1 /**
2 * collectd - src/utils_llist.c
3 * Copyright (C) 2006 Florian Forster <octo at collectd.org>
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the "Software"),
7 * to deal in the Software without restriction, including without limitation
8 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9 * and/or sell copies of the Software, and to permit persons to whom the
10 * Software is furnished to do so, subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice shall be included in
13 * all copies or substantial portions of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21 * DEALINGS IN THE SOFTWARE.
22 *
23 * Authors:
24 * Florian Forster <octo at collectd.org>
25 */
27 #include <stdlib.h>
28 #include <string.h>
30 #include "utils_llist.h"
32 /*
33 * Private data types
34 */
35 struct llist_s {
36 llentry_t *head;
37 llentry_t *tail;
38 int size;
39 };
41 /*
42 * Public functions
43 */
44 llist_t *llist_create(void) {
45 llist_t *ret;
47 ret = calloc(1, sizeof(*ret));
48 if (ret == NULL)
49 return (NULL);
51 return (ret);
52 }
54 void llist_destroy(llist_t *l) {
55 llentry_t *e_this;
56 llentry_t *e_next;
58 if (l == NULL)
59 return;
61 for (e_this = l->head; e_this != NULL; e_this = e_next) {
62 e_next = e_this->next;
63 llentry_destroy(e_this);
64 }
66 free(l);
67 }
69 llentry_t *llentry_create(char *key, void *value) {
70 llentry_t *e;
72 e = malloc(sizeof(*e));
73 if (e) {
74 e->key = key;
75 e->value = value;
76 e->next = NULL;
77 }
79 return (e);
80 }
82 void llentry_destroy(llentry_t *e) { free(e); }
84 void llist_append(llist_t *l, llentry_t *e) {
85 e->next = NULL;
87 if (l->tail == NULL)
88 l->head = e;
89 else
90 l->tail->next = e;
92 l->tail = e;
94 ++(l->size);
95 }
97 void llist_prepend(llist_t *l, llentry_t *e) {
98 e->next = l->head;
99 l->head = e;
101 if (l->tail == NULL)
102 l->tail = e;
104 ++(l->size);
105 }
107 void llist_remove(llist_t *l, llentry_t *e) {
108 llentry_t *prev;
110 if ((l == NULL) || (e == NULL))
111 return;
113 prev = l->head;
114 while ((prev != NULL) && (prev->next != e))
115 prev = prev->next;
117 if (prev != NULL)
118 prev->next = e->next;
119 if (l->head == e)
120 l->head = e->next;
121 if (l->tail == e)
122 l->tail = prev;
124 --(l->size);
125 }
127 int llist_size(llist_t *l) { return (l ? l->size : 0); }
129 static int llist_strcmp(llentry_t *e, void *ud) {
130 if ((e == NULL) || (ud == NULL))
131 return (-1);
132 return (strcmp(e->key, (const char *)ud));
133 }
135 llentry_t *llist_search(llist_t *l, const char *key) {
136 return (llist_search_custom(l, llist_strcmp, (void *)key));
137 }
139 llentry_t *llist_search_custom(llist_t *l, int (*compare)(llentry_t *, void *),
140 void *user_data) {
141 llentry_t *e;
143 if (l == NULL)
144 return (NULL);
146 e = l->head;
147 while (e != NULL) {
148 llentry_t *next = e->next;
150 if (compare(e, user_data) == 0)
151 break;
153 e = next;
154 }
156 return (e);
157 }
159 llentry_t *llist_head(llist_t *l) {
160 if (l == NULL)
161 return (NULL);
162 return (l->head);
163 }
165 llentry_t *llist_tail(llist_t *l) {
166 if (l == NULL)
167 return (NULL);
168 return (l->tail);
169 }