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| 1 | +/* |
| 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. |
| 28 | +package status |
| 29 | + |
| 30 | +import ( |
| 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. |
| 42 | +type Status struct { |
| 43 | + s *spb.Status |
| 44 | +} |
| 45 | + |
| 46 | +// New returns a Status representing c and msg. |
| 47 | +func 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...)). |
| 52 | +func 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. |
| 57 | +func 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. |
| 62 | +func Err(c codes.Code, msg string) error { |
| 63 | + return New(c, msg).Err() |
| 64 | +} |
| 65 | + |
| 66 | +// Errorf returns Error(c, fmt.Sprintf(format, a...)). |
| 67 | +func 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. |
| 72 | +func (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. |
| 80 | +func (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. |
| 88 | +func (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. |
| 96 | +func (s *Status) Err() error { |
| 97 | + if s.Code() == codes.OK { |
| 98 | + return nil |
| 99 | + } |
| 100 | + return (*Error)(s.Proto()) |
| 101 | +} |
| 102 | + |
| 103 | +func (s *Status) Error() string { |
| 104 | + p := s.Proto() |
| 105 | + return fmt.Sprintf("rpc error: code = %s desc = %s", codes.Code(p.GetCode()), p.GetMessage()) |
| 106 | +} |
| 107 | + |
| 108 | +// WithDetails returns a new status with the provided details messages appended to the status. |
| 109 | +// If any errors are encountered, it returns nil and the first error encountered. |
| 110 | +func (s *Status) WithDetails(details ...proto.Message) (*Status, error) { |
| 111 | + if s.Code() == codes.OK { |
| 112 | + return nil, errors.New("no error details for status with code OK") |
| 113 | + } |
| 114 | + // s.Code() != OK implies that s.Proto() != nil. |
| 115 | + p := s.Proto() |
| 116 | + for _, detail := range details { |
| 117 | + any, err := ptypes.MarshalAny(detail) |
| 118 | + if err != nil { |
| 119 | + return nil, err |
| 120 | + } |
| 121 | + p.Details = append(p.Details, any) |
| 122 | + } |
| 123 | + return &Status{s: p}, nil |
| 124 | +} |
| 125 | + |
| 126 | +// Details returns a slice of details messages attached to the status. |
| 127 | +// If a detail cannot be decoded, the error is returned in place of the detail. |
| 128 | +func (s *Status) Details() []interface{} { |
| 129 | + if s == nil || s.s == nil { |
| 130 | + return nil |
| 131 | + } |
| 132 | + details := make([]interface{}, 0, len(s.s.Details)) |
| 133 | + for _, any := range s.s.Details { |
| 134 | + detail := &ptypes.DynamicAny{} |
| 135 | + if err := ptypes.UnmarshalAny(any, detail); err != nil { |
| 136 | + details = append(details, err) |
| 137 | + continue |
| 138 | + } |
| 139 | + details = append(details, detail.Message) |
| 140 | + } |
| 141 | + return details |
| 142 | +} |
| 143 | + |
| 144 | +// Error is an alias of a status proto. It implements error and Status, |
| 145 | +// and a nil Error should never be returned by this package. |
| 146 | +type Error spb.Status |
| 147 | + |
| 148 | +func (se *Error) Error() string { |
| 149 | + p := (*spb.Status)(se) |
| 150 | + return fmt.Sprintf("rpc error: code = %s desc = %s", codes.Code(p.GetCode()), p.GetMessage()) |
| 151 | +} |
| 152 | + |
| 153 | +// GRPCStatus returns the Status represented by se. |
| 154 | +func (se *Error) GRPCStatus() *Status { |
| 155 | + return FromProto((*spb.Status)(se)) |
| 156 | +} |
| 157 | + |
| 158 | +// Is implements future error.Is functionality. |
| 159 | +// A Error is equivalent if the code and message are identical. |
| 160 | +func (se *Error) Is(target error) bool { |
| 161 | + tse, ok := target.(*Error) |
| 162 | + if !ok { |
| 163 | + return false |
| 164 | + } |
| 165 | + return proto.Equal((*spb.Status)(se), (*spb.Status)(tse)) |
| 166 | +} |
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