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// Copyright 2019 The Pigweed Authors
//
// 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.
#pragma once
namespace pw {
class Status {
public:
// These are the canonical Google error codes (copied from Tensorflow).
enum Code {
OK = 0,
// The operation was cancelled (typically by the caller).
CANCELLED = 1,
// Unknown error. An example of where this error may be returned is
// if 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,
// 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,
// Deadline expired before 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.
// For privacy reasons, this code *may* be returned when the client
// does not have the access right to the entity.
NOT_FOUND = 5,
// Some entity that we 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 cannot be identified (use UNAUTHENTICATED
// instead for those errors).
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 filesystem is out of space.
RESOURCE_EXHAUSTED = 8,
// Operation was rejected because the system is not in a state
// required for the operation's execution. For example, directory
// to be deleted may be 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. restarting 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
// they have first fixed up the directory by deleting files from it.
// (d) Use FAILED_PRECONDITION if the client performs conditional
// REST Get/Update/Delete on a resource and the resource on the
// server does not match the condition. E.g. conflicting
// read-modify-write on the same resource.
FAILED_PRECONDITION = 9,
// The operation was aborted, typically due to a concurrency issue
// like sequencer check failures, transaction aborts, etc.
//
// See litmus test above for deciding between FAILED_PRECONDITION,
// ABORTED, and UNAVAILABLE.
ABORTED = 10,
// Operation tried to iterate past the valid input 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,
// Operation is not implemented or not supported/enabled in this service.
UNIMPLEMENTED = 12,
// Internal errors. Means some invariants expected by underlying
// system has been broken. If you see one of these errors,
// something is very broken.
INTERNAL = 13,
// The service is currently unavailable. This is a most likely a
// transient condition and may be corrected by retrying with
// a backoff.
//
// 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 listed here. It may change in the future.
DO_NOT_USE_RESERVED_FOR_FUTURE_EXPANSION_USE_DEFAULT_IN_SWITCH_INSTEAD_,
};
constexpr Status(Code code = Code::OK) : code_(code) {}
constexpr Status(const Status&) = default;
constexpr Status& operator=(const Status&) = default;
constexpr Status& operator=(Code code) {
code_ = code;
return *this;
}
constexpr Code code() const { return code_; }
constexpr bool ok() const { return code_ == Code::OK; }
// Returns a string representation of the Status::Code.
const char* str() const;
private:
Code code_;
};
constexpr bool operator==(Status lhs, Status rhs) {
return lhs.code() == rhs.code();
}
constexpr bool operator!=(Status lhs, Status rhs) {
return lhs.code() != rhs.code();
}
} // namespace pw