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git.ipfire.org Git - thirdparty/systemd.git/blob - src/udev/libudev-list.c
2 * libudev - interface to udev device information
4 * Copyright (C) 2008 Kay Sievers <kay.sievers@vrfy.org>
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
20 #include "libudev-private.h"
23 * SECTION:libudev-list
24 * @short_description: list operation
26 * Libudev list operations.
32 * Opaque object representing one entry in a list. An entry contains
33 * contains a name, and optionally a value.
35 struct udev_list_entry
{
36 struct udev_list_node node
;
37 struct udev_list
*list
;
43 /* the list's head points to itself if empty */
44 void udev_list_node_init(struct udev_list_node
*list
)
50 int udev_list_node_is_empty(struct udev_list_node
*list
)
52 return list
->next
== list
;
55 static void udev_list_node_insert_between(struct udev_list_node
*new,
56 struct udev_list_node
*prev
,
57 struct udev_list_node
*next
)
65 void udev_list_node_append(struct udev_list_node
*new, struct udev_list_node
*list
)
67 udev_list_node_insert_between(new, list
->prev
, list
);
70 void udev_list_node_remove(struct udev_list_node
*entry
)
72 struct udev_list_node
*prev
= entry
->prev
;
73 struct udev_list_node
*next
= entry
->next
;
82 /* return list entry which embeds this node */
83 static struct udev_list_entry
*list_node_to_entry(struct udev_list_node
*node
)
88 list
-= offsetof(struct udev_list_entry
, node
);
89 return (struct udev_list_entry
*)list
;
92 void udev_list_init(struct udev
*udev
, struct udev_list
*list
, bool unique
)
94 memset(list
, 0x00, sizeof(struct udev_list
));
96 list
->unique
= unique
;
97 udev_list_node_init(&list
->node
);
100 /* insert entry into a list as the last element */
101 void udev_list_entry_append(struct udev_list_entry
*new, struct udev_list
*list
)
103 /* inserting before the list head make the node the last node in the list */
104 udev_list_node_insert_between(&new->node
, list
->node
.prev
, &list
->node
);
108 /* insert entry into a list, before a given existing entry */
109 void udev_list_entry_insert_before(struct udev_list_entry
*new, struct udev_list_entry
*entry
)
111 udev_list_node_insert_between(&new->node
, entry
->node
.prev
, &entry
->node
);
112 new->list
= entry
->list
;
115 /* binary search in sorted array */
116 static int list_search(struct udev_list
*list
, const char *name
)
118 unsigned int first
, last
;
121 last
= list
->entries_cur
;
122 while (first
< last
) {
126 i
= (first
+ last
)/2;
127 cmp
= strcmp(name
, list
->entries
[i
]->name
);
136 /* not found, return negative insertion-index+1 */
140 struct udev_list_entry
*udev_list_entry_add(struct udev_list
*list
, const char *name
, const char *value
)
142 struct udev_list_entry
*entry
;
146 /* lookup existing name or insertion-index */
147 i
= list_search(list
, name
);
149 entry
= list
->entries
[i
];
156 entry
->value
= strdup(value
);
157 if (entry
->value
== NULL
)
164 entry
= calloc(1, sizeof(struct udev_list_entry
));
167 entry
->name
= strdup(name
);
168 if (entry
->name
== NULL
) {
173 entry
->value
= strdup(value
);
174 if (entry
->value
== NULL
) {
182 /* allocate or enlarge sorted array if needed */
183 if (list
->entries_cur
>= list
->entries_max
) {
186 add
= list
->entries_max
;
189 list
->entries
= realloc(list
->entries
, (list
->entries_max
+ add
) * sizeof(struct udev_list_entry
*));
190 if (list
->entries
== NULL
) {
195 list
->entries_max
+= add
;
198 /* the negative i returned the insertion index */
201 /* insert into sorted list */
202 if ((unsigned int)i
< list
->entries_cur
)
203 udev_list_entry_insert_before(entry
, list
->entries
[i
]);
205 udev_list_entry_append(entry
, list
);
207 /* insert into sorted array */
208 memmove(&list
->entries
[i
+1], &list
->entries
[i
],
209 (list
->entries_cur
- i
) * sizeof(struct udev_list_entry
*));
210 list
->entries
[i
] = entry
;
213 udev_list_entry_append(entry
, list
);
219 void udev_list_entry_delete(struct udev_list_entry
*entry
)
221 if (entry
->list
->entries
!= NULL
) {
223 struct udev_list
*list
= entry
->list
;
225 /* remove entry from sorted array */
226 i
= list_search(list
, entry
->name
);
228 memmove(&list
->entries
[i
], &list
->entries
[i
+1],
229 ((list
->entries_cur
-1) - i
) * sizeof(struct udev_list_entry
*));
234 udev_list_node_remove(&entry
->node
);
240 void udev_list_cleanup(struct udev_list
*list
)
242 struct udev_list_entry
*entry_loop
;
243 struct udev_list_entry
*entry_tmp
;
246 list
->entries
= NULL
;
247 list
->entries_cur
= 0;
248 list
->entries_max
= 0;
249 udev_list_entry_foreach_safe(entry_loop
, entry_tmp
, udev_list_get_entry(list
))
250 udev_list_entry_delete(entry_loop
);
253 struct udev_list_entry
*udev_list_get_entry(struct udev_list
*list
)
255 if (udev_list_node_is_empty(&list
->node
))
257 return list_node_to_entry(list
->node
.next
);
261 * udev_list_entry_get_next:
262 * @list_entry: current entry
264 * Returns: the next entry from the list, #NULL is no more entries are found.
266 _public_
struct udev_list_entry
*udev_list_entry_get_next(struct udev_list_entry
*list_entry
)
268 struct udev_list_node
*next
;
270 if (list_entry
== NULL
)
272 next
= list_entry
->node
.next
;
273 /* empty list or no more entries */
274 if (next
== &list_entry
->list
->node
)
276 return list_node_to_entry(next
);
280 * udev_list_entry_get_by_name:
281 * @list_entry: current entry
282 * @name: name string to match
284 * Returns: the entry where @name matched, #NULL if no matching entry is found.
286 _public_
struct udev_list_entry
*udev_list_entry_get_by_name(struct udev_list_entry
*list_entry
, const char *name
)
290 if (list_entry
== NULL
)
293 if (!list_entry
->list
->unique
)
296 i
= list_search(list_entry
->list
, name
);
299 return list_entry
->list
->entries
[i
];
303 * udev_list_entry_get_name:
304 * @list_entry: current entry
306 * Returns: the name string of this entry.
308 _public_
const char *udev_list_entry_get_name(struct udev_list_entry
*list_entry
)
310 if (list_entry
== NULL
)
312 return list_entry
->name
;
316 * udev_list_entry_get_value:
317 * @list_entry: current entry
319 * Returns: the value string of this entry.
321 _public_
const char *udev_list_entry_get_value(struct udev_list_entry
*list_entry
)
323 if (list_entry
== NULL
)
325 return list_entry
->value
;
328 int udev_list_entry_get_num(struct udev_list_entry
*list_entry
)
330 if (list_entry
== NULL
)
332 return list_entry
->num
;
335 void udev_list_entry_set_num(struct udev_list_entry
*list_entry
, int num
)
337 if (list_entry
== NULL
)
339 list_entry
->num
= num
;