+++ /dev/null
-/*
- Unix SMB/CIFS implementation.
- some simple double linked list macros
-
- Copyright (C) Andrew Tridgell 1998-2010
-
- 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
-
-/*
- February 2010 - changed list format to have a prev pointer from the
- list head. This makes DLIST_ADD_END() O(1) even though we only have
- one list pointer.
-
- The scheme is as follows:
-
- 1) with no entries in the list:
- list_head == NULL
-
- 2) with 1 entry in the list:
- list_head->next == NULL
- list_head->prev == list_head
-
- 3) with 2 entries in the list:
- list_head->next == element2
- list_head->prev == element2
- element2->prev == list_head
- element2->next == NULL
-
- 4) with N entries in the list:
- list_head->next == element2
- list_head->prev == elementN
- elementN->prev == element{N-1}
- elementN->next == NULL
-
- This allows us to find the tail of the list by using
- list_head->prev, which means we can add to the end of the list in
- O(1) time
-
-
- Note that the 'type' arguments below are no longer needed, but
- are kept for now to prevent an incompatible argument change
- */
-
-
-/*
- add an element at the front of a list
-*/
-#define DLIST_ADD(list, p) \
-do { \
- if (!(list)) { \
- (p)->prev = (list) = (p); \
- (p)->next = NULL; \
- } else { \
- (p)->prev = (list)->prev; \
- (list)->prev = (p); \
- (p)->next = (list); \
- (list) = (p); \
- } \
-} while (0)
-
-/*
- remove an element from a list
- Note that the element doesn't have to be in the list. If it
- isn't then this is a no-op
-*/
-#define DLIST_REMOVE(list, p) \
-do { \
- if ((p) == (list)) { \
- if ((p)->next) (p)->next->prev = (p)->prev; \
- (list) = (p)->next; \
- } else if ((list) && (p) == (list)->prev) { \
- (p)->prev->next = NULL; \
- (list)->prev = (p)->prev; \
- } 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)
-
-/*
- find the head of the list given any element in it.
- Note that this costs O(N), so you should avoid this macro
- if at all possible!
-*/
-#define DLIST_HEAD(p, result_head) \
-do { \
- (result_head) = (p); \
- while (DLIST_PREV(result_head)) (result_head) = (result_head)->prev; \
-} while(0)
-
-/* return the last element in the list */
-#define DLIST_TAIL(list) ((list)?(list)->prev:NULL)
-
-/* return the previous element in the list. */
-#define DLIST_PREV(p) (((p)->prev && (p)->prev->next != NULL)?(p)->prev:NULL)
-
-/* 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); \
- if ((list)->prev == (el)) (list)->prev = (p); \
- }\
-} while (0)
-
-
-/*
- add to the end of a list.
- Note that 'type' is ignored
-*/
-#define DLIST_ADD_END(list, p, type) \
-do { \
- if (!(list)) { \
- DLIST_ADD(list, p); \
- } else { \
- DLIST_ADD_AFTER(list, p, (list)->prev); \
- } \
-} while (0)
-
-/* promote an element to the from of a list */
-#define DLIST_PROMOTE(list, p) \
-do { \
- DLIST_REMOVE(list, p); \
- DLIST_ADD(list, p); \
-} while (0)
-
-/*
- demote an element to the end of a list.
- Note that 'type' is ignored
-*/
-#define DLIST_DEMOTE(list, p, type) \
-do { \
- DLIST_REMOVE(list, p); \
- DLIST_ADD_END(list, p, NULL); \
-} while (0)
-
-/*
- concatenate two lists - putting all elements of the 2nd list at the
- end of the first list.
- Note that 'type' is ignored
-*/
-#define DLIST_CONCATENATE(list1, list2, type) \
-do { \
- if (!(list1)) { \
- (list1) = (list2); \
- } else { \
- (list1)->prev->next = (list2); \
- if (list2) { \
- void *_tmplist = (void *)(list1)->prev; \
- (list1)->prev = (list2)->prev; \
- (list2)->prev = _tmplist; \
- } \
- } \
-} while (0)
-
-#endif /* _DLINKLIST_H */
git.samba.org / kai / samba-autobuild / .git / blobdiff