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comparison: src/ucx/cx/linked_list.h

src/ucx/cx/linked_list.h

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1 /*
2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
3 *
4 * Copyright 2021 Mike Becker, 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 * \file linked_list.h
30 * \brief Linked list implementation.
31 * \details Also provides several low-level functions for custom linked list implementations.
32 * \author Mike Becker
33 * \author Olaf Wintermann
34 * \version 3.0
35 * \copyright 2-Clause BSD License
36 */
37
38 #ifndef UCX_LINKED_LIST_H
39 #define UCX_LINKED_LIST_H
40
41 #include "common.h"
42 #include "list.h"
43
44 #ifdef __cplusplus
45 extern "C" {
46 #endif
47
48 /**
49 * Allocates a linked list for storing elements with \p item_size bytes each.
50 *
51 * @remark Elements added to the list are copied, therefore a possible destructor
52 * MUST NOT free the memory pointed to by its argument.
53 *
54 * @param allocator the allocator for allocating the list nodes
55 * @param comparator the comparator for the elements
56 * @param item_size the size of each element in bytes
57 * @return the created list
58 */
59 CxList *cxLinkedListCreate(
60 CxAllocator const *allocator,
61 CxListComparator comparator,
62 size_t item_size
63 ) __attribute__((__nonnull__));
64
65 /**
66 * Allocates a linked list for storing pointers.
67 *
68 * If you want to store the elements directly in this list, use cxLinkedListCreate().
69 *
70 * @remark Since only pointers are stored in this list, a possible destructor
71 * MAY free the memory pointed to by its argument in order to prevent memory leaks.
72 *
73 * @param allocator the allocator for allocating the list nodes
74 * @param comparator the comparator for the elements
75 * @return the created list
76 */
77 CxList *cxPointerLinkedListCreate(
78 CxAllocator const *allocator,
79 CxListComparator comparator
80 ) __attribute__((__nonnull__));
81
82 /**
83 * Creates a linked list using the data from an array.
84 *
85 * @remark Elements added to the list are copied, therefore a possible destructor
86 * MUST NOT free the memory pointed to by its argument.
87 *
88 * @param allocator the allocator for allocating the list nodes
89 * @param comparator the comparator for the elements
90 * @param item_size the size of one item in the array
91 * @param num_items the number of items
92 * @param array the array data
93 * @return the created list
94 */
95 CxList *cxLinkedListFromArray(
96 CxAllocator const *allocator,
97 CxListComparator comparator,
98 size_t item_size,
99 size_t num_items,
100 void const *array
101 ) __attribute__((__nonnull__));
102
103 /**
104 * Finds the node at a certain index.
105 *
106 * This function can be used to start at an arbitrary position within the list.
107 * If the search index is large than the start index, \p loc_advance must denote
108 * the location of some sort of \c next pointer (i.e. a pointer to the next node).
109 * But it is also possible that the search index is smaller than the start index
110 * (e.g. in cases where traversing a list backwards is faster) in which case
111 * \p loc_advance must denote the location of some sort of \c prev pointer
112 * (i.e. a pointer to the previous node).
113 *
114 * @param start a pointer to the start node
115 * @param start_index the start index
116 * @param loc_advance the location of the pointer to advance
117 * @param index the search index
118 * @return the node found at the specified index
119 */
120 void *cx_linked_list_at(
121 void const *start,
122 size_t start_index,
123 ptrdiff_t loc_advance,
124 size_t index
125 ) __attribute__((__nonnull__));
126
127 /**
128 * Finds the index of an element within a linked list.
129 *
130 * @param start a pointer to the start node
131 * @param loc_advance the location of the pointer to advance
132 * @param loc_data the location of the \c data pointer within your node struct
133 * @param follow_ptr \c false if the pointer denoted by \p loc_data shall be passed to the \p cmp_func.
134 * If \c true, the data at \p loc_data is assumed to be a pointer, dereferenced, and then passed to \p cmp_func.
