blob: 681260692e366b2c4535c143afc1178fd17b4966 [file] [log] [blame]
amit.ghosh258d14c2020-10-02 15:13:38 +02001/*
2 *
3 * Copyright 2020 gRPC authors.
4 *
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
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
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.
16 *
17 */
18
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.
25//
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.
28package status
29
30import (
31 "errors"
32 "fmt"
33
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"
38)
39
40// Status represents an RPC status code, message, and details. It is immutable
41// and should be created with New, Newf, or FromProto.
42type Status struct {
43 s *spb.Status
44}
45
46// New returns a Status representing c and msg.
47func New(c codes.Code, msg string) *Status {
48 return &Status{s: &spb.Status{Code: int32(c), Message: msg}}
49}
50
51// Newf returns New(c, fmt.Sprintf(format, a...)).
52func Newf(c codes.Code, format string, a ...interface{}) *Status {
53 return New(c, fmt.Sprintf(format, a...))
54}
55
56// FromProto returns a Status representing s.
57func FromProto(s *spb.Status) *Status {
58 return &Status{s: proto.Clone(s).(*spb.Status)}
59}
60
61// Err returns an error representing c and msg. If c is OK, returns nil.
62func Err(c codes.Code, msg string) error {
63 return New(c, msg).Err()
64}
65
66// Errorf returns Error(c, fmt.Sprintf(format, a...)).
67func Errorf(c codes.Code, format string, a ...interface{}) error {
68 return Err(c, fmt.Sprintf(format, a...))
69}
70
71// Code returns the status code contained in s.
72func (s *Status) Code() codes.Code {
73 if s == nil || s.s == nil {
74 return codes.OK
75 }
76 return codes.Code(s.s.Code)
77}
78
79// Message returns the message contained in s.
80func (s *Status) Message() string {
81 if s == nil || s.s == nil {
82 return ""
83 }
84 return s.s.Message
85}
86
87// Proto returns s's status as an spb.Status proto message.
88func (s *Status) Proto() *spb.Status {
89 if s == nil {
90 return nil
91 }
92 return proto.Clone(s.s).(*spb.Status)
93}
94
95// Err returns an immutable error representing s; returns nil if s.Code() is OK.
96func (s *Status) Err() error {
97 if s.Code() == codes.OK {
98 return nil
99 }
100 return (*Error)(s.Proto())
101}
102
103// WithDetails returns a new status with the provided details messages appended to the status.
104// If any errors are encountered, it returns nil and the first error encountered.
105func (s *Status) WithDetails(details ...proto.Message) (*Status, error) {
106 if s.Code() == codes.OK {
107 return nil, errors.New("no error details for status with code OK")
108 }
109 // s.Code() != OK implies that s.Proto() != nil.
110 p := s.Proto()
111 for _, detail := range details {
112 any, err := ptypes.MarshalAny(detail)
113 if err != nil {
114 return nil, err
115 }
116 p.Details = append(p.Details, any)
117 }
118 return &Status{s: p}, nil
119}
120
121// Details returns a slice of details messages attached to the status.
122// If a detail cannot be decoded, the error is returned in place of the detail.
123func (s *Status) Details() []interface{} {
124 if s == nil || s.s == nil {
125 return nil
126 }
127 details := make([]interface{}, 0, len(s.s.Details))
128 for _, any := range s.s.Details {
129 detail := &ptypes.DynamicAny{}
130 if err := ptypes.UnmarshalAny(any, detail); err != nil {
131 details = append(details, err)
132 continue
133 }
134 details = append(details, detail.Message)
135 }
136 return details
137}
138
139// Error is an alias of a status proto. It implements error and Status,
140// and a nil Error should never be returned by this package.
141type Error spb.Status
142
143func (se *Error) Error() string {
144 p := (*spb.Status)(se)
145 return fmt.Sprintf("rpc error: code = %s desc = %s", codes.Code(p.GetCode()), p.GetMessage())
146}
147
148// GRPCStatus returns the Status represented by se.
149func (se *Error) GRPCStatus() *Status {
150 return FromProto((*spb.Status)(se))
151}
152
153// Is implements future error.Is functionality.
154// A Error is equivalent if the code and message are identical.
155func (se *Error) Is(target error) bool {
156 tse, ok := target.(*Error)
157 if !ok {
158 return false
159 }
160 return proto.Equal((*spb.Status)(se), (*spb.Status)(tse))
161}