diff options
Diffstat (limited to 'libglusterfs/src/list.h')
| -rw-r--r-- | libglusterfs/src/list.h | 74 |
1 files changed, 58 insertions, 16 deletions
diff --git a/libglusterfs/src/list.h b/libglusterfs/src/list.h index 52d98fc51..3bb991fac 100644 --- a/libglusterfs/src/list.h +++ b/libglusterfs/src/list.h @@ -1,20 +1,11 @@ /* - Copyright (c) 2008-2010 Gluster, Inc. <http://www.gluster.com> - This file is part of GlusterFS. - - GlusterFS is free software; you can redistribute it and/or modify - it under the terms of the GNU Affero General Public License as published - by the Free Software Foundation; either version 3 of the License, - or (at your option) any later version. - - GlusterFS 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 - Affero General Public License for more details. - - You should have received a copy of the GNU Affero General Public License - along with this program. If not, see - <http://www.gnu.org/licenses/>. + Copyright (c) 2008-2012 Red Hat, Inc. <http://www.redhat.com> + This file is part of GlusterFS. + + This file is licensed to you under your choice of the GNU Lesser + General Public License, version 3 or any later version (LGPLv3 or + later), or the GNU General Public License, version 2 (GPLv2), in all + cases as published by the Free Software Foundation. */ #ifndef _LLIST_H @@ -54,6 +45,31 @@ list_add_tail (struct list_head *new, struct list_head *head) } +/* This function will insert the element to the list in a order. + Order will be based on the compare function provided as a input. + If element to be inserted in ascending order compare should return: + 0: if both the arguments are equal + >0: if first argument is greater than second argument + <0: if first argument is less than second argument */ +static inline void +list_add_order (struct list_head *new, struct list_head *head, + int (*compare)(struct list_head *, struct list_head *)) +{ + struct list_head *pos = head->prev; + + while ( pos != head ) { + if (compare(new, pos) >= 0) + break; + + /* Iterate the list in the reverse order. This will have + better efficiency if the elements are inserted in the + ascending order */ + pos = pos->prev; + } + + list_add (new, pos); +} + static inline void list_del (struct list_head *old) { @@ -184,4 +200,30 @@ list_append_init (struct list_head *list, struct list_head *head) &pos->member != (head); \ pos = n, n = list_entry(n->member.next, typeof(*n), member)) +#define list_for_each_entry_reverse(pos, head, member) \ + for (pos = list_entry((head)->prev, typeof(*pos), member); \ + &pos->member != (head); \ + pos = list_entry(pos->member.prev, typeof(*pos), member)) + + +#define list_for_each_entry_safe_reverse(pos, n, head, member) \ + for (pos = list_entry((head)->prev, typeof(*pos), member), \ + n = list_entry(pos->member.prev, typeof(*pos), member); \ + &pos->member != (head); \ + pos = n, n = list_entry(n->member.prev, typeof(*n), member)) + +/* + * This list implementation has some advantages, but one disadvantage: you + * can't use NULL to check whether you're at the head or tail. Thus, the + * address of the head has to be an argument for these macros. + */ + +#define list_next(ptr,head,type,member) \ + (((ptr)->member.next == head) ? NULL \ + : list_entry((ptr)->member.next,type,member)) + +#define list_prev(ptr,head,type,member) \ + (((ptr)->member.prev == head) ? NULL \ + : list_entry((ptr)->member.prev,type,member)) + #endif /* _LLIST_H */ |