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package pwalk
import (
"errors"
"math/rand"
"os"
"path/filepath"
"runtime"
"sync/atomic"
"testing"
"time"
)
func TestWalk(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, _ os.FileInfo, _ 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 TestWalkManyErrors(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, i os.FileInfo, _ 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.Errorf("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 WalkFunc) error
func genWalkN(n int) walkerFunc {
return func(root string, walkFn WalkFunc) 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 filepath.WalkFunc
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.Walk", walker: filepath.Walk},
{name: "pwalk.Walk", walker: Walk},
// test WalkN with various values of N
{name: "pwalk.Walk1", walker: genWalkN(1)},
{name: "pwalk.Walk2", walker: genWalkN(2)},
{name: "pwalk.Walk4", walker: genWalkN(4)},
{name: "pwalk.Walk8", walker: genWalkN(8)},
{name: "pwalk.Walk16", walker: genWalkN(16)},
{name: "pwalk.Walk32", walker: genWalkN(32)},
{name: "pwalk.Walk64", walker: genWalkN(64)},
{name: "pwalk.Walk128", walker: genWalkN(128)},
{name: "pwalk.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, _ os.FileInfo, _ error) error {
return nil
}
func cbChownChmod(path string, info os.FileInfo, _ error) error {
_ = os.Chown(path, 0, 0)
mode := os.FileMode(0o644)
if info.Mode().IsDir() {
mode = os.FileMode(0o755)
}
_ = os.Chmod(path, mode)
return nil
}
func cbReadFile(path string, info os.FileInfo, _ error) error {
var err error
if info.Mode().IsRegular() {
_, err = os.ReadFile(path)
}
return err
}
func cbRandomSleep(_ string, _ os.FileInfo, _ error) error {
time.Sleep(time.Duration(rand.Intn(500)) * time.Microsecond) //nolint:gosec // ignore G404: Use of weak random number generator
return nil
}
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