diff options
Diffstat (limited to 'vendor/go.mongodb.org/mongo-driver/bson/bsoncodec/registry.go')
| -rw-r--r-- | vendor/go.mongodb.org/mongo-driver/bson/bsoncodec/registry.go | 160 |
1 files changed, 124 insertions, 36 deletions
diff --git a/vendor/go.mongodb.org/mongo-driver/bson/bsoncodec/registry.go b/vendor/go.mongodb.org/mongo-driver/bson/bsoncodec/registry.go index 42e362b6ad..02b63bbe46 100644 --- a/vendor/go.mongodb.org/mongo-driver/bson/bsoncodec/registry.go +++ b/vendor/go.mongodb.org/mongo-driver/bson/bsoncodec/registry.go @@ -8,6 +8,7 @@ package bsoncodec import ( "errors" + "fmt" "reflect" "sync" @@ -115,15 +116,79 @@ func buildDefaultRegistry() *Registry { // RegisterCodec will register the provided ValueCodec for the provided type. func (rb *RegistryBuilder) RegisterCodec(t reflect.Type, codec ValueCodec) *RegistryBuilder { - rb.RegisterEncoder(t, codec) - rb.RegisterDecoder(t, codec) + rb.RegisterTypeEncoder(t, codec) + rb.RegisterTypeDecoder(t, codec) return rb } -// RegisterEncoder will register the provided ValueEncoder to the provided type. +// RegisterTypeEncoder will register the provided ValueEncoder for the provided type. // -// The type registered 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. +// 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 marshalling a type that is that interface. It +// will not be called when marshalling a non-interface type that implements the interface. +func (rb *RegistryBuilder) RegisterTypeEncoder(t reflect.Type, enc ValueEncoder) *RegistryBuilder { + rb.typeEncoders[t] = enc + return rb +} + +// RegisterHookEncoder will register an encoder for the provided interface type t. This encoder will be called when +// marshalling 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. +func (rb *RegistryBuilder) RegisterHookEncoder(t reflect.Type, enc ValueEncoder) *RegistryBuilder { + if t.Kind() != reflect.Interface { + panicStr := fmt.Sprintf("RegisterHookEncoder expects a type with kind reflect.Interface, "+ + "got type %s with kind %s", t, t.Kind()) + panic(panicStr) + } + + for idx, encoder := range rb.interfaceEncoders { + if encoder.i == t { + rb.interfaceEncoders[idx].ve = enc + return rb + } + } + + rb.interfaceEncoders = append(rb.interfaceEncoders, interfaceValueEncoder{i: t, ve: 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 unmarshalling into a type that is that interface. +// It will not be called when unmarshalling into a non-interface type that implements the interface. +func (rb *RegistryBuilder) RegisterTypeDecoder(t reflect.Type, dec ValueDecoder) *RegistryBuilder { + rb.typeDecoders[t] = dec + return rb +} + +// RegisterHookDecoder will register an decoder for the provided interface type t. This decoder will be called when +// unmarshalling 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. +func (rb *RegistryBuilder) RegisterHookDecoder(t reflect.Type, dec ValueDecoder) *RegistryBuilder { + if t.Kind() != reflect.Interface { + panicStr := fmt.Sprintf("RegisterHookDecoder expects a type with kind reflect.Interface, "+ + "got type %s with kind %s", t, t.Kind()) + panic(panicStr) + } + + for idx, decoder := range rb.interfaceDecoders { + if decoder.i == t { + rb.interfaceDecoders[idx].vd = dec + return rb + } + } + + rb.interfaceDecoders = append(rb.interfaceDecoders, interfaceValueDecoder{i: t, vd: dec}) + return rb +} + +// RegisterEncoder has been deprecated and will be removed in a future major version release. Use RegisterTypeEncoder +// or RegisterHookEncoder instead. func (rb *RegistryBuilder) RegisterEncoder(t reflect.Type, enc ValueEncoder) *RegistryBuilder { if t == tEmpty { rb.typeEncoders[t] = enc @@ -145,10 +210,8 @@ func (rb *RegistryBuilder) RegisterEncoder(t reflect.Type, enc ValueEncoder) *Re return rb } -// RegisterDecoder will register the provided ValueDecoder to the provided type. -// -// The type registered 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. +// RegisterDecoder has been deprecated and will be removed in a future major version release. Use RegisterTypeDecoder +// or RegisterHookDecoder instead. func (rb *RegistryBuilder) RegisterDecoder(t reflect.Type, dec ValueDecoder) *RegistryBuilder { if t == nil { rb.typeDecoders[nil] = dec @@ -192,11 +255,10 @@ func (rb *RegistryBuilder) RegisterDefaultDecoder(kind reflect.Kind, dec ValueDe // mapping is decoding situations where an empty interface is used and a default type needs to be // created and decoded into. // -// NOTE: It is unlikely that registering a type for BSON Embedded Document is actually desired. By -// registering a type map entry for BSON Embedded Document the type registered will be used in any -// case where a BSON Embedded Document will be decoded into an empty interface. For example, if you -// register