1 /* 2 * 3 * Copyright 2014 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 codes defines the canonical error codes used by gRPC. It is 20 // consistent across various languages. 21 package codes // import "google.golang.org/grpc/codes" 22 23 import ( 24 "fmt" 25 "strconv" 26 ) 27 28 // A Code is a status code defined according to the [gRPC documentation]. 29 // 30 // Only the codes defined as consts in this package are valid codes. Do not use 31 // other code values. Behavior of other codes is implementation-specific and 32 // interoperability between implementations is not guaranteed. 33 // 34 // [gRPC documentation]: https://github.com/grpc/grpc/blob/master/doc/statuscodes.md 35 type Code uint32 36 37 const ( 38 // OK is returned on success. 39 OK Code = 0 40 41 // Canceled indicates the operation was canceled (typically by the caller). 42 // 43 // The gRPC framework will generate this error code when cancellation 44 // is requested. 45 Canceled Code = 1 46 47 // Unknown error. An example of where this error may be returned is 48 // if a Status value received from another address space belongs to 49 // an error-space that is not known in this address space. Also 50 // errors raised by APIs that do not return enough error information 51 // may be converted to this error. 52 // 53 // The gRPC framework will generate this error code in the above two 54 // mentioned cases. 55 Unknown Code = 2 56 57 // InvalidArgument indicates client specified an invalid argument. 58 // Note that this differs from FailedPrecondition. It indicates arguments 59 // that are problematic regardless of the state of the system 60 // (e.g., a malformed file name). 61 // 62 // This error code will not be generated by the gRPC framework. 63 InvalidArgument Code = 3 64 65 // DeadlineExceeded means operation expired before completion. 66 // For operations that change the state of the system, this error may be 67 // returned even if the operation has completed successfully. For 68 // example, a successful response from a server could have been delayed 69 // long enough for the deadline to expire. 70 // 71 // The gRPC framework will generate this error code when the deadline is 72 // exceeded. 73 DeadlineExceeded Code = 4 74 75 // NotFound means some requested entity (e.g., file or directory) was 76 // not found. 77 // 78 // This error code will not be generated by the gRPC framework. 79 NotFound Code = 5 80 81 // AlreadyExists means an attempt to create an entity failed because one 82 // already exists. 83 // 84 // This error code will not be generated by the gRPC framework. 85 AlreadyExists Code = 6 86 87 // PermissionDenied indicates the caller does not have permission to 88 // execute the specified operation. It must not be used for rejections 89 // caused by exhausting some resource (use ResourceExhausted 90 // instead for those errors). It must not be 91 // used if the caller cannot be identified (use Unauthenticated 92 // instead for those errors). 93 // 94 // This error code will not be generated by the gRPC core framework, 95 // but expect authentication middleware to use it. 96 PermissionDenied Code = 7 97 98 // ResourceExhausted indicates some resource has been exhausted, perhaps 99 // a per-user quota, or perhaps the entire file system is out of space. 100 // 101 // This error code will be generated by the gRPC framework in 102 // out-of-memory and server overload situations, or when a message is 103 // larger than the configured maximum size. 104 ResourceExhausted Code = 8 105 106 // FailedPrecondition indicates operation was rejected because the 107 // system is not in a state required for the operation's execution. 108 // For example, directory to be deleted may be non-empty, an rmdir 109 // operation is applied to a non-directory, etc. 110 // 111 // A litmus test that may help a service implementor in deciding 112 // between FailedPrecondition, Aborted, and Unavailable: 113 // (a) Use Unavailable if the client can retry just the failing call. 114 // (b) Use Aborted if the client should retry at a higher-level 115 // (e.g., restarting a read-modify-write sequence). 116 // (c) Use FailedPrecondition if the client should not retry until 117 // the system state has been explicitly fixed. E.g., if an "rmdir" 118 // fails because the directory is non-empty, FailedPrecondition 119 // should be returned since the client should not retry unless 120 // they have first fixed up the directory by deleting files from it. 121 // (d) Use FailedPrecondition if the client performs conditional 122 // REST Get/Update/Delete on a resource and the resource on the 123 // server does not match the condition. E.g., conflicting 124 // read-modify-write on the same resource. 