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- // 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.
- //
- // Deprecated: Use [go.mongodb.org/mongo-driver/bson.Marshaler] instead.
- 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.
- //
- // Deprecated: Use [go.mongodb.org/mongo-driver/bson.ValueMarshaler] instead.
- 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.
- //
- // Deprecated: Use [go.mongodb.org/mongo-driver/bson.Unmarshaler] instead.
- 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.
- //
- // Deprecated: Use [go.mongodb.org/mongo-driver/bson.ValueUnmarshaler] instead.
- 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 causes the Encoder to marshal Go integer values (int, int8, int16, int32, int64,
- // uint, uint8, uint16, uint32, or uint64) as the minimum BSON int size (either 32 or 64 bits)
- // that can represent the integer value.
- //
- // Deprecated: Use bson.Encoder.IntMinSize instead.
- MinSize bool
- errorOnInlineDuplicates bool
- stringifyMapKeysWithFmt bool
- nilMapAsEmpty bool
- nilSliceAsEmpty bool
- nilByteSliceAsEmpty bool
- omitZeroStruct bool
- useJSONStructTags bool
- }
- // ErrorOnInlineDuplicates causes the Encoder to return an error if there is a duplicate field in
- // the marshaled BSON when the "inline" struct tag option is set.
- //
- // Deprecated: Use [go.mongodb.org/mongo-driver/bson.Encoder.ErrorOnInlineDuplicates] instead.
- func (ec *EncodeContext) ErrorOnInlineDuplicates() {
- ec.errorOnInlineDuplicates = true
- }
- // StringifyMapKeysWithFmt causes the Encoder to convert Go map keys to BSON document field name
- // strings using fmt.Sprintf() instead of the default string conversion logic.
- //
- // Deprecated: Use [go.mongodb.org/mongo-driver/bson.Encoder.StringifyMapKeysWithFmt] instead.
- func (ec *EncodeContext) StringifyMapKeysWithFmt() {
- ec.stringifyMapKeysWithFmt = true
- }
- // NilMapAsEmpty causes the Encoder to marshal nil Go maps as empty BSON documents instead of BSON
- // null.
- //
- // Deprecated: Use [go.mongodb.org/mongo-driver/bson.Encoder.NilMapAsEmpty] instead.
- func (ec *EncodeContext) NilMapAsEmpty() {
- ec.nilMapAsEmpty = true
- }
- // NilSliceAsEmpty causes the Encoder to marshal nil Go slices as empty BSON arrays instead of BSON
- // null.
- //
- // Deprecated: Use [go.mongodb.org/mongo-driver/bson.Encoder.NilSliceAsEmpty] instead.
- func (ec *EncodeContext) NilSliceAsEmpty() {
- ec.nilSliceAsEmpty = true
- }
- // NilByteSliceAsEmpty causes the Encoder to marshal nil Go byte slices as empty BSON binary values
- // instead of BSON null.
- //
- // Deprecated: Use [go.mongodb.org/mongo-driver/bson.Encoder.NilByteSliceAsEmpty] instead.
- func (ec *EncodeContext) NilByteSliceAsEmpty() {
- ec.nilByteSliceAsEmpty = true
- }
- // OmitZeroStruct causes the Encoder to consider the zero value for a struct (e.g. MyStruct{})
- // as empty and omit it from the marshaled BSON when the "omitempty" struct tag option is set.
- //
- // Note that the Encoder only examines exported struct fields when determining if a struct is the
- // zero value. It considers pointers to a zero struct value (e.g. &MyStruct{}) not empty.
- //
- // Deprecated: Use [go.mongodb.org/mongo-driver/bson.Encoder.OmitZeroStruct] instead.
- func (ec *EncodeContext) OmitZeroStruct() {
- ec.omitZeroStruct = true
- }
- // UseJSONStructTags causes the Encoder to fall back to using the "json" struct tag if a "bson"
- // struct tag is not specified.
- //
- // Deprecated: Use [go.mongodb.org/mongo-driver/bson.Encoder.UseJSONStructTags] instead.
