diff options
Diffstat (limited to 'vendor/codeberg.org/gruf/go-errors/v2/once.go')
-rw-r--r-- | vendor/codeberg.org/gruf/go-errors/v2/once.go | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/vendor/codeberg.org/gruf/go-errors/v2/once.go b/vendor/codeberg.org/gruf/go-errors/v2/once.go new file mode 100644 index 000000000..83a45a61f --- /dev/null +++ b/vendor/codeberg.org/gruf/go-errors/v2/once.go @@ -0,0 +1,47 @@ +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) +} |