merge.go raw
1 // Copyright 2020 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 "fmt"
9 "reflect"
10
11 "google.golang.org/protobuf/proto"
12 "google.golang.org/protobuf/reflect/protoreflect"
13 "google.golang.org/protobuf/runtime/protoiface"
14 )
15
16 type mergeOptions struct{}
17
18 func (o mergeOptions) Merge(dst, src proto.Message) {
19 proto.Merge(dst, src)
20 }
21
22 // merge is protoreflect.Methods.Merge.
23 func (mi *MessageInfo) merge(in protoiface.MergeInput) protoiface.MergeOutput {
24 dp, ok := mi.getPointer(in.Destination)
25 if !ok {
26 return protoiface.MergeOutput{}
27 }
28 sp, ok := mi.getPointer(in.Source)
29 if !ok {
30 return protoiface.MergeOutput{}
31 }
32 mi.mergePointer(dp, sp, mergeOptions{})
33 return protoiface.MergeOutput{Flags: protoiface.MergeComplete}
34 }
35
36 func (mi *MessageInfo) mergePointer(dst, src pointer, opts mergeOptions) {
37 mi.init()
38 if dst.IsNil() {
39 panic(fmt.Sprintf("invalid value: merging into nil message"))
40 }
41 if src.IsNil() {
42 return
43 }
44
45 var presenceSrc presence
46 var presenceDst presence
47 if mi.presenceOffset.IsValid() {
48 presenceSrc = src.Apply(mi.presenceOffset).PresenceInfo()
49 presenceDst = dst.Apply(mi.presenceOffset).PresenceInfo()
50 }
51
52 for _, f := range mi.orderedCoderFields {
53 if f.funcs.merge == nil {
54 continue
55 }
56 sfptr := src.Apply(f.offset)
57
58 if f.presenceIndex != noPresence {
59 if !presenceSrc.Present(f.presenceIndex) {
60 continue
61 }
62 dfptr := dst.Apply(f.offset)
63 if f.isLazy {
64 if sfptr.AtomicGetPointer().IsNil() {
65 mi.lazyUnmarshal(src, f.num)
66 }
67 if presenceDst.Present(f.presenceIndex) && dfptr.AtomicGetPointer().IsNil() {
68 mi.lazyUnmarshal(dst, f.num)
69 }
70 }
71 f.funcs.merge(dst.Apply(f.offset), sfptr, f, opts)
72 presenceDst.SetPresentUnatomic(f.presenceIndex, mi.presenceSize)
73 continue
74 }
75
76 if f.isPointer && sfptr.Elem().IsNil() {
77 continue
78 }
79 f.funcs.merge(dst.Apply(f.offset), sfptr, f, opts)
80 }
81 if mi.extensionOffset.IsValid() {
82 sext := src.Apply(mi.extensionOffset).Extensions()
83 dext := dst.Apply(mi.extensionOffset).Extensions()
84 if *dext == nil {
85 *dext = make(map[int32]ExtensionField)
86 }
87 for num, sx := range *sext {
88 xt := sx.Type()
89 xi := getExtensionFieldInfo(xt)
90 if xi.funcs.merge == nil {
91 continue
92 }
93 dx := (*dext)[num]
94 var dv protoreflect.Value
95 if dx.Type() == sx.Type() {
96 dv = dx.Value()
97 }
98 if !dv.IsValid() && xi.unmarshalNeedsValue {
99 dv = xt.New()
100 }
101 dv = xi.funcs.merge(dv, sx.Value(), opts)
102 dx.Set(sx.Type(), dv)
103 (*dext)[num] = dx
104 }
105 }
106 if mi.unknownOffset.IsValid() {
107 su := mi.getUnknownBytes(src)
108 if su != nil && len(*su) > 0 {
109 du := mi.mutableUnknownBytes(dst)
110 *du = append(*du, *su...)
