libgo/go/syscall/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 // +build darwin freebsd netbsd openbsd
   6
   7 package syscall_test
   8
   9 import (
  10         "fmt"
  11         "io/ioutil"
  12         "os"
  13         "path/filepath"
  14         "sort"
  15         "strings"
  16         "syscall"
  17         "testing"
  18         "unsafe"
  19 )
  20
  21 func TestGetdirentries(t *testing.T) {
  22         for _, count := range []int{10, 1000} {
  23                 t.Run(fmt.Sprintf("n=%d", count), func(t *testing.T) {
  24                         testGetdirentries(t, count)
  25                 })
  26         }
  27 }
  28 func testGetdirentries(t *testing.T, count int) {
  29         if count > 100 && testing.Short() && os.Getenv("GO_BUILDER_NAME") == "" {
  30                 t.Skip("skipping in -short mode")
  31         }
  32         d, err := ioutil.TempDir("", "getdirentries-test")
  33         if err != nil {
  34                 t.Fatalf("Tempdir: %v", err)
  35         }
  36         defer os.RemoveAll(d)
  37         var names []string
  38         for i := 0; i < count; i++ {
  39                 names = append(names, fmt.Sprintf("file%03d", i))
  40         }
  41
  42         // Make files in the temp directory
  43         for _, name := range names {
  44                 err := ioutil.WriteFile(filepath.Join(d, name), []byte("data"), 0)
  45                 if err != nil {
  46                         t.Fatalf("WriteFile: %v", err)
  47                 }
  48         }
  49
  50         // Read files using Getdirentries
  51         var names2 []string
  52         fd, err := syscall.Open(d, syscall.O_RDONLY, 0)
  53         if err != nil {
  54                 t.Fatalf("Open: %v", err)
  55         }
  56         defer syscall.Close(fd)
  57         var base uintptr
  58         var buf [2048]byte
  59         for {
  60                 n, err := syscall.Getdirentries(fd, buf[:], &base)
  61                 if err != nil {
  62                         t.Fatalf("Getdirentries: %v", err)
  63                 }
  64                 if n == 0 {
  65                         break
  66                 }
  67                 data := buf[:n]
  68                 for len(data) > 0 {
  69                         // If multiple Dirents are written into buf, sometimes when we reach the final one,
  70                         // we have cap(buf) < Sizeof(Dirent). So use an appropriate slice to copy from data.
  71                         var dirent syscall.Dirent
  72                         copy((*[unsafe.Sizeof(dirent)]byte)(unsafe.Pointer(&dirent))[:], data)
  73
  74                         data = data[dirent.Reclen:]
  75                         name := make([]byte, dirent.Namlen)
  76                         for i := 0; i < int(dirent.Namlen); i++ {
  77                                 name[i] = byte(dirent.Name[i])
  78                         }
  79                         names2 = append(names2, string(name))
  80                 }
  81         }
  82
  83         names = append(names, ".", "..") // Getdirentries returns these also
  84         sort.Strings(names)
  85         sort.Strings(names2)
  86         if strings.Join(names, ":") != strings.Join(names2, ":") {
  87                 t.Errorf("names don't match\n names: %q\nnames2: %q", names, names2)
  88         }
  89 }