forked from mongodb/mongo-go-driver
-
Notifications
You must be signed in to change notification settings - Fork 0
/
registry.go
524 lines (471 loc) · 19 KB
/
registry.go
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
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
// Copyright (C) MongoDB, Inc. 2017-present.
//
// Licensed under the Apache License, Version 2.0 (the "License"); you may
// not use this file except in compliance with the License. You may obtain
// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
package bsoncodec
import (
"errors"
"fmt"
"reflect"
"sync"
"github.com/hongyuyang/mongo-go-driver/bson/bsontype"
)
// ErrNilType is returned when nil is passed to either LookupEncoder or LookupDecoder.
//
// Deprecated: ErrNilType will not be supported in Go Driver 2.0.
var ErrNilType = errors.New("cannot perform a decoder lookup on <nil>")
// ErrNotPointer is returned when a non-pointer type is provided to LookupDecoder.
//
// Deprecated: ErrNotPointer will not be supported in Go Driver 2.0.
var ErrNotPointer = errors.New("non-pointer provided to LookupDecoder")
// ErrNoEncoder is returned when there wasn't an encoder available for a type.
//
// Deprecated: ErrNoEncoder will not be supported in Go Driver 2.0.
type ErrNoEncoder struct {
Type reflect.Type
}
func (ene ErrNoEncoder) Error() string {
if ene.Type == nil {
return "no encoder found for <nil>"
}
return "no encoder found for " + ene.Type.String()
}
// ErrNoDecoder is returned when there wasn't a decoder available for a type.
//
// Deprecated: ErrNoDecoder will not be supported in Go Driver 2.0.
type ErrNoDecoder struct {
Type reflect.Type
}
func (end ErrNoDecoder) Error() string {
return "no decoder found for " + end.Type.String()
}
// ErrNoTypeMapEntry is returned when there wasn't a type available for the provided BSON type.
//
// Deprecated: ErrNoTypeMapEntry will not be supported in Go Driver 2.0.
type ErrNoTypeMapEntry struct {
Type bsontype.Type
}
func (entme ErrNoTypeMapEntry) Error() string {
return "no type map entry found for " + entme.Type.String()
}
// ErrNotInterface is returned when the provided type is not an interface.
//
// Deprecated: ErrNotInterface will not be supported in Go Driver 2.0.
var ErrNotInterface = errors.New("The provided type is not an interface")
// A RegistryBuilder is used to build a Registry. This type is not goroutine
// safe.
//
// Deprecated: Use Registry instead.
type RegistryBuilder struct {
registry *Registry
}
// NewRegistryBuilder creates a new empty RegistryBuilder.
//
// Deprecated: Use NewRegistry instead.
func NewRegistryBuilder() *RegistryBuilder {
return &RegistryBuilder{
registry: NewRegistry(),
}
}
// RegisterCodec will register the provided ValueCodec for the provided type.
//
// Deprecated: Use Registry.RegisterTypeEncoder and Registry.RegisterTypeDecoder instead.
func (rb *RegistryBuilder) RegisterCodec(t reflect.Type, codec ValueCodec) *RegistryBuilder {
rb.RegisterTypeEncoder(t, codec)
rb.RegisterTypeDecoder(t, codec)
return rb
}
// RegisterTypeEncoder will register the provided ValueEncoder for the provided type.
//
// The type will be used directly, so an encoder can be registered for a type and a different encoder can be registered
// for a pointer to that type.
//
// If the given type is an interface, the encoder will be called when marshaling a type that is that interface. It
// will not be called when marshaling a non-interface type that implements the interface.
//
// Deprecated: Use Registry.RegisterTypeEncoder instead.
func (rb *RegistryBuilder) RegisterTypeEncoder(t reflect.Type, enc ValueEncoder) *RegistryBuilder {
rb.registry.RegisterTypeEncoder(t, enc)
return rb
}
// RegisterHookEncoder will register an encoder for the provided interface type t. This encoder will be called when
// marshaling a type if the type implements t or a pointer to the type implements t. If the provided type is not
// an interface (i.e. t.Kind() != reflect.Interface), this method will panic.
