diff options
Diffstat (limited to 'vendor/go.mongodb.org/mongo-driver/bson/bsoncodec/bsoncodec.go')
-rw-r--r-- | vendor/go.mongodb.org/mongo-driver/bson/bsoncodec/bsoncodec.go | 238 |
1 files changed, 238 insertions, 0 deletions
diff --git a/vendor/go.mongodb.org/mongo-driver/bson/bsoncodec/bsoncodec.go b/vendor/go.mongodb.org/mongo-driver/bson/bsoncodec/bsoncodec.go new file mode 100644 index 000000000..098ed69f9 --- /dev/null +++ b/vendor/go.mongodb.org/mongo-driver/bson/bsoncodec/bsoncodec.go @@ -0,0 +1,238 @@ +// 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 "go.mongodb.org/mongo-driver/bson/bsoncodec" + +import ( + "fmt" + "reflect" + "strings" + + "go.mongodb.org/mongo-driver/bson/bsonrw" + "go.mongodb.org/mongo-driver/bson/bsontype" + "go.mongodb.org/mongo-driver/bson/primitive" +) + +var ( + emptyValue = reflect.Value{} +) + +// Marshaler is an interface implemented by types that can marshal themselves +// into a BSON document represented as bytes. The bytes returned must be a valid +// BSON document if the error is nil. +type Marshaler interface { + MarshalBSON() ([]byte, error) +} + +// ValueMarshaler is an interface implemented by types that can marshal +// themselves into a BSON value as bytes. The type must be the valid type for +// the bytes returned. The bytes and byte type together must be valid if the +// error is nil. +type ValueMarshaler interface { + MarshalBSONValue() (bsontype.Type, []byte, error) +} + +// Unmarshaler is an interface implemented by types that can unmarshal a BSON +// document representation of themselves. The BSON bytes can be assumed to be +// valid. UnmarshalBSON must copy the BSON bytes if it wishes to retain the data +// after returning. +type Unmarshaler interface { + UnmarshalBSON([]byte) error +} + +// ValueUnmarshaler is an interface implemented by types that can unmarshal a +// BSON value representation of themselves. The BSON bytes and type can be +// assumed to be valid. UnmarshalBSONValue must copy the BSON value bytes if it +// wishes to retain the data after returning. +type ValueUnmarshaler interface { + UnmarshalBSONValue(bsontype.Type, []byte) error +} + +// ValueEncoderError is an error returned from a ValueEncoder when the provided value can't be +// encoded by the ValueEncoder. +type ValueEncoderError struct { + Name string + Types []reflect.Type + Kinds []reflect.Kind + Received reflect.Value +} + +func (vee ValueEncoderError) Error() string { + typeKinds := make([]string, 0, len(vee.Types)+len(vee.Kinds)) + for _, t := range vee.Types { + typeKinds = append(typeKinds, t.String()) + } + for _, k := range vee.Kinds { + if k == reflect.Map { + typeKinds = append(typeKinds, "map[string]*") + continue + } + typeKinds = append(typeKinds, k.String()) + } + received := vee.Received.Kind().String() + if vee.Received.IsValid() { + received = vee.Received.Type().String() + } + return fmt.Sprintf("%s can only encode valid %s, but got %s", vee.Name, strings.Join(typeKinds, ", "), received) +} + +// ValueDecoderError is an error returned from a ValueDecoder when the provided value can't be +// decoded by the ValueDecoder. +type ValueDecoderError struct { + Name string + Types []reflect.Type + Kinds []reflect.Kind + Received reflect.Value +} + +func (vde ValueDecoderError) Error() string { + typeKinds := make([]string, 0, len(vde.Types)+len(vde.Kinds)) + for _, t := range vde.Types { + typeKinds = append(typeKinds, t.String()) + } + for _, k := range vde.Kinds { + if k == reflect.Map { + typeKinds = append(typeKinds, "map[string]*") + continue + } + typeKinds = append(typeKinds, k.String()) + } + received := vde.Received.Kind().String() + if vde.Received.IsValid() { + received = vde.Received.Type().String() + } + return fmt.Sprintf("%s can only decode valid and settable %s, but got %s", vde.Name, strings.Join(typeKinds, ", "), received) +} + +// EncodeContext is the contextual information required for a Codec to encode a +// value. +type EncodeContext struct { + *Registry + MinSize bool +} + +// DecodeContext is the contextual information required for a Codec to decode a +// value. +type DecodeContext struct { + *Registry + Truncate bool + + // Ancestor is the type of a containing document. This is mainly used to determine what type + // should be used when decoding an embedded document into an empty interface. For example, if + // Ancestor is a bson.M, BSON embedded document values being decoded into an empty interface + // will be decoded into a bson.M. + // + // Deprecated: Use DefaultDocumentM or DefaultDocumentD instead. + Ancestor reflect.Type + + // defaultDocumentType specifies the Go type to decode top-level and nested BSON documents into. In particular, the + // usage for this field is restricted to data typed as "interface{}" or "map[string]interface{}". If DocumentType is + // set to a type that a BSON document cannot be unmarshaled into (e.g. "string"), unmarshalling will result in an + // error. DocumentType overrides the Ancestor field. + defaultDocumentType reflect.Type +} + +// DefaultDocumentM will decode empty documents using the primitive.M type. This behavior is restricted to data typed as +// "interface{}" or "map[string]interface{}". +func (dc *DecodeContext) DefaultDocumentM() { + dc.defaultDocumentType = reflect.TypeOf(primitive.M{}) +} + +// DefaultDocumentD will decode empty documents using the primitive.D type. This behavior is restricted to data typed as +// "interface{}" or "map[string]interface{}". +func (dc *DecodeContext) DefaultDocumentD() { + dc.defaultDocumentType = reflect.TypeOf(primitive.D{}) +} + +// ValueCodec is the interface that groups the methods to encode and decode +// values. +type ValueCodec interface { + ValueEncoder + ValueDecoder +} + +// ValueEncoder is the interface implemented by types that can handle the encoding of a value. +type ValueEncoder interface { + EncodeValue(EncodeContext, bsonrw.ValueWriter, reflect.Value) error +} + +// ValueEncoderFunc is an adapter function that allows a function with the correct signature to be +// used as a ValueEncoder. +type ValueEncoderFunc func(EncodeContext, bsonrw.ValueWriter, reflect.Value) error + +// EncodeValue implements the ValueEncoder interface. +func (fn ValueEncoderFunc) EncodeValue(ec EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error { + return fn(ec, vw, val) +} + +// ValueDecoder is the interface implemented by types that can handle the decoding of a value. +type ValueDecoder interface { + DecodeValue(DecodeContext, bsonrw.ValueReader, reflect.Value) error +} + +// ValueDecoderFunc is an adapter function that allows a function with the correct signature to be +// used as a ValueDecoder. +type ValueDecoderFunc func(DecodeContext, bsonrw.ValueReader, reflect.Value) error + +// DecodeValue implements the ValueDecoder interface. +func (fn ValueDecoderFunc) DecodeValue(dc DecodeContext, vr bsonrw.ValueReader, val reflect.Value) error { + return fn(dc, vr, val) +} + +// typeDecoder is the interface implemented by types that can handle the decoding of a value given its type. +type typeDecoder interface { + decodeType(DecodeContext, bsonrw.ValueReader, reflect.Type) (reflect.Value, error) +} + +// typeDecoderFunc is an adapter function that allows a function with the correct signature to be used as a typeDecoder. +type typeDecoderFunc func(DecodeContext, bsonrw.ValueReader, reflect.Type) (reflect.Value, error) + +func (fn typeDecoderFunc) decodeType(dc DecodeContext, vr bsonrw.ValueReader, t reflect.Type) (reflect.Value, error) { + return fn(dc, vr, t) +} + +// decodeAdapter allows two functions with the correct signatures to be used as both a ValueDecoder and typeDecoder. +type decodeAdapter struct { + ValueDecoderFunc + typeDecoderFunc +} + +var _ ValueDecoder = decodeAdapter{} +var _ typeDecoder = decodeAdapter{} + +// decodeTypeOrValue calls decoder.decodeType is decoder is a typeDecoder. Otherwise, it allocates a new element of type +// t and calls decoder.DecodeValue on it. +func decodeTypeOrValue(decoder ValueDecoder, dc DecodeContext, vr bsonrw.ValueReader, t reflect.Type) (reflect.Value, error) { + td, _ := decoder.(typeDecoder) + return decodeTypeOrValueWithInfo(decoder, td, dc, vr, t, true) +} + +func decodeTypeOrValueWithInfo(vd ValueDecoder, td typeDecoder, dc DecodeContext, vr bsonrw.ValueReader, t reflect.Type, convert bool) (reflect.Value, error) { + if td != nil { + val, err := td.decodeType(dc, vr, t) + if err == nil && convert && val.Type() != t { + // This conversion step is necessary for slices and maps. If a user declares variables like: + // + // type myBool bool + // var m map[string]myBool + // + // and tries to decode BSON bytes into the map, the decoding will fail if this conversion is not present + // because we'll try to assign a value of type bool to one of type myBool. + val = val.Convert(t) + } + return val, err + } + + val := reflect.New(t).Elem() + err := vd.DecodeValue(dc, vr, val) + return val, err +} + +// CodecZeroer is the interface implemented by Codecs that can also determine if +// a value of the type that would be encoded is zero. +type CodecZeroer interface { + IsTypeZero(interface{}) bool +} |