]>
Commit | Line | Data |
---|---|---|
15c0b25d AP |
1 | // Go support for Protocol Buffers - Google's data interchange format |
2 | // | |
3 | // Copyright 2010 The Go Authors. All rights reserved. | |
4 | // https://github.com/golang/protobuf | |
5 | // | |
6 | // Redistribution and use in source and binary forms, with or without | |
7 | // modification, are permitted provided that the following conditions are | |
8 | // met: | |
9 | // | |
10 | // * Redistributions of source code must retain the above copyright | |
11 | // notice, this list of conditions and the following disclaimer. | |
12 | // * Redistributions in binary form must reproduce the above | |
13 | // copyright notice, this list of conditions and the following disclaimer | |
14 | // in the documentation and/or other materials provided with the | |
15 | // distribution. | |
16 | // * Neither the name of Google Inc. nor the names of its | |
17 | // contributors may be used to endorse or promote products derived from | |
18 | // this software without specific prior written permission. | |
19 | // | |
20 | // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | |
21 | // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | |
22 | // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR | |
23 | // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT | |
24 | // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | |
25 | // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT | |
26 | // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
27 | // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
28 | // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
29 | // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE | |
30 | // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
31 | ||
32 | package proto | |
33 | ||
34 | /* | |
35 | * Types and routines for supporting protocol buffer extensions. | |
36 | */ | |
37 | ||
38 | import ( | |
39 | "errors" | |
40 | "fmt" | |
41 | "io" | |
42 | "reflect" | |
43 | "strconv" | |
44 | "sync" | |
45 | ) | |
46 | ||
47 | // ErrMissingExtension is the error returned by GetExtension if the named extension is not in the message. | |
48 | var ErrMissingExtension = errors.New("proto: missing extension") | |
49 | ||
50 | // ExtensionRange represents a range of message extensions for a protocol buffer. | |
51 | // Used in code generated by the protocol compiler. | |
52 | type ExtensionRange struct { | |
53 | Start, End int32 // both inclusive | |
54 | } | |
55 | ||
56 | // extendableProto is an interface implemented by any protocol buffer generated by the current | |
57 | // proto compiler that may be extended. | |
58 | type extendableProto interface { | |
59 | Message | |
60 | ExtensionRangeArray() []ExtensionRange | |
61 | extensionsWrite() map[int32]Extension | |
62 | extensionsRead() (map[int32]Extension, sync.Locker) | |
63 | } | |
64 | ||
65 | // extendableProtoV1 is an interface implemented by a protocol buffer generated by the previous | |
66 | // version of the proto compiler that may be extended. | |
67 | type extendableProtoV1 interface { | |
68 | Message | |
69 | ExtensionRangeArray() []ExtensionRange | |
70 | ExtensionMap() map[int32]Extension | |
71 | } | |
72 | ||
73 | // extensionAdapter is a wrapper around extendableProtoV1 that implements extendableProto. | |
74 | type extensionAdapter struct { | |
75 | extendableProtoV1 | |
76 | } | |
77 | ||
78 | func (e extensionAdapter) extensionsWrite() map[int32]Extension { | |
79 | return e.ExtensionMap() | |
80 | } | |
81 | ||
82 | func (e extensionAdapter) extensionsRead() (map[int32]Extension, sync.Locker) { | |
83 | return e.ExtensionMap(), notLocker{} | |
84 | } | |
85 | ||
86 | // notLocker is a sync.Locker whose Lock and Unlock methods are nops. | |
87 | type notLocker struct{} | |
88 | ||
89 | func (n notLocker) Lock() {} | |
90 | func (n notLocker) Unlock() {} | |
91 | ||
92 | // extendable returns the extendableProto interface for the given generated proto message. | |
93 | // If the proto message has the old extension format, it returns a wrapper that implements | |