primitive.M, the EmptyInterface decoder will always use primitive.M, even if an ancestor -// was a primitive.D. +// 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{})) func (rb *RegistryBuilder) RegisterTypeMapEntry(bt bsontype.Type, rt reflect.Type) *RegistryBuilder { rb.typeMap[bt] = rt return rb @@ -240,11 +302,17 @@ func (rb *RegistryBuilder) Build() *Registry { return registry } -// LookupEncoder will inspect the registry for an encoder that satisfies the -// type provided. An encoder registered for a specific type will take -// precedence over an encoder registered for an interface the type satisfies, -// which takes precedence over an encoder for the reflect.Kind of the value. If -// no encoder can be found, an error is returned. +// LookupEncoder inspects the registry for an encoder for the given type. The lookup precendence works as follows: +// +// 1. An encoder registered for the exact type. If the given type represents an interface, an encoder registered using +// RegisterTypeEncoder for the interface will be selected. +// +// 2. An encoder registered using RegisterHookEncoder for an interface implemented by the type or by a pointer to the +// type. +// +// 3. An encoder registered for the reflect.Kind of the value. +// +// If no encoder is found, an error of type ErrNoEncoder is returned. func (r *Registry) LookupEncoder(t reflect.Type) (ValueEncoder, error) { encodererr := ErrNoEncoder{Type: t} r.mu.RLock() @@ -257,7 +325,7 @@ func (r *Registry) LookupEncoder(t reflect.Type) (ValueEncoder, error) { return enc, nil } - enc, found = r.lookupInterfaceEncoder(t) + enc, found = r.lookupInterfaceEncoder(t, true) if found { r.mu.Lock() r.typeEncoders[t] = enc @@ -291,25 +359,38 @@ func (r *Registry) lookupTypeEncoder(t reflect.Type) (ValueEncoder, bool) { return enc, found } -func (r *Registry) lookupInterfaceEncoder(t reflect.Type) (ValueEncoder, bool) { +func (r *Registry) lookupInterfaceEncoder(t reflect.Type, allowAddr bool) (ValueEncoder, bool) { if t == nil { return nil, false } for _, ienc := range r.interfaceEncoders { - if !t.Implements(ienc.i) { - continue + if t.Implements(ienc.i) { + return ienc.ve, true + } + if allowAddr && t.Kind() != reflect.Ptr && reflect.PtrTo(t).Implements(ienc.i) { + // if *t implements an interface, this will catch if t implements an interface further ahead + // in interfaceEncoders + defaultEnc, found := r.lookupInterfaceEncoder(t, false) + if !found { + defaultEnc, _ = r.kindEncoders[t.Kind()] + } + return newCondAddrEncoder(ienc.ve, defaultEnc), true } - - return ienc.ve, true } return nil, false } -// LookupDecoder will inspect the registry for a decoder that satisfies the -// type provided. A decoder registered for a specific type will take -// precedence over a decoder registered for an interface the type satisfies, -// which takes precedence over a decoder for the reflect.Kind of the value. If -// no decoder can be found, an error is returned. +// LookupDecoder inspects the registry for an decoder for the given type. The lookup precendence works as follows: +// +// 1. A decoder registered for the exact type. If the given type represents an interface, a decoder registered using +// RegisterTypeDecoder for the interface will be selected. +// +// 2. A decoder registered using RegisterHookDecoder for an interface implemented by the type or by a pointer to the +// type. +// +// 3. A decoder registered for the reflect.Kind of the value. +// +// If no decoder is found, an error of type ErrNoDecoder is returned. func (r *Registry) LookupDecoder(t reflect.Type) (ValueDecoder, error) { if t == nil { return nil, ErrNilType @@ -325,7 +406,7 @@ func (r *Registry) LookupDecoder(t reflect.Type) (ValueDecoder, error) { return dec, nil } - dec, found = r.lookupInterfaceDecoder(t) + dec, found = r.lookupInterfaceDecoder(t, true) if found { r.mu.Lock() r.typeDecoders[t] = dec @@ -352,13 +433,20 @@ func (r *Registry) lookupTypeDecoder(t reflect.Type) (ValueDecoder, bool) { return dec, found } -func (r *Registry) lookupInterfaceDecoder(t reflect.Type) (ValueDecoder, bool) { +func (r *Registry) lookupInterfaceDecoder(t reflect.Type, allowAddr bool) (ValueDecoder, bool) { for _, idec := range r.interfaceDecoders { - if !t.Implements(idec.i) && !reflect.PtrTo(t).Implements(idec.i) { - continue + if t.Implements(idec.i) { + return idec.vd, true + } + if allowAddr && t.Kind() != reflect.Ptr && reflect.PtrTo(t).Implements(idec.i) { + // if *t implements an interface, this will catch if t implements an interface further ahead + // in interfaceDecoders + defaultDec, found := r.lookupInterfaceDecoder(t, false) + if !found { + defaultDec, _ = r.kindDecoders[t.Kind()] + } + return newCondAddrDecoder(idec.vd, defaultDec), true } - - return idec.vd, true } return nil, false } |