libgo/go/os/dir_plan9.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         "io"
   9         "syscall"
  10 )
  11
  12 func (file *File) readdir(n int, mode readdirMode) (names []string, dirents []DirEntry, infos []FileInfo, err error) {
  13         // If this file has no dirinfo, create one.
  14         if file.dirinfo == nil {
  15                 file.dirinfo = new(dirInfo)
  16         }
  17         d := file.dirinfo
  18         size := n
  19         if size <= 0 {
  20                 size = 100
  21                 n = -1
  22         }
  23         for n != 0 {
  24                 // Refill the buffer if necessary.
  25                 if d.bufp >= d.nbuf {
  26                         nb, err := file.Read(d.buf[:])
  27
  28                         // Update the buffer state before checking for errors.
  29                         d.bufp, d.nbuf = 0, nb
  30
  31                         if err != nil {
  32                                 if err == io.EOF {
  33                                         break
  34                                 }
  35                                 return names, dirents, infos, &PathError{Op: "readdir", Path: file.name, Err: err}
  36                         }
  37                         if nb < syscall.STATFIXLEN {
  38                                 return names, dirents, infos, &PathError{Op: "readdir", Path: file.name, Err: syscall.ErrShortStat}
  39                         }
  40                 }
  41
  42                 // Get a record from the buffer.
  43                 b := d.buf[d.bufp:]
  44                 m := int(uint16(b[0])|uint16(b[1])<<8) + 2
  45                 if m < syscall.STATFIXLEN {
  46                         return names, dirents, infos, &PathError{Op: "readdir", Path: file.name, Err: syscall.ErrShortStat}
  47                 }
  48
  49                 dir, err := syscall.UnmarshalDir(b[:m])
  50                 if err != nil {
  51                         return names, dirents, infos, &PathError{Op: "readdir", Path: file.name, Err: err}
  52                 }
  53
  54                 if mode == readdirName {
  55                         names = append(names, dir.Name)
  56                 } else {
  57                         f := fileInfoFromStat(dir)
  58                         if mode == readdirDirEntry {
  59                                 dirents = append(dirents, dirEntry{f})
  60                         } else {
  61                                 infos = append(infos, f)
  62                         }
  63                 }
  64                 d.bufp += m
  65                 n--
  66         }
  67
  68         if n > 0 && len(names)+len(dirents)+len(infos) == 0 {
  69                 return nil, nil, nil, io.EOF
  70         }
  71         return names, dirents, infos, nil
  72 }
  73
  74 type dirEntry struct {
  75         fs *fileStat
  76 }
  77
  78 func (de dirEntry) Name() string            { return de.fs.Name() }
  79 func (de dirEntry) IsDir() bool             { return de.fs.IsDir() }
  80 func (de dirEntry) Type() FileMode          { return de.fs.Mode().Type() }
  81 func (de dirEntry) Info() (FileInfo, error) { return de.fs, nil }