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Diffstat (limited to 'src/libbasic/include/basic/list.h')
| -rw-r--r-- | src/libbasic/include/basic/list.h | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/src/libbasic/include/basic/list.h b/src/libbasic/include/basic/list.h new file mode 100644 index 0000000000..5962aa4211 --- /dev/null +++ b/src/libbasic/include/basic/list.h @@ -0,0 +1,182 @@ +#pragma once + +/*** + This file is part of systemd. + + Copyright 2010 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +/* The head of the linked list. Use this in the structure that shall + * contain the head of the linked list */ +#define LIST_HEAD(t,name) \ + t *name + +/* The pointers in the linked list's items. Use this in the item structure */ +#define LIST_FIELDS(t,name) \ + t *name##_next, *name##_prev + +/* Initialize the list's head */ +#define LIST_HEAD_INIT(head) \ + do { \ + (head) = NULL; } \ + while (false) + +/* Initialize a list item */ +#define LIST_INIT(name,item) \ + do { \ + typeof(*(item)) *_item = (item); \ + assert(_item); \ + _item->name##_prev = _item->name##_next = NULL; \ + } while (false) + +/* Prepend an item to the list */ +#define LIST_PREPEND(name,head,item) \ + do { \ + typeof(*(head)) **_head = &(head), *_item = (item); \ + assert(_item); \ + if ((_item->name##_next = *_head)) \ + _item->name##_next->name##_prev = _item; \ + _item->name##_prev = NULL; \ + *_head = _item; \ + } while (false) + +/* Append an item to the list */ +#define LIST_APPEND(name,head,item) \ + do { \ + typeof(*(head)) *_tail; \ + LIST_FIND_TAIL(name,head,_tail); \ + LIST_INSERT_AFTER(name,head,_tail,item); \ + } while (false) + +/* Remove an item from the list */ +#define LIST_REMOVE(name,head,item) \ + do { \ + typeof(*(head)) **_head = &(head), *_item = (item); \ + assert(_item); \ + if (_item->name##_next) \ + _item->name##_next->name##_prev = _item->name##_prev; \ + if (_item->name##_prev) \ + _item->name##_prev->name##_next = _item->name##_next; \ + else { \ + assert(*_head == _item); \ + *_head = _item->name##_next; \ + } \ + _item->name##_next = _item->name##_prev = NULL; \ + } while (false) + +/* Find the head of the list */ +#define LIST_FIND_HEAD(name,item,head) \ + do { \ + typeof(*(item)) *_item = (item); \ + if (!_item) \ + (head) = NULL; \ + else { \ + while (_item->name##_prev) \ + _item = _item->name##_prev; \ + (head) = _item; \ + } \ + } while (false) + +/* Find the tail of the list */ +#define LIST_FIND_TAIL(name,item,tail) \ + do { \ + typeof(*(item)) *_item = (item); \ + if (!_item) \ + (tail) = NULL; \ + else { \ + while (_item->name##_next) \ + _item = _item->name##_next; \ + (tail) = _item; \ + } \ + } while (false) + +/* Insert an item after another one (a = where, b = what) */ +#define LIST_INSERT_AFTER(name,head,a,b) \ + do { \ + typeof(*(head)) **_head = &(head), *_a = (a), *_b = (b); \ + assert(_b); \ + if (!_a) { \ + if ((_b->name##_next = *_head)) \ + _b->name##_next->name##_prev = _b; \ + _b->name##_prev = NULL; \ + *_head = _b; \ + } else { \ + if ((_b->name##_next = _a->name##_next)) \ + _b->name##_next->name##_prev = _b; \ + _b->name##_prev = _a; \ + _a->name##_next = _b; \ + } \ + } while (false) + +/* Insert an item before another one (a = where, b = what) */ +#define LIST_INSERT_BEFORE(name,head,a,b) \ + do { \ + typeof(*(head)) **_head = &(head), *_a = (a), *_b = (b); \ + assert(_b); \ + if (!_a) { \ + if (!*_head) { \ + _b->name##_next = NULL; \ + _b->name##_prev = NULL; \ + *_head = _b; \ + } else { \ + typeof(*(head)) *_tail = (head); \ + while (_tail->name##_next) \ + _tail = _tail->name##_next; \ + _b->name##_next = NULL; \ + _b->name##_prev = _tail; \ + _tail->name##_next = _b; \ + } \ + } else { \ + if ((_b->name##_prev = _a->name##_prev)) \ + _b->name##_prev->name##_next = _b; \ + _b->name##_next = _a; \ + _a->name##_prev = _b; \ + } \ + } while (false) + +#define LIST_JUST_US(name,item) \ + (!(item)->name##_prev && !(item)->name##_next) \ + +#define LIST_FOREACH(name,i,head) \ + for ((i) = (head); (i); (i) = (i)->name##_next) + +#define LIST_FOREACH_SAFE(name,i,n,head) \ + for ((i) = (head); (i) && (((n) = (i)->name##_next), 1); (i) = (n)) + +#define LIST_FOREACH_BEFORE(name,i,p) \ + for ((i) = (p)->name##_prev; (i); (i) = (i)->name##_prev) + +#define LIST_FOREACH_AFTER(name,i,p) \ + for ((i) = (p)->name##_next; (i); (i) = (i)->name##_next) + +/* Iterate through all the members of the list p is included in, but skip over p */ +#define LIST_FOREACH_OTHERS(name,i,p) \ + for (({ \ + (i) = (p); \ + while ((i) && (i)->name##_prev) \ + (i) = (i)->name##_prev; \ + if ((i) == (p)) \ + (i) = (p)->name##_next; \ + }); \ + (i); \ + (i) = (i)->name##_next == (p) ? (p)->name##_next : (i)->name##_next) + +/* Loop starting from p->next until p->prev. + p can be adjusted meanwhile. */ +#define LIST_LOOP_BUT_ONE(name,i,head,p) \ + for ((i) = (p)->name##_next ? (p)->name##_next : (head); \ + (i) != (p); \ + (i) = (i)->name##_next ? (i)->name##_next : (head)) |