47c003d329aaced2075ed8653bbb307aeb15df26
[strongswan.git] / src / libstrongswan / utils / linked_list.h
1 /*
2 * Copyright (C) 2007-2011 Tobias Brunner
3 * Copyright (C) 2005-2008 Martin Willi
4 * Copyright (C) 2005 Jan Hutter
5 * Hochschule fuer Technik Rapperswil
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the
9 * Free Software Foundation; either version 2 of the License, or (at your
10 * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
11 *
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
14 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 * for more details.
16 */
17
18 /**
19 * @defgroup linked_list linked_list
20 * @{ @ingroup utils
21 */
22
23 #ifndef LINKED_LIST_H_
24 #define LINKED_LIST_H_
25
26 typedef struct linked_list_t linked_list_t;
27
28 #include <utils/enumerator.h>
29
30 /**
31 * Method to match elements in a linked list (used in find_* functions)
32 *
33 * @param item current list item
34 * @param ... user supplied data (only pointers, at most 5)
35 * @return
36 * - TRUE, if the item matched
37 * - FALSE, otherwise
38 */
39 typedef bool (*linked_list_match_t)(void *item, ...);
40
41 /**
42 * Method to be invoked on elements in a linked list (used in invoke_* functions)
43 *
44 * @param item current list item
45 * @param ... user supplied data (only pointers, at most 5)
46 */
47 typedef void (*linked_list_invoke_t)(void *item, ...);
48
49 /**
50 * Class implementing a double linked list.
51 *
52 * General purpose linked list. This list is not synchronized.
53 */
54 struct linked_list_t {
55
56 /**
57 * Gets the count of items in the list.
58 *
59 * @return number of items in list
60 */
61 int (*get_count) (linked_list_t *this);
62
63 /**
64 * Create an enumerator over the list.
65 *
66 * @note The enumerator's position is invalid before the first call
67 * to enumerate().
68 *
69 * @return enumerator over list items
70 */
71 enumerator_t* (*create_enumerator)(linked_list_t *this);
72
73 /**
74 * Resets the enumerator's current position to the beginning of the list.
75 *
76 * @param enumerator enumerator to reset
77 */
78 void (*reset_enumerator)(linked_list_t *this, enumerator_t *enumerator);
79
80 /**
81 * Inserts a new item at the beginning of the list.
82 *
83 * @param item item value to insert in list
84 */
85 void (*insert_first) (linked_list_t *this, void *item);
86
87 /**
88 * Removes the first item in the list and returns its value.
89 *
90 * @param item returned value of first item, or NULL
91 * @return SUCCESS, or NOT_FOUND if list is empty
92 */
93 status_t (*remove_first) (linked_list_t *this, void **item);
94
95 /**
96 * Inserts a new item before the item the enumerator currently points to.
97 *
98 * If the enumerator's position is invalid, e.g. at the end of the list,
99 * the item is inserted last. This is helpful when inserting items into a
100 * sorted list.
101 *
102 * @note The position of the enumerator is not changed.
103 *
104 * @param enumerator enumerator with position
105 * @param item item value to insert in list
106 */
107 void (*insert_before)(linked_list_t *this, enumerator_t *enumerator,
108 void *item);
109
110 /**
111 * Replaces the item the enumerator currently points to with the given item.
112 *
113 * @param enumerator enumerator with position
114 * @param item item value to replace current item with
115 * @return current item or NULL if the enumerator is at an
116 * invalid position
117 */
118 void *(*replace)(linked_list_t *this, enumerator_t *enumerator, void *item);
119
120 /**
121 * Remove an item from the list where the enumerator points to.
122 *
123 * @param enumerator enumerator with position
124 */
125 void (*remove_at)(linked_list_t *this, enumerator_t *enumerator);
126
127 /**
128 * Remove items from the list matching the given item.
129 *
130 * If a compare function is given, it is called for each item, with the
131 * first parameter being the current list item and the second parameter
132 * being the supplied item. Return TRUE from the compare function to remove
133 * the item, return FALSE to keep it in the list.
134 *
135 * If compare is NULL, comparison is done by pointers.
136 *
137 * @param item item to remove/pass to comparator
138 * @param compare compare function, or NULL
139 * @return number of removed items
140 */
141 int (*remove)(linked_list_t *this, void *item, bool (*compare)(void*,void*));
142
143 /**
144 * Returns the value of the first list item without removing it.
145 *
146 * @param item returned value of first item
147 * @return SUCCESS, NOT_FOUND if list is empty
148 */
149 status_t (*get_first) (linked_list_t *this, void **item);
150
151 /**
152 * Inserts a new item at the end of the list.
153 *
154 * @param item value to insert into list
155 */
156 void (*insert_last) (linked_list_t *this, void *item);
157
158 /**
159 * Removes the last item in the list and returns its value.
