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 };
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 for (e_this = l->head; e_this != NULL; e_this = e_next)
62 {
63 e_next = e_this->next;
64 llentry_destroy (e_this);
65 }
67 free (l);
68 }
70 llentry_t *llentry_create (const char *key, void *value)
71 {
72 llentry_t *e;
74 e = (llentry_t *) malloc (sizeof (llentry_t));
75 if (e == NULL)
76 return (NULL);
78 e->key = strdup (key);
79 e->value = value;
80 e->next = NULL;
82 if (e->key == NULL)
83 {
84 free (e);
85 return (NULL);
86 }
88 return (e);
89 }
91 void llentry_destroy (llentry_t *e)
92 {
93 free (e->key);
94 free (e);
95 }
97 void llist_append (llist_t *l, llentry_t *e)
98 {
99 e->next = NULL;
101 if (l->tail == NULL)
102 l->head = e;
103 else
104 l->tail->next = e;
106 l->tail = e;
107 }
109 void llist_prepend (llist_t *l, llentry_t *e)
110 {
111 e->next = l->head;
112 l->head = e;
113 }
115 void llist_remove (llist_t *l, llentry_t *e)
116 {
117 llentry_t *prev;
119 prev = l->head;
120 while ((prev != NULL) && (prev->next != e))
121 prev = prev->next;
123 if (prev != NULL)
124 prev->next = e->next;
125 if (l->head == e)
126 l->head = e->next;
127 if (l->tail == e)
128 l->tail = prev;
129 }
131 llentry_t *llist_search (llist_t *l, const char *key)
132 {
133 llentry_t *e;
135 for (e = l->head; e != NULL; e = e->next)
136 if (strcmp (key, e->key) == 0)
137 break;
139 return (e);
140 }
142 llentry_t *llist_head (llist_t *l)
143 {
144 return (l->head);
145 }
147 llentry_t *llist_tail (llist_t *l)
148 {
149 return (l->tail);
150 }