//
// Deprecated: Use Registry.RegisterInterfaceEncoder instead.
func (rb *RegistryBuilder) RegisterHookEncoder(t reflect.Type, enc ValueEncoder) *RegistryBuilder {
rb.registry.RegisterInterfaceEncoder(t, enc)
return rb
}
// RegisterTypeDecoder will register the provided ValueDecoder for the provided type.
//
// The type will be used directly, so a decoder can be registered for a type and a different decoder can be registered
// for a pointer to that type.
//
// If the given type is an interface, the decoder will be called when unmarshaling into a type that is that interface.
// It will not be called when unmarshaling into a non-interface type that implements the interface.
//
// Deprecated: Use Registry.RegisterTypeDecoder instead.
func (rb *RegistryBuilder) RegisterTypeDecoder(t reflect.Type, dec ValueDecoder) *RegistryBuilder {
rb.registry.RegisterTypeDecoder(t, dec)
return rb
}
// RegisterHookDecoder will register an decoder for the provided interface type t. This decoder will be called when
// unmarshaling into a type if the type implements t or a pointer to the type implements t. If the provided type is not
// an interface (i.e. t.Kind() != reflect.Interface), this method will panic.
//
// Deprecated: Use Registry.RegisterInterfaceDecoder instead.
func (rb *RegistryBuilder) RegisterHookDecoder(t reflect.Type, dec ValueDecoder) *RegistryBuilder {
rb.registry.RegisterInterfaceDecoder(t, dec)
return rb
}
// RegisterEncoder registers the provided type and encoder pair.
//
// Deprecated: Use Registry.RegisterTypeEncoder or Registry.RegisterInterfaceEncoder instead.
func (rb *RegistryBuilder) RegisterEncoder(t reflect.Type, enc ValueEncoder) *RegistryBuilder {
if t == tEmpty {
rb.registry.RegisterTypeEncoder(t, enc)
return rb
}
switch t.Kind() {
case reflect.Interface:
rb.registry.RegisterInterfaceEncoder(t, enc)
default:
rb.registry.RegisterTypeEncoder(t, enc)
}
return rb
}
// RegisterDecoder registers the provided type and decoder pair.
//
// Deprecated: Use Registry.RegisterTypeDecoder or Registry.RegisterInterfaceDecoder instead.
func (rb *RegistryBuilder) RegisterDecoder(t reflect.Type, dec ValueDecoder) *RegistryBuilder {
if t == nil {
rb.registry.RegisterTypeDecoder(t, dec)
return rb
}
if t == tEmpty {
rb.registry.RegisterTypeDecoder(t, dec)
return rb
}
switch t.Kind() {
case reflect.Interface:
rb.registry.RegisterInterfaceDecoder(t, dec)
default:
rb.registry.RegisterTypeDecoder(t, dec)
}
return rb
}
// RegisterDefaultEncoder will register the provided ValueEncoder to the provided
// kind.
//
// Deprecated: Use Registry.RegisterKindEncoder instead.
func (rb *RegistryBuilder) RegisterDefaultEncoder(kind reflect.Kind, enc ValueEncoder) *RegistryBuilder {
rb.registry.RegisterKindEncoder(kind, enc)
return rb
}
// RegisterDefaultDecoder will register the provided ValueDecoder to the
// provided kind.
//
// Deprecated: Use Registry.RegisterKindDecoder instead.
func (rb *RegistryBuilder) RegisterDefaultDecoder(kind reflect.Kind, dec ValueDecoder) *RegistryBuilder {
rb.registry.RegisterKindDecoder(kind, dec)
return rb
}
// RegisterTypeMapEntry will register the provided type to the BSON type. The primary usage for this
// mapping is decoding situations where an empty interface is used and a default type needs to be
// created and decoded into.
//
// By default, BSON documents will decode into interface{} values as bson.D. To change the default type for BSON
// documents, a type map entry for bsontype.EmbeddedDocument should be registered. For example, to force BSON documents
// to decode to bson.Raw, use the following code:
//
// rb.RegisterTypeMapEntry(bsontype.EmbeddedDocument, reflect.TypeOf(bson.Raw{}))
//
// Deprecated: Use Registry.RegisterTypeMapEntry instead.
func (rb *RegistryBuilder) RegisterTypeMapEntry(bt bsontype.Type, rt reflect.Type) *RegistryBuilder {
rb.registry.RegisterTypeMapEntry(bt, rt)
return rb
}
// Build creates a Registry from the current state of this RegistryBuilder.