160 *
161 * @param item returned value of last item, or NULL
162 * @return SUCCESS, NOT_FOUND if list is empty
163 */
164 status_t (*remove_last) (linked_list_t *this, void **item);
165
166 /**
167 * Returns the value of the last list item without removing it.
168 *
169 * @param item returned value of last item
170 * @return SUCCESS, NOT_FOUND if list is empty
171 */
172 status_t (*get_last) (linked_list_t *this, void **item);
173
174 /** Find the first matching element in the list.
175 *
176 * The first object passed to the match function is the current list item,
177 * followed by the user supplied data.
178 * If the supplied function returns TRUE this function returns SUCCESS, and
179 * the current object is returned in the third parameter, otherwise,
180 * the next item is checked.
181 *
182 * If match is NULL, *item and the current object are compared.
183 *
184 * @warning Only use pointers as user supplied data.
185 *
186 * @param match comparison function to call on each object, or NULL
187 * @param item the list item, if found
188 * @param ... user data to supply to match function (limited to 5 arguments)
189 * @return SUCCESS if found, NOT_FOUND otherwise
190 */
191 status_t (*find_first) (linked_list_t *this, linked_list_match_t match,
192 void **item, ...);
193
194 /** Find the last matching element in the list.
195 *
196 * The first object passed to the match function is the current list item,
197 * followed by the user supplied data.
198 * If the supplied function returns TRUE this function returns SUCCESS, and
199 * the current object is returned in the third parameter, otherwise,
200 * the next item is checked.
201 *
202 * If match is NULL, *item and the current object are compared.
203 *
204 * @warning Only use pointers as user supplied data.
205 *
206 * @param match comparison function to call on each object, or NULL
207 * @param item the list item, if found
208 * @param ... user data to supply to match function (limited to 5 arguments)
209 * @return SUCCESS if found, NOT_FOUND otherwise
210 */
211 status_t (*find_last) (linked_list_t *this, linked_list_match_t match,
212 void **item, ...);
213
214 /**
215 * Invoke a method on all of the contained objects.
216 *
217 * If a linked list contains objects with function pointers,
218 * invoke() can call a method on each of the objects. The
219 * method is specified by an offset of the function pointer,
220 * which can be evalutated at compile time using the offsetof
221 * macro, e.g.: list->invoke(list, offsetof(object_t, method));
222 *
223 * @warning Only use pointers as user supplied data.
224 *
225 * @param offset offset of the method to invoke on objects
226 * @param ... user data to supply to called function (limited to 5 arguments)
227 */
228 void (*invoke_offset) (linked_list_t *this, size_t offset, ...);
229
230 /**
231 * Invoke a function on all of the contained objects.
232 *
233 * @warning Only use pointers as user supplied data.
234 *
235 * @param function offset of the method to invoke on objects
236 * @param ... user data to supply to called function (limited to 5 arguments)
237 */
238 void (*invoke_function) (linked_list_t *this, linked_list_invoke_t function, ...);
239
240 /**
241 * Clones a list and its objects using the objects' clone method.
242 *
243 * @param offset offset ot the objects clone function
244 * @return cloned list
245 */
246 linked_list_t *(*clone_offset) (linked_list_t *this, size_t offset);
247
248 /**
249 * Clones a list and its objects using a given function.
250 *
251 * @param function function that clones an object
252 * @return cloned list
253 */
254 linked_list_t *(*clone_function) (linked_list_t *this, void*(*)(void*));
255
256 /**
257 * Destroys a linked_list object.
258 */
259 void (*destroy) (linked_list_t *this);
260
261 /**
262 * Destroys a list and its objects using the destructor.
263 *
264 * If a linked list and the contained objects should be destroyed, use
265 * destroy_offset. The supplied offset specifies the destructor to
266 * call on each object. The offset may be calculated using the offsetof
267 * macro, e.g.: list->destroy_offset(list, offsetof(object_t, destroy));
268 *
269 * @param offset offset of the objects destructor
270 */
271 void (*destroy_offset) (linked_list_t *this, size_t offset);
272
273 /**
274 * Destroys a list and its contents using a a cleanup function.
275 *
276 * If a linked list and its contents should get destroyed using a specific
277 * cleanup function, use destroy_function. This is useful when the
278 * list contains malloc()-ed blocks which should get freed,
279 * e.g.: list->destroy_function(list, free);
280 *
281 * @param function function to call on each object
282 */
283 void (*destroy_function) (linked_list_t *this, void (*)(void*));
284 };
285
286 /**
287 * Creates an empty linked list object.
288 *
289 * @return linked_list_t object.
290 */
291 linked_list_t *linked_list_create(void);
292
293 #endif /** LINKED_LIST_H_ @}*/