dmmlib/include/dmmlib/lists.h

/*
 *   Copyright Institute of Communication and Computer Systems (ICCS) 
 *
 *   Licensed under the Apache License, Version 2.0 (the "License");
 *   you may not use this file except in compliance with the License.
 *   You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *   Unless required by applicable law or agreed to in writing, software
 *   distributed under the License is distributed on an "AS IS" BASIS,
 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *   See the License for the specific language governing permissions and
 *   limitations under the License.
 *
 */

/**
 * @file   lists.h
 * @author Ioannis Koutras (joko@microlab.ntua.gr)
 * @date   October 2012
 * @brief  Macros for singly-linked lists
 *
 * These macros were copied from /usr/include/sys/queue.h
 *
 */

#ifndef _DMMLIB_LISTS_H_
#define _DMMLIB_LISTS_H_

/*
 * Singly-linked List definitions.
 */

/** The head of a singly-linked list */
#define	SLIST_HEAD(name, type)						\
struct name {								\
	struct type *slh_first;	/* first element */			\
}

/** Initial value of the head of a singly-linked list */
#define	SLIST_HEAD_INITIALIZER(head)					\
	{ NULL }

/** Entry of a singly linked list */
#define	SLIST_ENTRY(type)						\
struct {								\
	struct type *sle_next;	/* next element */			\
}

/*
 * Singly-linked List functions.
 */

/** Initializes the head of a singly-linked list */
#define	SLIST_INIT(head) do {						\
	(head)->slh_first = NULL;					\
} while (/*CONSTCOND*/0)

/** Inserts an element after a specific one in a singly-linked list */
#define	SLIST_INSERT_AFTER(slistelm, elm, field) do {			\
	(elm)->field.sle_next = (slistelm)->field.sle_next;		\
	(slistelm)->field.sle_next = (elm);				\
} while (/*CONSTCOND*/0)

/** Inserts an element as the head of a singly-linked list */
#define	SLIST_INSERT_HEAD(head, elm, field) do {			\
	(elm)->field.sle_next = (head)->slh_first;			\
	(head)->slh_first = (elm);					\
} while (/*CONSTCOND*/0)

/** Removes the head element of a singly-linked list */
#define	SLIST_REMOVE_HEAD(head, field) do {				\
	(head)->slh_first = (head)->slh_first->field.sle_next;		\
} while (/*CONSTCOND*/0)

/** Removes an element from a singly-linked list */
#define	SLIST_REMOVE(head, elm, type, field) do {			\
	if ((head)->slh_first == (elm)) {				\
		SLIST_REMOVE_HEAD((head), field);			\
	}								\
	else {								\
		struct type *curelm = (head)->slh_first;		\
		while(curelm->field.sle_next != (elm))			\
			curelm = curelm->field.sle_next;		\
		curelm->field.sle_next =				\
		    curelm->field.sle_next->field.sle_next;		\
	}								\
} while (/*CONSTCOND*/0)

/** Iterates through a singly-linked list */
#define	SLIST_FOREACH(var, head, field)					\
	for((var) = (head)->slh_first; (var); (var) = (var)->field.sle_next)

/*
 * Singly-linked List access methods.
 */

/** Empties a singly-linked list */
#define	SLIST_EMPTY(head)	((head)->slh_first == NULL)

/** Gets the head of a singly-linked list */
#define	SLIST_FIRST(head)	((head)->slh_first)

/** Gets the next element of a specific element from a singly-linked list */
#define	SLIST_NEXT(elm, field)	((elm)->field.sle_next)

#endif /* _DMMLIB_LISTS_H_ */