1 /**
2 * collectd - src/utils_llist.c
3 * Copyright (C) 2006 Florian Forster <octo at verplant.org>
4 *
5 * This program is free software; you can redistribute it and/
6 * or modify it under the terms of the GNU General Public Li-
7 * cence as published by the Free Software Foundation; only
8 * version 2 of the Licence is applicable.
9 *
10 * This program is distributed in the hope that it will be use-
11 * ful, but WITHOUT ANY WARRANTY; without even the implied war-
12 * ranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
13 * See the GNU General Public Licence for more details.
14 *
15 * You should have received a copy of the GNU General Public License along
16 * with this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
18 *
19 * Authors:
20 * Florian Forster <octo at verplant.org>
21 */
23 #include "config.h"
25 #include <stdlib.h>
26 #include <string.h>
28 #include "utils_llist.h"
30 /*
31 * Private data types
32 */
33 struct llist_s
34 {
35 llentry_t *head;
36 llentry_t *tail;
37 int size;
38 };
40 /*
41 * Public functions
42 */
43 llist_t *llist_create (void)
44 {
45 llist_t *ret;
47 ret = (llist_t *) malloc (sizeof (llist_t));
48 if (ret == NULL)
49 return (NULL);
51 memset (ret, '\0', sizeof (llist_t));
53 return (ret);
54 }
56 void llist_destroy (llist_t *l)
57 {
58 llentry_t *e_this;
59 llentry_t *e_next;
61 if (l == NULL)
62 return;
64 for (e_this = l->head; e_this != NULL; e_this = e_next)
65 {
66 e_next = e_this->next;
67 llentry_destroy (e_this);
68 }
70 free (l);
71 }
73 llentry_t *llentry_create (char *key, void *value)
74 {
75 llentry_t *e;
77 e = (llentry_t *) malloc (sizeof (llentry_t));
78 if (e)
79 {
80 e->key = key;
81 e->value = value;
82 e->next = NULL;
83 }
85 return (e);
86 }
88 void llentry_destroy (llentry_t *e)
89 {
90 free (e);
91 }
93 void llist_append (llist_t *l, llentry_t *e)
94 {
95 e->next = NULL;
97 if (l->tail == NULL)
98 l->head = e;
99 else
100 l->tail->next = e;
102 l->tail = e;
104 ++(l->size);
105 }
107 void llist_prepend (llist_t *l, llentry_t *e)
108 {
109 e->next = l->head;
110 l->head = e;
112 if (l->tail == NULL)
113 l->tail = e;
115 ++(l->size);
116 }
118 void llist_remove (llist_t *l, llentry_t *e)
119 {
120 llentry_t *prev;
122 if ((l == NULL) || (e == NULL))
123 return;
125 prev = l->head;
126 while ((prev != NULL) && (prev->next != e))
127 prev = prev->next;
129 if (prev != NULL)
130 prev->next = e->next;
131 if (l->head == e)
132 l->head = e->next;
133 if (l->tail == e)
134 l->tail = prev;
136 --(l->size);
137 }
139 int llist_size (llist_t *l)
140 {
141 return (l ? l->size : 0);
142 }
144 static int llist_strcmp (llentry_t *e, void *ud)
145 {
146 if ((e == NULL) || (ud == NULL))
147 return (-1);
148 return (strcmp (e->key, (const char *)ud));
149 }
151 llentry_t *llist_search (llist_t *l, const char *key)
152 {
153 return (llist_search_custom (l, llist_strcmp, (void *)key));
154 }
156 llentry_t *llist_search_custom (llist_t *l,
157 int (*compare) (llentry_t *, void *), void *user_data)
158 {
159 llentry_t *e;
161 if (l == NULL)
162 return (NULL);
164 e = l->head;
165 while (e != NULL) {
166 llentry_t *next = e->next;
168 if (compare (e, user_data) == 0)
169 break;
171 e = next;
172 }
174 return (e);
175 }
177 llentry_t *llist_head (llist_t *l)
178 {
179 if (l == NULL)
180 return (NULL);
181 return (l->head);
182 }
184 llentry_t *llist_tail (llist_t *l)
185 {
186 if (l == NULL)
187 return (NULL);
188 return (l->tail);
189 }