status.go

package status

// Code defines the canonical status codes used by application use cases.
//
// Should be consistent across all use cases to be expressible with different transport protocols.
// Status codes are following gRPC conventions for RPC API:
//   - https://github.com/grpc/grpc/blob/master/doc/statuscodes.md
//   - https://github.com/grpc/grpc-go/blob/master/codes/codes.go
//   - https://github.com/googleapis/googleapis/blob/master/google/rpc/code.proto
type Code int

const (
	// OK is returned on success.
	//
	// HTTP Mapping: 200 OK.
	OK Code = 0

	// Canceled indicates the operation was canceled (typically by the caller).
	//
	// HTTP Mapping: 499 Client Closed Request.
	Canceled Code = 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.
	//
	// HTTP Mapping: 500 Internal Server Error.
	Unknown Code = 2

	// InvalidArgument indicates client specified an invalid argument.
	// Note that this differs from FailedPrecondition. It indicates arguments
	// that are problematic regardless of the state of the system
	// (e.g., a malformed file name).
	//
	// HTTP Mapping: 400 Bad Request.
	InvalidArgument Code = 3

	// DeadlineExceeded means operation expired before completion.
	// 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.
	//
	// HTTP Mapping: 504 Gateway Timeout.
	DeadlineExceeded Code = 4

	// NotFound means some requested entity (e.g., file or directory) was
	// not found.
	//
	// HTTP Mapping: 404 Not Found.
	NotFound Code = 5

	// AlreadyExists means an attempt to create an entity failed because one
	// already exists.
	//
	// HTTP Mapping: 409 Conflict.
	AlreadyExists Code = 6

	// PermissionDenied indicates the caller does not have permission to
	// execute the specified operation. It must not be used for rejections
	// caused by exhausting some resource (use ResourceExhausted
	// instead for those errors). It must not be
	// used if the caller cannot be identified (use Unauthenticated
	// instead for those errors).
	//
	// HTTP Mapping: 403 Forbidden.
	PermissionDenied Code = 7

	// ResourceExhausted indicates some resource has been exhausted, perhaps
	// a per-user quota, or perhaps the entire file system is out of space.
	//
	// HTTP Mapping: 429 Too Many Requests.
	ResourceExhausted Code = 8

	// FailedPrecondition indicates 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 implementor in deciding
	// between FailedPrecondition, 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 FailedPrecondition 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, FailedPrecondition
	//      should be returned since the client should not retry unless
	//      they have first fixed up the directory by deleting files from it.
	//  (d) Use FailedPrecondition 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.
	//
	// HTTP Mapping: 400 Bad Request.
	FailedPrecondition Code = 9

	// Aborted indicates the operation was aborted, typically due to a
	// concurrency issue like sequencer check failures, transaction aborts,
	// etc.
	//
	// See litmus test above for deciding between FailedPrecondition,
	// Aborted, and Unavailable.
	//
	// HTTP Mapping: 409 Conflict.
	Aborted Code = 10

	// OutOfRange means operation was attempted past the valid range.
	// E.g., seeking or reading past end of file.
	//
	// Unlike InvalidArgument, this error indicates a problem that may
	// be fixed if the system state changes. For example, a 32-bit file
	// system will generate InvalidArgument if asked to read at an
	// offset that is not in the range [0,2^32-1], but it will generate
	// OutOfRange if asked to read from an offset past the current
	// file size.
	//
	// There is a fair bit of overlap between FailedPrecondition and
	// OutOfRange. We recommend using OutOfRange (the more specific
	// error) when it applies so that callers who are iterating through
	// a space can easily look for an OutOfRange error to detect when
	// they are done.
	//
	// HTTP Mapping: 400 Bad Request.
	OutOfRange Code = 11

	// Unimplemented indicates operation is not implemented or not
	// supported/enabled in this service.
	//
	// HTTP Mapping: 501 Not Implemented.
	Unimplemented Code = 12

	// Internal errors. Means some invariants expected by underlying
	// system has been broken. If you see one of these errors,
	// something is very broken.
	//
	// HTTP Mapping: 500 Internal Server Error.
	Internal Code = 13

	// Unavailable indicates 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 FailedPrecondition,
	// Aborted, and Unavailable.
	//
	// HTTP Mapping: 503 Service Unavailable.
	Unavailable Code = 14

	// DataLoss indicates unrecoverable data loss or corruption.
	//
	// HTTP Mapping: 500 Internal Server Error.
	DataLoss Code = 15

	// Unauthenticated indicates the request does not have valid
	// authentication credentials for the operation.
	//
	// HTTP Mapping: 401 Unauthorized.
	Unauthenticated Code = 16
)

var (
	strToCode = map[string]Code{
		`OK`: OK,
		//nolint:misspell // Due to historical reasons `CANCELLED` should be spelled with double L.
		`CANCELLED`:           Canceled,
		`UNKNOWN`:             Unknown,
		`INVALID_ARGUMENT`:    InvalidArgument,
		`DEADLINE_EXCEEDED`:   DeadlineExceeded,
		`NOT_FOUND`:           NotFound,
		`ALREADY_EXISTS`:      AlreadyExists,
		`PERMISSION_DENIED`:   PermissionDenied,
		`RESOURCE_EXHAUSTED`:  ResourceExhausted,
		`FAILED_PRECONDITION`: FailedPrecondition,
		`ABORTED`:             Aborted,
		`OUT_OF_RANGE`:        OutOfRange,
		`UNIMPLEMENTED`:       Unimplemented,
		`INTERNAL`:            Internal,
		`UNAVAILABLE`:         Unavailable,
		`DATA_LOSS`:           DataLoss,
		`UNAUTHENTICATED`:     Unauthenticated,
	}

	codeToStr = func() map[Code]string {
		res := make(map[Code]string, len(strToCode))
		for str, code := range strToCode {
			res[code] = str
		}

		return res
	}()
)

// String returns string value of status code.
func (c Code) String() string {
	return codeToStr[c]
}

// Status is an accessor.
func (c Code) Status() Code {
	return c
}