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
5package os
6
7import (
8	"io"
9	"syscall"
10)
11
12func (file *File) readdir(n int) ([]FileInfo, 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	fi := make([]FileInfo, 0, size) // Empty with room to grow.
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 fi, &PathError{"readdir", file.name, err}
37			}
38			if nb < syscall.STATFIXLEN {
39				return fi, &PathError{"readdir", file.name, 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 fi, &PathError{"readdir", file.name, syscall.ErrShortStat}
48		}
49
50		dir, err := syscall.UnmarshalDir(b[:m])
51		if err != nil {
52			return fi, &PathError{"readdir", file.name, err}
53		}
54		fi = append(fi, fileInfoFromStat(dir))
55
56		d.bufp += m
57		n--
58	}
59
60	if n >= 0 && len(fi) == 0 {
61		return fi, io.EOF
62	}
63	return fi, nil
64}
65
66func (file *File) readdirnames(n int) (names []string, err error) {
67	fi, err := file.Readdir(n)
68	names = make([]string, len(fi))
69	for i := range fi {
70		names[i] = fi[i].Name()
71	}
72	return
73}
74