libgo/go/os/types_windows.go

   1 // Copyright 2009 The Go Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style
   3 // license that can be found in the LICENSE file.
   4
   5 package os
   6
   7 import (
   8         "sync"
   9         "syscall"
  10         "time"
  11 )
  12
  13 // A fileStat is the implementation of FileInfo returned by Stat and Lstat.
  14 type fileStat struct {
  15         name string
  16         sys  syscall.Win32FileAttributeData
  17
  18         // used to implement SameFile
  19         sync.Mutex
  20         path  string
  21         vol   uint32
  22         idxhi uint32
  23         idxlo uint32
  24 }
  25
  26 func (fs *fileStat) Size() int64 {
  27         return int64(fs.sys.FileSizeHigh)<<32 + int64(fs.sys.FileSizeLow)
  28 }
  29
  30 func (fs *fileStat) Mode() (m FileMode) {
  31         if fs == &devNullStat {
  32                 return ModeDevice | ModeCharDevice | 0666
  33         }
  34         if fs.sys.FileAttributes&syscall.FILE_ATTRIBUTE_DIRECTORY != 0 {
  35                 m |= ModeDir | 0111
  36         }
  37         if fs.sys.FileAttributes&syscall.FILE_ATTRIBUTE_READONLY != 0 {
  38                 m |= 0444
  39         } else {
  40                 m |= 0666
  41         }
  42         return m
  43 }
  44
  45 func (fs *fileStat) ModTime() time.Time {
  46         return time.Unix(0, fs.sys.LastWriteTime.Nanoseconds())
  47 }
  48
  49 // Sys returns syscall.Win32FileAttributeData for file fs.
  50 func (fs *fileStat) Sys() interface{} { return &fs.sys }
  51
  52 func (fs *fileStat) loadFileId() error {
  53         fs.Lock()
  54         defer fs.Unlock()
  55         if fs.path == "" {
  56                 // already done
  57                 return nil
  58         }
  59         pathp, err := syscall.UTF16PtrFromString(fs.path)
  60         if err != nil {
  61                 return err
  62         }
  63         h, err := syscall.CreateFile(pathp, 0, 0, nil, syscall.OPEN_EXISTING, syscall.FILE_FLAG_BACKUP_SEMANTICS, 0)
  64         if err != nil {
  65                 return err
  66         }
  67         defer syscall.CloseHandle(h)
  68         var i syscall.ByHandleFileInformation
  69         err = syscall.GetFileInformationByHandle(syscall.Handle(h), &i)
  70         if err != nil {
  71                 return err
  72         }
  73         fs.path = ""
  74         fs.vol = i.VolumeSerialNumber
  75         fs.idxhi = i.FileIndexHigh
  76         fs.idxlo = i.FileIndexLow
  77         return nil
  78 }
  79
  80 // devNullStat is fileStat structure describing DevNull file ("NUL").
  81 var devNullStat = fileStat{
  82         name: DevNull,
  83         // hopefully this will work for SameFile
  84         vol:   0,
  85         idxhi: 0,
  86         idxlo: 0,
  87 }
  88
  89 func sameFile(fs1, fs2 *fileStat) bool {
  90         e := fs1.loadFileId()
  91         if e != nil {
  92                 return false
  93         }
  94         e = fs2.loadFileId()
  95         if e != nil {
  96                 return false
  97         }
  98         return fs1.vol == fs2.vol && fs1.idxhi == fs2.idxhi && fs1.idxlo == fs2.idxlo
  99 }
 100
 101 // For testing.
 102 func atime(fi FileInfo) time.Time {
 103         return time.Unix(0, fi.Sys().(*syscall.Win32FileAttributeData).LastAccessTime.Nanoseconds())
 104 }