//
// Deprecated: Use NewRegistry instead.
func (rb *RegistryBuilder) Build() *Registry {
r := &Registry{
interfaceEncoders: append([]interfaceValueEncoder(nil), rb.registry.interfaceEncoders...),
interfaceDecoders: append([]interfaceValueDecoder(nil), rb.registry.interfaceDecoders...),
typeEncoders: rb.registry.typeEncoders.Clone(),
typeDecoders: rb.registry.typeDecoders.Clone(),
kindEncoders: rb.registry.kindEncoders.Clone(),
kindDecoders: rb.registry.kindDecoders.Clone(),
}
rb.registry.typeMap.Range(func(k, v interface{}) bool {
if k != nil && v != nil {
r.typeMap.Store(k, v)
}
return true
})
return r
}
// A Registry is used to store and retrieve codecs for types and interfaces. This type is the main
// typed passed around and Encoders and Decoders are constructed from it.
type Registry struct {
interfaceEncoders []interfaceValueEncoder
interfaceDecoders []interfaceValueDecoder
typeEncoders *typeEncoderCache
typeDecoders *typeDecoderCache
kindEncoders *kindEncoderCache
kindDecoders *kindDecoderCache
typeMap sync.Map // map[bsontype.Type]reflect.Type
}
// NewRegistry creates a new empty Registry.
func NewRegistry() *Registry {
return &Registry{
typeEncoders: new(typeEncoderCache),
typeDecoders: new(typeDecoderCache),
kindEncoders: new(kindEncoderCache),
kindDecoders: new(kindDecoderCache),
}
}
// RegisterTypeEncoder registers the provided ValueEncoder for the provided type.
//
// The type will be used as provided, so an encoder can be registered for a type and a different
// encoder can be registered for a pointer to that type.
//
// If the given type is an interface, the encoder will be called when marshaling a type that is
// that interface. It will not be called when marshaling a non-interface type that implements the
// interface. To get the latter behavior, call RegisterHookEncoder instead.
//
// RegisterTypeEncoder should not be called concurrently with any other Registry method.
func (r *Registry) RegisterTypeEncoder(valueType reflect.Type, enc ValueEncoder) {
r.typeEncoders.Store(valueType, enc)
}
// RegisterTypeDecoder registers the provided ValueDecoder for the provided type.
//
// The type will be used as provided, so a decoder can be registered for a type and a different
// decoder can be registered for a pointer to that type.
//
// If the given type is an interface, the decoder will be called when unmarshaling into a type that
// is that interface. It will not be called when unmarshaling into a non-interface type that
// implements the interface. To get the latter behavior, call RegisterHookDecoder instead.
//
// RegisterTypeDecoder should not be called concurrently with any other Registry method.
func (r *Registry) RegisterTypeDecoder(valueType reflect.Type, dec ValueDecoder) {
r.typeDecoders.Store(valueType, dec)
}
// RegisterKindEncoder registers the provided ValueEncoder for the provided kind.
//
// Use RegisterKindEncoder to register an encoder for any type with the same underlying kind. For
// example, consider the type MyInt defined as
//
// type MyInt int32
//
// To define an encoder for MyInt and int32, use RegisterKindEncoder like
//
// reg.RegisterKindEncoder(reflect.Int32, myEncoder)
//
// RegisterKindEncoder should not be called concurrently with any other Registry method.
func (r *Registry) RegisterKindEncoder(kind reflect.Kind, enc ValueEncoder) {
r.kindEncoders.Store(kind, enc)
}
// RegisterKindDecoder registers the provided ValueDecoder for the provided kind.
