/* list.h - libtf single and double linked list macros
 *
 * Copyright (C) 2009 Timo Teräs <timo.teras@iki.fi>
 * All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 or later as
 * published by the Free Software Foundation.
 *
 * See http://www.gnu.org/ for details.
 *
 * This based to some degree to the code in the linux kernel. This is subset
 * of the functionality, and tf_list has separate head and node types.
 */

#ifndef TF_LIST_H
#define TF_LIST_H

#include <libtf/defines.h>

struct tf_hlist_head {
	struct tf_hlist_node *first;
};

struct tf_hlist_node {
	struct tf_hlist_node *next;
	struct tf_hlist_node **pprev;
};

static inline int tf_hlist_empty(const struct tf_hlist_head *h)
{
	return !h->first;
}

static inline int tf_hlist_hashed(const struct tf_hlist_node *n)
{
	return n->pprev != NULL;
}

static inline void tf_hlist_del(struct tf_hlist_node *n)
{
	*n->pprev = n->next;
	n->next = NULL;
	n->pprev = NULL;
}

static inline void tf_hlist_add_head(struct tf_hlist_node *n, struct tf_hlist_head *h)
{
	struct tf_hlist_node *first = h->first;

	n->next = first;
	n->pprev = &h->first;
	h->first = n;
}

static inline void tf_hlist_add_after(struct tf_hlist_node *n, struct tf_hlist_node *prev)
{
	n->next = prev->next;
	n->pprev = &prev->next;
	prev->next = n;
}

static inline struct tf_hlist_node **tf_hlist_tail_ptr(struct tf_hlist_head *h)
{
	struct tf_hlist_node *n = h->first;
	if (n == NULL)
		return &h->first;
	while (n->next != NULL)
		n = n->next;
	return &n->next;
}

#define tf_hlist_entry(ptr, type, member) container_of(ptr,type,member)

#define tf_hlist_for_each(pos, head) \
	for (pos = (head)->first; pos; pos = pos->next)

#define tf_hlist_for_each_safe(pos, n, head) \
	for (pos = (head)->first; pos && ({ n = pos->next; 1; }); pos = n)

#define tf_hlist_for_each_entry(tpos, pos, head, member)			 \
	for (pos = (head)->first; pos && 				 \
		({ tpos = tf_hlist_entry(pos, typeof(*tpos), member); 1;}); \
	     pos = pos->next)

#define tf_hlist_for_each_entry_safe(tpos, pos, n, head, member) 		 \
	for (pos = (head)->first;					 \
	     pos && ({ n = pos->next; 1; }) &&				 \
		({ tpos = tf_hlist_entry(pos, typeof(*tpos), member); 1;}); \
	     pos = n)


struct tf_list_node {
	struct tf_list_node *next, *prev;
};

struct tf_list_head {
	struct tf_list_node node;
};

#define TF_LIST_INITIALIZER(l) { .next = &l, .prev = &l }
#define TF_LIST_HEAD_INITIALIZER(l) { .node = TF_LIST_INITIALIZER((l).node) }

static inline void tf_list_init(struct tf_list_node *list)
{
	list->next = list;
	list->prev = list;
}

static inline void tf_list_init_head(struct tf_list_head *head)
{
	tf_list_init(&head->node);
}

static inline void __tf_list_add(struct tf_list_node *new,
			      struct tf_list_node *prev,
			      struct tf_list_node *next)
{
	next->prev = new;
	new->next = next;
	new->prev = prev;
	prev->next = new;
}

static inline void tf_list_add_after(struct tf_list_node *new, struct tf_list_node *head)
{
	__tf_list_add(new, head, head->next);
}

static inline void tf_list_add_before(struct tf_list_node *new, struct tf_list_node *head)
{
	__tf_list_add(new, head->prev, head);
}

static inline void tf_list_add_head(struct tf_list_node *new, struct tf_list_head *head)
{
	tf_list_add_after(new, &head->node);
}

static inline void tf_list_add_tail(struct tf_list_node *new, struct tf_list_head *head)
{
	tf_list_add_before(new, &head->node);
}

static inline void __tf_list_del(struct tf_list_node * prev, struct tf_list_node *next)
{
	next->prev = prev;
	prev->next = next;
}

static inline void tf_list_del(struct tf_list_node *entry)
{
	__tf_list_del(entry->prev, entry->next);
	entry->next = NULL;
	entry->prev = NULL;
}

static inline int tf_list_hashed(const struct tf_list_node *n)
{
	return n->next != n && n->next != NULL;
}

static inline int tf_list_empty(const struct tf_list_head *h)
{
	return !tf_list_hashed(&h->node);
}

#define tf_list_next(ptr, type, member) \
	(tf_list_hashed(ptr) ? container_of((ptr)->next,type,member) : NULL)

#define tf_list_first(head, type, member) \
	tf_list_next(&((head)->node), type, member)

#define tf_list_entry(ptr, type, member) container_of(ptr,type,member)

#define tf_list_for_each(pos, head) \
	for (pos = (head)->next; pos != (head); pos = pos->next)

#define tf_list_for_each_safe(pos, n, head) \
	for (pos = (head)->next, n = pos->next; pos != (head); \
		pos = n, n = pos->next)

#define tf_list_for_each_entry(pos, head, member)				\
	for (pos = tf_list_entry((head)->next, typeof(*pos), member);	\
	     &pos->member != (head); 					\
	     pos = tf_list_entry(pos->member.next, typeof(*pos), member))

#define tf_list_for_each_entry_safe(pos, n, head, member)			\
	for (pos = tf_list_entry((head)->next, typeof(*pos), member),	\
		n = tf_list_entry(pos->member.next, typeof(*pos), member);	\
	     &pos->member != (head); 					\
	     pos = n, n = tf_list_entry(n->member.next, typeof(*n), member))

#endif