mirror of
https://github.com/minio/minio.git
synced 2024-12-29 00:23:21 -05:00
52 lines
1.3 KiB
Go
52 lines
1.3 KiB
Go
|
// Copyright (c) 2015-2023 MinIO, Inc.
|
||
|
|
//
|
||
|
|
// This file is part of MinIO Object Storage stack
|
||
|
|
//
|
||
|
|
// This program is free software: you can redistribute it and/or modify
|
||
|
|
// it under the terms of the GNU Affero General Public License as published by
|
||
|
|
// the Free Software Foundation, either version 3 of the License, or
|
||
|
|
// (at your option) any later version.
|
||
|
|
//
|
||
|
|
// This program is distributed in the hope that it will be useful
|
||
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
|
|
// GNU Affero General Public License for more details.
|
||
|
|
//
|
||
|
|
// You should have received a copy of the GNU Affero General Public License
|
||
|
|
// along with this program. If not, see <http://www.gnu.org/licenses/>.
|
||
|
|
|
||
|
|
package target
|
||
|
|
|
||
|
|
import (
|
||
|
|
"sync"
|
||
|
|
"sync/atomic"
|
||
|
|
)
|
||
|
|
|
||
|
|
// Inspired from Golang sync.Once but it is only marked
|
||
|
|
// initialized when the provided function returns nil.
|
||
|
|
|
||
|
|
type lazyInit struct {
|
||
|
|
done uint32
|
||
|
|
m sync.Mutex
|
||
|
|
}
|
||
|
|
|
||
|
|
func (l *lazyInit) Do(f func() error) error {
|
||
|
|
if atomic.LoadUint32(&l.done) == 0 {
|
||
|
|
return l.doSlow(f)
|
||
|
|
}
|
||
|
|
return nil
|
||
|
|
}
|
||
|
|
|
||
|
|
func (l *lazyInit) doSlow(f func() error) error {
|
||
|
|
l.m.Lock()
|
||
|
|
defer l.m.Unlock()
|
||
|
|
if atomic.LoadUint32(&l.done) == 0 {
|
||
|
|
if err := f(); err != nil {
|
||
|
|
return err
|
||
|
|
}
|
||
|
|
// Mark as done only when f() is successful
|
||
|
|
atomic.StoreUint32(&l.done, 1)
|
||
|
|
}
|
||
|
|
return nil
|
||
|
|
}
|