94 | // the extendableProto interface. | |
95 | func extendable(p interface{}) (extendableProto, error) { | |
96 | switch p := p.(type) { | |
97 | case extendableProto: | |
98 | if isNilPtr(p) { | |
99 | return nil, fmt.Errorf("proto: nil %T is not extendable", p) | |
100 | } | |
101 | return p, nil | |
102 | case extendableProtoV1: | |
103 | if isNilPtr(p) { | |
104 | return nil, fmt.Errorf("proto: nil %T is not extendable", p) | |
105 | } | |
106 | return extensionAdapter{p}, nil | |
107 | } | |
108 | // Don't allocate a specific error containing %T: | |
109 | // this is the hot path for Clone and MarshalText. | |
110 | return nil, errNotExtendable | |
111 | } | |
112 | ||
113 | var errNotExtendable = errors.New("proto: not an extendable proto.Message") | |
114 | ||
115 | func isNilPtr(x interface{}) bool { | |
116 | v := reflect.ValueOf(x) | |
117 | return v.Kind() == reflect.Ptr && v.IsNil() | |
118 | } | |
119 | ||
120 | // XXX_InternalExtensions is an internal representation of proto extensions. | |
121 | // | |
122 | // Each generated message struct type embeds an anonymous XXX_InternalExtensions field, | |
123 | // thus gaining the unexported 'extensions' method, which can be called only from the proto package. | |
124 | // | |
125 | // The methods of XXX_InternalExtensions are not concurrency safe in general, | |
126 | // but calls to logically read-only methods such as has and get may be executed concurrently. | |
127 | type XXX_InternalExtensions struct { | |
128 | // The struct must be indirect so that if a user inadvertently copies a | |
129 | // generated message and its embedded XXX_InternalExtensions, they | |
130 | // avoid the mayhem of a copied mutex. | |
131 | // | |
132 | // The mutex serializes all logically read-only operations to p.extensionMap. | |
133 | // It is up to the client to ensure that write operations to p.extensionMap are | |
134 | // mutually exclusive with other accesses. | |
135 | p *struct { | |
136 | mu sync.Mutex | |
137 | extensionMap map[int32]Extension | |
138 | } | |
139 | } | |
140 | ||
141 | // extensionsWrite returns the extension map, creating it on first use. | |
142 | func (e *XXX_InternalExtensions) extensionsWrite() map[int32]Extension { | |
143 | if e.p == nil { | |
144 | e.p = new(struct { | |
145 | mu sync.Mutex | |
146 | extensionMap map[int32]Extension | |
147 | }) | |
148 | e.p.extensionMap = make(map[int32]Extension) | |
149 | } | |
150 | return e.p.extensionMap | |
151 | } | |
152 | ||
153 | // extensionsRead returns the extensions map for read-only use. It may be nil. | |
154 | // The caller must hold the returned mutex's lock when accessing Elements within the map. | |
155 | func (e *XXX_InternalExtensions) extensionsRead() (map[int32]Extension, sync.Locker) { | |
156 | if e.p == nil { | |
157 | return nil, nil | |
158 | } | |
159 | return e.p.extensionMap, &e.p.mu | |
160 | } | |
161 | ||
162 | // ExtensionDesc represents an extension specification. | |
163 | // Used in generated code from the protocol compiler. | |
164 | type ExtensionDesc struct { | |
165 | ExtendedType Message // nil pointer to the type that is being extended | |
166 | ExtensionType interface{} // nil pointer to the extension type | |
167 | Field int32 // field number | |
168 | Name string // fully-qualified name of extension, for text formatting | |
169 | Tag string // protobuf tag style | |
170 | Filename string // name of the file in which the extension is defined | |
171 | } | |
172 | ||
173 | func (ed *ExtensionDesc) repeated() bool { | |
174 | t := reflect.TypeOf(ed.ExtensionType) | |
175 | return t.Kind() == reflect.Slice && t.Elem().Kind() != reflect.Uint8 | |
176 | } | |
177 | ||
178 | // Extension represents an extension in a message. | |
179 | type Extension struct { | |
180 | // When an extension is stored in a message using SetExtension | |
181 | // only desc and value are set. When the message is marshaled | |
182 | // enc will be set to the encoded form of the message. | |
183 | // | |
