993ff10f8406b1f19bb0ecb65021078d6ff74443
[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 * @return TRUE if more elements follow after the current item
86 */
87 bool (*has_more)(linked_list_t *this, enumerator_t *enumerator);
88
89 /**
90 * Inserts a new item at the beginning of the list.
91 *
92 * @param item item value to insert in list
93 */
94 void (*insert_first) (linked_list_t *this, void *item);
95
96 /**
97 * Removes the first item in the list and returns its value.
98 *
99 * @param item returned value of first item, or NULL
100 * @return SUCCESS, or NOT_FOUND if list is empty
101 */
102 status_t (*remove_first) (linked_list_t *this, void **item);
103
104 /**
105 * Inserts a new item before the item the enumerator currently points to.
106 *
107 * If this method is called before starting the enumeration the item is
108 * inserted first. If it is called after all items have been enumerated
109 * the item is inserted last. This is helpful when inserting items into
110 * a sorted list.
111 *
112 * @note The position of the enumerator is not changed.
113 *
114 * @param enumerator enumerator with position
115 * @param item item value to insert in list
116 */
117 void (*insert_before)(linked_list_t *this, enumerator_t *enumerator,
118 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 /**
175 * Find the first matching element in the list.
176 *
177 * The first object passed to the match function is the current list item,
178 * followed by the user supplied data.
179 * If the supplied function returns TRUE this function returns SUCCESS, and
180 * the current object is returned in the third parameter, otherwise,
181 * the next item is checked.
182 *
183 * If match is NULL, *item and the current object are compared.
184 *
185 * @warning Only use pointers as user supplied data.
186 *
187 * @param match comparison function to call on each object, or NULL
188 * @param item the list item, if found
189 * @param ... user data to supply to match function (limited to 5 arguments)
190 * @return SUCCESS if found, NOT_FOUND otherwise
191 */
192 status_t (*find_first) (linked_list_t *this, linked_list_match_t match,
193 void **item, ...);
194
195 /**
196 * Find the last matching element in the list.
197 *
198 * The first object passed to the match function is the current list item,
199 * followed by the user supplied data.
200 * If the supplied function returns TRUE this function returns SUCCESS, and
201 * the current object is returned in the third parameter, otherwise,
202 * the next item is checked.
203 *
204 * If match is NULL, *item and the current object are compared.
205 *
206 * @warning Only use pointers as user supplied data.
207 *
208 * @param match comparison function to call on each object, or NULL
209 * @param item the list item, if found
210 * @param ... user data to supply to match function (limited to 5 arguments)
211 * @return SUCCESS if found, NOT_FOUND otherwise
212 */
213 status_t (*find_last) (linked_list_t *this, linked_list_match_t match,
214 void **item, ...);
215
216 /**
217 * Invoke a method on all of the contained objects.
218 *
219 * If a linked list contains objects with function pointers,
220 * invoke() can call a method on each of the objects. The
221 * method is specified by an offset of the function pointer,
222 * which can be evalutated at compile time using the offsetof
223 * macro, e.g.: list->invoke(list, offsetof(object_t, method));
224 *
225 * @warning Only use pointers as user supplied data.
226 *
227 * @param offset offset of the method to invoke on objects
228 * @param ... user data to supply to called function (limited to 5 arguments)
229 */
230 void (*invoke_offset) (linked_list_t *this, size_t offset, ...);
231
232 /**
233 * Invoke a function on all of the contained objects.
234 *
235 * @warning Only use pointers as user supplied data.
236 *
237 * @param function offset of the method to invoke on objects
238 * @param ... user data to supply to called function (limited to 5 arguments)
239 */
240 void (*invoke_function) (linked_list_t *this, linked_list_invoke_t function, ...);
241
242 /**
243 * Clones a list and its objects using the objects' clone method.
244 *
245 * @param offset offset ot the objects clone function
246 * @return cloned list
247 */
248 linked_list_t *(*clone_offset) (linked_list_t *this, size_t offset);
249
250 /**
251 * Clones a list and its objects using a given function.
252 *
253 * @param function function that clones an object
254 * @return cloned list
255 */
256 linked_list_t *(*clone_function) (linked_list_t *this, void*(*)(void*));
257
258 /**
259 * Destroys a linked_list object.
260 */
261 void (*destroy) (linked_list_t *this);
262
263 /**
264 * Destroys a list and its objects using the destructor.
265 *
266 * If a linked list and the contained objects should be destroyed, use
267 * destroy_offset. The supplied offset specifies the destructor to
268 * call on each object. The offset may be calculated using the offsetof
269 * macro, e.g.: list->destroy_offset(list, offsetof(object_t, destroy));
270 *
271 * @param offset offset of the objects destructor
272 */
273 void (*destroy_offset) (linked_list_t *this, size_t offset);
274
275 /**
276 * Destroys a list and its contents using a a cleanup function.
277 *
278 * If a linked list and its contents should get destroyed using a specific
279 * cleanup function, use destroy_function. This is useful when the
280 * list contains malloc()-ed blocks which should get freed,
281 * e.g.: list->destroy_function(list, free);
282 *
283 * @param function function to call on each object
284 */
285 void (*destroy_function) (linked_list_t *this, void (*)(void*));
286 };
287
288 /**
289 * Creates an empty linked list object.
290 *
291 * @return linked_list_t object.
292 */
293 linked_list_t *linked_list_create(void);
294
295 /**
296 * Creates a linked list from an enumerator.
297 *
298 * @param enumerator enumerator over void*, gets destroyed
299 * @return linked_list_t object, containing enumerated values
300 */
301 linked_list_t *linked_list_create_from_enumerator(enumerator_t *enumerator);
302
303 /**
304 * Creates a linked list from a NULL terminated vararg list of items.
305 *
306 * @param first first item
307 * @param ... subsequent items, terminated by NULL
308 * @return linked_list_t object, containing passed items
309 */
310 linked_list_t *linked_list_create_with_items(void *first, ...);
311
312 #endif /** LINKED_LIST_H_ @}*/