old_e2fsprogs/blkid/list.c

/* vi: set sw=4 ts=4: */

#include "list.h"

/*
 * Insert a new entry between two known consecutive entries.
 *
 * This is only for internal list manipulation where we know
 * the prev/next entries already!
 */
void __list_add(struct list_head * add,
	struct list_head * prev,
	struct list_head * next)
{
	next->prev = add;
	add->next = next;
	add->prev = prev;
	prev->next = add;
}

/*
 * list_add - add a new entry
 * @add:	new entry to be added
 * @head:	list head to add it after
 *
 * Insert a new entry after the specified head.
 * This is good for implementing stacks.
 */
void list_add(struct list_head *add, struct list_head *head)
{
	__list_add(add, head, head->next);
}

/*
 * list_add_tail - add a new entry
 * @add:	new entry to be added
 * @head:	list head to add it before
 *
 * Insert a new entry before the specified head.
 * This is useful for implementing queues.
 */
void list_add_tail(struct list_head *add, struct list_head *head)
{
	__list_add(add, head->prev, head);
}

/*
 * Delete a list entry by making the prev/next entries
 * point to each other.
 *
 * This is only for internal list manipulation where we know
 * the prev/next entries already!
 */
void __list_del(struct list_head * prev, struct list_head * next)
{
	next->prev = prev;
	prev->next = next;
}

/*
 * list_del - deletes entry from list.
 * @entry:	the element to delete from the list.
 *
 * list_empty() on @entry does not return true after this, @entry is
 * in an undefined state.
 */
void list_del(struct list_head *entry)
{
	__list_del(entry->prev, entry->next);
}

/*
 * list_del_init - deletes entry from list and reinitialize it.
 * @entry:	the element to delete from the list.
 */
void list_del_init(struct list_head *entry)
{
	__list_del(entry->prev, entry->next);
	INIT_LIST_HEAD(entry);
}

/*
 * list_empty - tests whether a list is empty
 * @head:	the list to test.
 */
int list_empty(struct list_head *head)
{
	return head->next == head;
}

/*
 * list_splice - join two lists
 * @list:	the new list to add.
 * @head:	the place to add it in the first list.
 */
void list_splice(struct list_head *list, struct list_head *head)
{
	struct list_head *first = list->next;

	if (first != list) {
		struct list_head *last = list->prev;
		struct list_head *at = head->next;

		first->prev = head;
		head->next = first;

		last->next = at;
		at->prev = last;
	}
}
1	/* vi: set sw=4 ts=4: */
2
3	#include "list.h"
4
5	/*
6	* Insert a new entry between two known consecutive entries.
7	*
8	* This is only for internal list manipulation where we know
9	* the prev/next entries already!
10	*/
11	void __list_add(struct list_head * add,
12	struct list_head * prev,
13	struct list_head * next)
14	{
15	next->prev = add;
16	add->next = next;
17	add->prev = prev;
18	prev->next = add;
19	}
20
21	/*
22	* list_add - add a new entry
23	* @add: new entry to be added
24	* @head: list head to add it after
25	*
26	* Insert a new entry after the specified head.
27	* This is good for implementing stacks.
28	*/
29	void list_add(struct list_head add, struct list_head head)
30	{
31	__list_add(add, head, head->next);
32	}
33
34	/*
35	* list_add_tail - add a new entry
36	* @add: new entry to be added
37	* @head: list head to add it before
38	*
39	* Insert a new entry before the specified head.
40	* This is useful for implementing queues.
41	*/
42	void list_add_tail(struct list_head add, struct list_head head)
43	{
44	__list_add(add, head->prev, head);
45	}
46
47	/*
48	* Delete a list entry by making the prev/next entries
49	* point to each other.
50	*
51	* This is only for internal list manipulation where we know
52	* the prev/next entries already!
53	*/
54	void __list_del(struct list_head * prev, struct list_head * next)
55	{
56	next->prev = prev;
57	prev->next = next;
58	}
59
60	/*
61	* list_del - deletes entry from list.
62	* @entry: the element to delete from the list.
63	*
64	* list_empty() on @entry does not return true after this, @entry is
65	* in an undefined state.
66	*/
67	void list_del(struct list_head *entry)
68	{
69	__list_del(entry->prev, entry->next);
70	}
71
72	/*
73	* list_del_init - deletes entry from list and reinitialize it.
74	* @entry: the element to delete from the list.
75	*/
76	void list_del_init(struct list_head *entry)
77	{
78	__list_del(entry->prev, entry->next);
79	INIT_LIST_HEAD(entry);
80	}
81
82	/*
83	* list_empty - tests whether a list is empty
84	* @head: the list to test.
85	*/
86	int list_empty(struct list_head *head)
87	{
88	return head->next == head;
89	}
90
91	/*
92	* list_splice - join two lists
93	* @list: the new list to add.
94	* @head: the place to add it in the first list.
95	*/
96	void list_splice(struct list_head list, struct list_head head)
97	{
98	struct list_head *first = list->next;
99
100	if (first != list) {
101	struct list_head *last = list->prev;
102	struct list_head *at = head->next;
103
104	first->prev = head;
105	head->next = first;
106
107	last->next = at;
108	at->prev = last;
109	}
110	}