#ifndef LIST_H
#define LIST_H 1
#include <isc/assertions.h>
#define LIST(type) struct { type *head, *tail; }
#define INIT_LIST(list) \
do { (list).head = NULL; (list).tail = NULL; } while (0)
#define LINK(type) struct { type *prev, *next; }
#define INIT_LINK_TYPE(elt, link, type) \
do { \
(elt)->link.prev = (type *)(-1); \
(elt)->link.next = (type *)(-1); \
} while (0)
#define INIT_LINK(elt, link) \
INIT_LINK_TYPE(elt, link, void)
#define LINKED(elt, link) ((void *)((elt)->link.prev) != (void *)(-1))
#define HEAD(list) ((list).head)
#define TAIL(list) ((list).tail)
#define EMPTY(list) ((list).head == NULL)
#define PREPEND(list, elt, link) \
do { \
INSIST(!LINKED(elt, link));\
if ((list).head != NULL) \
(list).head->link.prev = (elt); \
else \
(list).tail = (elt); \
(elt)->link.prev = NULL; \
(elt)->link.next = (list).head; \
(list).head = (elt); \
} while (0)
#define APPEND(list, elt, link) \
do { \
INSIST(!LINKED(elt, link));\
if ((list).tail != NULL) \
(list).tail->link.next = (elt); \
else \
(list).head = (elt); \
(elt)->link.prev = (list).tail; \
(elt)->link.next = NULL; \
(list).tail = (elt); \
} while (0)
#define UNLINK_TYPE(list, elt, link, type) \
do { \
INSIST(LINKED(elt, link));\
if ((elt)->link.next != NULL) \
(elt)->link.next->link.prev = (elt)->link.prev; \
else \
(list).tail = (elt)->link.prev; \
if ((elt)->link.prev != NULL) \
(elt)->link.prev->link.next = (elt)->link.next; \
else \
(list).head = (elt)->link.next; \
INIT_LINK_TYPE(elt, link, type); \
} while (0)
#define UNLINK(list, elt, link) \
UNLINK_TYPE(list, elt, link, void)
#define PREV(elt, link) ((elt)->link.prev)
#define NEXT(elt, link) ((elt)->link.next)
#define INSERT_BEFORE(list, before, elt, link) \
do { \
INSIST(!LINKED(elt, link));\
if ((before)->link.prev == NULL) \
PREPEND(list, elt, link); \
else { \
(elt)->link.prev = (before)->link.prev; \
(before)->link.prev = (elt); \
(elt)->link.prev->link.next = (elt); \
(elt)->link.next = (before); \
} \
} while (0)
#define INSERT_AFTER(list, after, elt, link) \
do { \
INSIST(!LINKED(elt, link));\
if ((after)->link.next == NULL) \
APPEND(list, elt, link); \
else { \
(elt)->link.next = (after)->link.next; \
(after)->link.next = (elt); \
(elt)->link.next->link.prev = (elt); \
(elt)->link.prev = (after); \
} \
} while (0)
#define ENQUEUE(list, elt, link) APPEND(list, elt, link)
#define DEQUEUE(list, elt, link) UNLINK(list, elt, link)
#endif