135 * @param cmp_func a compare function to compare \p elem against the node data
136 * @param elem a pointer to the element to find
137 * @return the index of the element or a past-one index if the element could not be found
138 */
139 size_t cx_linked_list_find(
140 void const *start,
141 ptrdiff_t loc_advance,
142 ptrdiff_t loc_data,
143 bool follow_ptr,
144 CxListComparator cmp_func,
145 void const *elem
146 ) __attribute__((__nonnull__));
147
148 /**
149 * Finds the first node in a linked list.
150 *
151 * The function starts with the pointer denoted by \p node and traverses the list
152 * along a prev pointer whose location within the node struct is
153 * denoted by \p loc_prev.
154 *
155 * @param node a pointer to a node in the list
156 * @param loc_prev the location of the \c prev pointer
157 * @return a pointer to the first node
158 */
159 void *cx_linked_list_first(
160 void const *node,
161 ptrdiff_t loc_prev
162 ) __attribute__((__nonnull__));
163
164 /**
165 * Finds the last node in a linked list.
166 *
167 * The function starts with the pointer denoted by \p node and traverses the list
168 * along a next pointer whose location within the node struct is
169 * denoted by \p loc_next.
170 *
171 * @param node a pointer to a node in the list
172 * @param loc_next the location of the \c next pointer
173 * @return a pointer to the last node
174 */
175 void *cx_linked_list_last(
176 void const *node,
177 ptrdiff_t loc_next
178 ) __attribute__((__nonnull__));
179
180 /**
181 * Finds the predecessor of a node in case it is not linked.
182 *
183 * \remark If \p node is not contained in the list starting with \p begin, the behavior is undefined.
184 *
185 * @param begin the node where to start the search
186 * @param loc_next the location of the \c next pointer
187 * @param node the successor of the node to find
188 * @return the node or \c NULL if \p node has no predecessor
189 */
190 void *cx_linked_list_prev(
191 void const *begin,
192 ptrdiff_t loc_next,
193 void const *node
194 ) __attribute__((__nonnull__));
195
196 /**
197 * Adds a new node to a linked list.
198 * The node must not be part of any list already.
199 *
200 * \remark One of the pointers \p begin or \p end may be \c NULL, but not both.
201 *
202 * @param begin a pointer to the begin node pointer (if your list has one)
203 * @param end a pointer to the end node pointer (if your list has one)
204 * @param loc_prev the location of a \c prev pointer within your node struct (negative if your struct does not have one)
205 * @param loc_next the location of a \c next pointer within your node struct (required)
206 * @param new_node a pointer to the node that shall be appended
207 */
208 void cx_linked_list_add(
209 void **begin,
210 void **end,
211 ptrdiff_t loc_prev,
212 ptrdiff_t loc_next,
213 void *new_node
214 ) __attribute__((__nonnull__(5)));
215
216 /**
217 * Prepends a new node to a linked list.
218 * The node must not be part of any list already.
219 *
220 * \remark One of the pointers \p begin or \p end may be \c NULL, but not both.
221 *
222 * @param begin a pointer to the begin node pointer (if your list has one)
223 * @param end a pointer to the end node pointer (if your list has one)
224 * @param loc_prev the location of a \c prev pointer within your node struct (negative if your struct does not have one)
225 * @param loc_next the location of a \c next pointer within your node struct (required)
226 * @param new_node a pointer to the node that shall be prepended
227 */
228 void cx_linked_list_prepend(
229 void **begin,
230 void **end,
231 ptrdiff_t loc_prev,
232 ptrdiff_t loc_next,
233 void *new_node
234 ) __attribute__((__nonnull__(5)));
235
236 /**
237 * Links two nodes.
238 *
239 * @param left the new predecessor of \p right
240 * @param right the new successor of \p left
241 * @param loc_prev the location of a \c prev pointer within your node struct (negative if your struct does not have one)
242 * @param loc_next the location of a \c next pointer within your node struct (required)
243 */
244 void cx_linked_list_link(
245 void *left,
246 void *right,
247 ptrdiff_t loc_prev,
248 ptrdiff_t loc_next
249 ) __attribute__((__nonnull__));
250
251 /**
252 * Unlinks two nodes.
253 *
254 * If right is not the successor of left, the behavior is undefined.
