list.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident	"%Z%%M%	%I%	%E% SMI"

/*
 * Routines for manipulating linked lists
 */

#include <stdio.h>
#include <assert.h>
#include <stdlib.h>

#include "list.h"
#include "memory.h"

struct list {
	void *l_data;
	struct list *l_next;
};

/* Add an element to a list */
void
list_add(list_t **list, void *data)
{
	list_t *le;

	le = xmalloc(sizeof (list_t));
	le->l_data = data;
	le->l_next = *list;
	*list = le;
}

/* Add an element to a sorted list */
void
slist_add(list_t **list, void *data, int (*cmp)(void *, void *))
{
	list_t **nextp;

	for (nextp = list; *nextp; nextp = &((*nextp)->l_next)) {
		if (cmp((*nextp)->l_data, data) > 0)
			break;
	}

	list_add(nextp, data);
}

/*ARGSUSED2*/
static int
list_defcmp(void *d1, void *d2, void *private __unused)
{
	return (d1 != d2);
}

void *
list_remove(list_t **list, void *data, int (*cmp)(void *, void *, void *),
    void *private)
{
	list_t *le, **le2;
	void *led;

	if (!cmp)
		cmp = list_defcmp;

	for (le = *list, le2 = list; le; le2 = &le->l_next, le = le->l_next) {
		if (cmp(le->l_data, data, private) == 0) {
			*le2 = le->l_next;
			led = le->l_data;
			free(le);
			return (led);
		}
	}

	return (NULL);
}

void
list_free(list_t *list, void (*datafree)(void *, void *), void *private)
{
	list_t *le;

	while (list) {
		le = list;
		list = list->l_next;
		if (le->l_data && datafree)
			datafree(le->l_data, private);
		free(le);
	}
}

/*
 * This iterator is specifically designed to tolerate the deletion of the
 * node being iterated over.
 */
int
list_iter(list_t *list, int (*func)(void *, void *), void *private)
{
	list_t *lnext;
	int cumrc = 0;
	int cbrc;

	while (list) {
		lnext = list->l_next;
		if ((cbrc = func(list->l_data, private)) < 0)
			return (cbrc);
		cumrc += cbrc;
		list = lnext;
	}

	return (cumrc);
}

/*ARGSUSED*/
static int
list_count_cb(void *data __unused, void *private __unused)
{
	return (1);
}

int
list_count(list_t *list)
{
	return (list_iter(list, list_count_cb, NULL));
}

int
list_empty(list_t *list)
{
	return (list == NULL);
}

void *
list_find(list_t *list, void *tmpl, int (*cmp)(void *, void *))
{
	for (; list; list = list->l_next) {
		if (cmp(list->l_data, tmpl) == 0)
			return (list->l_data);
	}

	return (NULL);
}

void *
list_first(list_t *list)
{
	return (list ? list->l_data : NULL);
}

void
list_concat(list_t **list1, list_t *list2)
{
	list_t *l, *last;

	for (l = *list1, last = NULL; l; last = l, l = l->l_next)
		continue;

	if (last == NULL)
		*list1 = list2;
	else
		last->l_next = list2;
}

/*
 * Merges two sorted lists.  Equal nodes (as determined by cmp) are retained.
 */
void
slist_merge(list_t **list1p, list_t *list2, int (*cmp)(void *, void *))
{
	list_t *list1, *next2;
	list_t *last1 = NULL;

	if (*list1p == NULL) {
		*list1p = list2;
		return;
	}

	list1 = *list1p;
	while (list2 != NULL) {
		if (cmp(list1->l_data, list2->l_data) > 0) {
			next2 = list2->l_next;

			if (last1 == NULL) {
				/* Insert at beginning */
				*list1p = last1 = list2;
				list2->l_next = list1;
			} else {
				list2->l_next = list1;
				last1->l_next = list2;
				last1 = list2;
			}

			list2 = next2;
		} else {

			last1 = list1;
			list1 = list1->l_next;

			if (list1 == NULL) {
				/* Add the rest to the end of list1 */
				last1->l_next = list2;
				list2 = NULL;
			}
		}
	}
}