getdirentries_test.go

     1  // Copyright 2019 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  
     5  //go:build darwin || freebsd || netbsd || openbsd
     6  
     7  package syscall_test
     8  
     9  import (
    10  	"fmt"
    11  	"os"
    12  	"path/filepath"
    13  	"sort"
    14  	"strings"
    15  	"syscall"
    16  	"testing"
    17  	"unsafe"
    18  )
    19  
    20  func TestGetdirentries(t *testing.T) {
    21  	for _, count := range []int{10, 1000} {
    22  		t.Run(fmt.Sprintf("n=%d", count), func(t *testing.T) {
    23  			testGetdirentries(t, count)
    24  		})
    25  	}
    26  }
    27  func testGetdirentries(t *testing.T, count int) {
    28  	if count > 100 && testing.Short() && os.Getenv("GO_BUILDER_NAME") == "" {
    29  		t.Skip("skipping in -short mode")
    30  	}
    31  	d := t.TempDir()
    32  	var names []string
    33  	for i := 0; i < count; i++ {
    34  		names = append(names, fmt.Sprintf("file%03d", i))
    35  	}
    36  
    37  	// Make files in the temp directory
    38  	for _, name := range names {
    39  		err := os.WriteFile(filepath.Join(d, name), []byte("data"), 0)
    40  		if err != nil {
    41  			t.Fatalf("WriteFile: %v", err)
    42  		}
    43  	}
    44  
    45  	// Read files using Getdirentries
    46  	var names2 []string
    47  	fd, err := syscall.Open(d, syscall.O_RDONLY, 0)
    48  	if err != nil {
    49  		t.Fatalf("Open: %v", err)
    50  	}
    51  	defer syscall.Close(fd)
    52  	var base uintptr
    53  	var buf [2048]byte
    54  	for {
    55  		n, err := syscall.Getdirentries(fd, buf[:], &base)
    56  		if err != nil {
    57  			t.Fatalf("Getdirentries: %v", err)
    58  		}
    59  		if n == 0 {
    60  			break
    61  		}
    62  		data := buf[:n]
    63  		for len(data) > 0 {
    64  			// If multiple Dirents are written into buf, sometimes when we reach the final one,
    65  			// we have cap(buf) < Sizeof(Dirent). So use an appropriate slice to copy from data.
    66  			var dirent syscall.Dirent
    67  			copy((*[unsafe.Sizeof(dirent)]byte)(unsafe.Pointer(&dirent))[:], data)
    68  
    69  			data = data[dirent.Reclen:]
    70  			name := make([]byte, dirent.Namlen)
    71  			for i := 0; i < int(dirent.Namlen); i++ {
    72  				name[i] = byte(dirent.Name[i])
    73  			}
    74  			names2 = append(names2, string(name))
    75  		}
    76  	}
    77  
    78  	names = append(names, ".", "..") // Getdirentries returns these also
    79  	sort.Strings(names)
    80  	sort.Strings(names2)
    81  	if strings.Join(names, ":") != strings.Join(names2, ":") {
    82  		t.Errorf("names don't match\n names: %q\nnames2: %q", names, names2)
    83  	}
    84  }
    85
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