1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
|
// Copyright 2018 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:build unix
package syscall_test
import (
"bytes"
"fmt"
"os"
"path/filepath"
"runtime"
"sort"
"strconv"
"strings"
"syscall"
"testing"
"unsafe"
)
func TestDirent(t *testing.T) {
const (
direntBufSize = 2048 // arbitrary? See https://go.dev/issue/37323.
filenameMinSize = 11
)
d := t.TempDir()
t.Logf("tmpdir: %s", d)
for i, c := range []byte("0123456789") {
name := string(bytes.Repeat([]byte{c}, filenameMinSize+i))
err := os.WriteFile(filepath.Join(d, name), nil, 0644)
if err != nil {
t.Fatalf("writefile: %v", err)
}
}
names := make([]string, 0, 10)
fd, err := syscall.Open(d, syscall.O_RDONLY, 0)
if err != nil {
t.Fatalf("syscall.open: %v", err)
}
defer syscall.Close(fd)
buf := bytes.Repeat([]byte{0xCD}, direntBufSize)
for {
n, err := syscall.ReadDirent(fd, buf)
if err == syscall.EINVAL {
// On linux, 'man getdents64' says that EINVAL indicates “result buffer is too small”.
// Try a bigger buffer.
t.Logf("ReadDirent: %v; retrying with larger buffer", err)
buf = bytes.Repeat([]byte{0xCD}, len(buf)*2)
continue
}
if err != nil {
t.Fatalf("syscall.readdir: %v", err)
}
t.Logf("ReadDirent: read %d bytes", n)
if n == 0 {
break
}
var consumed, count int
consumed, count, names = syscall.ParseDirent(buf[:n], -1, names)
t.Logf("ParseDirent: %d new name(s)", count)
if consumed != n {
t.Fatalf("ParseDirent: consumed %d bytes; expected %d", consumed, n)
}
}
sort.Strings(names)
t.Logf("names: %q", names)
if len(names) != 10 {
t.Errorf("got %d names; expected 10", len(names))
}
for i, name := range names {
ord, err := strconv.Atoi(name[:1])
if err != nil {
t.Fatalf("names[%d] is non-integer %q: %v", i, names[i], err)
}
if expected := string(strings.Repeat(name[:1], filenameMinSize+ord)); name != expected {
t.Errorf("names[%d] is %q (len %d); expected %q (len %d)", i, name, len(name), expected, len(expected))
}
}
}
func TestDirentRepeat(t *testing.T) {
const N = 100
// Note: the size of the buffer is small enough that the loop
// below will need to execute multiple times. See issue #31368.
size := N * unsafe.Offsetof(syscall.Dirent{}.Name) / 4
if runtime.GOOS == "freebsd" || runtime.GOOS == "netbsd" {
if size < 1024 {
size = 1024 // DIRBLKSIZ, see issue 31403.
}
}
// Make a directory containing N files
d := t.TempDir()
var files []string
for i := 0; i < N; i++ {
files = append(files, fmt.Sprintf("file%d", i))
}
for _, file := range files {
err := os.WriteFile(filepath.Join(d, file), []byte("contents"), 0644)
if err != nil {
t.Fatalf("writefile: %v", err)
}
}
// Read the directory entries using ReadDirent.
fd, err := syscall.Open(d, syscall.O_RDONLY, 0)
if err != nil {
t.Fatalf("syscall.open: %v", err)
}
defer syscall.Close(fd)
var files2 []string
for {
buf := make([]byte, size)
n, err := syscall.ReadDirent(fd, buf)
if err != nil {
t.Fatalf("syscall.readdir: %v", err)
}
if n == 0 {
break
}
buf = buf[:n]
for len(buf) > 0 {
var consumed int
consumed, _, files2 = syscall.ParseDirent(buf, -1, files2)
buf = buf[consumed:]
}
}
// Check results
sort.Strings(files)
sort.Strings(files2)
if strings.Join(files, "|") != strings.Join(files2, "|") {
t.Errorf("bad file list: want\n%q\ngot\n%q", files, files2)
}
}
|
