9dcff95a29
Define base `Status` interface. Provide the functionality to distinguish success and failure returns. Provide functionality to transport statuses over NeoFS API V2 protocol. Support success `OK` and failure `INTERNAL` returns. Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
44 lines
1.7 KiB
Go
44 lines
1.7 KiB
Go
package apistatus
|
|
|
|
// Status defines a variety of NeoFS API status returns.
|
|
//
|
|
// All statuses are split into two disjoint subsets: successful and failed, and:
|
|
// * statuses that implement the build-in error interface are considered failed statuses;
|
|
// * all other value types are considered successes (nil is a default success).
|
|
//
|
|
// In Go code type of success can be determined by a type switch, failure - by a switch with errors.As calls.
|
|
// Nil should be considered as a success, and default switch section - as an unrecognized Status.
|
|
//
|
|
// To convert statuses into errors and vice versa, use functions ErrToStatus and ErrFromStatus, respectively.
|
|
// ErrFromStatus function returns nil for successful statuses. However, to simplify the check of statuses for success,
|
|
// IsSuccessful function should be used (try to avoid nil comparison).
|
|
// It should be noted that using direct typecasting is not a compatible approach.
|
|
//
|
|
// To transport statuses using the NeoFS API V2 protocol, see StatusV2 interface and FromStatusV2 and ToStatusV2 functions.
|
|
type Status interface{}
|
|
|
|
// ErrFromStatus converts Status instance to error if it is failed. Returns nil on successful Status.
|
|
//
|
|
// Note: direct assignment may not be compatibility-safe.
|
|
func ErrFromStatus(st Status) error {
|
|
if err, ok := st.(error); ok {
|
|
return err
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
// ErrToStatus converts the error instance to Status instance.
|
|
//
|
|
// Note: direct assignment may not be compatibility-safe.
|
|
func ErrToStatus(err error) Status {
|
|
return err
|
|
}
|
|
|
|
// IsSuccessful checks if status is successful.
|
|
//
|
|
// Note: direct cast may not be compatibility-safe.
|
|
func IsSuccessful(st Status) bool {
|
|
_, ok := st.(error)
|
|
return !ok
|
|
}
|