184 | // When a message is unmarshaled and contains extensions, each | |
185 | // extension will have only enc set. When such an extension is | |
186 | // accessed using GetExtension (or GetExtensions) desc and value | |
187 | // will be set. | |
107c1cdb ND |
188 | desc *ExtensionDesc |
189 | ||
190 | // value is a concrete value for the extension field. Let the type of | |
191 | // desc.ExtensionType be the "API type" and the type of Extension.value | |
192 | // be the "storage type". The API type and storage type are the same except: | |
193 | // * For scalars (except []byte), the API type uses *T, | |
194 | // while the storage type uses T. | |
195 | // * For repeated fields, the API type uses []T, while the storage type | |
196 | // uses *[]T. | |
197 | // | |
198 | // The reason for the divergence is so that the storage type more naturally | |
199 | // matches what is expected of when retrieving the values through the | |
200 | // protobuf reflection APIs. | |
201 | // | |
202 | // The value may only be populated if desc is also populated. | |
15c0b25d | 203 | value interface{} |
107c1cdb ND |
204 | |
205 | // enc is the raw bytes for the extension field. | |
206 | enc []byte | |
15c0b25d AP |
207 | } |
208 | ||
209 | // SetRawExtension is for testing only. | |
210 | func SetRawExtension(base Message, id int32, b []byte) { | |
211 | epb, err := extendable(base) | |
212 | if err != nil { | |
213 | return | |
214 | } | |
215 | extmap := epb.extensionsWrite() | |
216 | extmap[id] = Extension{enc: b} | |
217 | } | |
218 | ||
219 | // isExtensionField returns true iff the given field number is in an extension range. | |
220 | func isExtensionField(pb extendableProto, field int32) bool { | |
221 | for _, er := range pb.ExtensionRangeArray() { | |
222 | if er.Start <= field && field <= er.End { | |
223 | return true | |
224 | } | |
225 | } | |
226 | return false | |
227 | } | |
228 | ||
229 | // checkExtensionTypes checks that the given extension is valid for pb. | |
230 | func checkExtensionTypes(pb extendableProto, extension *ExtensionDesc) error { | |
231 | var pbi interface{} = pb | |
232 | // Check the extended type. | |
233 | if ea, ok := pbi.(extensionAdapter); ok { | |
234 | pbi = ea.extendableProtoV1 | |
235 | } | |
236 | if a, b := reflect.TypeOf(pbi), reflect.TypeOf(extension.ExtendedType); a != b { | |
237 | return fmt.Errorf("proto: bad extended type; %v does not extend %v", b, a) | |
238 | } | |
239 | // Check the range. | |
240 | if !isExtensionField(pb, extension.Field) { | |
241 | return errors.New("proto: bad extension number; not in declared ranges") | |
242 | } | |
243 | return nil | |
244 | } | |
245 | ||
246 | // extPropKey is sufficient to uniquely identify an extension. | |
247 | type extPropKey struct { | |
248 | base reflect.Type | |
249 | field int32 | |
250 | } | |
251 | ||
252 | var extProp = struct { | |
253 | sync.RWMutex | |
254 | m map[extPropKey]*Properties | |
255 | }{ | |
256 | m: make(map[extPropKey]*Properties), | |
257 | } | |
258 | ||
259 | func extensionProperties(ed *ExtensionDesc) *Properties { | |
260 | key := extPropKey{base: reflect.TypeOf(ed.ExtendedType), field: ed.Field} | |
261 | ||
262 | extProp.RLock() | |
263 | if prop, ok := extProp.m[key]; ok { | |
264 | extProp.RUnlock() | |
265 | return prop | |
266 | } | |
267 | extProp.RUnlock() | |
268 | ||
269 | extProp.Lock() | |
270 | defer extProp.Unlock() | |
271 | // Check again. | |
272 | if prop, ok := extProp.m[key]; ok { | |
273 | return prop | |
274 | } | |
275 | ||
276 | prop := new(Properties) | |
277 | prop.Init(reflect.TypeOf(ed.ExtensionType), "unknown_name", ed.Tag, nil) | |
278 | extProp.m[key] = prop | |
279 | return prop | |
280 | } | |
281 | ||
282 | // HasExtension returns whether the given extension is present in pb. | |
283 | func HasExtension(pb Message, extension *ExtensionDesc) bool { | |
284 | // TODO: Check types, field numbers, etc.? | |
285 | epb, err := extendable(pb) | |
286 | if err != nil { | |
287 | return false | |
288 | } | |
289 | extmap, mu := epb.extensionsRead() | |
290 | if extmap == nil { | |
