dlinklist.h revision 2b490bc947dbe0094417304840bd721417a162d9
/*
Unix SMB/CIFS implementation.
some simple double linked list macros
Copyright (C) Andrew Tridgell 1998
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/>.
*/
/* To use these macros you must have a structure containing a next and
prev pointer */
#ifndef _DLINKLIST_H
#define _DLINKLIST_H
/* hook into the front of the list */
#define DLIST_ADD(list, p) \
do { \
if (!(list)) { \
(list) = (p); \
(p)->next = (p)->prev = NULL; \
} else { \
(list)->prev = (p); \
(p)->next = (list); \
(p)->prev = NULL; \
(list) = (p); \
}\
} while (0)
/* remove an element from a list - element doesn't have to be in list. */
#define DLIST_REMOVE(list, p) \
do { \
if ((p) == (list)) { \
(list) = (p)->next; \
if (list) (list)->prev = NULL; \
} else { \
if ((p)->prev) (p)->prev->next = (p)->next; \
if ((p)->next) (p)->next->prev = (p)->prev; \
} \
if ((p) != (list)) (p)->next = (p)->prev = NULL; \
} while (0)
/* promote an element to the top of the list */
#define DLIST_PROMOTE(list, p) \
do { \
DLIST_REMOVE(list, p); \
DLIST_ADD(list, p); \
} while (0)
/* hook into the end of the list - needs a tmp pointer */
#define DLIST_ADD_END(list, p, type) \
do { \
if (!(list)) { \
(list) = (p); \
(p)->next = (p)->prev = NULL; \
} else { \
type tmp; \
for (tmp = (list); tmp->next; tmp = tmp->next) { \
/* no op */ \
} \
tmp->next = (p); \
(p)->next = NULL; \
(p)->prev = tmp; \
} \
} while (0)
/* insert 'p' after the given element 'el' in a list. If el is NULL then
this is the same as a DLIST_ADD() */
#define DLIST_ADD_AFTER(list, p, el) \
do { \
if (!(list) || !(el)) { \
DLIST_ADD(list, p); \
} else { \
p->prev = el; \
p->next = el->next; \
el->next = p; \
if (p->next) p->next->prev = p; \
}\
} while (0)
/* demote an element to the end of the list, needs a tmp pointer */
#define DLIST_DEMOTE(list, p, type) \
do { \
DLIST_REMOVE(list, p); \
DLIST_ADD_END(list, p, type); \
} while (0)
/* concatenate two lists - putting all elements of the 2nd list at the
end of the first list */
#define DLIST_CONCATENATE(list1, list2, type) \
do { \
if (!(list1)) { \
(list1) = (list2); \
} else { \
type tmp; \
for (tmp = (list1); tmp->next; tmp = tmp->next) { \
/* no op */ \
} \
tmp->next = (list2); \
if (list2) { \
(list2)->prev = tmp; \
} \
} \
} while (0)
/* insert all elements from list2 after the given element 'el' in the
* first list */
#define DLIST_ADD_LIST_AFTER(list1, el, list2, type) \
do { \
if (!(list1) || !(el) || !(list2)) { \
DLIST_CONCATENATE(list1, list2, type); \
} else { \
type tmp; \
for (tmp = (list2); tmp->next; tmp = tmp->next) { \
/* no op */ \
} \
(list2)->prev = (el); \
tmp->next = (el)->next; \
(el)->next = (list2); \
if (tmp->next != NULL) tmp->next->prev = tmp; \
} \
} while (0);
#define DLIST_FOR_EACH(p, list) \
for ((p) = (list); (p) != NULL; (p) = (p)->next)
#endif /* _DLINKLIST_H */