Files
cgrates/loaders/locker.go
2022-03-09 14:14:30 +01:00

97 lines
2.4 KiB
Go

/*
Real-time Online/Offline Charging System (OCS) for Telecom & ISP environments
Copyright (C) ITsysCOM GmbH
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>
*/
package loaders
import (
"io"
"os"
"github.com/cgrates/cgrates/guardian"
"github.com/cgrates/cgrates/utils"
)
type Locker interface {
Lock() error
Unlock() error
Locked() (bool, error)
IsLockFile(string) bool
}
func newLocker(path, loaderID string) Locker {
switch path {
case utils.EmptyString:
return new(nopLock)
case utils.MetaMemory:
return &memoryLock{loaderID: loaderID}
default:
return folderLock(path)
}
}
type folderLock string
// lockFolder will attempt to lock the folder by creating the lock file
func (fl folderLock) Lock() (err error) {
var file io.Closer
file, err = os.OpenFile(string(fl),
os.O_RDONLY|os.O_CREATE, 0644)
file.Close()
return
}
func (fl folderLock) Unlock() (err error) {
return os.Remove(string(fl))
}
func (fl folderLock) Locked() (lk bool, err error) {
if _, err = os.Stat(string(fl)); err != nil {
if os.IsNotExist(err) {
lk, err = false, nil
}
return
}
lk = true
return
}
func (fl folderLock) IsLockFile(path string) bool { return path == string(fl) }
type nopLock struct{}
func (nopLock) Lock() (_ error) { return }
func (nopLock) Unlock() (_ error) { return }
func (nopLock) Locked() (_ bool, _ error) { return }
func (nopLock) IsLockFile(string) (_ bool) { return }
type memoryLock struct {
loaderID string
refID string
}
func (m *memoryLock) Lock() (_ error) {
m.refID = guardian.Guardian.GuardIDs(m.refID, 0, utils.ConcatenatedKey(utils.LoaderS, m.loaderID))
return
}
func (m *memoryLock) Unlock() (_ error) {
guardian.Guardian.UnguardIDs(m.refID)
m.refID = utils.EmptyString
return
}
func (m memoryLock) Locked() (bool, error) { return len(m.refID) != 0, nil }
func (m memoryLock) IsLockFile(string) (_ bool) { return }