124 lines
4.0 KiB
Go
124 lines
4.0 KiB
Go
// 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 bson
|
|
|
|
import (
|
|
"reflect"
|
|
"sync"
|
|
)
|
|
|
|
// This pool is used to keep the allocations of Encoders down. This is only used for the Marshal*
|
|
// methods and is not consumable from outside of this package. The Encoders retrieved from this pool
|
|
// must have both Reset and SetRegistry called on them.
|
|
var encPool = sync.Pool{
|
|
New: func() interface{} {
|
|
return new(Encoder)
|
|
},
|
|
}
|
|
|
|
// An Encoder writes a serialization format to an output stream. It writes to a ValueWriter
|
|
// as the destination of BSON data.
|
|
type Encoder struct {
|
|
ec EncodeContext
|
|
vw ValueWriter
|
|
}
|
|
|
|
// NewEncoder returns a new encoder that writes to vw.
|
|
func NewEncoder(vw ValueWriter) *Encoder {
|
|
return &Encoder{
|
|
ec: EncodeContext{Registry: defaultRegistry},
|
|
vw: vw,
|
|
}
|
|
}
|
|
|
|
// Encode writes the BSON encoding of val to the stream.
|
|
//
|
|
// See [Marshal] for details about BSON marshaling behavior.
|
|
func (e *Encoder) Encode(val interface{}) error {
|
|
if marshaler, ok := val.(Marshaler); ok {
|
|
// TODO(skriptble): Should we have a MarshalAppender interface so that we can have []byte reuse?
|
|
buf, err := marshaler.MarshalBSON()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
return copyDocumentFromBytes(e.vw, buf)
|
|
}
|
|
|
|
encoder, err := e.ec.LookupEncoder(reflect.TypeOf(val))
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
return encoder.EncodeValue(e.ec, e.vw, reflect.ValueOf(val))
|
|
}
|
|
|
|
// Reset will reset the state of the Encoder, using the same *EncodeContext used in
|
|
// the original construction but using vw.
|
|
func (e *Encoder) Reset(vw ValueWriter) {
|
|
e.vw = vw
|
|
}
|
|
|
|
// SetRegistry replaces the current registry of the Encoder with r.
|
|
func (e *Encoder) SetRegistry(r *Registry) {
|
|
e.ec.Registry = r
|
|
}
|
|
|
|
// 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.
|
|
func (e *Encoder) ErrorOnInlineDuplicates() {
|
|
e.ec.errorOnInlineDuplicates = true
|
|
}
|
|
|
|
// IntMinSize 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.
|
|
func (e *Encoder) IntMinSize() {
|
|
e.ec.minSize = true
|
|
}
|
|
|
|
// StringifyMapKeysWithFmt causes the Encoder to convert Go map keys to BSON document field name
|
|
// strings using fmt.Sprint instead of the default string conversion logic.
|
|
func (e *Encoder) StringifyMapKeysWithFmt() {
|
|
e.ec.stringifyMapKeysWithFmt = true
|
|
}
|
|
|
|
// NilMapAsEmpty causes the Encoder to marshal nil Go maps as empty BSON documents instead of BSON
|
|
// null.
|
|
func (e *Encoder) NilMapAsEmpty() {
|
|
e.ec.nilMapAsEmpty = true
|
|
}
|
|
|
|
// NilSliceAsEmpty causes the Encoder to marshal nil Go slices as empty BSON arrays instead of BSON
|
|
// null.
|
|
func (e *Encoder) NilSliceAsEmpty() {
|
|
e.ec.nilSliceAsEmpty = true
|
|
}
|
|
|
|
// NilByteSliceAsEmpty causes the Encoder to marshal nil Go byte slices as empty BSON binary values
|
|
// instead of BSON null.
|
|
func (e *Encoder) NilByteSliceAsEmpty() {
|
|
e.ec.nilByteSliceAsEmpty = true
|
|
}
|
|
|
|
// TODO(GODRIVER-2820): Update the description to remove the note about only examining exported
|
|
// TODO struct fields once the logic is updated to also inspect private struct fields.
|
|
|
|
// 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.
|
|
func (e *Encoder) OmitZeroStruct() {
|
|
e.ec.omitZeroStruct = true
|
|
}
|
|
|
|
// UseJSONStructTags causes the Encoder to fall back to using the "json" struct tag if a "bson"
|
|
// struct tag is not specified.
|
|
func (e *Encoder) UseJSONStructTags() {
|
|
e.ec.useJSONStructTags = true
|
|
}
|