8f4d61de83e74f9dfffc6e6b837f576d1cefb4cb
[reactos.git] / reactos / include / wine / list.h
1 /*
2 * Linked lists support
3 *
4 * Copyright (C) 2002 Alexandre Julliard
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 */
20
21 #ifndef __WINE_SERVER_LIST_H
22 #define __WINE_SERVER_LIST_H
23
24 struct list
25 {
26 struct list *next;
27 struct list *prev;
28 };
29
30 /* Define a list like so:
31 *
32 * struct gadget
33 * {
34 * struct list entry; <-- doesn't have to be the first item in the struct
35 * int a, b;
36 * };
37 *
38 * static struct list global_gadgets = LIST_INIT( global_gadgets );
39 *
40 * or
41 *
42 * struct some_global_thing
43 * {
44 * struct list gadgets;
45 * };
46 *
47 * list_init( &some_global_thing->gadgets );
48 *
49 * Manipulate it like this:
50 *
51 * list_add_head( &global_gadgets, &new_gadget->entry );
52 * list_remove( &new_gadget->entry );
53 * list_add_after( &some_random_gadget->entry, &new_gadget->entry );
54 *
55 * And to iterate over it:
56 *
57 * struct list *cursor;
58 * LIST_FOR_EACH( cursor, &global_gadgets )
59 * {
60 * struct gadget *gadget = LIST_ENTRY( cursor, struct gadget, entry );
61 * }
62 *
63 */
64
65 /* add an element after the specified one */
66 inline static void list_add_after( struct list *elem, struct list *to_add )
67 {
68 to_add->next = elem->next;
69 to_add->prev = elem;
70 elem->next->prev = to_add;
71 elem->next = to_add;
72 }
73
74 /* add an element before the specified one */
75 inline static void list_add_before( struct list *elem, struct list *to_add )
76 {
77 to_add->next = elem;
78 to_add->prev = elem->prev;
79 elem->prev->next = to_add;
80 elem->prev = to_add;
81 }
82
83 /* add element at the head of the list */
84 inline static void list_add_head( struct list *list, struct list *elem )
85 {
86 list_add_after( list, elem );
87 }
88
89 /* add element at the tail of the list */
90 inline static void list_add_tail( struct list *list, struct list *elem )
91 {
92 list_add_before( list, elem );
93 }
94
95 /* remove an element from its list */
96 inline static void list_remove( struct list *elem )
97 {
98 elem->next->prev = elem->prev;
99 elem->prev->next = elem->next;
100 }
101
102 /* get the next element */
103 inline static struct list *list_next( struct list *list, struct list *elem )
104 {
105 struct list *ret = elem->next;
106 if (elem->next == list) ret = NULL;
107 return ret;
108 }
109
110 /* get the previous element */
111 inline static struct list *list_prev( struct list *list, struct list *elem )
112 {
113 struct list *ret = elem->prev;
114 if (elem->prev == list) ret = NULL;
115 return ret;
116 }
117
118 /* get the first element */
119 inline static struct list *list_head( struct list *list )
120 {
121 return list_next( list, list );
122 }
123
124 /* get the last element */
125 inline static struct list *list_tail( struct list *list )
126 {
127 return list_prev( list, list );
128 }
129
130 /* check if a list is empty */
131 inline static int list_empty( struct list *list )
132 {
133 return list->next == list;
134 }
135
136 /* initialize a list */
137 inline static void list_init( struct list *list )
138 {
139 list->next = list->prev = list;
140 }
141
142 /* iterate through the list */
143 #define LIST_FOR_EACH(cursor,list) \
144 for ((cursor) = (list)->next; (cursor) != (list); (cursor) = (cursor)->next)
145
146 /* iterate through the list, with safety against removal */
147 #define LIST_FOR_EACH_SAFE(cursor, cursor2, list) \
148 for ((cursor) = (list)->next, (cursor2) = (cursor)->next; \
149 (cursor) != (list); \
150 (cursor) = (cursor2), (cursor2) = (cursor)->next)
151
152 /* iterate through the list using a list entry */
153 #define LIST_FOR_EACH_ENTRY(elem, list, type, field) \
154 for ((elem) = LIST_ENTRY((list)->next, type, field); \
155 &(elem)->field != (list); \
156 (elem) = LIST_ENTRY((elem)->field.next, type, field))
157
158 /* macros for statically initialized lists */
159 #define LIST_INIT(list) { &(list), &(list) }
160
161 /* get pointer to object containing list element */
162 #define LIST_ENTRY(elem, type, field) \
163 ((type *)((char *)(elem) - (unsigned int)(&((type *)0)->field)))
164
165 #endif /* __WINE_SERVER_LIST_H */