windows: fix sorting on Windows

dirent_portable.go

@@ -10,6 +10,7 @@ import (
 	"os"
 	"slices"
 	"strings"
+	"sync"
 )
 
 var _ DirEntry = (*portableDirent)(nil)
@@ -46,17 +47,35 @@ func fileInfoToDirEntry(dirname string, fi fs.FileInfo) DirEntry {
 	return newDirEntry(dirname, fs.FileInfoToDirEntry(fi))
 }
 
-func sortDirents(mode SortMode, dents []fs.DirEntry) {
+var direntSlicePool = sync.Pool{
+	New: func() any {
+		a := make([]DirEntry, 0, 32)
+		return &a
+	},
+}
+
+func putDirentSlice(p *[]DirEntry) {
+	if p != nil && cap(*p) <= 32*1024 /* 256Kb */ {
+		a := *p
+		for i := range a {
+			a[i] = nil
+		}
+		*p = a[:0]
+		direntSlicePool.Put(p)
+	}
+}
+
+func sortDirents(mode SortMode, dents []DirEntry) {
 	if len(dents) <= 1 {
 		return
 	}
 	switch mode {
 	case SortLexical:
-		slices.SortFunc(dents, func(d1, d2 fs.DirEntry) int {
+		slices.SortFunc(dents, func(d1, d2 DirEntry) int {
 			return strings.Compare(d1.Name(), d2.Name())
 		})
 	case SortFilesFirst:
-		slices.SortFunc(dents, func(d1, d2 fs.DirEntry) int {
+		slices.SortFunc(dents, func(d1, d2 DirEntry) int {
 			r1 := d1.Type().IsRegular()
 			r2 := d2.Type().IsRegular()
 			switch {
@@ -78,7 +97,7 @@ func sortDirents(mode SortMode, dents []fs.DirEntry) {
 			return strings.Compare(d1.Name(), d2.Name())
 		})
 	case SortDirsFirst:
-		slices.SortFunc(dents, func(d1, d2 fs.DirEntry) int {
+		slices.SortFunc(dents, func(d1, d2 DirEntry) int {
 			dd1 := d1.Type().IsDir()
 			dd2 := d2.Type().IsDir()
 			switch {

dirent_portable_test.go

@@ -10,7 +10,7 @@ import (
 	"time"
 )
 
-var _ fs.DirEntry = dirEntry{}
+var _ DirEntry = dirEntry{}
 
 // Minimal DirEntry for testing
 type dirEntry struct {
@@ -21,7 +21,8 @@ type dirEntry struct {
 func (de dirEntry) Name() string               { return de.name }
 func (de dirEntry) IsDir() bool                { return de.typ.IsDir() }
 func (de dirEntry) Type() fs.FileMode          { return de.typ.Type() }
-func (de dirEntry) Info() (fs.FileInfo, error) { return nil, nil }
+func (de dirEntry) Info() (fs.FileInfo, error) { panic("not implemented") }
+func (de dirEntry) Stat() (fs.FileInfo, error) { panic("not implemented") }
 
 func (de dirEntry) String() string {
 	return fs.FormatDirEntry(de)
@@ -30,7 +31,7 @@ func (de dirEntry) String() string {
 // NB: this must be kept in sync with the
 // TestSortDirents in dirent_unix_test.go
 func TestSortDirents(t *testing.T) {
-	direntNames := func(dents []fs.DirEntry) []string {
+	direntNames := func(dents []DirEntry) []string {
 		names := make([]string, len(dents))
 		for i, d := range dents {
 			names[i] = d.Name()
@@ -39,7 +40,7 @@ func TestSortDirents(t *testing.T) {
 	}
 
 	t.Run("None", func(t *testing.T) {
-		dents := []fs.DirEntry{
+		dents := []DirEntry{
 			dirEntry{name: "b"},
 			dirEntry{name: "a"},
 			dirEntry{name: "d"},
@@ -54,15 +55,15 @@ func TestSortDirents(t *testing.T) {
 	})
 
 	rr := rand.New(rand.NewSource(time.Now().UnixNano()))
-	shuffleDirents := func(dents []fs.DirEntry) []fs.DirEntry {
+	shuffleDirents := func(dents []DirEntry) []DirEntry {
 		rr.Shuffle(len(dents), func(i, j int) {
 			dents[i], dents[j] = dents[j], dents[i]
 		})
 		return dents
 	}
 
 	// dents needs to be in the expected order
-	test := func(t *testing.T, dents []fs.DirEntry, mode SortMode) {
+	test := func(t *testing.T, dents []DirEntry, mode SortMode) {
 		want := direntNames(dents)
 		// Run multiple times with different shuffles
 		for i := 0; i < 10; i++ {
@@ -77,7 +78,7 @@ func TestSortDirents(t *testing.T) {
 	}
 
 	t.Run("Lexical", func(t *testing.T) {
-		dents := []fs.DirEntry{
+		dents := []DirEntry{
 			dirEntry{name: "a"},
 			dirEntry{name: "b"},
 			dirEntry{name: "c"},
@@ -87,7 +88,7 @@ func TestSortDirents(t *testing.T) {
 	})
 
 	t.Run("FilesFirst", func(t *testing.T) {
-		dents := []fs.DirEntry{
+		dents := []DirEntry{
 			// Files lexically
 			dirEntry{name: "f1", typ: 0},
 			dirEntry{name: "f2", typ: 0},
@@ -108,7 +109,7 @@ func TestSortDirents(t *testing.T) {
 	})
 
 	t.Run("DirsFirst", func(t *testing.T) {
-		dents := []fs.DirEntry{
+		dents := []DirEntry{
 			// Dirs lexically
 			dirEntry{name: "d1", typ: fs.ModeDir},
 			dirEntry{name: "d2", typ: fs.ModeDir},

fastwalk_portable.go

@@ -21,20 +21,47 @@ func (w *walker) readDir(dirName string) error {
 		return readErr
 	}
 
+	var p *[]DirEntry
+	if w.sortMode != SortNone {
+		p = direntSlicePool.Get().(*[]DirEntry)
+	}
+	defer putDirentSlice(p)
+
 	var skipFiles bool
 	for _, d := range des {
 		if skipFiles && d.Type().IsRegular() {
 			continue
 		}
 		// Need to use FileMode.Type().Type() for fs.DirEntry
 		e := newDirEntry(dirName, d)
-		if err := w.onDirEnt(dirName, d.Name(), e); err != nil {
+		if w.sortMode != SortNone {
+			if err := w.onDirEnt(dirName, d.Name(), e); err != nil {
+				if err != ErrSkipFiles {
+					return err
+				}
+				skipFiles = true
+			}
+		} else {
+			*p = append(*p, e)
+		}
+	}
+	if w.sortMode == SortNone {
+		return readErr
+	}
+
+	dents := *p
+	sortDirents(w.sortMode, dents)
+	for _, d := range dents {
+		d := d
+		if skipFiles && d.Type().IsRegular() {
+			continue
+		}
+		if err := w.onDirEnt(dirName, d.Name(), d); err != nil {
 			if err != ErrSkipFiles {
 				return err
 			}
 			skipFiles = true
 		}
 	}
-
 	return readErr
 }