mutter/cogl/cogl/cogl-list.h

127 lines
5.1 KiB
C

/*
* Copyright © 2008 Kristian Høgsberg
* Copyright © 2012, 2013 Intel Corporation
*
* Permission to use, copy, modify, distribute, and sell this software and its
* documentation for any purpose is hereby granted without fee, provided that
* the above copyright notice appear in all copies and that both that copyright
* notice and this permission notice appear in supporting documentation, and
* that the name of the copyright holders not be used in advertising or
* publicity pertaining to distribution of the software without specific,
* written prior permission. The copyright holders make no representations
* about the suitability of this software for any purpose. It is provided "as
* is" without express or implied warranty.
*
* THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
* EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
* DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
* TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
* OF THIS SOFTWARE.
*/
#pragma once
/* This list implementation is based on the Wayland source code */
#include <stddef.h>
/**
* CoglList - linked list
*
* The list head is of "CoglList" type, and must be initialized
* using cogl_list_init(). All entries in the list must be of the same
* type. The item type must have a "CoglList" member. This
* member will be initialized by cogl_list_insert(). There is no need to
* call cogl_list_init() on the individual item. To query if the list is
* empty in O(1), use cogl_list_empty().
*
* Let's call the list reference "CoglList foo_list", the item type as
* "item_t", and the item member as "CoglList link". The following code
*
* The following code will initialize a list:
*
* cogl_list_init (foo_list);
* cogl_list_insert (foo_list, item1); Pushes item1 at the head
* cogl_list_insert (foo_list, item2); Pushes item2 at the head
* cogl_list_insert (item2, item3); Pushes item3 after item2
*
* The list now looks like [item2, item3, item1]
*
* Will iterate the list in ascending order:
*
* item_t *item;
* cogl_list_for_each(item, foo_list, link) {
* Do_something_with_item(item);
* }
*/
typedef struct _CoglList CoglList;
struct _CoglList
{
CoglList *prev;
CoglList *next;
};
void
_cogl_list_init (CoglList *list);
void
_cogl_list_insert (CoglList *list,
CoglList *elm);
void
_cogl_list_remove (CoglList *elm);
int
_cogl_list_length (CoglList *list);
int
_cogl_list_empty (CoglList *list);
void
_cogl_list_insert_list (CoglList *list,
CoglList *other);
/* This assigns to iterator first so that taking a reference to it
* later in the second step won't be an undefined operation. It
* assigns the value of list_node rather than 0 so that it is possible
* have list_node be based on the previous value of iterator. In that
* respect iterator is just used as a convenient temporary variable.
* The compiler optimises all of this down to a single subtraction by
* a constant */
#define _cogl_list_set_iterator(list_node, iterator, member) \
((iterator) = (void *) (list_node), \
(iterator) = (void *) ((char *) (iterator) - \
(((char *) &(iterator)->member) - \
(char *) (iterator))))
#define _cogl_container_of(ptr, type, member) \
(type *) ((char *) (ptr) - offsetof (type, member))
#define _cogl_list_for_each(pos, head, member) \
for (_cogl_list_set_iterator ((head)->next, pos, member); \
&pos->member != (head); \
_cogl_list_set_iterator (pos->member.next, pos, member))
#define _cogl_list_for_each_safe(pos, tmp, head, member) \
for (_cogl_list_set_iterator ((head)->next, pos, member), \
_cogl_list_set_iterator ((pos)->member.next, tmp, member); \
&pos->member != (head); \
pos = tmp, \
_cogl_list_set_iterator (pos->member.next, tmp, member))
#define _cogl_list_for_each_reverse(pos, head, member) \
for (_cogl_list_set_iterator ((head)->prev, pos, member); \
&pos->member != (head); \
_cogl_list_set_iterator (pos->member.prev, pos, member))
#define _cogl_list_for_each_reverse_safe(pos, tmp, head, member) \
for (_cogl_list_set_iterator ((head)->prev, pos, member), \
_cogl_list_set_iterator ((pos)->member.prev, tmp, member); \
&pos->member != (head); \
pos = tmp, \
_cogl_list_set_iterator (pos->member.prev, tmp, member))