github.com/kaydxh/golang@v0.0.131/go/sync/atomic/file_lock.go (about)

     1  /*
     2   *Copyright (c) 2022, kaydxh
     3   *
     4   *Permission is hereby granted, free of charge, to any person obtaining a copy
     5   *of this software and associated documentation files (the "Software"), to deal
     6   *in the Software without restriction, including without limitation the rights
     7   *to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
     8   *copies of the Software, and to permit persons to whom the Software is
     9   *furnished to do so, subject to the following conditions:
    10   *
    11   *The above copyright notice and this permission notice shall be included in all
    12   *copies or substantial portions of the Software.
    13   *
    14   *THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    15   *IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    16   *FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    17   *AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    18   *LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    19   *OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
    20   *SOFTWARE.
    21   */
    22  package atomic
    23  
    24  import (
    25  	"fmt"
    26  	"os"
    27  	"path/filepath"
    28  	"strings"
    29  
    30  	os_ "github.com/kaydxh/golang/go/os"
    31  )
    32  
    33  type FileLock string
    34  
    35  func (m *FileLock) TryLock() error {
    36  	if m == nil {
    37  		return fmt.Errorf("nil pointer")
    38  	}
    39  	if *m == "" {
    40  		return fmt.Errorf("invalid file")
    41  	}
    42  	name := string(*m)
    43  	if !strings.HasSuffix(name, ".lock") {
    44  		*m += ".lock"
    45  	}
    46  
    47  	dir := filepath.Dir(name)
    48  	err := os_.MakeDirAll(dir)
    49  	if err != nil {
    50  		return err
    51  	}
    52  
    53  	f, err := os.OpenFile(string(*m), os.O_CREATE|os.O_EXCL, 0600)
    54  	if err != nil {
    55  		return err
    56  	}
    57  
    58  	return f.Close()
    59  }
    60  
    61  func (m *FileLock) TryUnLock() error {
    62  	if m == nil || *m == "" {
    63  		return nil
    64  	}
    65  
    66  	return os.Remove(string(*m))
    67  }
    68  
    69  /*
    70  func makePidFile(name string) (tmpname string, cleanup func(), err error) {
    71  	tmplock, err := ioutil.TempFile(
    72  		filepath.Dir(name),
    73  		filepath.Base(name)+fmt.Sprintf("%d", os.GetPid())+".lock",
    74  	)
    75  	if err != nil {
    76  		return "", nil, err
    77  	}
    78  
    79  	cleanup = func() {
    80  		_ = tmplock.Close()
    81  		_ = os.Remove(tmplock.Name())
    82  	}
    83  
    84  }
    85  */