You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
99 lines
2.8 KiB
99 lines
2.8 KiB
// 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 (
|
|
"errors"
|
|
"reflect"
|
|
"sync"
|
|
|
|
"go.mongodb.org/mongo-driver/bson/bsoncodec"
|
|
"go.mongodb.org/mongo-driver/bson/bsonrw"
|
|
)
|
|
|
|
// 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 bsonrw.ValueWriter
|
|
// as the destination of BSON data.
|
|
type Encoder struct {
|
|
ec bsoncodec.EncodeContext
|
|
vw bsonrw.ValueWriter
|
|
}
|
|
|
|
// NewEncoder returns a new encoder that uses the DefaultRegistry to write to vw.
|
|
func NewEncoder(vw bsonrw.ValueWriter) (*Encoder, error) {
|
|
if vw == nil {
|
|
return nil, errors.New("cannot create a new Encoder with a nil ValueWriter")
|
|
}
|
|
|
|
return &Encoder{
|
|
ec: bsoncodec.EncodeContext{Registry: DefaultRegistry},
|
|
vw: vw,
|
|
}, nil
|
|
}
|
|
|
|
// NewEncoderWithContext returns a new encoder that uses EncodeContext ec to write to vw.
|
|
func NewEncoderWithContext(ec bsoncodec.EncodeContext, vw bsonrw.ValueWriter) (*Encoder, error) {
|
|
if ec.Registry == nil {
|
|
ec = bsoncodec.EncodeContext{Registry: DefaultRegistry}
|
|
}
|
|
if vw == nil {
|
|
return nil, errors.New("cannot create a new Encoder with a nil ValueWriter")
|
|
}
|
|
|
|
return &Encoder{
|
|
ec: ec,
|
|
vw: vw,
|
|
}, nil
|
|
}
|
|
|
|
// Encode writes the BSON encoding of val to the stream.
|
|
//
|
|
// The documentation for Marshal contains details about the conversion of Go
|
|
// values to BSON.
|
|
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 bsonrw.Copier{}.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 bsonrw.ValueWriter) error {
|
|
e.vw = vw
|
|
return nil
|
|
}
|
|
|
|
// SetRegistry replaces the current registry of the encoder with r.
|
|
func (e *Encoder) SetRegistry(r *bsoncodec.Registry) error {
|
|
e.ec.Registry = r
|
|
return nil
|
|
}
|
|
|
|
// SetContext replaces the current EncodeContext of the encoder with er.
|
|
func (e *Encoder) SetContext(ec bsoncodec.EncodeContext) error {
|
|
e.ec = ec
|
|
return nil
|
|
}
|
|
|