list.h

/*
 * The MIT License (MIT)
 *
 * Copyright (c) <2020> <Stephan Gatzka>
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#ifndef SCRAMJET_LIST_H
#define SCRAMJET_LIST_H

#include "util.h"

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

#define LIST_HEAD_INIT(name)     \
	{                        \
		&(name), &(name) \
	}

#define LIST_HEAD(name) \
	struct list_head name = LIST_HEAD_INIT(name)

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

static inline void __list_add(struct list_head *new_entry, struct list_head *prev, struct list_head *next)
{
	next->prev = new_entry;
	new_entry->next = next;
	new_entry->prev = prev;
	prev->next = new_entry;
}

static inline void list_add_tail(struct list_head *new_entry, struct list_head *head)
{
	__list_add(new_entry, head->prev, head);
}

static inline int list_empty(const struct list_head *head)
{
	return head->next == head;
}

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

#define list_entry(ptr, type, member) \
	container_of(ptr, type, member)

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

static inline void list_del(struct list_head *entry)
{
	__list_del(entry->prev, entry->next);
}

#endif