1 /* active_list.h - the opkg package management system
3 Tick Chen <tick@openmoko.com>
5 Copyright (C) 2008 Openmoko Inc.
7 This program is free software; you can redistribute it and/or
8 modify it under the terms of the GNU General Public License as
9 published by the Free Software Foundation; either version 2, or (at
10 your option) any later version.
12 This program is distributed in the hope that it will be useful, but
13 WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 General Public License for more details.
18 #include "active_list.h"
23 #include "libbb/libbb.h"
25 void active_list_init(struct active_list *ptr)
27 INIT_LIST_HEAD(&ptr->node);
28 INIT_LIST_HEAD(&ptr->depend);
34 struct active_list *active_list_next(struct active_list *head,
35 struct active_list *ptr)
37 struct active_list *next = NULL;
39 opkg_msg(ERROR, "Internal error: head=%p, ptr=%p\n", head, ptr);
44 next = list_entry(ptr->node.next, struct active_list, node);
48 if (ptr->depended && &ptr->depended->depend == ptr->node.next) {
51 while (next->depend.next != &next->depend) {
52 next = list_entry(next->depend.next, struct active_list, node);
57 struct active_list *active_list_prev(struct active_list *head,
58 struct active_list *ptr)
60 struct active_list *prev = NULL;
62 opkg_msg(ERROR, "Internal error: head=%p, ptr=%p\n", head, ptr);
67 if (ptr->depend.prev != &ptr->depend) {
68 prev = list_entry(ptr->depend.prev, struct active_list, node);
71 if (ptr->depended && ptr->depended != head
72 && &ptr->depended->depend == ptr->node.prev) {
74 list_entry(ptr->depended->node.prev, struct active_list,
77 prev = list_entry(ptr->node.prev, struct active_list, node);
83 struct active_list *active_list_move_node(struct active_list *old_head,
84 struct active_list *new_head,
85 struct active_list *node)
87 struct active_list *prev;
88 if (!old_head || !new_head || !node)
90 if (old_head == new_head)
92 prev = active_list_prev(old_head, node);
93 active_list_add(new_head, node);
97 static void list_head_clear(struct list_head *head)
99 struct active_list *next;
100 struct list_head *n, *ptr;
103 list_for_each_safe(ptr, n, head) {
104 next = list_entry(ptr, struct active_list, node);
105 if (next->depend.next != &next->depend) {
106 list_head_clear(&next->depend);
108 active_list_init(next);
112 void active_list_clear(struct active_list *head)
114 list_head_clear(&head->node);
115 if (head->depend.next != &head->depend) {
116 list_head_clear(&head->depend);
118 active_list_init(head);
121 void active_list_add_depend(struct active_list *node,
122 struct active_list *depend)
124 list_del_init(&depend->node);
125 list_add_tail(&depend->node, &node->depend);
126 depend->depended = node;
129 void active_list_add(struct active_list *head, struct active_list *node)
131 list_del_init(&node->node);
132 list_add_tail(&node->node, &head->node);
133 node->depended = head;
136 struct active_list *active_list_head_new(void)
138 struct active_list *head = xcalloc(1, sizeof(struct active_list));
139 active_list_init(head);
143 void active_list_head_delete(struct active_list *head)
145 active_list_clear(head);
151 * Note. the list should not be large, or it will be very inefficient.
154 struct active_list *active_list_sort(struct active_list *head,
155 int (*compare) (const void *,
158 struct active_list tmphead;
159 struct active_list *node, *ptr;
162 active_list_init(&tmphead);
163 for (node = active_list_next(head, NULL); node;
164 node = active_list_next(head, NULL)) {
165 if (tmphead.node.next == &tmphead.node) {
166 active_list_move_node(head, &tmphead, node);
168 for (ptr = active_list_next(&tmphead, NULL); ptr;
169 ptr = active_list_next(&tmphead, ptr)) {
170 if (compare(ptr, node) <= 0) {
175 active_list_move_node(head, &tmphead, node);
177 active_list_move_node(head, ptr, node);
180 node->depended = &tmphead;
182 for (ptr = active_list_prev(&tmphead, NULL); ptr;
183 ptr = active_list_prev(&tmphead, NULL)) {
184 active_list_move_node(&tmphead, head, ptr);