cycle-check.h

/* cycle-check.h: help detect directory cycles efficiently

   Copyright (C) 2003-2004, 2006, 2009-2012 Free Software Foundation, Inc.

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>  */

/* Written by Jim Meyering */

#ifndef CYCLE_CHECK_H
# define CYCLE_CHECK_H 1

# include <stdint.h>
# include <stdbool.h>
# include "dev-ino.h"
# include "same-inode.h"

struct cycle_check_state
{
  struct dev_ino dev_ino;
  uintmax_t chdir_counter;
  int magic;
  int padding; /* should be 4 bytes */
};

void cycle_check_init(struct cycle_check_state *state);
bool cycle_check(struct cycle_check_state *state, struct stat const *sb);

# define CYCLE_CHECK_REFLECT_CHDIR_UP(State, SB_dir, SB_subdir) \
  do {                                                           \
    /* You must use cycle_check at least once before using this macro: */ \
    if ((State)->chdir_counter == 0)                          \
      abort();                                                \
    if (SAME_INODE((State)->dev_ino, SB_subdir))              \
      {                                                       \
        (State)->dev_ino.st_dev = (SB_dir).st_dev;            \
        (State)->dev_ino.st_ino = (SB_dir).st_ino;            \
      }                                                       \
  } while (0)

#endif /* !CYCLE_CHECK_H */

/* EOF */