1: /* help detect directory cycles efficiently
    2: 
    3:    Copyright (C) 2003, 2004, 2006 Free Software Foundation, Inc.
    4: 
    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)
    8:    any later version.
    9: 
   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.
   14: 
   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.  */
   19: 
   20: /* Written by Jim Meyering */
   21: 
   22: #ifndef CYCLE_CHECK_H
   23: # define CYCLE_CHECK_H 1
   24: 
   25: # include <stdint.h>
   26: # include <stdbool.h>
   27: # include "dev-ino.h"
   28: # include "same-inode.h"
   29: 
   30: struct cycle_check_state
   31: {
   32:   struct dev_ino dev_ino;
   33:   uintmax_t chdir_counter;
   34:   int magic;
   35: };
   36: 
   37: void cycle_check_init (struct cycle_check_state *state);
   38: bool cycle_check (struct cycle_check_state *state, struct stat const *sb);
   39: 
   40: # define CYCLE_CHECK_REFLECT_CHDIR_UP(State, SB_dir, SB_subdir) \
   41:   do                                                            \
   42:     {                                                           \
   43:       /* You must call cycle_check at least once before using this macro.  */ \
   44:       if ((State)->chdir_counter == 0)                          \
   45:         abort ();                                               \
   46:       if (SAME_INODE ((State)->dev_ino, SB_subdir))             \
   47:         {                                                      \
   48:           (State)->dev_ino.st_dev = (SB_dir).st_dev;           \
   49:           (State)->dev_ino.st_ino = (SB_dir).st_ino;           \
   50:         }                                                      \
   51:     }                                                           \
   52:   while (0)
   53: 
   54: #endif