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/* |
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* Copyright 2008-2011 Various Authors |
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* Copyright 2005 Timo Hirvonen |
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* |
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* This program is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU General Public License as |
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* published by the Free Software Foundation; either version 2 of the |
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* License, or (at your option) any later version. |
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* |
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* This program is distributed in the hope that it will be useful, but |
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* WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* General Public License for more details. |
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* |
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* You should have received a copy of the GNU General Public License |
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* along with this program; if not, see <http://www.gnu.org/licenses/>. |
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*/ |
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|
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#ifndef _ITER_H |
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#define _ITER_H |
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|
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#include <stddef.h> /* NULL */ |
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|
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struct iter { |
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/* this usually points to the list head */ |
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void *data0; |
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|
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/* these point to the list item, for simple lists data2 is usually NULL */ |
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void *data1; |
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void *data2; |
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}; |
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|
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static inline void iter_init(struct iter *iter) |
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{ |
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iter->data0 = NULL; |
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iter->data1 = NULL; |
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iter->data2 = NULL; |
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} |
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|
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static inline void iter_head(struct iter *iter) |
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{ |
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iter->data1 = NULL; |
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iter->data2 = NULL; |
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} |
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|
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static inline int iters_equal(struct iter *a, struct iter *b) |
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{ |
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return a->data0 == b->data0 && |
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a->data1 == b->data1 && |
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a->data2 == b->data2; |
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} |
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|
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static inline int iter_is_head(struct iter *iter) |
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{ |
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return iter->data0 != NULL && |
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iter->data1 == NULL && |
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iter->data2 == NULL; |
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} |
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|
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static inline int iter_is_null(struct iter *iter) |
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{ |
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return iter->data0 == NULL && |
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iter->data1 == NULL && |
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iter->data2 == NULL; |
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} |
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|
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static inline int iter_is_empty(struct iter *iter) |
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{ |
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return iter->data0 == NULL || (iter->data1 == NULL && iter->data2 == NULL); |
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} |
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|
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#define GENERIC_ITER_PREV(FUNC, TYPE, MEMBER) \ |
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int FUNC(struct iter *iter) \ |
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{ \ |
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struct list_head *head = iter->data0; \ |
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TYPE *e = iter->data1; \ |
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\ |
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if (head == NULL) \ |
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return 0; \ |
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if (e == NULL) { \ |
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/* head, get last */ \ |
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if (head->prev == head) { \ |
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/* empty, iter points to the head already */ \ |
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return 0; \ |
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} \ |
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iter->data1 = container_of(head->prev, TYPE, MEMBER); \ |
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return 1; \ |
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} \ |
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if (e->MEMBER.prev == head) { \ |
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iter->data1 = NULL; \ |
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return 0; \ |
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} \ |
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iter->data1 = container_of(e->MEMBER.prev, TYPE, MEMBER); \ |
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return 1; \ |
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} |
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|
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#define GENERIC_ITER_NEXT(FUNC, TYPE, MEMBER) \ |
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int FUNC(struct iter *iter) \ |
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{ \ |
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struct list_head *head = iter->data0; \ |
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TYPE *e = iter->data1; \ |
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\ |
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if (head == NULL) \ |
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return 0; \ |
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if (e == NULL) { \ |
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/* head, get first */ \ |
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if (head->next == head) { \ |
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/* empty, iter points to the head already */ \ |
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return 0; \ |
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} \ |
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iter->data1 = container_of(head->next, TYPE, MEMBER); \ |
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return 1; \ |
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} \ |
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if (e->MEMBER.next == head) { \ |
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iter->data1 = NULL; \ |
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return 0; \ |
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} \ |
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iter->data1 = container_of(e->MEMBER.next, TYPE, MEMBER); \ |
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return 1; \ |
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} |
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|
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#define GENERIC_TREE_ITER_PREV(FUNC, TYPE, MEMBER) \ |
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int FUNC(struct iter *iter) \ |
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{ \ |
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struct rb_root *root = iter->data0; \ |
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TYPE *e = iter->data1; \ |
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\ |
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if (root == NULL) \ |
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return 0; \ |
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if (e == NULL) { \ |
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/* head, get last */ \ |
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if (rb_root_empty(root)) { \ |
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/* empty, iter points to the head already */ \ |
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return 0; \ |
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} \ |
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iter->data1 = container_of(rb_last(root), TYPE, MEMBER); \ |
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return 1; \ |
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} \ |
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if (rb_prev(&e->MEMBER) == NULL) { \ |
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iter->data1 = NULL; \ |
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return 0; \ |
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} \ |
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iter->data1 = container_of(rb_prev(&e->MEMBER), TYPE, MEMBER); \ |
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return 1; \ |
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} |
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|
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#define GENERIC_TREE_ITER_NEXT(FUNC, TYPE, MEMBER) \ |
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int FUNC(struct iter *iter) \ |
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{ \ |
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struct rb_root *root = iter->data0; \ |
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TYPE *e = iter->data1; \ |
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\ |
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if (root == NULL) \ |
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return 0; \ |
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if (e == NULL) { \ |
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/* head, get first */ \ |
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if (rb_root_empty(root)) { \ |
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/* empty, iter points to the head already */ \ |
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return 0; \ |
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} \ |
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iter->data1 = container_of(rb_first(root), TYPE, MEMBER); \ |
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return 1; \ |
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} \ |
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if (rb_next(&e->MEMBER) == NULL) { \ |
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iter->data1 = NULL; \ |
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return 0; \ |
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} \ |
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iter->data1 = container_of(rb_next(&e->MEMBER), TYPE, MEMBER); \ |
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return 1; \ |
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} |
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|
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#endif |