291 | return false | |
292 | } | |
293 | mu.Lock() | |
294 | _, ok := extmap[extension.Field] | |
295 | mu.Unlock() | |
296 | return ok | |
297 | } | |
298 | ||
299 | // ClearExtension removes the given extension from pb. | |
300 | func ClearExtension(pb Message, extension *ExtensionDesc) { | |
301 | epb, err := extendable(pb) | |
302 | if err != nil { | |
303 | return | |
304 | } | |
305 | // TODO: Check types, field numbers, etc.? | |
306 | extmap := epb.extensionsWrite() | |
307 | delete(extmap, extension.Field) | |
308 | } | |
309 | ||
310 | // GetExtension retrieves a proto2 extended field from pb. | |
311 | // | |
312 | // If the descriptor is type complete (i.e., ExtensionDesc.ExtensionType is non-nil), | |
313 | // then GetExtension parses the encoded field and returns a Go value of the specified type. | |
314 | // If the field is not present, then the default value is returned (if one is specified), | |
315 | // otherwise ErrMissingExtension is reported. | |
316 | // | |
317 | // If the descriptor is not type complete (i.e., ExtensionDesc.ExtensionType is nil), | |
318 | // then GetExtension returns the raw encoded bytes of the field extension. | |
319 | func GetExtension(pb Message, extension *ExtensionDesc) (interface{}, error) { | |
320 | epb, err := extendable(pb) | |
321 | if err != nil { | |
322 | return nil, err | |
323 | } | |
324 | ||
325 | if extension.ExtendedType != nil { | |
326 | // can only check type if this is a complete descriptor | |
327 | if err := checkExtensionTypes(epb, extension); err != nil { | |
328 | return nil, err | |
329 | } | |
330 | } | |
331 | ||
332 | emap, mu := epb.extensionsRead() | |
333 | if emap == nil { | |
334 | return defaultExtensionValue(extension) | |
335 | } | |
336 | mu.Lock() | |
337 | defer mu.Unlock() | |
338 | e, ok := emap[extension.Field] | |
339 | if !ok { | |
340 | // defaultExtensionValue returns the default value or | |
341 | // ErrMissingExtension if there is no default. | |
342 | return defaultExtensionValue(extension) | |
343 | } | |
344 | ||
345 | if e.value != nil { | |
346 | // Already decoded. Check the descriptor, though. | |
347 | if e.desc != extension { | |
348 | // This shouldn't happen. If it does, it means that | |
349 | // GetExtension was called twice with two different | |
350 | // descriptors with the same field number. | |
351 | return nil, errors.New("proto: descriptor conflict") | |
352 | } | |
107c1cdb | 353 | return extensionAsLegacyType(e.value), nil |
15c0b25d AP |
354 | } |
355 | ||
356 | if extension.ExtensionType == nil { | |
357 | // incomplete descriptor | |
358 | return e.enc, nil | |
359 | } | |
360 | ||
361 | v, err := decodeExtension(e.enc, extension) | |
362 | if err != nil { | |
363 | return nil, err | |
364 | } | |
365 | ||
366 | // Remember the decoded version and drop the encoded version. | |
367 | // That way it is safe to mutate what we return. | |
107c1cdb | 368 | e.value = extensionAsStorageType(v) |
15c0b25d AP |
369 | e.desc = extension |
370 | e.enc = nil | |
371 | emap[extension.Field] = e | |
107c1cdb | 372 | return extensionAsLegacyType(e.value), nil |
15c0b25d AP |
373 | } |
374 | ||
375 | // defaultExtensionValue returns the default value for extension. | |
376 | // If no default for an extension is defined ErrMissingExtension is returned. | |
377 | func defaultExtensionValue(extension *ExtensionDesc) (interface{}, error) { | |
378 | if extension.ExtensionType == nil { | |
379 | // incomplete descriptor, so no default | |
380 | return nil, ErrMissingExtension | |
381 | } | |
382 | ||
383 | t := reflect.TypeOf(extension.ExtensionType) | |
384 | props := extensionProperties(extension) | |
385 | ||
386 | sf, _, err := fieldDefault(t, props) | |
387 | if err != nil { | |
388 | return nil, err | |
389 | } | |
390 | ||
391 | if sf == nil || sf.value == nil { | |
392 | // There is no default value. | |
393 | return nil, ErrMissingExtension | |
394 | } | |
395 | ||
396 | if t.Kind() != reflect.Ptr { | |
397 | // We do not need to return a Ptr, we can directly return sf.value. | |
