github.com/wasilibs/wazerox@v0.0.0-20240124024944-4923be63ab5f/experimental/sys/dir.go (about)

     1  package sys
     2  
     3  import (
     4  	"fmt"
     5  	"io/fs"
     6  
     7  	"github.com/wasilibs/wazerox/sys"
     8  )
     9  
    10  // FileType is fs.FileMode masked on fs.ModeType. For example, zero is a
    11  // regular file, fs.ModeDir is a directory and fs.ModeIrregular is unknown.
    12  //
    13  // Note: This is defined by Linux, not POSIX.
    14  type FileType = fs.FileMode
    15  
    16  // Dirent is an entry read from a directory via File.Readdir.
    17  //
    18  // # Notes
    19  //
    20  //   - This extends `dirent` defined in POSIX with some fields defined by
    21  //     Linux. See https://man7.org/linux/man-pages/man3/readdir.3.html and
    22  //     https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/dirent.h.html
    23  //   - This has a subset of fields defined in sys.Stat_t. Notably, there is no
    24  //     field corresponding to Stat_t.Dev because that value will be constant
    25  //     for all files in a directory. To get the Dev value, call File.Stat on
    26  //     the directory File.Readdir was called on.
    27  type Dirent struct {
    28  	// Ino is the file serial number, or zero if not available. See Ino for
    29  	// more details including impact returning a zero value.
    30  	Ino sys.Inode
    31  
    32  	// Name is the base name of the directory entry. Empty is invalid.
    33  	Name string
    34  
    35  	// Type is fs.FileMode masked on fs.ModeType. For example, zero is a
    36  	// regular file, fs.ModeDir is a directory and fs.ModeIrregular is unknown.
    37  	//
    38  	// Note: This is defined by Linux, not POSIX.
    39  	Type fs.FileMode
    40  }
    41  
    42  func (d *Dirent) String() string {
    43  	return fmt.Sprintf("name=%s, type=%v, ino=%d", d.Name, d.Type, d.Ino)
    44  }
    45  
    46  // IsDir returns true if the Type is fs.ModeDir.
    47  func (d *Dirent) IsDir() bool {
    48  	return d.Type == fs.ModeDir
    49  }
    50  
    51  // DirFile is embeddable to reduce the amount of functions to implement a file.
    52  type DirFile struct{}
    53  
    54  // IsAppend implements File.IsAppend
    55  func (DirFile) IsAppend() bool {
    56  	return false
    57  }
    58  
    59  // SetAppend implements File.SetAppend
    60  func (DirFile) SetAppend(bool) Errno {
    61  	return EISDIR
    62  }
    63  
    64  // IsDir implements File.IsDir
    65  func (DirFile) IsDir() (bool, Errno) {
    66  	return true, 0
    67  }
    68  
    69  // Read implements File.Read
    70  func (DirFile) Read([]byte) (int, Errno) {
    71  	return 0, EISDIR
    72  }
    73  
    74  // Pread implements File.Pread
    75  func (DirFile) Pread([]byte, int64) (int, Errno) {
    76  	return 0, EISDIR
    77  }
    78  
    79  // Write implements File.Write
    80  func (DirFile) Write([]byte) (int, Errno) {
    81  	return 0, EISDIR
    82  }
    83  
    84  // Pwrite implements File.Pwrite
    85  func (DirFile) Pwrite([]byte, int64) (int, Errno) {
    86  	return 0, EISDIR
    87  }
    88  
    89  // Truncate implements File.Truncate
    90  func (DirFile) Truncate(int64) Errno {
    91  	return EISDIR
    92  }