1  /* Copyright (C) 1993-2023 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 */