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  	"io/fs"
    10  	"syscall"
    11  )
    12  
    13  func (file *File) readdir(n int, mode readdirMode) (names []string, dirents []DirEntry, infos []FileInfo, err error) {
    14  	// If this file has no dirinfo, create one.
    15  	if file.dirinfo == nil {
    16  		file.dirinfo = new(dirInfo)
    17  	}
    18  	d := file.dirinfo
    19  	size := n
    20  	if size <= 0 {
    21  		size = 100
    22  		n = -1
    23  	}
    24  	for n != 0 {
    25  		// Refill the buffer if necessary.
    26  		if d.bufp >= d.nbuf {
    27  			nb, err := file.Read(d.buf[:])
    28  
    29  			// Update the buffer state before checking for errors.
    30  			d.bufp, d.nbuf = 0, nb
    31  
    32  			if err != nil {
    33  				if err == io.EOF {
    34  					break
    35  				}
    36  				return names, dirents, infos, &PathError{Op: "readdir", Path: file.name, Err: err}
    37  			}
    38  			if nb < syscall.STATFIXLEN {
    39  				return names, dirents, infos, &PathError{Op: "readdir", Path: file.name, Err: syscall.ErrShortStat}
    40  			}
    41  		}
    42  
    43  		// Get a record from the buffer.
    44  		b := d.buf[d.bufp:]
    45  		m := int(uint16(b[0])|uint16(b[1])<<8) + 2
    46  		if m < syscall.STATFIXLEN {
    47  			return names, dirents, infos, &PathError{Op: "readdir", Path: file.name, Err: syscall.ErrShortStat}
    48  		}
    49  
    50  		dir, err := syscall.UnmarshalDir(b[:m])
    51  		if err != nil {
    52  			return names, dirents, infos, &PathError{Op: "readdir", Path: file.name, Err: err}
    53  		}
    54  
    55  		if mode == readdirName {
    56  			names = append(names, dir.Name)
    57  		} else {
    58  			f := fileInfoFromStat(dir)
    59  			if mode == readdirDirEntry {
    60  				dirents = append(dirents, dirEntry{f})
    61  			} else {
    62  				infos = append(infos, f)
    63  			}
    64  		}
    65  		d.bufp += m
    66  		n--
    67  	}
    68  
    69  	if n > 0 && len(names)+len(dirents)+len(infos) == 0 {
    70  		return nil, nil, nil, io.EOF
    71  	}
    72  	return names, dirents, infos, nil
    73  }
    74  
    75  type dirEntry struct {
    76  	fs *fileStat
    77  }
    78  
    79  func (de dirEntry) Name() string            { return de.fs.Name() }
    80  func (de dirEntry) IsDir() bool             { return de.fs.IsDir() }
    81  func (de dirEntry) Type() FileMode          { return de.fs.Mode().Type() }
    82  func (de dirEntry) Info() (FileInfo, error) { return de.fs, nil }
    83  
    84  func (de dirEntry) String() string {
    85  	return fs.FormatDirEntry(de)
    86  }
    87
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