255 *
256 * @param left the predecessor of \p right
257 * @param right the successor of \p left
258 * @param loc_prev the location of a \c prev pointer within your node struct (negative if your struct does not have one)
259 * @param loc_next the location of a \c next pointer within your node struct (required)
260 */
261 void cx_linked_list_unlink(
262 void *left,
263 void *right,
264 ptrdiff_t loc_prev,
265 ptrdiff_t loc_next
266 ) __attribute__((__nonnull__));
267
268 /**
269 * Inserts a new node after a given node of a linked list.
270 * The new node must not be part of any list already.
271 *
272 * \note If you specify \c NULL as the \p node to insert after, this function needs either the \p begin or
273 * the \p end pointer to determine the start of the list. Then the new node will be prepended to the list.
274 *
275 * @param begin a pointer to the begin node pointer (if your list has one)
276 * @param end a pointer to the end node pointer (if your list has one)
277 * @param loc_prev the location of a \c prev pointer within your node struct (negative if your struct does not have one)
278 * @param loc_next the location of a \c next pointer within your node struct (required)
279 * @param node the node after which to insert (\c NULL if you want to prepend the node to the list)
280 * @param new_node a pointer to the node that shall be prepended
281 */
282 void cx_linked_list_insert(
283 void **begin,
284 void **end,
285 ptrdiff_t loc_prev,
286 ptrdiff_t loc_next,
287 void *node,
288 void *new_node
289 ) __attribute__((__nonnull__(6)));
290
291 /**
292 * Inserts a chain of nodes after a given node of a linked list.
293 * The chain must not be part of any list already.
294 *
295 * If you do not explicitly specify the end of the chain, it will be determined by traversing
296 * the \c next pointer.
297 *
298 * \note If you specify \c NULL as the \p node to insert after, this function needs either the \p begin or
299 * the \p end pointer to determine the start of the list. If only the \p end pointer is specified, you also need
300 * to provide a valid \p loc_prev location.
301 * Then the chain will be prepended to the list.
302 *
303 * @param begin a pointer to the begin node pointer (if your list has one)
304 * @param end a pointer to the end node pointer (if your list has one)
305 * @param loc_prev the location of a \c prev pointer within your node struct (negative if your struct does not have one)
306 * @param loc_next the location of a \c next pointer within your node struct (required)
307 * @param node the node after which to insert (\c NULL to prepend the chain to the list)
308 * @param insert_begin a pointer to the first node of the chain that shall be inserted
309 * @param insert_end a pointer to the last node of the chain (or NULL if the last node shall be determined)
310 */
311 void cx_linked_list_insert_chain(
312 void **begin,
313 void **end,
314 ptrdiff_t loc_prev,
315 ptrdiff_t loc_next,
316 void *node,
317 void *insert_begin,
318 void *insert_end
319 ) __attribute__((__nonnull__(6)));
320
321 /**
322 * Removes a node from the linked list.
323 *
324 * If the node to remove is the begin (resp. end) node of the list and if \p begin (resp. \p end)
325 * addresses are provided, the pointers are adjusted accordingly.
326 *
327 * The following combinations of arguments are valid (more arguments are optional):
328 * \li \p loc_next and \p loc_prev (ancestor node is determined by using the prev pointer, overall O(1) performance)
329 * \li \p loc_next and \p begin (ancestor node is determined by list traversal, overall O(n) performance)
330 *
331 * \remark The \c next and \c prev pointers of the removed node are not cleared by this function and may still be used
332 * to traverse to a former adjacent node in the list.
333 *
334 * @param begin a pointer to the begin node pointer (optional)
335 * @param end a pointer to the end node pointer (optional)
336 * @param loc_prev the location of a \c prev pointer within your node struct (negative if your struct does not have one)
337 * @param loc_next the location of a \c next pointer within your node struct (required)
338 * @param node the node to remove
339 */
340 void cx_linked_list_remove(
341 void **begin,
342 void **end,
343 ptrdiff_t loc_prev,
344 ptrdiff_t loc_next,
345 void *node
346 ) __attribute__((__nonnull__(5)));
347
348
349 /**
350 * Determines the size of a linked list starting with \p node.
