1 files changed, 141 insertions, 0 deletions
diff --git a/vendor/go.mongodb.org/mongo-driver/bson/decoder.go b/vendor/go.mongodb.org/mongo-driver/bson/decoder.go
new file mode 100644
index 000000000..6e189fa58
--- /dev/null
+++ b/vendor/go.mongodb.org/mongo-driver/bson/decoder.go
@@ -0,0 +1,141 @@
+// 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
+}
+
+// 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.
+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.
+//
+// The documentation for Unmarshal contains details about of BSON into a Go
+// value.
+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()
+	}
+	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 {
+	d.vr = vr
+	return nil
+}
+
+// SetRegistry replaces the current registry of the decoder with r.
+func (d *Decoder) SetRegistry(r *bsoncodec.Registry) error {
+	d.dc.Registry = r
+	return nil
+}
+
+// SetContext replaces the current registry of the decoder with dc.
+func (d *Decoder) SetContext(dc bsoncodec.DecodeContext) error {
+	d.dc = dc
+	return nil
+}
+
+// DefaultDocumentM will decode empty documents using 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 will decode empty documents using the primitive.D type. This behavior is restricted to data typed as
+// "interface{}" or "map[string]interface{}".
+func (d *Decoder) DefaultDocumentD() {
+	d.defaultDocumentD = true
+}