mirror of
https://github.com/superseriousbusiness/gotosocial.git
synced 2024-12-22 10:12:11 +00:00
209 lines
6.1 KiB
Go
209 lines
6.1 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 (
|
|
"errors"
|
|
"fmt"
|
|
"reflect"
|
|
"sync"
|
|
|
|
"go.mongodb.org/mongo-driver/bson/bsoncodec"
|
|
"go.mongodb.org/mongo-driver/bson/bsonrw"
|
|
)
|
|
|
|
// ErrDecodeToNil is the error returned when trying to decode to a nil value
|
|
var ErrDecodeToNil = errors.New("cannot Decode to nil value")
|
|
|
|
// This pool is used to keep the allocations of Decoders down. This is only used for the Marshal*
|
|
// methods and is not consumable from outside of this package. The Decoders retrieved from this pool
|
|
// must have both Reset and SetRegistry called on them.
|
|
var decPool = sync.Pool{
|
|
New: func() interface{} {
|
|
return new(Decoder)
|
|
},
|
|
}
|
|
|
|
// A Decoder reads and decodes BSON documents from a stream. It reads from a bsonrw.ValueReader as
|
|
// the source of BSON data.
|
|
type Decoder struct {
|
|
dc bsoncodec.DecodeContext
|
|
vr bsonrw.ValueReader
|
|
|
|
// We persist defaultDocumentM and defaultDocumentD on the Decoder to prevent overwriting from
|
|
// (*Decoder).SetContext.
|
|
defaultDocumentM bool
|
|
defaultDocumentD bool
|
|
|
|
binaryAsSlice bool
|
|
useJSONStructTags bool
|
|
useLocalTimeZone bool
|
|
zeroMaps bool
|
|
zeroStructs bool
|
|
}
|
|
|
|
// NewDecoder returns a new decoder that uses the DefaultRegistry to read from vr.
|
|
func NewDecoder(vr bsonrw.ValueReader) (*Decoder, error) {
|
|
if vr == nil {
|
|
return nil, errors.New("cannot create a new Decoder with a nil ValueReader")
|
|
}
|
|
|
|
return &Decoder{
|
|
dc: bsoncodec.DecodeContext{Registry: DefaultRegistry},
|
|
vr: vr,
|
|
}, nil
|
|
}
|
|
|
|
// NewDecoderWithContext returns a new decoder that uses DecodeContext dc to read from vr.
|
|
//
|
|
// Deprecated: Use [NewDecoder] and use the Decoder configuration methods set the desired unmarshal
|
|
// behavior instead.
|
|
func NewDecoderWithContext(dc bsoncodec.DecodeContext, vr bsonrw.ValueReader) (*Decoder, error) {
|
|
if dc.Registry == nil {
|
|
dc.Registry = DefaultRegistry
|
|
}
|
|
if vr == nil {
|
|
return nil, errors.New("cannot create a new Decoder with a nil ValueReader")
|
|
}
|
|
|
|
return &Decoder{
|
|
dc: dc,
|
|
vr: vr,
|
|
}, nil
|
|
}
|
|
|
|
// Decode reads the next BSON document from the stream and decodes it into the
|
|
// value pointed to by val.
|
|
//
|
|
// See [Unmarshal] for details about BSON unmarshaling behavior.
|
|
func (d *Decoder) Decode(val interface{}) error {
|
|
if unmarshaler, ok := val.(Unmarshaler); ok {
|
|
// TODO(skriptble): Reuse a []byte here and use the AppendDocumentBytes method.