//
// Use RegisterKindDecoder to register a decoder for any type with the same underlying kind. For
// example, consider the type MyInt defined as
//
// type MyInt int32
//
// To define an decoder for MyInt and int32, use RegisterKindDecoder like
//
// reg.RegisterKindDecoder(reflect.Int32, myDecoder)
//
// RegisterKindDecoder should not be called concurrently with any other Registry method.
func (r *Registry) RegisterKindDecoder(kind reflect.Kind, dec ValueDecoder) {
r.kindDecoders.Store(kind, dec)
}
// RegisterInterfaceEncoder registers an encoder for the provided interface type iface. This encoder will
// be called when marshaling a type if the type implements iface or a pointer to the type
// implements iface. If the provided type is not an interface
// (i.e. iface.Kind() != reflect.Interface), this method will panic.
//
// RegisterInterfaceEncoder should not be called concurrently with any other Registry method.
func (r *Registry) RegisterInterfaceEncoder(iface reflect.Type, enc ValueEncoder) {
if iface.Kind() != reflect.Interface {
panicStr := fmt.Errorf("RegisterInterfaceEncoder expects a type with kind reflect.Interface, "+
"got type %s with kind %s", iface, iface.Kind())
panic(panicStr)
}
for idx, encoder := range r.interfaceEncoders {
if encoder.i == iface {
r.interfaceEncoders[idx].ve = enc
return
}
}
r.interfaceEncoders = append(r.interfaceEncoders, interfaceValueEncoder{i: iface, ve: enc})
}
// RegisterInterfaceDecoder registers an decoder for the provided interface type iface. This decoder will
// be called when unmarshaling into a type if the type implements iface or a pointer to the type
// implements iface. If the provided type is not an interface (i.e. iface.Kind() != reflect.Interface),
// this method will panic.
//
// RegisterInterfaceDecoder should not be called concurrently with any other Registry method.
func (r *Registry) RegisterInterfaceDecoder(iface reflect.Type, dec ValueDecoder) {
if iface.Kind() != reflect.Interface {
panicStr := fmt.Errorf("RegisterInterfaceDecoder expects a type with kind reflect.Interface, "+
"got type %s with kind %s", iface, iface.Kind())
panic(panicStr)
}
for idx, decoder := range r.interfaceDecoders {
if decoder.i == iface {
r.interfaceDecoders[idx].vd = dec
return
}
}
r.interfaceDecoders = append(r.interfaceDecoders, interfaceValueDecoder{i: iface, vd: dec})
}
// RegisterTypeMapEntry will register the provided type to the BSON type. The primary usage for this
// mapping is decoding situations where an empty interface is used and a default type needs to be
// created and decoded into.
//
// By default, BSON documents will decode into interface{} values as bson.D. To change the default type for BSON
// documents, a type map entry for bsontype.EmbeddedDocument should be registered. For example, to force BSON documents
// to decode to bson.Raw, use the following code:
//
// reg.RegisterTypeMapEntry(bsontype.EmbeddedDocument, reflect.TypeOf(bson.Raw{}))
func (r *Registry) RegisterTypeMapEntry(bt bsontype.Type, rt reflect.Type) {
r.typeMap.Store(bt, rt)
}
// LookupEncoder returns the first matching encoder in the Registry. It uses the following lookup
// order:
//
// 1. An encoder registered for the exact type. If the given type is an interface, an encoder
// registered using RegisterTypeEncoder for that interface will be selected.
//
// 2. An encoder registered using RegisterInterfaceEncoder for an interface implemented by the type
// or by a pointer to the type.
//
// 3. An encoder registered using RegisterKindEncoder for the kind of value.
//
// If no encoder is found, an error of type ErrNoEncoder is returned. LookupEncoder is safe for
// concurrent use by multiple goroutines after all codecs and encoders are registered.
