GoToSocial/vendor/codeberg.org/gruf/go-errors/v2/once.go
tobi 5004e0a9da
[bugfix] Fix remote media pruning failing if media already gone (#548)
* fix error check of prune to allow missing files

* update go-store library, add test for pruning item with db entry but no file

Signed-off-by: kim <grufwub@gmail.com>

* remove now-unneccessary error check

Signed-off-by: kim <grufwub@gmail.com>

Co-authored-by: kim <grufwub@gmail.com>
2022-05-08 18:49:45 +01:00

48 lines
946 B
Go

package errors
import (
"sync/atomic"
"unsafe"
)
// OnceError is an error structure that supports safe multi
// threaded usage and setting only once (until reset).
type OnceError struct{ err unsafe.Pointer }
// NewOnce returns a new OnceError instance.
func NewOnce() OnceError {
return OnceError{
err: nil,
}
}
// Store will safely set the OnceError to value, no-op if nil.
func (e *OnceError) Store(err error) {
// Nothing to do
if err == nil {
return
}
// Only set if not already
atomic.CompareAndSwapPointer(
&e.err,
nil,
unsafe.Pointer(&err),
)
}
// Load will load the currently stored error.
func (e *OnceError) Load() error {
return *(*error)(atomic.LoadPointer(&e.err))
}
// IsSet returns whether OnceError has been set.
func (e *OnceError) IsSet() bool {
return (atomic.LoadPointer(&e.err) != nil)
}
// Reset will reset the OnceError value.
func (e *OnceError) Reset() {
atomic.StorePointer(&e.err, nil)
}