codes.proto

/*
 * Copyright 2021 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

syntax = "proto2";

package util.error;

option java_package = "com.google.apphosting.base.protos";

// The canonical error codes for Google3 APIs.
//
enum Code {
  // Not an error; returned on success
  OK = 0;

  // The operation was cancelled, typically by the caller.
  CANCELLED = 1;

  // Unknown error.  For example, this error may be returned when
  // a Status value received from another address space belongs to
  // an error-space that is not known in this address space.  Also
  // errors raised by APIs that do not return enough error information
  // may be converted to this error.
  UNKNOWN = 2;

  // The client specified an invalid argument.  Note that this differs
  // from FAILED_PRECONDITION.  INVALID_ARGUMENT indicates arguments
  // that are problematic regardless of the state of the system
  // (e.g., a malformed file name).
  INVALID_ARGUMENT = 3;

  // The deadline expired before the operation could complete. For operations
  // that change the state of the system, this error may be returned
  // even if the operation has completed successfully.  For example, a
  // successful response from a server could have been delayed long
  // enough for the deadline to expire.
  DEADLINE_EXCEEDED = 4;

  // Some requested entity (e.g., file or directory) was not found.
  //
  // Note to server developers: if a request is denied for an entire class
  // of users, such as gradual feature rollout or undocumented allowlist,
  // `NOT_FOUND` may be used. If a request is denied for some users within
  // a class of users, such as user-based access control, `PERMISSION_DENIED`
  // must be used.
  NOT_FOUND = 5;

  // The entity that a client attempted to create (e.g., file or directory)
  // already exists.
  ALREADY_EXISTS = 6;

  // The caller does not have permission to execute the specified
  // operation. `PERMISSION_DENIED` must not be used for rejections
  // caused by exhausting some resource (use `RESOURCE_EXHAUSTED`
  // instead for those errors). `PERMISSION_DENIED` must not be
  // used if the caller can not be identified (use `UNAUTHENTICATED`
  // instead for those errors). This error code does not imply the
  // request is valid or the requested entity exists or satisfies
  // other pre-conditions.
  PERMISSION_DENIED = 7;

  // The request does not have valid authentication credentials for the
  // operation.
  UNAUTHENTICATED = 16;

  // Some resource has been exhausted, perhaps a per-user quota, or
  // perhaps the entire file system is out of space.
  RESOURCE_EXHAUSTED = 8;

  // The operation was rejected because the system is not in a state
  // required for the operation's execution.  For example, the directory
  // to be deleted is non-empty, an rmdir operation is applied to
  // a non-directory, etc.
  //
  // A litmus test that may help a service implementer in deciding
  // between FAILED_PRECONDITION, ABORTED, and UNAVAILABLE:
  //  (a) Use UNAVAILABLE if the client can retry just the failing call.
  //  (b) Use ABORTED if the client should retry at a higher-level
  //      (e.g., when a client-specified test-and-set fails, indicating the
  //      client should restart a read-modify-write sequence).
  //  (c) Use FAILED_PRECONDITION if the client should not retry until
  //      the system state has been explicitly fixed.  E.g., if an "rmdir"
  //      fails because the directory is non-empty, FAILED_PRECONDITION
  //      should be returned since the client should not retry unless
  //      the files are deleted from the directory.
  FAILED_PRECONDITION = 9;

  // The operation was aborted, typically due to a concurrency issue such as
  // a sequencer check failure or transaction abort.
  //
  // See litmus test above for deciding between FAILED_PRECONDITION,
  // ABORTED, and UNAVAILABLE.
  ABORTED = 10;

  // The operation was attempted past the valid range.  E.g., seeking or
  // reading past end-of-file.
  //
  // Unlike INVALID_ARGUMENT, this error indicates a problem that may
  // be fixed if the system state changes. For example, a 32-bit file
  // system will generate INVALID_ARGUMENT if asked to read at an
  // offset that is not in the range [0,2^32-1], but it will generate
  // OUT_OF_RANGE if asked to read from an offset past the current
  // file size.
  //
  // There is a fair bit of overlap between FAILED_PRECONDITION and
  // OUT_OF_RANGE.  We recommend using OUT_OF_RANGE (the more specific
  // error) when it applies so that callers who are iterating through
  // a space can easily look for an OUT_OF_RANGE error to detect when
  // they are done.
  OUT_OF_RANGE = 11;

  // The operation is not implemented or is not supported/enabled in this
  // service.
  UNIMPLEMENTED = 12;

  // Internal errors.  This means that some invariants expected by the
  // underlying system have been broken.  This error code is reserved
  // for serious errors.
  INTERNAL = 13;

  // The service is currently unavailable.  This is most likely a
  // transient condition, which can be corrected by retrying with
  // a backoff. Note that it is not always safe to retry
  // non-idempotent operations.
  //
  // See litmus test above for deciding between FAILED_PRECONDITION,
  // ABORTED, and UNAVAILABLE.
  UNAVAILABLE = 14;

  // Unrecoverable data loss or corruption.
  DATA_LOSS = 15;

  // An extra enum entry to prevent people from writing code that
  // fails to compile when a new code is added.
  //
  // Nobody should ever reference this enumeration entry. In particular,
  // if you write C++ code that switches on this enumeration, add a default:
  // case instead of a case that mentions this enumeration entry.
  //
  // Nobody should rely on the value (currently 20) listed here.  It
  // may change in the future.
  DO_NOT_USE_RESERVED_FOR_FUTURE_EXPANSION_USE_DEFAULT_IN_SWITCH_INSTEAD_ = 20;
}