Moved data structures to new collections subfolder
[strongswan.git] / src / libstrongswan / collections / 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 collections
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 <collections/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 * Checks if there are more elements following after the enumerator's
82 * current position.
83 *
84 * @param enumerator enumerator to check
85 */
86 bool (*has_more)(linked_list_t *this, enumerator_t *enumerator);
87
88 /**
89 * Inserts a new item at the beginning of the list.
90 *
91 * @param item item value to insert in list
92 */
93 void (*insert_first) (linked_list_t *this, void *item);
94
95 /**
96 * Removes the first item in the list and returns its value.
97 *
98 * @param item returned value of first item, or NULL
99 * @return SUCCESS, or NOT_FOUND if list is empty
100 */
101 status_t (*remove_first) (linked_list_t *this, void **item);
102
103 /**
104 * Inserts a new item before the item the enumerator currently points to.
105 *
106 * If this method is called before starting the enumeration the item is
107 * inserted first. If it is called after all items have been enumerated
108 * the item is inserted last. This is helpful when inserting items into
109 * a sorted list.
110 *
111 * @note The position of the enumerator is not changed.
112 *
113 * @param enumerator enumerator with position
114 * @param item item value to insert in list
115 */
116 void (*insert_before)(linked_list_t *this, enumerator_t *enumerator,
117 void *item);
118
119 /**
120 * Replaces the item the enumerator currently points to with the given item.
121 *
122 * @param enumerator enumerator with position
123 * @param item item value to replace current item with
124 * @return current item or NULL if the enumerator is at an
125 * invalid position
126 */
127 void *(*replace)(linked_list_t *this, enumerator_t *enumerator, void *item);
128
129 /**
130 * Remove an item from the list where the enumerator points to.
131 *
132 * @param enumerator enumerator with position
133 */
134 void (*remove_at)(linked_list_t *this, enumerator_t *enumerator);
135
136 /**
137 * Remove items from the list matching the given item.
138 *
139 * If a compare function is given, it is called for each item, with the
140 * first parameter being the current list item and the second parameter
141 * being the supplied item. Return TRUE from the compare function to remove
142 * the item, return FALSE to keep it in the list.
143 *
144 * If compare is NULL, comparison is done by pointers.
145 *
146 * @param item item to remove/pass to comparator
147 * @param compare compare function, or NULL
148 * @return number of removed items
149 */
150 int (*remove)(linked_list_t *this, void *item, bool (*compare)(void*,void*));
151
152 /**
153 * Returns the value of the first list item without removing it.
154 *
155 * @param item returned value of first item
156 * @return SUCCESS, NOT_FOUND if list is empty
157 */
158 status_t (*get_first) (linked_list_t *this, void **item);
159
160 /**
161 * Inserts a new item at the end of the list.
162 *
163 * @param item value to insert into list
164 */
165 void (*insert_last) (linked_list_t *this, void *item);
166
167 /**
168 * Removes the last item in the list and returns its value.
169 *
170 * @param item returned value of last item, or NULL
171 * @return SUCCESS, NOT_FOUND if list is empty
172 */
173 status_t (*remove_last) (linked_list_t *this, void **item);
174
175 /**
176 * Returns the value of the last list item without removing it.
177 *
178 * @param item returned value of last item
179 * @return SUCCESS, NOT_FOUND if list is empty
180 */
181 status_t (*get_last) (linked_list_t *this, void **item);
182
183 /** Find the first matching element in the list.
184 *
185 * The first object passed to the match function is the current list item,
186 * followed by the user supplied data.
187 * If the supplied function returns TRUE this function returns SUCCESS, and
188 * the current object is returned in the third parameter, otherwise,
189 * the next item is checked.
190 *
191 * If match is NULL, *item and the current object are compared.
192 *
193 * @warning Only use pointers as user supplied data.
194 *
195 * @param match comparison function to call on each object, or NULL
196 * @param item the list item, if found
197 * @param ... user data to supply to match function (limited to 5 arguments)
198 * @return SUCCESS if found, NOT_FOUND otherwise
199 */
200 status_t (*find_first) (linked_list_t *this, linked_list_match_t match,
201 void **item, ...);
202
203 /** Find the last matching element in the list.