125 // 126 // This error code will not be generated by the gRPC framework. 127 FailedPrecondition Code = 9 128 129 // Aborted indicates the operation was aborted, typically due to a 130 // concurrency issue like sequencer check failures, transaction aborts, 131 // etc. 132 // 133 // See litmus test above for deciding between FailedPrecondition, 134 // Aborted, and Unavailable. 135 // 136 // This error code will not be generated by the gRPC framework. 137 Aborted Code = 10 138 139 // OutOfRange means operation was attempted past the valid range. 140 // E.g., seeking or reading past end of file. 141 // 142 // Unlike InvalidArgument, this error indicates a problem that may 143 // be fixed if the system state changes. For example, a 32-bit file 144 // system will generate InvalidArgument if asked to read at an 145 // offset that is not in the range [0,2^32-1], but it will generate 146 // OutOfRange if asked to read from an offset past the current 147 // file size. 148 // 149 // There is a fair bit of overlap between FailedPrecondition and 150 // OutOfRange. We recommend using OutOfRange (the more specific 151 // error) when it applies so that callers who are iterating through 152 // a space can easily look for an OutOfRange error to detect when 153 // they are done. 154 // 155 // This error code will not be generated by the gRPC framework. 156 OutOfRange Code = 11 157 158 // Unimplemented indicates operation is not implemented or not 159 // supported/enabled in this service. 160 // 161 // This error code will be generated by the gRPC framework. Most 162 // commonly, you will see this error code when a method implementation 163 // is missing on the server. It can also be generated for unknown 164 // compression algorithms or a disagreement as to whether an RPC should 165 // be streaming. 166 Unimplemented Code = 12 167 168 // Internal errors. Means some invariants expected by underlying 169 // system has been broken. If you see one of these errors, 170 // something is very broken. 171 // 172 // This error code will be generated by the gRPC framework in several 173 // internal error conditions. 174 Internal Code = 13 175 176 // Unavailable indicates the service is currently unavailable. 177 // This is a most likely a transient condition and may be corrected 178 // by retrying with a backoff. Note that it is not always safe to retry 179 // non-idempotent operations. 180 // 181 // See litmus test above for deciding between FailedPrecondition, 182 // Aborted, and Unavailable. 183 // 184 // This error code will be generated by the gRPC framework during 185 // abrupt shutdown of a server process or network connection. 186 Unavailable Code = 14 187 188 // DataLoss indicates unrecoverable data loss or corruption. 189 // 190 // This error code will not be generated by the gRPC framework. 191 DataLoss Code = 15 192 193 // Unauthenticated indicates the request does not have valid 194 // authentication credentials for the operation. 195 // 196 // The gRPC framework will generate this error code when the 197 // authentication metadata is invalid or a Credentials callback fails, 198 // but also expect authentication middleware to generate it. 199 Unauthenticated Code = 16 200 201 _maxCode = 17 202 ) 203 204 var strToCode = map[string]Code{ 205 `"OK"`: OK, 206 `"CANCELLED"`:/* [sic] */ Canceled, 207 `"UNKNOWN"`: Unknown, 208 `"INVALID_ARGUMENT"`: InvalidArgument, 209 `"DEADLINE_EXCEEDED"`: DeadlineExceeded, 210 `"NOT_FOUND"`: NotFound, 211 `"ALREADY_EXISTS"`: AlreadyExists, 212 `"PERMISSION_DENIED"`: PermissionDenied, 213 `"RESOURCE_EXHAUSTED"`: ResourceExhausted, 214 `"FAILED_PRECONDITION"`: FailedPrecondition, 215 `"ABORTED"`: Aborted, 216 `"OUT_OF_RANGE"`: OutOfRange, 217 `"UNIMPLEMENTED"`: Unimplemented, 218 `"INTERNAL"`: Internal, 219 `"UNAVAILABLE"`: Unavailable, 220 `"DATA_LOSS"`: DataLoss, 221 `"UNAUTHENTICATED"`: Unauthenticated, 222 } 223 224 // UnmarshalJSON unmarshals b into the Code. 225 func (c *Code) UnmarshalJSON(b []byte) error { 226 // From json.Unmarshaler: By convention, to approximate the behavior of 227 // Unmarshal itself, Unmarshalers implement UnmarshalJSON([]byte("null")) as 228 // a no-op. 229 if string(b) == "null" { 230 return nil 231 } 232 if c == nil { 233 return fmt.Errorf("nil receiver passed to UnmarshalJSON") 234 } 235 236 if ci, err := strconv.ParseUint(string(b), 10, 32); err == nil { 237 if ci >= _maxCode { 238 return fmt.Errorf("invalid code: %d", ci) 239 } 240 241 *c = Code(ci) 242 return nil 243 } 244 245 if jc, ok := strToCode[string(b)]; ok { 246 *c = jc 247 return nil 248 } 249 return fmt.Errorf("invalid code: %q", string(b)) 250 } 251