|
1 // Copyright 2019 The Go Authors. All rights reserved. |
|
2 // Use of this source code is governed by a BSD-style |
|
3 // license that can be found in the LICENSE file. |
|
4 |
|
5 package impl |
|
6 |
|
7 import ( |
|
8 "reflect" |
|
9 "sync" |
|
10 "sync/atomic" |
|
11 |
|
12 pref "google.golang.org/protobuf/reflect/protoreflect" |
|
13 piface "google.golang.org/protobuf/runtime/protoiface" |
|
14 ) |
|
15 |
|
16 // ExtensionInfo implements ExtensionType. |
|
17 // |
|
18 // This type contains a number of exported fields for legacy compatibility. |
|
19 // The only non-deprecated use of this type is through the methods of the |
|
20 // ExtensionType interface. |
|
21 type ExtensionInfo struct { |
|
22 // An ExtensionInfo may exist in several stages of initialization. |
|
23 // |
|
24 // extensionInfoUninitialized: Some or all of the legacy exported |
|
25 // fields may be set, but none of the unexported fields have been |
|
26 // initialized. This is the starting state for an ExtensionInfo |
|
27 // in legacy generated code. |
|
28 // |
|
29 // extensionInfoDescInit: The desc field is set, but other unexported fields |
|
30 // may not be initialized. Legacy exported fields may or may not be set. |
|
31 // This is the starting state for an ExtensionInfo in newly generated code. |
|
32 // |
|
33 // extensionInfoFullInit: The ExtensionInfo is fully initialized. |
|
34 // This state is only entered after lazy initialization is complete. |
|
35 init uint32 |
|
36 mu sync.Mutex |
|
37 |
|
38 goType reflect.Type |
|
39 desc extensionTypeDescriptor |
|
40 conv Converter |
|
41 info *extensionFieldInfo // for fast-path method implementations |
|
42 |
|
43 // ExtendedType is a typed nil-pointer to the parent message type that |
|
44 // is being extended. It is possible for this to be unpopulated in v2 |
|
45 // since the message may no longer implement the MessageV1 interface. |
|
46 // |
|
47 // Deprecated: Use the ExtendedType method instead. |
|
48 ExtendedType piface.MessageV1 |
|
49 |
|
50 // ExtensionType is the zero value of the extension type. |
|
51 // |
|
52 // For historical reasons, reflect.TypeOf(ExtensionType) and the |
|
53 // type returned by InterfaceOf may not be identical. |
|
54 // |
|
55 // Deprecated: Use InterfaceOf(xt.Zero()) instead. |
|
56 ExtensionType interface{} |
|
57 |
|
58 // Field is the field number of the extension. |
|
59 // |
|
60 // Deprecated: Use the Descriptor().Number method instead. |
|
61 Field int32 |
|
62 |
|
63 // Name is the fully qualified name of extension. |
|
64 // |
|
65 // Deprecated: Use the Descriptor().FullName method instead. |
|
66 Name string |
|
67 |
|
68 // Tag is the protobuf struct tag used in the v1 API. |
|
69 // |
|
70 // Deprecated: Do not use. |
|
71 Tag string |
|
72 |
|
73 // Filename is the proto filename in which the extension is defined. |
|
74 // |
|
75 // Deprecated: Use Descriptor().ParentFile().Path() instead. |
|
76 Filename string |
|
77 } |
|
78 |
|
79 // Stages of initialization: See the ExtensionInfo.init field. |
|
80 const ( |
|
81 extensionInfoUninitialized = 0 |
|
82 extensionInfoDescInit = 1 |
|
83 extensionInfoFullInit = 2 |
|
84 ) |
|
85 |
|
86 func InitExtensionInfo(xi *ExtensionInfo, xd pref.ExtensionDescriptor, goType reflect.Type) { |
|
87 xi.goType = goType |
|
88 xi.desc = extensionTypeDescriptor{xd, xi} |
|
89 xi.init = extensionInfoDescInit |
|
90 } |
|
91 |
|
92 func (xi *ExtensionInfo) New() pref.Value { |
|
93 return xi.lazyInit().New() |
|
94 } |
|
95 func (xi *ExtensionInfo) Zero() pref.Value { |
|
96 return xi.lazyInit().Zero() |
|
97 } |
|
98 func (xi *ExtensionInfo) ValueOf(v interface{}) pref.Value { |
|
99 return xi.lazyInit().PBValueOf(reflect.ValueOf(v)) |
|
100 } |
|
101 func (xi *ExtensionInfo) InterfaceOf(v pref.Value) interface{} { |
|
102 return xi.lazyInit().GoValueOf(v).Interface() |
|
103 } |
|
104 func (xi *ExtensionInfo) IsValidValue(v pref.Value) bool { |
|
105 return xi.lazyInit().IsValidPB(v) |
|
106 } |
|
107 func (xi *ExtensionInfo) IsValidInterface(v interface{}) bool { |
|
108 return xi.lazyInit().IsValidGo(reflect.ValueOf(v)) |
|
109 } |
|
110 func (xi *ExtensionInfo) TypeDescriptor() pref.ExtensionTypeDescriptor { |
|
111 if atomic.LoadUint32(&xi.init) < extensionInfoDescInit { |
|
112 xi.lazyInitSlow() |
|
113 } |
|
114 return &xi.desc |
|
115 } |
|
116 |
|
117 func (xi *ExtensionInfo) lazyInit() Converter { |
|
118 if atomic.LoadUint32(&xi.init) < extensionInfoFullInit { |
|
119 xi.lazyInitSlow() |
|
120 } |
|
121 return xi.conv |
|
122 } |
|
123 |
|
124 func (xi *ExtensionInfo) lazyInitSlow() { |
|
125 xi.mu.Lock() |
|
126 defer xi.mu.Unlock() |
|
127 |
|
128 if xi.init == extensionInfoFullInit { |
|
129 return |
|
130 } |
|
131 defer atomic.StoreUint32(&xi.init, extensionInfoFullInit) |
|
132 |
|
133 if xi.desc.ExtensionDescriptor == nil { |
|
134 xi.initFromLegacy() |
|
135 } |
|
136 if !xi.desc.ExtensionDescriptor.IsPlaceholder() { |
|
137 if xi.ExtensionType == nil { |
|
138 xi.initToLegacy() |
|
139 } |
|
140 xi.conv = NewConverter(xi.goType, xi.desc.ExtensionDescriptor) |
|
141 xi.info = makeExtensionFieldInfo(xi.desc.ExtensionDescriptor) |
|
142 xi.info.validation = newValidationInfo(xi.desc.ExtensionDescriptor, xi.goType) |
|
143 } |
|
144 } |
|
145 |
|
146 type extensionTypeDescriptor struct { |
|
147 pref.ExtensionDescriptor |
|
148 xi *ExtensionInfo |
|
149 } |
|
150 |
|
151 func (xtd *extensionTypeDescriptor) Type() pref.ExtensionType { |
|
152 return xtd.xi |
|
153 } |
|
154 func (xtd *extensionTypeDescriptor) Descriptor() pref.ExtensionDescriptor { |
|
155 return xtd.ExtensionDescriptor |
|
156 } |