1 /* Copyright (C) 1993-2022 Free Software Foundation, Inc.
2    This file is part of the GNU C Library.
3 
4    The GNU C Library is free software; you can redistribute it and/or
5    modify it under the terms of the GNU Lesser General Public
6    License as published by the Free Software Foundation; either
7    version 2.1 of the License, or (at your option) any later version.
8 
9    The GNU C Library is distributed in the hope that it will be useful,
10    but WITHOUT ANY WARRANTY; without even the implied warranty of
11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12    Lesser General Public License for more details.
13 
14    You should have received a copy of the GNU Lesser General Public
15    License along with the GNU C Library; if not, see
16    <https://www.gnu.org/licenses/>.  */
17 
18 #ifndef	_DIRSTREAM_H
19 #define	_DIRSTREAM_H	1
20 
21 #include <sys/types.h>
22 
23 #include <libc-lock.h>
24 
25 /* Directory stream type.
26 
27    The miscellaneous Unix `readdir' implementations read directory data
28    into a buffer and return `struct dirent *' pointers into it.  */
29 
30 struct __dirstream
31   {
32     int fd;			/* File descriptor.  */
33 
34     __libc_lock_define (, lock) /* Mutex lock for this structure.  */
35 
36     size_t allocation;		/* Space allocated for the block.  */
37     size_t size;		/* Total valid data in the block.  */
38     size_t offset;		/* Current offset into the block.  */
39 
40     off_t filepos;		/* Position of next entry to read.  */
41 
42     int errcode;		/* Delayed error code.  */
43 
44     /* Directory block.  We must make sure that this block starts
45        at an address that is aligned adequately enough to store
46        dirent entries.  Using the alignment of "void *" is not
47        sufficient because dirents on 32-bit platforms can require
48        64-bit alignment.  We use "long double" here to be consistent
49        with what malloc uses.  */
50     char data[0] __attribute__ ((aligned (__alignof__ (long double))));
51   };
52 
53 #define _DIR_dirfd(dirp)	((dirp)->fd)
54 
55 #endif	/* dirstream.h */
56