204 *
205 * The first object passed to the match function is the current list item,
206 * followed by the user supplied data.
207 * If the supplied function returns TRUE this function returns SUCCESS, and
208 * the current object is returned in the third parameter, otherwise,
209 * the next item is checked.
210 *
211 * If match is NULL, *item and the current object are compared.
212 *
213 * @warning Only use pointers as user supplied data.
214 *
215 * @param match comparison function to call on each object, or NULL
216 * @param item the list item, if found
217 * @param ... user data to supply to match function (limited to 5 arguments)
218 * @return SUCCESS if found, NOT_FOUND otherwise
219 */
220 status_t (*find_last) (linked_list_t *this, linked_list_match_t match,
221 void **item, ...);
222
223 /**
224 * Invoke a method on all of the contained objects.
225 *
226 * If a linked list contains objects with function pointers,
227 * invoke() can call a method on each of the objects. The
228 * method is specified by an offset of the function pointer,
229 * which can be evalutated at compile time using the offsetof
230 * macro, e.g.: list->invoke(list, offsetof(object_t, method));
231 *
232 * @warning Only use pointers as user supplied data.
233 *
234 * @param offset offset of the method to invoke on objects
235 * @param ... user data to supply to called function (limited to 5 arguments)
236 */
237 void (*invoke_offset) (linked_list_t *this, size_t offset, ...);
238
239 /**
240 * Invoke a function on all of the contained objects.
241 *
242 * @warning Only use pointers as user supplied data.
243 *
244 * @param function offset of the method to invoke on objects
245 * @param ... user data to supply to called function (limited to 5 arguments)
246 */
247 void (*invoke_function) (linked_list_t *this, linked_list_invoke_t function, ...);
248
249 /**
250 * Clones a list and its objects using the objects' clone method.
251 *
252 * @param offset offset ot the objects clone function
253 * @return cloned list
254 */
255 linked_list_t *(*clone_offset) (linked_list_t *this, size_t offset);
256
257 /**
258 * Clones a list and its objects using a given function.
259 *
260 * @param function function that clones an object
261 * @return cloned list
262 */
263 linked_list_t *(*clone_function) (linked_list_t *this, void*(*)(void*));
264
265 /**
266 * Destroys a linked_list object.
267 */
268 void (*destroy) (linked_list_t *this);
269
270 /**
271 * Destroys a list and its objects using the destructor.
272 *
273 * If a linked list and the contained objects should be destroyed, use
274 * destroy_offset. The supplied offset specifies the destructor to
275 * call on each object. The offset may be calculated using the offsetof
276 * macro, e.g.: list->destroy_offset(list, offsetof(object_t, destroy));
277 *
278 * @param offset offset of the objects destructor
279 */
280 void (*destroy_offset) (linked_list_t *this, size_t offset);
281
282 /**
283 * Destroys a list and its contents using a a cleanup function.
284 *
285 * If a linked list and its contents should get destroyed using a specific
286 * cleanup function, use destroy_function. This is useful when the
287 * list contains malloc()-ed blocks which should get freed,
288 * e.g.: list->destroy_function(list, free);
289 *
290 * @param function function to call on each object
291 */
292 void (*destroy_function) (linked_list_t *this, void (*)(void*));
293 };
294
295 /**
296 * Creates an empty linked list object.
297 *
298 * @return linked_list_t object.
299 */
300 linked_list_t *linked_list_create(void);
301
302 /**
303 * Creates a linked list from an enumerator.
304 *
305 * @param enumerator enumerator over void*, gets destroyed
306 * @return linked_list_t object, containing enumerated values
307 */
308 linked_list_t *linked_list_create_from_enumerator(enumerator_t *enumerator);
309
310 /**
311 * Creates a linked list from a NULL terminated vararg list of items.
312 *
313 * @param first first item
314 * @param ... subsequent items, terminated by NULL
315 * @return linked_list_t object, containing passed items
316 */
317 linked_list_t *linked_list_create_with_items(void *first, ...);
318
319 #endif /** LINKED_LIST_H_ @}*/