- func (ec *EncodeContext) UseJSONStructTags() {
- ec.useJSONStructTags = true
- }
- // DecodeContext is the contextual information required for a Codec to decode a
- // value.
- type DecodeContext struct {
- *Registry
- // Truncate, if true, instructs decoders to to truncate the fractional part of BSON "double"
- // values when attempting to unmarshal them into a Go integer (int, int8, int16, int32, int64,
- // uint, uint8, uint16, uint32, or uint64) struct field. The truncation logic does not apply to
- // BSON "decimal128" values.
- //
- // Deprecated: Use bson.Decoder.AllowTruncatingDoubles instead.
- 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 bson.Decoder.DefaultDocumentM or bson.Decoder.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
- binaryAsSlice bool
- useJSONStructTags bool
- useLocalTimeZone bool
- zeroMaps bool
- zeroStructs bool
- }
- // BinaryAsSlice causes the Decoder to unmarshal BSON binary field values that are the "Generic" or
- // "Old" BSON binary subtype as a Go byte slice instead of a primitive.Binary.
- //
- // Deprecated: Use [go.mongodb.org/mongo-driver/bson.Decoder.BinaryAsSlice] instead.
- func (dc *DecodeContext) BinaryAsSlice() {
- dc.binaryAsSlice = true
- }
- // UseJSONStructTags causes the Decoder to fall back to using the "json" struct tag if a "bson"
- // struct tag is not specified.
- //
- // Deprecated: Use [go.mongodb.org/mongo-driver/bson.Decoder.UseJSONStructTags] instead.
- func (dc *DecodeContext) UseJSONStructTags() {
- dc.useJSONStructTags = true
- }
- // UseLocalTimeZone causes the Decoder to unmarshal time.Time values in the local timezone instead
- // of the UTC timezone.
- //
- // Deprecated: Use [go.mongodb.org/mongo-driver/bson.Decoder.UseLocalTimeZone] instead.
- func (dc *DecodeContext) UseLocalTimeZone() {
- dc.useLocalTimeZone = true
- }
- // ZeroMaps causes the Decoder to delete any existing values from Go maps in the destination value
- // passed to Decode before unmarshaling BSON documents into them.
- //
- // Deprecated: Use [go.mongodb.org/mongo-driver/bson.Decoder.ZeroMaps] instead.
- func (dc *DecodeContext) ZeroMaps() {
- dc.zeroMaps = true
- }
- // ZeroStructs causes the Decoder to delete any existing values from Go structs in the destination
- // value passed to Decode before unmarshaling BSON documents into them.
- //
- // Deprecated: Use [go.mongodb.org/mongo-driver/bson.Decoder.ZeroStructs] instead.
- func (dc *DecodeContext) ZeroStructs() {
- dc.zeroStructs = true
- }
- // DefaultDocumentM causes the Decoder to always unmarshal documents into the primitive.M type. This
- // behavior is restricted to data typed as "interface{}" or "map[string]interface{}".
- //
- // Deprecated: Use [go.mongodb.org/mongo-driver/bson.Decoder.DefaultDocumentM] instead.
- func (dc *DecodeContext) DefaultDocumentM() {
- dc.defaultDocumentType = reflect.TypeOf(primitive.M{})
- }
- // DefaultDocumentD causes the Decoder to always unmarshal documents into the primitive.D type. This
- // behavior is restricted to data typed as "interface{}" or "map[string]interface{}".
- //
- // Deprecated: Use [go.mongodb.org/mongo-driver/bson.Decoder.DefaultDocumentD] instead.
- func (dc *DecodeContext) DefaultDocumentD() {
- dc.defaultDocumentType = reflect.TypeOf(primitive.D{})
- }
- // ValueCodec is an interface for encoding and decoding a reflect.Value.
- // values.
- //
- // Deprecated: Use [ValueEncoder] and [ValueDecoder] instead.
- 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.
- //
- // Deprecated: Defining custom rules for the zero/empty value will not be supported in Go Driver
- // 2.0. Users who want to omit empty complex values should use a pointer field and set the value to
- // nil instead.
- type CodecZeroer interface {
- IsTypeZero(interface{}) bool
- }
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