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comparison vendor/golang.org/x/sys/unix/dirent.go @ 66:787b5ee0289d draft

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Use vendored modules Signed-off-by: Izuru Yakumo <yakumo.izuru@chaotic.ninja>
author yakumo.izuru
date Sun, 23 Jul 2023 13:18:53 +0000
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65:6d985efa0f7a 66:787b5ee0289d
1 // Copyright 2009 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 aix || darwin || dragonfly || freebsd || linux || netbsd || openbsd || solaris
6 // +build aix darwin dragonfly freebsd linux netbsd openbsd solaris
7
8 package unix
9
10 import "unsafe"
11
12 // readInt returns the size-bytes unsigned integer in native byte order at offset off.
13 func readInt(b []byte, off, size uintptr) (u uint64, ok bool) {
14 if len(b) < int(off+size) {
15 return 0, false
16 }
17 if isBigEndian {
18 return readIntBE(b[off:], size), true
19 }
20 return readIntLE(b[off:], size), true
21 }
22
23 func readIntBE(b []byte, size uintptr) uint64 {
24 switch size {
25 case 1:
26 return uint64(b[0])
27 case 2:
28 _ = b[1] // bounds check hint to compiler; see golang.org/issue/14808
29 return uint64(b[1]) | uint64(b[0])<<8
30 case 4:
31 _ = b[3] // bounds check hint to compiler; see golang.org/issue/14808
32 return uint64(b[3]) | uint64(b[2])<<8 | uint64(b[1])<<16 | uint64(b[0])<<24
33 case 8:
34 _ = b[7] // bounds check hint to compiler; see golang.org/issue/14808
35 return uint64(b[7]) | uint64(b[6])<<8 | uint64(b[5])<<16 | uint64(b[4])<<24 |
36 uint64(b[3])<<32 | uint64(b[2])<<40 | uint64(b[1])<<48 | uint64(b[0])<<56
37 default:
38 panic("syscall: readInt with unsupported size")
39 }
40 }
41
42 func readIntLE(b []byte, size uintptr) uint64 {
43 switch size {
44 case 1:
45 return uint64(b[0])
46 case 2:
47 _ = b[1] // bounds check hint to compiler; see golang.org/issue/14808
48 return uint64(b[0]) | uint64(b[1])<<8
49 case 4:
50 _ = b[3] // bounds check hint to compiler; see golang.org/issue/14808
51 return uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24
52 case 8:
53 _ = b[7] // bounds check hint to compiler; see golang.org/issue/14808
54 return uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 |
55 uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56
56 default:
57 panic("syscall: readInt with unsupported size")
58 }
59 }
60
61 // ParseDirent parses up to max directory entries in buf,
62 // appending the names to names. It returns the number of
63 // bytes consumed from buf, the number of entries added
64 // to names, and the new names slice.
65 func ParseDirent(buf []byte, max int, names []string) (consumed int, count int, newnames []string) {
66 origlen := len(buf)
67 count = 0
68 for max != 0 && len(buf) > 0 {
69 reclen, ok := direntReclen(buf)
70 if !ok || reclen > uint64(len(buf)) {
71 return origlen, count, names
72 }
73 rec := buf[:reclen]
74 buf = buf[reclen:]
75 ino, ok := direntIno(rec)
76 if !ok {
77 break
78 }
79 if ino == 0 { // File absent in directory.
80 continue
81 }
82 const namoff = uint64(unsafe.Offsetof(Dirent{}.Name))
83 namlen, ok := direntNamlen(rec)
84 if !ok || namoff+namlen > uint64(len(rec)) {
85 break
86 }
87 name := rec[namoff : namoff+namlen]
88 for i, c := range name {
89 if c == 0 {
90 name = name[:i]
91 break
92 }
93 }
94 // Check for useless names before allocating a string.
95 if string(name) == "." || string(name) == ".." {
96 continue
97 }
98 max--
99 count++
100 names = append(names, string(name))
101 }
102 return origlen - len(buf), count, names
103 }