3 * Copyright 2017 gRPC authors.
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
9 * http://www.apache.org/licenses/LICENSE-2.0
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
19 // Package status implements errors returned by gRPC. These errors are
20 // serialized and transmitted on the wire between server and client, and allow
21 // for additional data to be transmitted via the Details field in the status
22 // proto. gRPC service handlers should return an error created by this
23 // package, and gRPC clients should expect a corresponding error to be
24 // returned from the RPC call.
26 // This package upholds the invariants that a non-nil error may not
27 // contain an OK code, and an OK code must result in a nil error.
34 "github.com/golang/protobuf/proto"
35 "github.com/golang/protobuf/ptypes"
36 spb "google.golang.org/genproto/googleapis/rpc/status"
37 "google.golang.org/grpc/codes"
40 // statusError is an alias of a status proto. It implements error and Status,
41 // and a nil statusError should never be returned by this package.
42 type statusError spb.Status
44 func (se *statusError) Error() string {
45 p := (*spb.Status)(se)
46 return fmt.Sprintf("rpc error: code = %s desc = %s", codes.Code(p.GetCode()), p.GetMessage())
49 func (se *statusError) status() *Status {
50 return &Status{s: (*spb.Status)(se)}
53 // Status represents an RPC status code, message, and details. It is immutable
54 // and should be created with New, Newf, or FromProto.
59 // Code returns the status code contained in s.
60 func (s *Status) Code() codes.Code {
61 if s == nil || s.s == nil {
64 return codes.Code(s.s.Code)
67 // Message returns the message contained in s.
68 func (s *Status) Message() string {
69 if s == nil || s.s == nil {
75 // Proto returns s's status as an spb.Status proto message.
76 func (s *Status) Proto() *spb.Status {
80 return proto.Clone(s.s).(*spb.Status)
83 // Err returns an immutable error representing s; returns nil if s.Code() is
85 func (s *Status) Err() error {
86 if s.Code() == codes.OK {
89 return (*statusError)(s.s)
92 // New returns a Status representing c and msg.
93 func New(c codes.Code, msg string) *Status {
94 return &Status{s: &spb.Status{Code: int32(c), Message: msg}}
97 // Newf returns New(c, fmt.Sprintf(format, a...)).
98 func Newf(c codes.Code, format string, a ...interface{}) *Status {
99 return New(c, fmt.Sprintf(format, a...))
102 // Error returns an error representing c and msg. If c is OK, returns nil.
103 func Error(c codes.Code, msg string) error {
104 return New(c, msg).Err()
107 // Errorf returns Error(c, fmt.Sprintf(format, a...)).
108 func Errorf(c codes.Code, format string, a ...interface{}) error {
109 return Error(c, fmt.Sprintf(format, a...))
112 // ErrorProto returns an error representing s. If s.Code is OK, returns nil.
113 func ErrorProto(s *spb.Status) error {
114 return FromProto(s).Err()
117 // FromProto returns a Status representing s.
118 func FromProto(s *spb.Status) *Status {
119 return &Status{s: proto.Clone(s).(*spb.Status)}
122 // FromError returns a Status representing err if it was produced from this
123 // package, otherwise it returns nil, false.
124 func FromError(err error) (s *Status, ok bool) {
126 return &Status{s: &spb.Status{Code: int32(codes.OK)}}, true
128 if s, ok := err.(*statusError); ok {
129 return s.status(), true
134 // WithDetails returns a new status with the provided details messages appended to the status.
135 // If any errors are encountered, it returns nil and the first error encountered.
136 func (s *Status) WithDetails(details ...proto.Message) (*Status, error) {
137 if s.Code() == codes.OK {
138 return nil, errors.New("no error details for status with code OK")
140 // s.Code() != OK implies that s.Proto() != nil.
142 for _, detail := range details {
143 any, err := ptypes.MarshalAny(detail)
147 p.Details = append(p.Details, any)
149 return &Status{s: p}, nil
152 // Details returns a slice of details messages attached to the status.
153 // If a detail cannot be decoded, the error is returned in place of the detail.
154 func (s *Status) Details() []interface{} {
155 if s == nil || s.s == nil {
158 details := make([]interface{}, 0, len(s.s.Details))
159 for _, any := range s.s.Details {
160 detail := &ptypes.DynamicAny{}
161 if err := ptypes.UnmarshalAny(any, detail); err != nil {
162 details = append(details, err)
165 details = append(details, detail.Message)