// This pattern enables static analysis tools to verify that the asserted type
// matches the Go type associated with the extension field and
// also enables a possible future migration to a type-safe extension API.
//
// Since singular messages are the most common extension type, the pattern of
// calling HasExtension followed by GetExtension may be simplified to:
//
// if mm := proto.GetExtension(m, foopb.E_MyExtension).(*foopb.MyMessage); mm != nil {
// ... // make use of mm
// }
//
// The mm variable is non-nil if and only if HasExtension reports true.
func GetExtension(m Message, xt protoreflect.ExtensionType) any {
// Treat nil message interface as an empty message; return the default.
if m == nil {
return xt.InterfaceOf(xt.Zero())
}
return xt.InterfaceOf(m.ProtoReflect().Get(xt.TypeDescriptor()))
}
// SetExtension stores the value of an extension field.
// It panics if m is invalid, xt does not extend m, or if type of v
// is invalid for the specified extension field.
//
// The type of the value is dependent on the field type of the extension.
// For extensions generated by protoc-gen-go, the Go type is as follows:
//
// ╔═══════════════════╤═════════════════════════╗
// ║ Go type │ Protobuf kind ║
// ╠═══════════════════╪═════════════════════════╣
// ║ bool │ bool ║
// ║ int32 │ int32, sint32, sfixed32 ║
// ║ int64 │ int64, sint64, sfixed64 ║
// ║ uint32 │ uint32, fixed32 ║
// ║ uint64 │ uint64, fixed64 ║
// ║ float32 │ float ║
// ║ float64 │ double ║
// ║ string │ string ║
// ║ []byte │ bytes ║
// ║ protoreflect.Enum │ enum ║
// ║ proto.Message │ message, group ║
// ╚═══════════════════╧═════════════════════════╝
//
// The protoreflect.Enum and proto.Message types are the concrete Go type
// associated with the named enum or message. Repeated fields are represented
// using a Go slice of the base element type.
//
// If a generated extension descriptor variable is directly passed to
// SetExtension (e.g., foopb.E_MyExtension), then the value should be a
// concrete type that matches the expected Go type for the extension descriptor
// so that static analysis tools can verify type correctness.
// This also enables a possible future migration to a type-safe extension API.
func SetExtension(m Message, xt protoreflect.ExtensionType, v any) {
xd := xt.TypeDescriptor()
pv := xt.ValueOf(v)
// Specially treat an invalid list, map, or message as clear.
isValid := true
switch {
case xd.IsList():
isValid = pv.List().IsValid()
case xd.IsMap():
isValid = pv.Map().IsValid()
case xd.Message() != nil:
isValid = pv.Message().IsValid()
}
if !isValid {
m.ProtoReflect().Clear(xd)
return
}
m.ProtoReflect().Set(xd, pv)
}
// RangeExtensions iterates over every populated extension field in m in an
// undefined order, calling f for each extension type and value encountered.
// It returns immediately if f returns false.
// While iterating, mutating operations may only be performed
// on the current extension field.
func RangeExtensions(m Message, f func(protoreflect.ExtensionType, any) bool) {
// Treat nil message interface as an empty message; nothing to range over.
if m == nil {
return
}
m.ProtoReflect().Range(func(fd protoreflect.FieldDescriptor, v protoreflect.Value) bool {
if fd.IsExtension() {
xt := fd.(protoreflect.ExtensionTypeDescriptor).Type()
vi := xt.InterfaceOf(v)
return f(xt, vi)
}
return true
})
}
|