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	niro	532	/* 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			}