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