1 /* help detect directory cycles efficiently
3 Copyright (C) 2003, 2004, 2006 Free Software Foundation, Inc.
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2, or (at your option)
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program; see the file COPYING.
17 If not, write to the Free Software Foundation,
18 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
20 /* Written by Jim Meyering */
23 # define CYCLE_CHECK_H 1
28 # include "same-inode.h"
30 struct cycle_check_state
32 struct dev_ino dev_ino;
33 uintmax_t chdir_counter;
37 void cycle_check_init (struct cycle_check_state *state);
38 bool cycle_check (struct cycle_check_state *state, struct stat const *sb);
40 # define CYCLE_CHECK_REFLECT_CHDIR_UP(State, SB_dir, SB_subdir) \
43 /* You must call cycle_check at least once before using this macro. */ \
44 if ((State)->chdir_counter == 0) \
46 if (SAME_INODE ((State)->dev_ino, SB_subdir)) \
48 (State)->dev_ino.st_dev = (SB_dir).st_dev; \
49 (State)->dev_ino.st_ino = (SB_dir).st_ino; \