398 | return sf.value, nil | |
399 | } | |
400 | ||
401 | // We need to return an interface{} that is a pointer to sf.value. | |
402 | value := reflect.New(t).Elem() | |
403 | value.Set(reflect.New(value.Type().Elem())) | |
404 | if sf.kind == reflect.Int32 { | |
405 | // We may have an int32 or an enum, but the underlying data is int32. | |
406 | // Since we can't set an int32 into a non int32 reflect.value directly | |
407 | // set it as a int32. | |
408 | value.Elem().SetInt(int64(sf.value.(int32))) | |
409 | } else { | |
410 | value.Elem().Set(reflect.ValueOf(sf.value)) | |
411 | } | |
412 | return value.Interface(), nil | |
413 | } | |
414 | ||
415 | // decodeExtension decodes an extension encoded in b. | |
416 | func decodeExtension(b []byte, extension *ExtensionDesc) (interface{}, error) { | |
417 | t := reflect.TypeOf(extension.ExtensionType) | |
418 | unmarshal := typeUnmarshaler(t, extension.Tag) | |
419 | ||
420 | // t is a pointer to a struct, pointer to basic type or a slice. | |
421 | // Allocate space to store the pointer/slice. | |
422 | value := reflect.New(t).Elem() | |
423 | ||
424 | var err error | |
425 | for { | |
426 | x, n := decodeVarint(b) | |
427 | if n == 0 { | |
428 | return nil, io.ErrUnexpectedEOF | |
429 | } | |
430 | b = b[n:] | |
431 | wire := int(x) & 7 | |
432 | ||
433 | b, err = unmarshal(b, valToPointer(value.Addr()), wire) | |
434 | if err != nil { | |
435 | return nil, err | |
436 | } | |
437 | ||
438 | if len(b) == 0 { | |
439 | break | |
440 | } | |
441 | } | |
442 | return value.Interface(), nil | |
443 | } | |
444 | ||
445 | // GetExtensions returns a slice of the extensions present in pb that are also listed in es. | |
446 | // The returned slice has the same length as es; missing extensions will appear as nil elements. | |
447 | func GetExtensions(pb Message, es []*ExtensionDesc) (extensions []interface{}, err error) { | |
448 | epb, err := extendable(pb) | |
449 | if err != nil { | |
450 | return nil, err | |
451 | } | |
452 | extensions = make([]interface{}, len(es)) | |
453 | for i, e := range es { | |
454 | extensions[i], err = GetExtension(epb, e) | |
455 | if err == ErrMissingExtension { | |
456 | err = nil | |
457 | } | |
458 | if err != nil { | |
459 | return | |
460 | } | |
461 | } | |
462 | return | |
463 | } | |
464 | ||
465 | // ExtensionDescs returns a new slice containing pb's extension descriptors, in undefined order. | |
466 | // For non-registered extensions, ExtensionDescs returns an incomplete descriptor containing | |
467 | // just the Field field, which defines the extension's field number. | |
468 | func ExtensionDescs(pb Message) ([]*ExtensionDesc, error) { | |
469 | epb, err := extendable(pb) | |
470 | if err != nil { | |
471 | return nil, err | |
472 | } | |
473 | registeredExtensions := RegisteredExtensions(pb) | |
474 | ||
475 | emap, mu := epb.extensionsRead() | |
476 | if emap == nil { | |
477 | return nil, nil | |
478 | } | |
479 | mu.Lock() | |
480 | defer mu.Unlock() | |
481 | extensions := make([]*ExtensionDesc, 0, len(emap)) | |
482 | for extid, e := range emap { | |
483 | desc := e.desc | |
484 | if desc == nil { | |
485 | desc = registeredExtensions[extid] | |
486 | if desc == nil { | |
487 | desc = &ExtensionDesc{Field: extid} | |
488 | } | |
489 | } | |
490 | ||
491 | extensions = append(extensions, desc) | |
492 | } | |
493 | return extensions, nil | |
494 | } | |
495 | ||
496 | // SetExtension sets the specified extension of pb to the specified value. | |
497 | func SetExtension(pb Message, extension *ExtensionDesc, value interface{}) error { | |
498 | epb, err := extendable(pb) | |
499 | if err != nil { | |
500 | return err | |
501 | } | |
502 | if err := checkExtensionTypes(epb, extension); err != nil { | |
503 | return err | |
504 | } | |
505 | typ := reflect.TypeOf(extension.ExtensionType) | |
506 | if typ != reflect.TypeOf(value) { | |
107c1cdb | 507 | return fmt.Errorf("proto: bad extension value type. got: %T, want: %T", value, extension.ExtensionType) |
15c0b25d AP |
508 | } |
509 | // nil extension values need to be caught early, because the | |
