diff options
Diffstat (limited to 'vendor/go.mongodb.org/mongo-driver/bson/bsoncodec/empty_interface_codec.go')
-rw-r--r-- | vendor/go.mongodb.org/mongo-driver/bson/bsoncodec/empty_interface_codec.go | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/vendor/go.mongodb.org/mongo-driver/bson/bsoncodec/empty_interface_codec.go b/vendor/go.mongodb.org/mongo-driver/bson/bsoncodec/empty_interface_codec.go new file mode 100644 index 000000000..eda417cff --- /dev/null +++ b/vendor/go.mongodb.org/mongo-driver/bson/bsoncodec/empty_interface_codec.go @@ -0,0 +1,147 @@ +// 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 ( + "reflect" + + "go.mongodb.org/mongo-driver/bson/bsonoptions" + "go.mongodb.org/mongo-driver/bson/bsonrw" + "go.mongodb.org/mongo-driver/bson/bsontype" + "go.mongodb.org/mongo-driver/bson/primitive" +) + +// EmptyInterfaceCodec is the Codec used for interface{} values. +type EmptyInterfaceCodec struct { + DecodeBinaryAsSlice bool +} + +var ( + defaultEmptyInterfaceCodec = NewEmptyInterfaceCodec() + + _ ValueCodec = defaultEmptyInterfaceCodec + _ typeDecoder = defaultEmptyInterfaceCodec +) + +// NewEmptyInterfaceCodec returns a EmptyInterfaceCodec with options opts. +func NewEmptyInterfaceCodec(opts ...*bsonoptions.EmptyInterfaceCodecOptions) *EmptyInterfaceCodec { + interfaceOpt := bsonoptions.MergeEmptyInterfaceCodecOptions(opts...) + + codec := EmptyInterfaceCodec{} + if interfaceOpt.DecodeBinaryAsSlice != nil { + codec.DecodeBinaryAsSlice = *interfaceOpt.DecodeBinaryAsSlice + } + return &codec +} + +// EncodeValue is the ValueEncoderFunc for interface{}. +func (eic EmptyInterfaceCodec) EncodeValue(ec EncodeContext, vw bsonrw.ValueWriter, val reflect.Value) error { + if !val.IsValid() || val.Type() != tEmpty { + return ValueEncoderError{Name: "EmptyInterfaceEncodeValue", Types: []reflect.Type{tEmpty}, Received: val} + } + + if val.IsNil() { + return vw.WriteNull() + } + encoder, err := ec.LookupEncoder(val.Elem().Type()) + if err != nil { + return err + } + + return encoder.EncodeValue(ec, vw, val.Elem()) +} + +func (eic EmptyInterfaceCodec) getEmptyInterfaceDecodeType(dc DecodeContext, valueType bsontype.Type) (reflect.Type, error) { + isDocument := valueType == bsontype.Type(0) || valueType == bsontype.EmbeddedDocument + if isDocument { + if dc.defaultDocumentType != nil { + // If the bsontype is an embedded document and the DocumentType is set on the DecodeContext, then return + // that type. + return dc.defaultDocumentType, nil + } + if dc.Ancestor != nil { + // Using ancestor information rather than looking up the type map entry forces consistent decoding. + // If we're decoding into a bson.D, subdocuments should also be decoded as bson.D, even if a type map entry + // has been registered. + return dc.Ancestor, nil + } + } + + rtype, err := dc.LookupTypeMapEntry(valueType) + if err == nil { + return rtype, nil + } + + if isDocument { + // For documents, fallback to looking up a type map entry for bsontype.Type(0) or bsontype.EmbeddedDocument, + // depending on the original valueType. + var lookupType bsontype.Type + switch valueType { + case bsontype.Type(0): + lookupType = bsontype.EmbeddedDocument + case bsontype.EmbeddedDocument: + lookupType = bsontype.Type(0) + } + + rtype, err = dc.LookupTypeMapEntry(lookupType) + if err == nil { + return rtype, nil + } + } + + return nil, err +} + +func (eic EmptyInterfaceCodec) decodeType(dc DecodeContext, vr bsonrw.ValueReader, t reflect.Type) (reflect.Value, error) { + if t != tEmpty { + return emptyValue, ValueDecoderError{Name: "EmptyInterfaceDecodeValue", Types: []reflect.Type{tEmpty}, Received: reflect.Zero(t)} + } + + rtype, err := eic.getEmptyInterfaceDecodeType(dc, vr.Type()) + if err != nil { + switch vr.Type() { + case bsontype.Null: + return reflect.Zero(t), vr.ReadNull() + default: + return emptyValue, err + } + } + + decoder, err := dc.LookupDecoder(rtype) + if err != nil { + return emptyValue, err + } + + elem, err := decodeTypeOrValue(decoder, dc, vr, rtype) + if err != nil { + return emptyValue, err + } + + if eic.DecodeBinaryAsSlice && rtype == tBinary { + binElem := elem.Interface().(primitive.Binary) + if binElem.Subtype == bsontype.BinaryGeneric || binElem.Subtype == bsontype.BinaryBinaryOld { + elem = reflect.ValueOf(binElem.Data) + } + } + + return elem, nil +} + +// DecodeValue is the ValueDecoderFunc for interface{}. +func (eic EmptyInterfaceCodec) DecodeValue(dc DecodeContext, vr bsonrw.ValueReader, val reflect.Value) error { + if !val.CanSet() || val.Type() != tEmpty { + return ValueDecoderError{Name: "EmptyInterfaceDecodeValue", Types: []reflect.Type{tEmpty}, Received: val} + } + + elem, err := eic.decodeType(dc, vr, val.Type()) + if err != nil { + return err + } + + val.Set(elem) + return nil +} |