1// Copyright 2023 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 wasip1
6
7package os
8
9import (
10	"syscall"
11	"unsafe"
12)
13
14// https://github.com/WebAssembly/WASI/blob/main/legacy/preview1/docs.md#-dirent-record
15const sizeOfDirent = 24
16
17func direntIno(buf []byte) (uint64, bool) {
18	return readInt(buf, unsafe.Offsetof(syscall.Dirent{}.Ino), unsafe.Sizeof(syscall.Dirent{}.Ino))
19}
20
21func direntReclen(buf []byte) (uint64, bool) {
22	namelen, ok := direntNamlen(buf)
23	return sizeOfDirent + namelen, ok
24}
25
26func direntNamlen(buf []byte) (uint64, bool) {
27	return readInt(buf, unsafe.Offsetof(syscall.Dirent{}.Namlen), unsafe.Sizeof(syscall.Dirent{}.Namlen))
28}
29
30func direntType(buf []byte) FileMode {
31	off := unsafe.Offsetof(syscall.Dirent{}.Type)
32	if off >= uintptr(len(buf)) {
33		return ^FileMode(0) // unknown
34	}
35	switch syscall.Filetype(buf[off]) {
36	case syscall.FILETYPE_BLOCK_DEVICE:
37		return ModeDevice
38	case syscall.FILETYPE_CHARACTER_DEVICE:
39		return ModeDevice | ModeCharDevice
40	case syscall.FILETYPE_DIRECTORY:
41		return ModeDir
42	case syscall.FILETYPE_REGULAR_FILE:
43		return 0
44	case syscall.FILETYPE_SOCKET_DGRAM:
45		return ModeSocket
46	case syscall.FILETYPE_SOCKET_STREAM:
47		return ModeSocket
48	case syscall.FILETYPE_SYMBOLIC_LINK:
49		return ModeSymlink
50	}
51	return ^FileMode(0) // unknown
52}
53