510 | // encoder can't distinguish an ErrNil due to a nil extension | |
511 | // from an ErrNil due to a missing field. Extensions are | |
512 | // always optional, so the encoder would just swallow the error | |
513 | // and drop all the extensions from the encoded message. | |
514 | if reflect.ValueOf(value).IsNil() { | |
515 | return fmt.Errorf("proto: SetExtension called with nil value of type %T", value) | |
516 | } | |
517 | ||
518 | extmap := epb.extensionsWrite() | |
107c1cdb | 519 | extmap[extension.Field] = Extension{desc: extension, value: extensionAsStorageType(value)} |
15c0b25d AP |
520 | return nil |
521 | } | |
522 | ||
523 | // ClearAllExtensions clears all extensions from pb. | |
524 | func ClearAllExtensions(pb Message) { | |
525 | epb, err := extendable(pb) | |
526 | if err != nil { | |
527 | return | |
528 | } | |
529 | m := epb.extensionsWrite() | |
530 | for k := range m { | |
531 | delete(m, k) | |
532 | } | |
533 | } | |
534 | ||
535 | // A global registry of extensions. | |
536 | // The generated code will register the generated descriptors by calling RegisterExtension. | |
537 | ||
538 | var extensionMaps = make(map[reflect.Type]map[int32]*ExtensionDesc) | |
539 | ||
540 | // RegisterExtension is called from the generated code. | |
541 | func RegisterExtension(desc *ExtensionDesc) { | |
542 | st := reflect.TypeOf(desc.ExtendedType).Elem() | |
543 | m := extensionMaps[st] | |
544 | if m == nil { | |
545 | m = make(map[int32]*ExtensionDesc) | |
546 | extensionMaps[st] = m | |
547 | } | |
548 | if _, ok := m[desc.Field]; ok { | |
549 | panic("proto: duplicate extension registered: " + st.String() + " " + strconv.Itoa(int(desc.Field))) | |
550 | } | |
551 | m[desc.Field] = desc | |
552 | } | |
553 | ||
554 | // RegisteredExtensions returns a map of the registered extensions of a | |
555 | // protocol buffer struct, indexed by the extension number. | |
556 | // The argument pb should be a nil pointer to the struct type. | |
557 | func RegisteredExtensions(pb Message) map[int32]*ExtensionDesc { | |
558 | return extensionMaps[reflect.TypeOf(pb).Elem()] | |
559 | } | |
107c1cdb ND |
560 | |
561 | // extensionAsLegacyType converts an value in the storage type as the API type. | |
562 | // See Extension.value. | |
563 | func extensionAsLegacyType(v interface{}) interface{} { | |
564 | switch rv := reflect.ValueOf(v); rv.Kind() { | |
565 | case reflect.Bool, reflect.Int32, reflect.Int64, reflect.Uint32, reflect.Uint64, reflect.Float32, reflect.Float64, reflect.String: | |
566 | // Represent primitive types as a pointer to the value. | |
567 | rv2 := reflect.New(rv.Type()) | |
568 | rv2.Elem().Set(rv) | |
569 | v = rv2.Interface() | |
570 | case reflect.Ptr: | |
571 | // Represent slice types as the value itself. | |
572 | switch rv.Type().Elem().Kind() { | |
573 | case reflect.Slice: | |
574 | if rv.IsNil() { | |
575 | v = reflect.Zero(rv.Type().Elem()).Interface() | |
576 | } else { | |
577 | v = rv.Elem().Interface() | |
578 | } | |
579 | } | |
580 | } | |
581 | return v | |
582 | } | |
583 | ||
584 | // extensionAsStorageType converts an value in the API type as the storage type. | |
585 | // See Extension.value. | |
586 | func extensionAsStorageType(v interface{}) interface{} { | |
587 | switch rv := reflect.ValueOf(v); rv.Kind() { | |
588 | case reflect.Ptr: | |
589 | // Represent slice types as the value itself. | |
590 | switch rv.Type().Elem().Kind() { | |
591 | case reflect.Bool, reflect.Int32, reflect.Int64, reflect.Uint32, reflect.Uint64, reflect.Float32, reflect.Float64, reflect.String: | |
592 | if rv.IsNil() { | |
593 | v = reflect.Zero(rv.Type().Elem()).Interface() | |
594 | } else { | |
595 | v = rv.Elem().Interface() | |
596 | } | |
597 | } | |
598 | case reflect.Slice: | |
599 | // Represent slice types as a pointer to the value. | |
600 | if rv.Type().Elem().Kind() != reflect.Uint8 { | |
601 | rv2 := reflect.New(rv.Type()) | |
602 | rv2.Elem().Set(rv) | |
603 | v = rv2.Interface() | |
604 | } | |
605 | } | |
606 | return v | |
607 | } |