351 * @param node the first node
352 * @param loc_next the location of the \c next pointer within the node struct
353 * @return the size of the list or zero if \p node is \c NULL
354 */
355 size_t cx_linked_list_size(
356 void const *node,
357 ptrdiff_t loc_next
358 );
359
360 /**
361 * Sorts a linked list based on a comparison function.
362 *
363 * This function can work with linked lists of the following structures:
364 * \code
365 * typedef struct node node;
366 * struct node {
367 * node* prev;
368 * node* next;
369 * my_payload data; // in this case set follow_ptr = 0
370 * }
371 *
372 * typedef struct ptr_node ptr_node;
373 * struct ptr_node {
374 * ptr_node* prev;
375 * ptr_node* next;
376 * my_payload* data; // in this case set follow_ptr = 1
377 * }
378 * \endcode
379 *
380 * @note This is a recursive function with at most logarithmic recursion depth.
381 *
382 * @param begin a pointer to the begin node pointer (required)
383 * @param end a pointer to the end node pointer (optional)
384 * @param loc_prev the location of a \c prev pointer within your node struct (negative if not present)
385 * @param loc_next the location of a \c next pointer within your node struct (required)
386 * @param loc_data the location of the \c data pointer within your node struct
387 * @param follow_ptr \c false if the pointer denoted by \p loc_data shall be passed to the \p cmp_func.
388 * If \c true, the data at \p loc_data is assumed to be a pointer, dereferenced, and then passed to \p cmp_func.
389 * @param cmp_func the compare function defining the sort order
390 */
391 void cx_linked_list_sort(
392 void **begin,
393 void **end,
394 ptrdiff_t loc_prev,
395 ptrdiff_t loc_next,
396 ptrdiff_t loc_data,
397 bool follow_ptr,
398 CxListComparator cmp_func
399 ) __attribute__((__nonnull__(1, 7)));
400
401
402 /**
403 * Compares two lists element wise.
404 *
405 * The \c follow_ptr flags have the following meaning: if \c false, the pointer denoted by \p loc_data shall
406 * directly be passed to the \p cmp_func.
407 * If \c true, the data at \p loc_data is assumed to be a pointer, dereferenced, and then passed to \p cmp_func.
408 *
409 * \note Both list must have the same structure.
410 *
411 * @param begin_left the begin of the left list (\c NULL denotes an empty list)
412 * @param begin_right the begin of the right list (\c NULL denotes an empty list)
413 * @param loc_advance the location of the pointer to advance
414 * @param loc_data the location of the \c data pointer within your node struct
415 * @param follow_ptr_left indicates whether pointers in the left list shall be dereferenced
416 * @param follow_ptr_right indicates whether pointers in the right list shall be dereferenced
417 * @param cmp_func the function to compare the elements
418 * @return the first non-zero result of invoking \p cmp_func or: negative if the left list is smaller than the
419 * right list, positive if the left list is larger than the right list, zero if both lists are equal.
420 */
421 int cx_linked_list_compare(
422 void const *begin_left,
423 void const *begin_right,
424 ptrdiff_t loc_advance,
425 ptrdiff_t loc_data,
426 bool follow_ptr_left,
427 bool follow_ptr_right,
428 CxListComparator cmp_func
429 ) __attribute__((__nonnull__(7)));
430
431 /**
432 * Reverses the order of the nodes in a linked list.
433 *
434 * @param begin a pointer to the begin node pointer (required)
435 * @param end a pointer to the end node pointer (optional)
436 * @param loc_prev the location of a \c prev pointer within your node struct (negative if your struct does not have one)
437 * @param loc_next the location of a \c next pointer within your node struct (required)
438 */
439 void cx_linked_list_reverse(
440 void **begin,
441 void **end,
442 ptrdiff_t loc_prev,
443 ptrdiff_t loc_next
444 ) __attribute__((__nonnull__(1)));
445
446 #ifdef __cplusplus
447 } /* extern "C" */
448 #endif
449
450 #endif /* UCX_LINKED_LIST_H */

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