1// Copyright 2018 Google LLC 2// 3// Licensed under the Apache License, Version 2.0 (the "License"); 4// you may not use this file except in compliance with the License. 5// You may obtain a copy of the License at 6// 7// http://www.apache.org/licenses/LICENSE-2.0 8// 9// Unless required by applicable law or agreed to in writing, software 10// distributed under the License is distributed on an "AS IS" BASIS, 11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12// See the License for the specific language governing permissions and 13// limitations under the License. 14 15package types 16 17import ( 18 "fmt" 19 "reflect" 20 21 "github.com/golang/protobuf/jsonpb" 22 "github.com/golang/protobuf/proto" 23 "github.com/golang/protobuf/ptypes" 24 25 "github.com/google/cel-go/common/types/pb" 26 "github.com/google/cel-go/common/types/ref" 27 28 structpb "github.com/golang/protobuf/ptypes/struct" 29) 30 31type protoObj struct { 32 ref.TypeAdapter 33 value proto.Message 34 refValue reflect.Value 35 typeDesc *pb.TypeDescription 36 typeValue *TypeValue 37 isAny bool 38} 39 40// NewObject returns an object based on a proto.Message value which handles 41// conversion between protobuf type values and expression type values. 42// Objects support indexing and iteration. 43// 44// Note: the type value is pulled from the list of registered types within the 45// type provider. If the proto type is not registered within the type provider, 46// then this will result in an error within the type adapter / provider. 47func NewObject(adapter ref.TypeAdapter, 48 typeDesc *pb.TypeDescription, 49 typeValue *TypeValue, 50 value proto.Message) ref.Val { 51 return &protoObj{ 52 TypeAdapter: adapter, 53 value: value, 54 refValue: reflect.ValueOf(value), 55 typeDesc: typeDesc, 56 typeValue: typeValue} 57} 58 59func (o *protoObj) ConvertToNative(typeDesc reflect.Type) (interface{}, error) { 60 pb := o.Value().(proto.Message) 61 switch typeDesc { 62 case anyValueType: 63 if o.isAny { 64 return pb, nil 65 } 66 return ptypes.MarshalAny(pb) 67 case jsonValueType: 68 // Marshal the proto to JSON first, and then rehydrate as protobuf.Value as there is no 69 // support for direct conversion from proto.Message to protobuf.Value. 70 jsonTxt, err := (&jsonpb.Marshaler{}).MarshalToString(pb) 71 if err != nil { 72 return nil, err 73 } 74 json := &structpb.Value{} 75 err = jsonpb.UnmarshalString(jsonTxt, json) 76 if err != nil { 77 return nil, err 78 } 79 return json, nil 80 } 81 if o.refValue.Type().AssignableTo(typeDesc) { 82 return pb, nil 83 } 84 return nil, fmt.Errorf("type conversion error from '%v' to '%v'", 85 o.refValue.Type(), typeDesc) 86} 87 88func (o *protoObj) ConvertToType(typeVal ref.Type) ref.Val { 89 switch typeVal { 90 default: 91 if o.Type().TypeName() == typeVal.TypeName() { 92 return o 93 } 94 case TypeType: 95 return o.typeValue 96 } 97 return NewErr("type conversion error from '%s' to '%s'", 98 o.typeDesc.Name(), typeVal) 99} 100 101func (o *protoObj) Equal(other ref.Val) ref.Val { 102 if o.typeDesc.Name() != other.Type().TypeName() { 103 return ValOrErr(other, "no such overload") 104 } 105 return Bool(proto.Equal(o.value, other.Value().(proto.Message))) 106} 107 108// IsSet tests whether a field which is defined is set to a non-default value. 109func (o *protoObj) IsSet(field ref.Val) ref.Val { 110 protoFieldName, ok := field.(String) 111 if !ok { 112 return ValOrErr(field, "no such overload") 113 } 114 protoFieldStr := string(protoFieldName) 115 fd, found := o.typeDesc.FieldByName(protoFieldStr) 116 if !found { 117 return NewErr("no such field '%s'", field) 118 } 119 if !fd.SupportsPresence() { 120 return NewErr("field does not support presence testing.") 121 } 122 if fd.IsSet(o.refValue) { 123 return True 124 } 125 return False 126} 127 128func (o *protoObj) Get(index ref.Val) ref.Val { 129 protoFieldName, ok := index.(String) 130 if !ok { 131 return ValOrErr(index, "no such overload") 132 } 133 protoFieldStr := string(protoFieldName) 134 fd, found := o.typeDesc.FieldByName(protoFieldStr) 135 if !found { 136 return NewErr("no such field '%s'", index) 137 } 138 fv, err := fd.GetFrom(o.refValue) 139 if err != nil { 140 return NewErr(err.Error()) 141 } 142 return o.NativeToValue(fv) 143} 144 145func (o *protoObj) Type() ref.Type { 146 return o.typeValue 147} 148 149func (o *protoObj) Value() interface{} { 150 return o.value 151} 152