func (r *Registry) LookupEncoder(valueType reflect.Type) (ValueEncoder, error) {
if valueType == nil {
return nil, ErrNoEncoder{Type: valueType}
}
enc, found := r.lookupTypeEncoder(valueType)
if found {
if enc == nil {
return nil, ErrNoEncoder{Type: valueType}
}
return enc, nil
}
enc, found = r.lookupInterfaceEncoder(valueType, true)
if found {
return r.typeEncoders.LoadOrStore(valueType, enc), nil
}
if v, ok := r.kindEncoders.Load(valueType.Kind()); ok {
return r.storeTypeEncoder(valueType, v), nil
}
return nil, ErrNoEncoder{Type: valueType}
}
func (r *Registry) storeTypeEncoder(rt reflect.Type, enc ValueEncoder) ValueEncoder {
return r.typeEncoders.LoadOrStore(rt, enc)
}
func (r *Registry) lookupTypeEncoder(rt reflect.Type) (ValueEncoder, bool) {
return r.typeEncoders.Load(rt)
}
func (r *Registry) lookupInterfaceEncoder(valueType reflect.Type, allowAddr bool) (ValueEncoder, bool) {
if valueType == nil {
return nil, false
}
for _, ienc := range r.interfaceEncoders {
if valueType.Implements(ienc.i) {
return ienc.ve, true
}
if allowAddr && valueType.Kind() != reflect.Ptr && reflect.PtrTo(valueType).Implements(ienc.i) {
// if *t implements an interface, this will catch if t implements an interface further
// ahead in interfaceEncoders
defaultEnc, found := r.lookupInterfaceEncoder(valueType, false)
if !found {
defaultEnc, _ = r.kindEncoders.Load(valueType.Kind())
}
return newCondAddrEncoder(ienc.ve, defaultEnc), true
}
}
return nil, false
}
// LookupDecoder returns the first matching decoder in the Registry. It uses the following lookup
// order:
//
// 1. A decoder registered for the exact type. If the given type is an interface, a decoder
// registered using RegisterTypeDecoder for that interface will be selected.
//
// 2. A decoder registered using RegisterInterfaceDecoder for an interface implemented by the type or by
// a pointer to the type.
//
// 3. A decoder registered using RegisterKindDecoder for the kind of value.
//
// If no decoder is found, an error of type ErrNoDecoder is returned. LookupDecoder is safe for
// concurrent use by multiple goroutines after all codecs and decoders are registered.
func (r *Registry) LookupDecoder(valueType reflect.Type) (ValueDecoder, error) {
if valueType == nil {
return nil, ErrNilType
}
dec, found := r.lookupTypeDecoder(valueType)
if found {
if dec == nil {
return nil, ErrNoDecoder{Type: valueType}
}
return dec, nil
}
dec, found = r.lookupInterfaceDecoder(valueType, true)
if found {
return r.storeTypeDecoder(valueType, dec), nil
}
if v, ok := r.kindDecoders.Load(valueType.Kind()); ok {
return r.storeTypeDecoder(valueType, v), nil
}
return nil, ErrNoDecoder{Type: valueType}
}
func (r *Registry) lookupTypeDecoder(valueType reflect.Type) (ValueDecoder, bool) {
return r.typeDecoders.Load(valueType)
}
func (r *Registry) storeTypeDecoder(typ reflect.Type, dec ValueDecoder) ValueDecoder {
return r.typeDecoders.LoadOrStore(typ, dec)
}
func (r *Registry) lookupInterfaceDecoder(valueType reflect.Type, allowAddr bool) (ValueDecoder, bool) {
for _, idec := range r.interfaceDecoders {
if valueType.Implements(idec.i) {
return idec.vd, true
}
if allowAddr && valueType.Kind() != reflect.Ptr && reflect.PtrTo(valueType).Implements(idec.i) {
// if *t implements an interface, this will catch if t implements an interface further
// ahead in interfaceDecoders
defaultDec, found := r.lookupInterfaceDecoder(valueType, false)
if !found {
defaultDec, _ = r.kindDecoders.Load(valueType.Kind())
}
return newCondAddrDecoder(idec.vd, defaultDec), true
}
}
return nil, false
}
// LookupTypeMapEntry inspects the registry's type map for a Go type for the corresponding BSON
// type. If no type is found, ErrNoTypeMapEntry is returned.
//
// LookupTypeMapEntry should not be called concurrently with any other Registry method.
func (r *Registry) LookupTypeMapEntry(bt bsontype.Type) (reflect.Type, error) {
v, ok := r.typeMap.Load(bt)
if v == nil || !ok {
return nil, ErrNoTypeMapEntry{Type: bt}
}
return v.(reflect.Type), nil
}
type interfaceValueEncoder struct {
i reflect.Type
ve ValueEncoder
}
type interfaceValueDecoder struct {
i reflect.Type
vd ValueDecoder
}