1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 /*
30  * Routines for manipulating linked lists
31  */
32 
33 #include <stdio.h>
34 #include <assert.h>
35 #include <stdlib.h>
36 
37 #include "list.h"
38 #include "memory.h"
39 
40 struct list {
41 	void *l_data;
42 	struct list *l_next;
43 };
44 
45 /* Add an element to a list */
46 void
47 list_add(list_t **list, void *data)
48 {
49 	list_t *le;
50 
51 	le = xmalloc(sizeof (list_t));
52 	le->l_data = data;
53 	le->l_next = *list;
54 	*list = le;
55 }
56 
57 /* Add an element to a sorted list */
58 void
59 slist_add(list_t **list, void *data, int (*cmp)(void *, void *))
60 {
61 	list_t **nextp;
62 
63 	for (nextp = list; *nextp; nextp = &((*nextp)->l_next)) {
64 		if (cmp((*nextp)->l_data, data) > 0)
65 			break;
66 	}
67 
68 	list_add(nextp, data);
69 }
70 
71 /*ARGSUSED2*/
72 static int
73 list_defcmp(void *d1, void *d2, void *private __unused)
74 {
75 	return (d1 != d2);
76 }
77 
78 void *
79 list_remove(list_t **list, void *data, int (*cmp)(void *, void *, void *),
80     void *private)
81 {
82 	list_t *le, **le2;
83 	void *led;
84 
85 	if (!cmp)
86 		cmp = list_defcmp;
87 
88 	for (le = *list, le2 = list; le; le2 = &le->l_next, le = le->l_next) {
89 		if (cmp(le->l_data, data, private) == 0) {
90 			*le2 = le->l_next;
91 			led = le->l_data;
92 			free(le);
93 			return (led);
94 		}
95 	}
96 
97 	return (NULL);
98 }
99 
100 void
101 list_free(list_t *list, void (*datafree)(void *, void *), void *private)
102 {
103 	list_t *le;
104 
105 	while (list) {
106 		le = list;
107 		list = list->l_next;
108 		if (le->l_data && datafree)
109 			datafree(le->l_data, private);
110 		free(le);
111 	}
112 }
113 
114 /*
115  * This iterator is specifically designed to tolerate the deletion of the
116  * node being iterated over.
117  */
118 int
119 list_iter(list_t *list, int (*func)(void *, void *), void *private)
120 {
121 	list_t *lnext;
122 	int cumrc = 0;
123 	int cbrc;
124 
125 	while (list) {
126 		lnext = list->l_next;
127 		if ((cbrc = func(list->l_data, private)) < 0)
128 			return (cbrc);
129 		cumrc += cbrc;
130 		list = lnext;
131 	}
132 
133 	return (cumrc);
134 }
135 
136 /*ARGSUSED*/
137 static int
138 list_count_cb(void *data __unused, void *private __unused)
139 {
140 	return (1);
141 }
142 
143 int
144 list_count(list_t *list)
145 {
146 	return (list_iter(list, list_count_cb, NULL));
147 }
148 
149 int
150 list_empty(list_t *list)
151 {
152 	return (list == NULL);
153 }
154 
155 void *
156 list_find(list_t *list, void *tmpl, int (*cmp)(void *, void *))
157 {
158 	for (; list; list = list->l_next) {
159 		if (cmp(list->l_data, tmpl) == 0)
160 			return (list->l_data);
161 	}
162 
163 	return (NULL);
164 }
165 
166 void *
167 list_first(list_t *list)
168 {
169 	return (list ? list->l_data : NULL);
170 }
171 
172 void
173 list_concat(list_t **list1, list_t *list2)
174 {
175 	list_t *l, *last;
176 
177 	for (l = *list1, last = NULL; l; last = l, l = l->l_next)
178 		continue;
179 
180 	if (last == NULL)
181 		*list1 = list2;
182 	else
183 		last->l_next = list2;
184 }
185 
186 /*
187  * Merges two sorted lists.  Equal nodes (as determined by cmp) are retained.
188  */
189 void
190 slist_merge(list_t **list1p, list_t *list2, int (*cmp)(void *, void *))
191 {
192 	list_t *list1, *next2;
193 	list_t *last1 = NULL;
194 
195 	if (*list1p == NULL) {
196 		*list1p = list2;
197 		return;
198 	}
199 
200 	list1 = *list1p;
201 	while (list2 != NULL) {
202 		if (cmp(list1->l_data, list2->l_data) > 0) {
203 			next2 = list2->l_next;
204 
205 			if (last1 == NULL) {
206 				/* Insert at beginning */
207 				*list1p = last1 = list2;
208 				list2->l_next = list1;
209 			} else {
210 				list2->l_next = list1;
211 				last1->l_next = list2;
212 				last1 = list2;
213 			}
214 
215 			list2 = next2;
216 		} else {
217 
218 			last1 = list1;
219 			list1 = list1->l_next;
220 
221 			if (list1 == NULL) {
222 				/* Add the rest to the end of list1 */
223 				last1->l_next = list2;
224 				list2 = NULL;
225 			}
226 		}
227 	}
228 }
229