]>
git.ipfire.org Git - thirdparty/systemd.git/blob - src/libudev/libudev-list.c
2 This file is part of systemd.
4 Copyright 2008-2012 Kay Sievers <kay@vrfy.org>
6 systemd is free software; you can redistribute it and/or modify it
7 under the terms of the GNU Lesser General Public License as published by
8 the Free Software Foundation; either version 2.1 of the License, or
9 (at your option) any later version.
11 systemd is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
16 You should have received a copy of the GNU Lesser General Public License
17 along with systemd; If not, see <http://www.gnu.org/licenses/>.
25 #include "libudev-private.h"
28 * SECTION:libudev-list
29 * @short_description: list operation
31 * Libudev list operations.
37 * Opaque object representing one entry in a list. An entry contains
38 * contains a name, and optionally a value.
40 struct udev_list_entry
{
41 struct udev_list_node node
;
42 struct udev_list
*list
;
48 /* the list's head points to itself if empty */
49 void udev_list_node_init(struct udev_list_node
*list
)
55 int udev_list_node_is_empty(struct udev_list_node
*list
)
57 return list
->next
== list
;
60 static void udev_list_node_insert_between(struct udev_list_node
*new,
61 struct udev_list_node
*prev
,
62 struct udev_list_node
*next
)
70 void udev_list_node_append(struct udev_list_node
*new, struct udev_list_node
*list
)
72 udev_list_node_insert_between(new, list
->prev
, list
);
75 void udev_list_node_remove(struct udev_list_node
*entry
)
77 struct udev_list_node
*prev
= entry
->prev
;
78 struct udev_list_node
*next
= entry
->next
;
87 /* return list entry which embeds this node */
88 static inline struct udev_list_entry
*list_node_to_entry(struct udev_list_node
*node
)
90 return container_of(node
, struct udev_list_entry
, node
);
93 void udev_list_init(struct udev
*udev
, struct udev_list
*list
, bool unique
)
95 memzero(list
, sizeof(struct udev_list
));
97 list
->unique
= unique
;
98 udev_list_node_init(&list
->node
);
101 /* insert entry into a list as the last element */
102 static void udev_list_entry_append(struct udev_list_entry
*new, struct udev_list
*list
)
104 /* inserting before the list head make the node the last node in the list */
105 udev_list_node_insert_between(&new->node
, list
->node
.prev
, &list
->node
);
109 /* insert entry into a list, before a given existing entry */
110 static void udev_list_entry_insert_before(struct udev_list_entry
*new, struct udev_list_entry
*entry
)
112 udev_list_node_insert_between(&new->node
, entry
->node
.prev
, &entry
->node
);
113 new->list
= entry
->list
;
116 /* binary search in sorted array */
117 static int list_search(struct udev_list
*list
, const char *name
)
119 unsigned int first
, last
;
122 last
= list
->entries_cur
;
123 while (first
< last
) {
127 i
= (first
+ last
)/2;
128 cmp
= strcmp(name
, list
->entries
[i
]->name
);
137 /* not found, return negative insertion-index+1 */
141 struct udev_list_entry
*udev_list_entry_add(struct udev_list
*list
, const char *name
, const char *value
)
143 struct udev_list_entry
*entry
;
147 /* lookup existing name or insertion-index */
148 i
= list_search(list
, name
);
150 entry
= list
->entries
[i
];
157 entry
->value
= strdup(value
);
158 if (entry
->value
== NULL
)
165 entry
= new0(struct udev_list_entry
, 1);
168 entry
->name
= strdup(name
);
169 if (entry
->name
== NULL
) {
174 entry
->value
= strdup(value
);
175 if (entry
->value
== NULL
) {
183 /* allocate or enlarge sorted array if needed */
184 if (list
->entries_cur
>= list
->entries_max
