159 lines
3.7 KiB
C
159 lines
3.7 KiB
C
/*
|
|
* Copyright (c) 2007-2008, 2010 Todd C. Miller <Todd.Miller@courtesan.com>
|
|
*
|
|
* Permission to use, copy, modify, and distribute this software for any
|
|
* purpose with or without fee is hereby granted, provided that the above
|
|
* copyright notice and this permission notice appear in all copies.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
|
|
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
|
|
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
|
|
* ANY SPECIAL, DIRECT, 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.
|
|
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
|
|
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
|
|
#include <config.h>
|
|
|
|
#include <sys/types.h>
|
|
#include <stdio.h>
|
|
#ifdef STDC_HEADERS
|
|
# include <stdlib.h>
|
|
# include <stddef.h>
|
|
#else
|
|
# ifdef HAVE_STDLIB_H
|
|
# include <stdlib.h>
|
|
# endif
|
|
#endif /* STDC_HEADERS */
|
|
|
|
#include <missing.h>
|
|
#include <list.h>
|
|
#ifdef DEBUG
|
|
# include <error.h>
|
|
#endif
|
|
|
|
struct list_proto {
|
|
struct list_proto *prev;
|
|
struct list_proto *next;
|
|
};
|
|
|
|
struct list_head_proto {
|
|
struct list_proto *first;
|
|
struct list_proto *last;
|
|
};
|
|
|
|
/*
|
|
* Pop the last element off the end of vh.
|
|
* Returns the popped element.
|
|
*/
|
|
void *
|
|
tq_pop(void *vh)
|
|
{
|
|
struct list_head_proto *h = (struct list_head_proto *)vh;
|
|
void *last = NULL;
|
|
|
|
if (!tq_empty(h)) {
|
|
last = (void *)h->last;
|
|
if (h->first == h->last) {
|
|
h->first = NULL;
|
|
h->last = NULL;
|
|
} else {
|
|
h->last = h->last->prev;
|
|
h->last->next = NULL;
|
|
}
|
|
}
|
|
return (last);
|
|
}
|
|
|
|
/*
|
|
* Convert from a semi-circle queue to normal doubly-linked list
|
|
* with a head node.
|
|
*/
|
|
void
|
|
list2tq(void *vh, void *vl)
|
|
{
|
|
struct list_head_proto *h = (struct list_head_proto *)vh;
|
|
struct list_proto *l = (struct list_proto *)vl;
|
|
|
|
if (l != NULL) {
|
|
#ifdef DEBUG
|
|
if (l->prev == NULL) {
|
|
warningx("list2tq called with non-semicircular list");
|
|
abort();
|
|
}
|
|
#endif
|
|
h->first = l;
|
|
h->last = l->prev; /* l->prev points to the last member of l */
|
|
l->prev = NULL; /* zero last ptr now that we have a head */
|
|
} else {
|
|
h->first = NULL;
|
|
h->last = NULL;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Append one queue (or single entry) to another using the
|
|
* circular properties of the prev pointer to simplify the logic.
|
|
*/
|
|
void
|
|
list_append(void *vl1, void *vl2)
|
|
{
|
|
struct list_proto *l1 = (struct list_proto *)vl1;
|
|
struct list_proto *l2 = (struct list_proto *)vl2;
|
|
void *tail = l2->prev;
|
|
|
|
l1->prev->next = l2;
|
|
l2->prev = l1->prev;
|
|
l1->prev = tail;
|
|
}
|
|
|
|
/*
|
|
* Append the list of entries to the head node and convert
|
|
* e from a semi-circle queue to normal doubly-linked list.
|
|
*/
|
|
void
|
|
tq_append(void *vh, void *vl)
|
|
{
|
|
struct list_head_proto *h = (struct list_head_proto *)vh;
|
|
struct list_proto *l = (struct list_proto *)vl;
|
|
void *tail = l->prev;
|
|
|
|
if (h->first == NULL)
|
|
h->first = l;
|
|
else
|
|
h->last->next = l;
|
|
l->prev = h->last;
|
|
h->last = tail;
|
|
}
|
|
|
|
/*
|
|
* Remove element from the tail_queue
|
|
*/
|
|
void
|
|
tq_remove(void *vh, void *vl)
|
|
{
|
|
struct list_head_proto *h = (struct list_head_proto *)vh;
|
|
struct list_proto *l = (struct list_proto *)vl;
|
|
|
|
if (h->first == l && h->last == l) {
|
|
/* Single element in the list. */
|
|
h->first = NULL;
|
|
h->last = NULL;
|
|
} else {
|
|
/* At least two elements in the list. */
|
|
if (h->first == l) {
|
|
h->first = l->next;
|
|
h->first->prev = h->first;
|
|
} else if (h->last == l) {
|
|
h->last = l->prev;
|
|
h->last->next = NULL;
|
|
} else {
|
|
l->prev->next = l->next;
|
|
l->next->prev = l->prev;
|
|
}
|
|
}
|
|
}
|