111 }
112 }
113 }
114
115 func mergeScalarValue(dst, src protoreflect.Value, opts mergeOptions) protoreflect.Value {
116 return src
117 }
118
119 func mergeBytesValue(dst, src protoreflect.Value, opts mergeOptions) protoreflect.Value {
120 return protoreflect.ValueOfBytes(append(emptyBuf[:], src.Bytes()...))
121 }
122
123 func mergeListValue(dst, src protoreflect.Value, opts mergeOptions) protoreflect.Value {
124 dstl := dst.List()
125 srcl := src.List()
126 for i, llen := 0, srcl.Len(); i < llen; i++ {
127 dstl.Append(srcl.Get(i))
128 }
129 return dst
130 }
131
132 func mergeBytesListValue(dst, src protoreflect.Value, opts mergeOptions) protoreflect.Value {
133 dstl := dst.List()
134 srcl := src.List()
135 for i, llen := 0, srcl.Len(); i < llen; i++ {
136 sb := srcl.Get(i).Bytes()
137 db := append(emptyBuf[:], sb...)
138 dstl.Append(protoreflect.ValueOfBytes(db))
139 }
140 return dst
141 }
142
143 func mergeMessageListValue(dst, src protoreflect.Value, opts mergeOptions) protoreflect.Value {
144 dstl := dst.List()
145 srcl := src.List()
146 for i, llen := 0, srcl.Len(); i < llen; i++ {
147 sm := srcl.Get(i).Message()
148 dm := proto.Clone(sm.Interface()).ProtoReflect()
149 dstl.Append(protoreflect.ValueOfMessage(dm))
150 }
151 return dst
152 }
153
154 func mergeMessageValue(dst, src protoreflect.Value, opts mergeOptions) protoreflect.Value {
155 opts.Merge(dst.Message().Interface(), src.Message().Interface())
156 return dst
157 }
158
159 func mergeMessage(dst, src pointer, f *coderFieldInfo, opts mergeOptions) {
160 if f.mi != nil {
161 if dst.Elem().IsNil() {
162 dst.SetPointer(pointerOfValue(reflect.New(f.mi.GoReflectType.Elem())))
163 }
164 f.mi.mergePointer(dst.Elem(), src.Elem(), opts)
165 } else {
166 dm := dst.AsValueOf(f.ft).Elem()
167 sm := src.AsValueOf(f.ft).Elem()
168 if dm.IsNil() {
169 dm.Set(reflect.New(f.ft.Elem()))
170 }
171 opts.Merge(asMessage(dm), asMessage(sm))
172 }
173 }
174
175 func mergeMessageSlice(dst, src pointer, f *coderFieldInfo, opts mergeOptions) {
176 for _, sp := range src.PointerSlice() {
177 dm := reflect.New(f.ft.Elem().Elem())
178 if f.mi != nil {
179 f.mi.mergePointer(pointerOfValue(dm), sp, opts)
180 } else {
181 opts.Merge(asMessage(dm), asMessage(sp.AsValueOf(f.ft.Elem().Elem())))
182 }
183 dst.AppendPointerSlice(pointerOfValue(dm))
184 }
185 }
186
187 func mergeBytes(dst, src pointer, _ *coderFieldInfo, _ mergeOptions) {
188 *dst.Bytes() = append(emptyBuf[:], *src.Bytes()...)
189 }
190
191 func mergeBytesNoZero(dst, src pointer, _ *coderFieldInfo, _ mergeOptions) {
192 v := *src.Bytes()
193 if len(v) > 0 {
194 *dst.Bytes() = append(emptyBuf[:], v...)
195 }
196 }
197
198 func mergeBytesSlice(dst, src pointer, _ *coderFieldInfo, _ mergeOptions) {
199 ds := dst.BytesSlice()
200 for _, v := range *src.BytesSlice() {
201 *ds = append(*ds, append(emptyBuf[:], v...))
202 }
203 }
204