1  /*
       2   * Copyright (C) 2009 Karel Zak <kzak@redhat.com>
       3   *
       4   * This file may be redistributed under the terms of the
       5   * GNU Lesser General Public License.
       6   */
       7  
       8  /**
       9   * SECTION: iter
      10   * @title: Iterator
      11   * @short_description: unified iterator
      12   *
      13   * The iterator keeps the direction and the last position for access to the
      14   * internal library tables/lists.
      15   *
      16   * It's very unusual to use the same iterator on multiple places in your
      17   * application or share the same iterator, for this purpose libfdisk does not
      18   * provide reference counting for this object. It's recommended to initialize
      19   * the iterator by fdisk_new_iter() at begin of your function and then
      20   * fdisk_free_iter() before you return from the function.
      21   *
      22   * Don't forget to call fdisk_reset_iter() if you want to use the iterator more
      23   * than once.
      24   */
      25  #include <stdio.h>
      26  #include <string.h>
      27  #include <stdlib.h>
      28  
      29  #include "fdiskP.h"
      30  
      31  /**
      32   * fdisk_new_iter:
      33   * @direction: FDISK_INTER_{FOR,BACK}WARD direction
      34   *
      35   * Returns: newly allocated generic libmount iterator.
      36   */
      37  struct fdisk_iter *fdisk_new_iter(int direction)
      38  {
      39  	struct fdisk_iter *itr = calloc(1, sizeof(*itr));
      40  	if (!itr)
      41  		return NULL;
      42  	itr->direction = direction;
      43  	return itr;
      44  }
      45  
      46  /**
      47   * fdisk_free_iter:
      48   * @itr: iterator pointer
      49   *
      50   * Deallocates the iterator.
      51   */
      52  void fdisk_free_iter(struct fdisk_iter *itr)
      53  {
      54  	free(itr);
      55  }
      56  
      57  /**
      58   * fdisk_reset_iter:
      59   * @itr: iterator pointer
      60   * @direction: FDISK_ITER_{FOR,BACK}WARD or -1 to keep the direction unchanged
      61   *
      62   * Resets the iterator.
      63   */
      64  void fdisk_reset_iter(struct fdisk_iter *itr, int direction)
      65  {
      66  	if (direction == -1)
      67  		direction = itr->direction;
      68  
      69  	memset(itr, 0, sizeof(*itr));
      70  	itr->direction = direction;
      71  }
      72  
      73  /**
      74   * fdisk_iter_get_direction:
      75   * @itr: iterator pointer
      76   *
      77   * Returns: FDISK_INTER_{FOR,BACK}WARD
      78   */
      79  int fdisk_iter_get_direction(struct fdisk_iter *itr)
      80  {
      81  	return itr->direction;
      82  }