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
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
|
//go:build go1.16
// +build go1.16
package pwalkdir
import (
"errors"
"io/fs"
"math/rand"
"os"
"path/filepath"
"runtime"
"sync/atomic"
"testing"
"time"
)
func TestWalkDir(t *testing.T) {
var count uint32
concurrency := runtime.NumCPU() * 2
dir, total, err := prepareTestSet(3, 2, 1)
if err != nil {
t.Fatalf("dataset creation failed: %v", err)
}
defer os.RemoveAll(dir)
err = WalkN(dir,
func(_ string, _ fs.DirEntry, _ error) error {
atomic.AddUint32(&count, 1)
return nil
},
concurrency)
if err != nil {
t.Errorf("Walk failed: %v", err)
}
if count != uint32(total) {
t.Errorf("File count mismatch: found %d, expected %d", count, total)
}
t.Logf("concurrency: %d, files found: %d\n", concurrency, count)
}
func TestWalkDirManyErrors(t *testing.T) {
var count uint32
dir, total, err := prepareTestSet(3, 3, 2)
if err != nil {
t.Fatalf("dataset creation failed: %v", err)
}
defer os.RemoveAll(dir)
max := uint32(total / 2)
e42 := errors.New("42")
err = Walk(dir,
func(p string, e fs.DirEntry, _ error) error {
if atomic.AddUint32(&count, 1) > max {
return e42
}
return nil
})
t.Logf("found %d of %d files", count, total)
if err == nil {
t.Error("Walk succeeded, but error is expected")
if count != uint32(total) {
t.Errorf("File count mismatch: found %d, expected %d", count, total)
}
}
}
func makeManyDirs(prefix string, levels, dirs, files int) (count int, err error) {
for d := 0; d < dirs; d++ {
var dir string
dir, err = os.MkdirTemp(prefix, "d-")
if err != nil {
return
}
count++
for f := 0; f < files; f++ {
var fi *os.File
fi, err = os.CreateTemp(dir, "f-")
if err != nil {
return count, err
}
fi.Close()
count++
}
if levels == 0 {
continue
}
var c int
if c, err = makeManyDirs(dir, levels-1, dirs, files); err != nil {
return
}
count += c
}
return
}
// prepareTestSet() creates a directory tree of shallow files,
// to be used for testing or benchmarking.
//
// Total dirs: dirs^levels + dirs^(levels-1) + ... + dirs^1
// Total files: total_dirs * files
func prepareTestSet(levels, dirs, files int) (dir string, total int, err error) {
dir, err = os.MkdirTemp(".", "pwalk-test-")
if err != nil {
return
}
total, err = makeManyDirs(dir, levels, dirs, files)
if err != nil && total > 0 {
_ = os.RemoveAll(dir)
dir = ""
total = 0
return
}
total++ // this dir
return
}
type walkerFunc func(root string, walkFn fs.WalkDirFunc) error
func genWalkN(n int) walkerFunc {
return func(root string, walkFn fs.WalkDirFunc) error {
return WalkN(root, walkFn, n)
}
}
func BenchmarkWalk(b *testing.B) {
const (
levels = 5 // how deep
dirs = 3 // dirs on each levels
files = 8 // files on each levels
)
benchmarks := []struct {
walk fs.WalkDirFunc
name string
}{
{name: "Empty", walk: cbEmpty},
{name: "ReadFile", walk: cbReadFile},
{name: "ChownChmod", walk: cbChownChmod},
{name: "RandomSleep", walk: cbRandomSleep},
}
walkers := []struct {
walker walkerFunc
name string
}{
{name: "filepath.WalkDir", walker: filepath.WalkDir},
{name: "pwalkdir.Walk", walker: Walk},
// test WalkN with various values of N
{name: "pwalkdir.Walk1", walker: genWalkN(1)},
{name: "pwalkdir.Walk2", walker: genWalkN(2)},
{name: "pwalkdir.Walk4", walker: genWalkN(4)},
{name: "pwalkdir.Walk8", walker: genWalkN(8)},
{name: "pwalkdir.Walk16", walker: genWalkN(16)},
{name: "pwalkdir.Walk32", walker: genWalkN(32)},
{name: "pwalkdir.Walk64", walker: genWalkN(64)},
{name: "pwalkdir.Walk128", walker: genWalkN(128)},
{name: "pwalkdir.Walk256", walker: genWalkN(256)},
}
dir, total, err := prepareTestSet(levels, dirs, files)
if err != nil {
b.Fatalf("dataset creation failed: %v", err)
}
defer os.RemoveAll(dir)
b.Logf("dataset: %d levels x %d dirs x %d files, total entries: %d", levels, dirs, files, total)
for _, bm := range benchmarks {
for _, w := range walkers {
walker := w.walker
walkFn := bm.walk
// preheat
if err := w.walker(dir, bm.walk); err != nil {
b.Errorf("walk failed: %v", err)
}
// benchmark
b.Run(bm.name+"/"+w.name, func(b *testing.B) {
for i := 0; i < b.N; i++ {
if err := walker(dir, walkFn); err != nil {
b.Errorf("walk failed: %v", err)
}
}
})
}
}
}
func cbEmpty(_ string, _ fs.DirEntry, _ error) error {
return nil
}
func cbChownChmod(path string, e fs.DirEntry, _ error) error {
_ = os.Chown(path, 0, 0)
mode := os.FileMode(0o644)
if e.IsDir() {
mode = os.FileMode(0o755)
}
_ = os.Chmod(path, mode)
return nil
}
func cbReadFile(path string, e fs.DirEntry, _ error) error {
var err error
if e.Type().IsRegular() {
_, err = os.ReadFile(path)
}
return err
}
func cbRandomSleep(_ string, _ fs.DirEntry, _ error) error {
time.Sleep(time.Duration(rand.Intn(500)) * time.Microsecond) //nolint:gosec // ignore G404: Use of weak random number generator
return nil
}
|
