1 /*
2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
3 *
4 * Copyright 2016 Olaf Wintermann. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 *
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
20 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
28 /**
29 * Doubly linked list implementation.
30 *
31 * @file list.h
32 * @author Mike Becker
33 * @author Olaf Wintermann
34 */
35
36 #ifndef UCX_LIST_H
37 #define UCX_LIST_H
38
39 #include "ucx.h"
40 #include "allocator.h"
41
42 #ifdef __cplusplus
43 extern "C" {
44 #endif
45
46 /**
47 * Loop statement for UCX lists.
48 *
49 * The first argument is the name of the iteration variable. The scope of
50 * this variable is limited to the <code>UCX_FOREACH</code> statement.
51 *
52 * The second argument is a pointer to the list. In most cases this will be the
53 * pointer to the first element of the list, but it may also be an arbitrary
54 * element of the list. The iteration will then start with that element.
55 *
56 * @param list The first element of the list
57 * @param elem The variable name of the element
58 */
59 #define UCX_FOREACH(elem,list) \
60 for (UcxList* elem = list ; elem != NULL ; elem = elem->next)
61
62 /**
63 * UCX list type.
64 * @see UcxList
65 */
66 typedef struct UcxList UcxList;
67
68 /**
69 * UCX list structure.
70 */
71 struct UcxList {
72 /**
73 * List element payload.
74 */
75 void *data;
76 /**
77 * Pointer to the next list element or <code>NULL</code>, if this is the
78 * last element.
79 */
80 UcxList *next;
81 /**
82 * Pointer to the previous list element or <code>NULL</code>, if this is
83 * the first element.
84 */
85 UcxList *prev;
86 };
87
88 /**
89 * Creates an element-wise copy of a list.
90 *
91 * This function clones the specified list by creating new list elements and
92 * copying the data with the specified copy_func(). If no copy_func() is
93 * specified, a shallow copy is created and the new list will reference the
94 * same data as the source list.
95 *
96 * @param list the list to copy
97 * @param cpyfnc a pointer to the function that shall copy an element (may be
98 * <code>NULL</code>)
99 * @param data additional data for the copy_func()
100 * @return a pointer to the copy
101 */
102 UcxList *ucx_list_clone(UcxList *list, copy_func cpyfnc, void* data);
103
104 /**
105 * Creates an element-wise copy of a list using a UcxAllocator.
106 *
107 * See ucx_list_clone() for details.
108 *
109 * You might want to pass the allocator via the <code>data</code> parameter,
110 * to access it within the copy function for making deep copies.
111 *
112 * @param allocator the allocator to use
113 * @param list the list to copy
114 * @param cpyfnc a pointer to the function that shall copy an element (may be
115 * <code>NULL</code>)
116 * @param data additional data for the copy_func()
117 * @return a pointer to the copy
118 * @see ucx_list_clone()
119 */
120 UcxList *ucx_list_clone_a(UcxAllocator *allocator, UcxList *list,
121 copy_func cpyfnc, void* data);
122
123 /**
124 * Compares two UCX lists element-wise by using a compare function.
125 *
126 * Each element of the two specified lists are compared by using the specified
127 * compare function and the additional data. The type and content of this
128 * additional data depends on the cmp_func() used.
129 *
130 * If the list pointers denote elements within a list, the lists are compared
131 * starting with the denoted elements. Thus any previous elements are not taken
132 * into account. This might be useful to check, if certain list tails match
133 * each other.
134 *
135 * @param list1 the first list
136 * @param list2 the second list
137 * @param cmpfnc the compare function
138 * @param data additional data for the compare function
139 * @return 1, if and only if the two lists equal element-wise, 0 otherwise
140 */
141 int ucx_list_equals(const UcxList *list1, const UcxList *list2,
142 cmp_func cmpfnc, void* data);
143
144 /**
145 * Destroys the entire list.
146 *
147 * The members of the list are not automatically freed, so ensure they are
148 * otherwise referenced or destroyed by ucx_list_free_contents().
149 * Otherwise, a memory leak is likely to occur.
