github.com/miolini/go@v0.0.0-20160405192216-fca68c8cb408/src/os/stat_plan9.go (about)

     1  // Copyright 2011 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  	"syscall"
     9  	"time"
    10  )
    11  
    12  const _BIT16SZ = 2
    13  
    14  func sameFile(fs1, fs2 *fileStat) bool {
    15  	a := fs1.sys.(*syscall.Dir)
    16  	b := fs2.sys.(*syscall.Dir)
    17  	return a.Qid.Path == b.Qid.Path && a.Type == b.Type && a.Dev == b.Dev
    18  }
    19  
    20  func fileInfoFromStat(d *syscall.Dir) FileInfo {
    21  	fs := &fileStat{
    22  		name:    d.Name,
    23  		size:    int64(d.Length),
    24  		modTime: time.Unix(int64(d.Mtime), 0),
    25  		sys:     d,
    26  	}
    27  	fs.mode = FileMode(d.Mode & 0777)
    28  	if d.Mode&syscall.DMDIR != 0 {
    29  		fs.mode |= ModeDir
    30  	}
    31  	if d.Mode&syscall.DMAPPEND != 0 {
    32  		fs.mode |= ModeAppend
    33  	}
    34  	if d.Mode&syscall.DMEXCL != 0 {
    35  		fs.mode |= ModeExclusive
    36  	}
    37  	if d.Mode&syscall.DMTMP != 0 {
    38  		fs.mode |= ModeTemporary
    39  	}
    40  	return fs
    41  }
    42  
    43  // arg is an open *File or a path string.
    44  func dirstat(arg interface{}) (*syscall.Dir, error) {
    45  	var name string
    46  	var err error
    47  
    48  	size := syscall.STATFIXLEN + 16*4
    49  
    50  	for i := 0; i < 2; i++ {
    51  		buf := make([]byte, _BIT16SZ+size)
    52  
    53  		var n int
    54  		switch a := arg.(type) {
    55  		case *File:
    56  			name = a.name
    57  			n, err = syscall.Fstat(a.fd, buf)
    58  		case string:
    59  			name = a
    60  			n, err = syscall.Stat(a, buf)
    61  		default:
    62  			panic("phase error in dirstat")
    63  		}
    64  
    65  		if n < _BIT16SZ {
    66  			return nil, &PathError{"stat", name, err}
    67  		}
    68  
    69  		// Pull the real size out of the stat message.
    70  		size = int(uint16(buf[0]) | uint16(buf[1])<<8)
    71  
    72  		// If the stat message is larger than our buffer we will
    73  		// go around the loop and allocate one that is big enough.
    74  		if size <= n {
    75  			d, err := syscall.UnmarshalDir(buf[:n])
    76  			if err != nil {
    77  				return nil, &PathError{"stat", name, err}
    78  			}
    79  			return d, nil
    80  		}
    81  
    82  	}
    83  
    84  	if err == nil {
    85  		err = syscall.ErrBadStat
    86  	}
    87  
    88  	return nil, &PathError{"stat", name, err}
    89  }
    90  
    91  // Stat returns a FileInfo describing the named file.
    92  // If there is an error, it will be of type *PathError.
    93  func Stat(name string) (FileInfo, error) {
    94  	d, err := dirstat(name)
    95  	if err != nil {
    96  		return nil, err
    97  	}
    98  	return fileInfoFromStat(d), nil
    99  }
   100  
   101  // Lstat returns a FileInfo describing the named file.
   102  // If the file is a symbolic link, the returned FileInfo
   103  // describes the symbolic link. Lstat makes no attempt to follow the link.
   104  // If there is an error, it will be of type *PathError.
   105  func Lstat(name string) (FileInfo, error) {
   106  	return Stat(name)
   107  }
   108  
   109  // For testing.
   110  func atime(fi FileInfo) time.Time {
   111  	return time.Unix(int64(fi.Sys().(*syscall.Dir).Atime), 0)
   112  }