github.com/muesli/go@v0.0.0-20170208044820-e410d2a81ef2/src/os/types_windows.go (about)

     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  	filetype uint32 // what syscall.GetFileType returns
    18  
    19  	// used to implement SameFile
    20  	sync.Mutex
    21  	path  string
    22  	vol   uint32
    23  	idxhi uint32
    24  	idxlo uint32
    25  }
    26  
    27  func (fs *fileStat) Size() int64 {
    28  	return int64(fs.sys.FileSizeHigh)<<32 + int64(fs.sys.FileSizeLow)
    29  }
    30  
    31  func (fs *fileStat) Mode() (m FileMode) {
    32  	if fs == &devNullStat {
    33  		return ModeDevice | ModeCharDevice | 0666
    34  	}
    35  	if fs.sys.FileAttributes&syscall.FILE_ATTRIBUTE_DIRECTORY != 0 {
    36  		m |= ModeDir | 0111
    37  	}
    38  	if fs.sys.FileAttributes&syscall.FILE_ATTRIBUTE_READONLY != 0 {
    39  		m |= 0444
    40  	} else {
    41  		m |= 0666
    42  	}
    43  	if fs.sys.FileAttributes&syscall.FILE_ATTRIBUTE_REPARSE_POINT != 0 {
    44  		m |= ModeSymlink
    45  	}
    46  	switch fs.filetype {
    47  	case syscall.FILE_TYPE_PIPE:
    48  		m |= ModeNamedPipe
    49  	case syscall.FILE_TYPE_CHAR:
    50  		m |= ModeCharDevice
    51  	}
    52  	return m
    53  }
    54  
    55  func (fs *fileStat) ModTime() time.Time {
    56  	return time.Unix(0, fs.sys.LastWriteTime.Nanoseconds())
    57  }
    58  
    59  // Sys returns syscall.Win32FileAttributeData for file fs.
    60  func (fs *fileStat) Sys() interface{} { return &fs.sys }
    61  
    62  func (fs *fileStat) loadFileId() error {
    63  	fs.Lock()
    64  	defer fs.Unlock()
    65  	if fs.path == "" {
    66  		// already done
    67  		return nil
    68  	}
    69  	pathp, err := syscall.UTF16PtrFromString(fs.path)
    70  	if err != nil {
    71  		return err
    72  	}
    73  	h, err := syscall.CreateFile(pathp, 0, 0, nil, syscall.OPEN_EXISTING, syscall.FILE_FLAG_BACKUP_SEMANTICS, 0)
    74  	if err != nil {
    75  		return err
    76  	}
    77  	defer syscall.CloseHandle(h)
    78  	var i syscall.ByHandleFileInformation
    79  	err = syscall.GetFileInformationByHandle(h, &i)
    80  	if err != nil {
    81  		return err
    82  	}
    83  	fs.path = ""
    84  	fs.vol = i.VolumeSerialNumber
    85  	fs.idxhi = i.FileIndexHigh
    86  	fs.idxlo = i.FileIndexLow
    87  	return nil
    88  }
    89  
    90  // devNullStat is fileStat structure describing DevNull file ("NUL").
    91  var devNullStat = fileStat{
    92  	name: DevNull,
    93  	// hopefully this will work for SameFile
    94  	vol:   0,
    95  	idxhi: 0,
    96  	idxlo: 0,
    97  }
    98  
    99  func sameFile(fs1, fs2 *fileStat) bool {
   100  	e := fs1.loadFileId()
   101  	if e != nil {
   102  		return false
   103  	}
   104  	e = fs2.loadFileId()
   105  	if e != nil {
   106  		return false
   107  	}
   108  	return fs1.vol == fs2.vol && fs1.idxhi == fs2.idxhi && fs1.idxlo == fs2.idxlo
   109  }
   110  
   111  // For testing.
   112  func atime(fi FileInfo) time.Time {
   113  	return time.Unix(0, fi.Sys().(*syscall.Win32FileAttributeData).LastAccessTime.Nanoseconds())
   114  }