150 *
151 * <b>Caution:</b> the argument <b>MUST</b> denote an entire list (i.e. a call
152 * to ucx_list_first() on the argument must return the argument itself)
153 *
154 * @param list the list to free
155 * @see ucx_list_free_contents()
156 */
157 void ucx_list_free(UcxList *list);
158
159 /**
160 * Destroys the entire list using a UcxAllocator.
161 *
162 * See ucx_list_free() for details.
163 *
164 * @param allocator the allocator to use
165 * @param list the list to free
166 * @see ucx_list_free()
167 */
168 void ucx_list_free_a(UcxAllocator *allocator, UcxList *list);
169
170 /**
171 * Destroys the contents of the specified list by calling the specified
172 * destructor on each of them.
173 *
174 * Note, that the contents are not usable afterwards and the list should be
175 * destroyed with ucx_list_free().
176 *
177 * @param list the list for which the contents shall be freed
178 * @param destr the destructor function (e.g. stdlib free())
179 * @see ucx_list_free()
180 */
181 void ucx_list_free_content(UcxList* list, ucx_destructor destr);
182
183
184 /**
185 * Inserts an element at the end of the list.
186 *
187 * This is generally an O(n) operation, as the end of the list is retrieved with
188 * ucx_list_last().
189 *
190 * @param list the list where to append the data, or <code>NULL</code> to
191 * create a new list
192 * @param data the data to insert
193 * @return <code>list</code>, if it is not <code>NULL</code> or a pointer to
194 * the newly created list otherwise
195 */
196 UcxList *ucx_list_append(UcxList *list, void *data);
197
198 /**
199 * Inserts an element at the end of the list using a UcxAllocator.
200 *
201 * See ucx_list_append() for details.
202 *
203 * @param allocator the allocator to use
204 * @param list the list where to append the data, or <code>NULL</code> to
205 * create a new list
206 * @param data the data to insert
207 * @return <code>list</code>, if it is not <code>NULL</code> or a pointer to
208 * the newly created list otherwise
209 * @see ucx_list_append()
210 */
211 UcxList *ucx_list_append_a(UcxAllocator *allocator, UcxList *list, void *data);
212
213 /**
214 * Inserts an element at the beginning of the list.
215 *
216 * You <i>should</i> overwrite the old list pointer by calling
217 * <code>mylist = ucx_list_prepend(mylist, mydata);</code>. However, you may
218 * also perform successive calls of ucx_list_prepend() on the same list pointer,
219 * as this function always searchs for the head of the list with
220 * ucx_list_first().
221 *
222 * @param list the list where to insert the data or <code>NULL</code> to create
223 * a new list
224 * @param data the data to insert
225 * @return a pointer to the new list head
226 */
227 UcxList *ucx_list_prepend(UcxList *list, void *data);
228
229 /**
230 * Inserts an element at the beginning of the list using a UcxAllocator.
231 *
232 * See ucx_list_prepend() for details.
233 *
234 * @param allocator the allocator to use
235 * @param list the list where to insert the data or <code>NULL</code> to create
236 * a new list
237 * @param data the data to insert
238 * @return a pointer to the new list head
239 * @see ucx_list_prepend()
240 */
241 UcxList *ucx_list_prepend_a(UcxAllocator *allocator, UcxList *list, void *data);
242
243 /**
244 * Concatenates two lists.
245 *
246 * Either of the two arguments may be <code>NULL</code>.
247 *
248 * This function modifies the references to the next/previous element of
249 * the last/first element of <code>list1</code>/<code>
250 * list2</code>.
251 *
252 * @param list1 first list
253 * @param list2 second list
254 * @return if <code>list1</code> is <code>NULL</code>, <code>list2</code> is
255 * returned, otherwise <code>list1</code> is returned
256 */
257 UcxList *ucx_list_concat(UcxList *list1, UcxList *list2);
258
259 /**
260 * Returns the first element of a list.
261 *
262 * If the argument is the list pointer, it is directly returned. Otherwise
263 * this function traverses to the first element of the list and returns the
264 * list pointer.
265 *
266 * @param elem one element of the list
267 * @return the first element of the list, the specified element is a member of
268 */
269 UcxList *ucx_list_first(const UcxList *elem);
270
271 /**
272 * Returns the last element of a list.