|
|
buf, err := bsonrw.Copier{}.CopyDocumentToBytes(d.vr)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
return unmarshaler.UnmarshalBSON(buf)
|
|
}
|
|
|
|
rval := reflect.ValueOf(val)
|
|
switch rval.Kind() {
|
|
case reflect.Ptr:
|
|
if rval.IsNil() {
|
|
return ErrDecodeToNil
|
|
}
|
|
rval = rval.Elem()
|
|
case reflect.Map:
|
|
if rval.IsNil() {
|
|
return ErrDecodeToNil
|
|
}
|
|
default:
|
|
return fmt.Errorf("argument to Decode must be a pointer or a map, but got %v", rval)
|
|
}
|
|
decoder, err := d.dc.LookupDecoder(rval.Type())
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
if d.defaultDocumentM {
|
|
d.dc.DefaultDocumentM()
|
|
}
|
|
if d.defaultDocumentD {
|
|
d.dc.DefaultDocumentD()
|
|
}
|
|
if d.binaryAsSlice {
|
|
d.dc.BinaryAsSlice()
|
|
}
|
|
if d.useJSONStructTags {
|
|
d.dc.UseJSONStructTags()
|
|
}
|
|
if d.useLocalTimeZone {
|
|
d.dc.UseLocalTimeZone()
|
|
}
|
|
if d.zeroMaps {
|
|
d.dc.ZeroMaps()
|
|
}
|
|
if d.zeroStructs {
|
|
d.dc.ZeroStructs()
|
|
}
|
|
|
|
return decoder.DecodeValue(d.dc, d.vr, rval)
|
|
}
|
|
|
|
// Reset will reset the state of the decoder, using the same *DecodeContext used in
|
|
// the original construction but using vr for reading.
|
|
func (d *Decoder) Reset(vr bsonrw.ValueReader) error {
|
|
// TODO:(GODRIVER-2719): Remove error return value.
|
|
d.vr = vr
|
|
return nil
|
|
}
|
|
|
|
// SetRegistry replaces the current registry of the decoder with r.
|
|
func (d *Decoder) SetRegistry(r *bsoncodec.Registry) error {
|
|
// TODO:(GODRIVER-2719): Remove error return value.
|
|
d.dc.Registry = r
|
|
return nil
|
|
}
|
|
|
|
// SetContext replaces the current registry of the decoder with dc.
|
|
//
|
|
// Deprecated: Use the Decoder configuration methods to set the desired unmarshal behavior instead.
|
|
func (d *Decoder) SetContext(dc bsoncodec.DecodeContext) error {
|
|
// TODO:(GODRIVER-2719): Remove error return value.
|
|
d.dc = dc
|
|
return nil
|
|
}
|
|
|
|
// 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{}".
|
|
func (d *Decoder) DefaultDocumentM() {
|
|
d.defaultDocumentM = true
|
|
}
|
|
|
|
// 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{}".
|
|
func (d *Decoder) DefaultDocumentD() {
|
|
d.defaultDocumentD = true
|
|
}
|
|
|
|
// AllowTruncatingDoubles causes the Decoder to truncate the fractional part of BSON "double" values
|
|
// when attempting to unmarshal them into a Go integer (int, int8, int16, int32, or int64) struct
|
|
// field. The truncation logic does not apply to BSON "decimal128" values.
|
|
func (d *Decoder) AllowTruncatingDoubles() {
|
|
d.dc.Truncate = true
|
|
}
|
|
|
|
// 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.
|
|
func (d *Decoder) BinaryAsSlice() {
|
|
d.binaryAsSlice = true
|
|
}
|
|
|
|
// UseJSONStructTags causes the Decoder to fall back to using the "json" struct tag if a "bson"
|
|
// struct tag is not specified.
|
|
func (d *Decoder) UseJSONStructTags() {
|
|
d.useJSONStructTags = true
|
|
}
|
|
|
|
// UseLocalTimeZone causes the Decoder to unmarshal time.Time values in the local timezone instead
|
|
// of the UTC timezone.
|
|
func (d *Decoder) UseLocalTimeZone() {
|
|
d.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.
|
|
func (d *Decoder) ZeroMaps() {
|
|
d.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.
|
|
func (d *Decoder) ZeroStructs() {
|
|
d.zeroStructs = true
|
|
}
|