) {
185 struct udev_list_entry
**entries
;
188 add
= list
->entries_max
;
191 entries
= realloc(list
->entries
, (list
->entries_max
+ add
) * sizeof(struct udev_list_entry
*));
192 if (entries
== NULL
) {
198 list
->entries
= entries
;
199 list
->entries_max
+= add
;
202 /* the negative i returned the insertion index */
205 /* insert into sorted list */
206 if ((unsigned int)i
< list
->entries_cur
)
207 udev_list_entry_insert_before(entry
, list
->entries
[i
]);
209 udev_list_entry_append(entry
, list
);
211 /* insert into sorted array */
212 memmove(&list
->entries
[i
+1], &list
->entries
[i
],
213 (list
->entries_cur
- i
) * sizeof(struct udev_list_entry
*));
214 list
->entries
[i
] = entry
;
217 udev_list_entry_append(entry
, list
);
223 void udev_list_entry_delete(struct udev_list_entry
*entry
)
225 if (entry
->list
->entries
!= NULL
) {
227 struct udev_list
*list
= entry
->list
;
229 /* remove entry from sorted array */
230 i
= list_search(list
, entry
->name
);
232 memmove(&list
->entries
[i
], &list
->entries
[i
+1],
233 ((list
->entries_cur
-1) - i
) * sizeof(struct udev_list_entry
*));
238 udev_list_node_remove(&entry
->node
);
244 void udev_list_cleanup(struct udev_list
*list
)
246 struct udev_list_entry
*entry_loop
;
247 struct udev_list_entry
*entry_tmp
;
249 list
->entries
= mfree(list
->entries
);
250 list
->entries_cur
= 0;
251 list
->entries_max
= 0;
252 udev_list_entry_foreach_safe(entry_loop
, entry_tmp
, udev_list_get_entry(list
))
253 udev_list_entry_delete(entry_loop
);
256 struct udev_list_entry
*udev_list_get_entry(struct udev_list
*list
)
258 if (udev_list_node_is_empty(&list
->node
))
260 return list_node_to_entry(list
->node
.next
);
264 * udev_list_entry_get_next:
265 * @list_entry: current entry
267 * Get the next entry from the list.
269 * Returns: udev_list_entry, #NULL if no more entries are available.
271 _public_
struct udev_list_entry
*udev_list_entry_get_next(struct udev_list_entry
*list_entry
)
273 struct udev_list_node
*next
;
275 if (list_entry
== NULL
)
277 next
= list_entry
->node
.next
;
278 /* empty list or no more entries */
279 if (next
== &list_entry
->list
->node
)
281 return list_node_to_entry(next
);
285 * udev_list_entry_get_by_name:
286 * @list_entry: current entry
287 * @name: name string to match
289 * Lookup an entry in the list with a certain name.
291 * Returns: udev_list_entry, #NULL if no matching entry is found.
293 _public_
struct udev_list_entry
*udev_list_entry_get_by_name(struct udev_list_entry
*list_entry
, const char *name
)
297 if (list_entry
== NULL
)
300 if (!list_entry
->list
->unique
)
303 i
= list_search(list_entry
->list
, name
);
306 return list_entry
->list
->entries
[i
];
310 * udev_list_entry_get_name:
311 * @list_entry: current entry
313 * Get the name of a list entry.
315 * Returns: the name string of this entry.
317 _public_
const char *udev_list_entry_get_name(struct udev_list_entry
*list_entry
)
319 if (list_entry
== NULL
)
321 return list_entry
->name
;
325 * udev_list_entry_get_value:
326 * @list_entry: current entry
328 * Get the value of list entry.
330 * Returns: the value string of this entry.
332 _public_
const char *udev_list_entry_get_value(struct udev_list_entry
*list_entry
)
334 if (list_entry
== NULL
)
336 return list_entry
->value
;
339 int udev_list_entry_get_num(struct udev_list_entry
*list_entry
)
341 if (list_entry
== NULL
)
343 return list_entry
->num
;
346 void udev_list_entry_set_num(struct udev_list_entry
*list_entry
, int num
)
348 if (list_entry
== NULL
)
350 list_entry
->num
= num
;