273 *
274 * If the argument has no successor, it is the last element and therefore
275 * directly returned. Otherwise this function traverses to the last element of
276 * the list and returns it.
277 *
278 * @param elem one element of the list
279 * @return the last element of the list, the specified element is a member of
280 */
281 UcxList *ucx_list_last(const UcxList *elem);
282
283 /**
284 * Returns the list element at the specified index.
285 *
286 * @param list the list to retrieve the element from
287 * @param index index of the element to return
288 * @return the element at the specified index or <code>NULL</code>, if the
289 * index is greater than the list size
290 */
291 UcxList *ucx_list_get(const UcxList *list, size_t index);
292
293 /**
294 * Returns the index of an element.
295 *
296 * @param list the list where to search for the element
297 * @param elem the element to find
298 * @return the index of the element or -1 if the list does not contain the
299 * element
300 */
301 ssize_t ucx_list_indexof(const UcxList *list, const UcxList *elem);
302
303 /**
304 * Returns the element count of the list.
305 *
306 * @param list the list whose elements are counted
307 * @return the element count
308 */
309 size_t ucx_list_size(const UcxList *list);
310
311 /**
312 * Returns the index of an element containing the specified data.
313 *
314 * This function uses a cmp_func() to compare the data of each list element
315 * with the specified data. If no cmp_func is provided, the pointers are
316 * compared.
317 *
318 * If the list contains the data more than once, the index of the first
319 * occurrence is returned.
320 *
321 * @param list the list where to search for the data
322 * @param elem the element data
323 * @param cmpfnc the compare function
324 * @param data additional data for the compare function
325 * @return the index of the element containing the specified data or -1 if the
326 * data is not found in this list
327 */
328 ssize_t ucx_list_find(UcxList *list, void *elem, cmp_func cmpfnc, void *data);
329
330 /**
331 * Checks, if a list contains a specific element.
332 *
333 * An element is found, if ucx_list_find() returns a value greater than -1.
334 *
335 * @param list the list where to search for the data
336 * @param elem the element data
337 * @param cmpfnc the compare function
338 * @param data additional data for the compare function
339 * @return 1, if and only if the list contains the specified element data
340 * @see ucx_list_find()
341 */
342 int ucx_list_contains(UcxList *list, void *elem, cmp_func cmpfnc, void *data);
343
344 /**
345 * Sorts a UcxList with natural merge sort.
346 *
347 * This function uses O(n) additional temporary memory for merge operations
348 * that is automatically freed after each merge.
349 *
350 * As the head of the list might change, you <b>MUST</b> call this function
351 * as follows: <code>mylist = ucx_list_sort(mylist, mycmpfnc, mydata);</code>.
352 *
353 * @param list the list to sort
354 * @param cmpfnc the function that shall be used to compare the element data
355 * @param data additional data for the cmp_func()
356 * @return the sorted list
357 */
358 UcxList *ucx_list_sort(UcxList *list, cmp_func cmpfnc, void *data);
359
360 /**
361 * Removes an element from the list.
362 *
363 * If the first element is removed, the list pointer changes. So it is
364 * <i>highly recommended</i> to <i>always</i> update the pointer by calling
365 * <code>mylist = ucx_list_remove(mylist, myelem);</code>.
366 *
367 * @param list the list from which the element shall be removed
368 * @param element the element to remove
369 * @return returns the updated list pointer or <code>NULL</code>, if the list
370 * is now empty
371 */
372 UcxList *ucx_list_remove(UcxList *list, UcxList *element);
373
374 /**
375 * Removes an element from the list using a UcxAllocator.
376 *
377 * See ucx_list_remove() for details.
378 *
379 * @param allocator the allocator to use
380 * @param list the list from which the element shall be removed
381 * @param element the element to remove
382 * @return returns the updated list pointer or <code>NULL</code>, if the list
383 * @see ucx_list_remove()
384 */
385 UcxList *ucx_list_remove_a(UcxAllocator *allocator, UcxList *list,
386 UcxList *element);
387
388 #ifdef __cplusplus
389 }
390 #endif
391
392 #endif /* UCX_LIST_H */
393
394