forked from mirrors/gotosocial
45 lines
747 B
Go
45 lines
747 B
Go
package errors
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import (
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"sync/atomic"
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"unsafe"
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)
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// OnceError is an error structure that supports safe multi-threaded
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// usage and setting only once (until reset)
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type OnceError struct {
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err unsafe.Pointer
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}
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// NewOnce returns a new OnceError instance
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func NewOnce() OnceError {
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return OnceError{
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err: nil,
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}
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}
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func (e *OnceError) Store(err error) {
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// Nothing to do
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if err == nil {
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return
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}
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// Only set if not already
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atomic.CompareAndSwapPointer(
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&e.err,
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nil,
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unsafe.Pointer(&err),
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)
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}
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func (e *OnceError) Load() error {
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return *(*error)(atomic.LoadPointer(&e.err))
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}
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func (e *OnceError) IsSet() bool {
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return (atomic.LoadPointer(&e.err) != nil)
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}
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func (e *OnceError) Reset() {
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atomic.StorePointer(&e.err, nil)
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}
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