github.com/insionng/yougam@v0.0.0-20170714101924-2bc18d833463/libraries/syndtr/goleveldb/leveldb/storage/file_storage_plan9.go (about)

     1  // Copyright (c) 2012, Suryandaru Triandana <syndtr@gmail.com>
     2  // All rights reserved.
     3  //
     4  // Use of this source code is governed by a BSD-style license that can be
     5  // found in the LICENSE file.
     6  
     7  package storage
     8  
     9  import (
    10  	"os"
    11  	"path/filepath"
    12  )
    13  
    14  type plan9FileLock struct {
    15  	f *os.File
    16  }
    17  
    18  func (fl *plan9FileLock) release() error {
    19  	return fl.f.Close()
    20  }
    21  
    22  func newFileLock(path string, readOnly bool) (fl fileLock, err error) {
    23  	var (
    24  		flag int
    25  		perm os.FileMode
    26  	)
    27  	if readOnly {
    28  		flag = os.O_RDONLY
    29  	} else {
    30  		flag = os.O_RDWR
    31  		perm = os.ModeExclusive
    32  	}
    33  	f, err := os.OpenFile(path, flag, perm)
    34  	if os.IsNotExist(err) {
    35  		f, err = os.OpenFile(path, flag|os.O_CREATE, perm|0644)
    36  	}
    37  	if err != nil {
    38  		return
    39  	}
    40  	fl = &plan9FileLock{f: f}
    41  	return
    42  }
    43  
    44  func rename(oldpath, newpath string) error {
    45  	if _, err := os.Stat(newpath); err == nil {
    46  		if err := os.Remove(newpath); err != nil {
    47  			return err
    48  		}
    49  	}
    50  
    51  	_, fname := filepath.Split(newpath)
    52  	return os.Rename(oldpath, fname)
    53  }
    54  
    55  func syncDir(name string) error {
    56  	f, err := os.Open(name)
    57  	if err != nil {
    58  		return err
    59  	}
    60  	defer f.Close()
    61  	if err := f.Sync(); err != nil {
    62  		return err
    63  	}
    64  	return nil
    65  }