Scert/backend/internal/processlock/lock.go

53 lines
1.2 KiB
Go

package processlock
import (
"errors"
"fmt"
"os"
"path/filepath"
)
var ErrLocked = errors.New("进程锁已被占用")
type Lock struct {
file *os.File
}
func Acquire(path string) (*Lock, error) {
path = filepath.Clean(path)
if err := os.MkdirAll(filepath.Dir(path), 0o700); err != nil {
return nil, fmt.Errorf("创建进程锁目录失败:%w", err)
}
if info, err := os.Lstat(path); err == nil {
if info.Mode()&os.ModeSymlink != 0 || !info.Mode().IsRegular() {
return nil, errors.New("进程锁路径必须是普通文件")
}
} else if !errors.Is(err, os.ErrNotExist) {
return nil, fmt.Errorf("检查进程锁失败:%w", err)
}
file, err := os.OpenFile(path, os.O_CREATE|os.O_RDWR, 0o600)
if err != nil {
return nil, fmt.Errorf("打开进程锁失败:%w", err)
}
if err := lockFile(file); err != nil {
_ = file.Close()
return nil, err
}
if err := os.Chmod(path, 0o600); err != nil {
_ = unlockFile(file)
_ = file.Close()
return nil, fmt.Errorf("设置进程锁权限失败:%w", err)
}
return &Lock{file: file}, nil
}
func (lock *Lock) Close() error {
if lock == nil || lock.file == nil {
return nil
}
file := lock.file
lock.file = nil
return errors.Join(unlockFile(file), file.Close())
}