forked from struCoder/pmgo
/
filemutex.go
44 lines (39 loc) · 959 Bytes
/
filemutex.go
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package utils
import (
"os"
"sync"
"syscall"
)
// FileMutex is a wrapper used to create lock on files.
type FileMutex struct {
mutex *sync.Mutex
file *os.File
}
// MakeFileMutex will create a FileMutex intance.
// Returns a FileMutex instance.
func MakeFileMutex(filename string) *FileMutex {
file, err := os.OpenFile(filename, os.O_RDONLY|os.O_CREATE, 0777)
if err != nil {
return &FileMutex{file: nil}
}
mutex := &sync.Mutex{}
return &FileMutex{file: file, mutex: mutex}
}
// Lock will try to acquire a lock on the file.
func (fMutex *FileMutex) Lock() {
fMutex.mutex.Lock()
if fMutex.file != nil {
if err := syscall.Flock(int(fMutex.file.Fd()), syscall.LOCK_EX); err != nil {
panic(err)
}
}
}
// Unlock will try to release a lock on a file.
func (fMutex *FileMutex) Unlock() {
fMutex.mutex.Unlock()
if fMutex.file != nil {
if err := syscall.Flock(int(fMutex.file.Fd()), syscall.LOCK_UN); err != nil {
panic(err)
}
}
}