mirror of
https://gitlab.freedesktop.org/emersion/libliftoff.git
synced 2024-09-29 05:36:51 +02:00
a08c4d1f08
Introduce a function to swap elements in a doubly linked list. This will be helpful when keeping the list of output layers sorted by priority. v2: re-define in terms of list_inserts and list_removes
61 lines
1 KiB
C
61 lines
1 KiB
C
#include "list.h"
|
|
|
|
void
|
|
liftoff_list_init(struct liftoff_list *list)
|
|
{
|
|
list->prev = list;
|
|
list->next = list;
|
|
}
|
|
|
|
void
|
|
liftoff_list_insert(struct liftoff_list *list, struct liftoff_list *elm)
|
|
{
|
|
elm->prev = list;
|
|
elm->next = list->next;
|
|
list->next = elm;
|
|
elm->next->prev = elm;
|
|
}
|
|
|
|
void
|
|
liftoff_list_remove(struct liftoff_list *elm)
|
|
{
|
|
elm->prev->next = elm->next;
|
|
elm->next->prev = elm->prev;
|
|
elm->next = NULL;
|
|
elm->prev = NULL;
|
|
}
|
|
|
|
void
|
|
liftoff_list_swap(struct liftoff_list *this, struct liftoff_list *other)
|
|
{
|
|
struct liftoff_list tmp;
|
|
|
|
liftoff_list_insert(other, &tmp);
|
|
liftoff_list_remove(other);
|
|
liftoff_list_insert(this, other);
|
|
liftoff_list_remove(this);
|
|
liftoff_list_insert(&tmp, this);
|
|
liftoff_list_remove(&tmp);
|
|
}
|
|
|
|
size_t
|
|
liftoff_list_length(const struct liftoff_list *list)
|
|
{
|
|
struct liftoff_list *e;
|
|
size_t count;
|
|
|
|
count = 0;
|
|
e = list->next;
|
|
while (e != list) {
|
|
e = e->next;
|
|
count++;
|
|
}
|
|
|
|
return count;
|
|
}
|
|
|
|
bool
|
|
liftoff_list_empty(const struct liftoff_list *list)
|
|
{
|
|
return list->next == list;
|
|
}
|