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
16 * Licence along with this program; if not, write to the Free
17 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139,
18 * USA.
19 *
20 * Authors:
21 * Florian Forster <octo at verplant.org>
22 */
24 #include "config.h"
26 #include <stdlib.h>
27 #include <string.h>
29 #include "utils_llist.h"
31 /*
32 * Private data types
33 */
34 struct llist_s
35 {
36 llentry_t *head;
37 llentry_t *tail;
38 int size;
39 };
41 /*
42 * Public functions
43 */
44 llist_t *llist_create (void)
45 {
46 llist_t *ret;
48 ret = (llist_t *) malloc (sizeof (llist_t));
49 if (ret == NULL)
50 return (NULL);
52 memset (ret, '\0', sizeof (llist_t));
54 return (ret);
55 }
57 void llist_destroy (llist_t *l)
58 {
59 llentry_t *e_this;
60 llentry_t *e_next;
62 if (l == NULL)
63 return;
65 for (e_this = l->head; e_this != NULL; e_this = e_next)
66 {
67 e_next = e_this->next;
68 llentry_destroy (e_this);
69 }
71 free (l);
72 }
74 llentry_t *llentry_create (char *key, void *value)
75 {
76 llentry_t *e;
78 e = (llentry_t *) malloc (sizeof (llentry_t));
79 if (e)
80 {
81 e->key = key;
82 e->value = value;
83 e->next = NULL;
84 }
86 return (e);
87 }
89 void llentry_destroy (llentry_t *e)
90 {
91 free (e);
92 }
94 void llist_append (llist_t *l, llentry_t *e)
95 {
96 e->next = NULL;
98 if (l->tail == NULL)
99 l->head = e;
100 else
101 l->tail->next = e;
103 l->tail = e;
105 ++(l->size);
106 }
108 void llist_prepend (llist_t *l, llentry_t *e)
109 {
110 e->next = l->head;
111 l->head = e;
113 if (l->tail == NULL)
114 l->tail = e;
116 ++(l->size);
117 }
119 void llist_remove (llist_t *l, llentry_t *e)
120 {
121 llentry_t *prev;
123 if ((l == NULL) || (e == NULL))
124 return;
126 prev = l->head;
127 while ((prev != NULL) && (prev->next != e))
128 prev = prev->next;
130 if (prev != NULL)
131 prev->next = e->next;
132 if (l->head == e)
133 l->head = e->next;
134 if (l->tail == e)
135 l->tail = prev;
137 --(l->size);
138 }
140 int llist_size (llist_t *l)
141 {
142 return (l ? l->size : 0);
143 }
145 static int llist_strcmp (llentry_t *e, void *ud)
146 {
147 if ((e == NULL) || (ud == NULL))
148 return (-1);
149 return (strcmp (e->key, (const char *)ud));
150 }
152 llentry_t *llist_search (llist_t *l, const char *key)
153 {
154 return (llist_search_custom (l, llist_strcmp, (void *)key));
155 }
157 llentry_t *llist_search_custom (llist_t *l,
158 int (*compare) (llentry_t *, void *), void *user_data)
159 {
160 llentry_t *e;
162 if (l == NULL)
163 return (NULL);
165 e = l->head;
166 while (e != NULL) {
167 llentry_t *next = e->next;
169 if (compare (e, user_data) == 0)
170 break;
172 e = next;
173 }
175 return (e);
176 }
178 llentry_t *llist_head (llist_t *l)
179 {
180 if (l == NULL)
181 return (NULL);
182 return (l->head);
183 }
185 llentry_t *llist_tail (llist_t *l)
186 {
187 if (l == NULL)
188 return (NULL);
189 return (l->tail);
190 }