src/cx/linked_list.h

Thu, 23 Dec 2021 15:20:50 +0100

author
Mike Becker <universe@uap-core.de>
date
Thu, 23 Dec 2021 15:20:50 +0100
changeset 481
eef025d82a34
parent 480
e3be53a3354f
child 484
9e6900b1cf9d
permissions
-rw-r--r--

add several new linked list functions

* cx_linked_list_insert()
* cx_linked_list_insert_chain()
* cx_linked_list_link()
* cx_linked_list_unlink()

Also uses the most general function wherever possible.

universe@398 1 /*
universe@398 2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
universe@398 3 *
universe@398 4 * Copyright 2021 Mike Becker, Olaf Wintermann All rights reserved.
universe@398 5 *
universe@398 6 * Redistribution and use in source and binary forms, with or without
universe@398 7 * modification, are permitted provided that the following conditions are met:
universe@398 8 *
universe@398 9 * 1. Redistributions of source code must retain the above copyright
universe@398 10 * notice, this list of conditions and the following disclaimer.
universe@398 11 *
universe@398 12 * 2. Redistributions in binary form must reproduce the above copyright
universe@398 13 * notice, this list of conditions and the following disclaimer in the
universe@398 14 * documentation and/or other materials provided with the distribution.
universe@398 15 *
universe@398 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
universe@398 17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
universe@398 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
universe@398 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
universe@398 20 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
universe@398 21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
universe@398 22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
universe@398 23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
universe@398 24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
universe@398 25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
universe@398 26 * POSSIBILITY OF SUCH DAMAGE.
universe@398 27 */
universe@453 28 /**
universe@453 29 * \file linked_list.h
universe@453 30 * \brief Linked list implementation.
universe@453 31 * \details Also provides several low-level functions for custom linked list implementations.
universe@453 32 * \author Mike Becker
universe@453 33 * \author Olaf Wintermann
universe@453 34 * \version 3.0
universe@453 35 * \copyright 2-Clause BSD License
universe@453 36 */
universe@398 37
universe@398 38 #ifndef UCX_LINKED_LIST_H
universe@398 39 #define UCX_LINKED_LIST_H
universe@398 40
universe@400 41 #include <stddef.h>
universe@398 42 #include "list.h"
universe@398 43
universe@415 44 #ifdef __cplusplus
universe@415 45 extern "C" {
universe@415 46 #endif
universe@415 47
universe@466 48 /**
universe@466 49 * Allocates a linked list for storing elements with \p item_size bytes each.
universe@466 50 *
universe@466 51 * Elements added to the list are copied.
universe@466 52 *
universe@466 53 * @param allocator the allocator for allocating the list nodes
universe@466 54 * @param comparator the comparator for the elements
universe@466 55 * @param item_size the size of each element in bytes
universe@466 56 * @return the created list
universe@466 57 */
universe@481 58 CxList cxLinkedListCreate(
universe@481 59 CxAllocator allocator,
universe@481 60 CxListComparator comparator,
universe@481 61 size_t item_size
universe@481 62 );
universe@453 63
universe@466 64 /**
universe@466 65 * Allocates a linked list for storing pointers.
universe@466 66 *
universe@466 67 * If you want to store the elements directly in this list, use cxLinkedListCreate().
universe@466 68 *
universe@466 69 * @param allocator the allocator for allocating the list nodes
universe@466 70 * @param comparator the comparator for the elements
universe@466 71 * @return the created list
universe@466 72 */
universe@481 73 CxList cxPointerLinkedListCreate(
universe@481 74 CxAllocator allocator,
universe@481 75 CxListComparator comparator
universe@481 76 );
universe@466 77
universe@466 78 /**
universe@466 79 * Deallocates the memory of the entire list.
universe@466 80 *
universe@466 81 * \attention If this is a pointer list, the memory the pointers are referring to is \em not freed.
universe@466 82 *
universe@466 83 * @param list the list
universe@466 84 */
universe@453 85 void cxLinkedListDestroy(CxList list);
universe@453 86
universe@438 87 /**
universe@438 88 * Finds the node at a certain index.
universe@438 89 *
universe@438 90 * This function can be used to start at an arbitrary position within the list.
universe@438 91 * If the search index is large than the start index, \p loc_advance must denote
universe@438 92 * the location of some sort of \c next pointer (i.e. a pointer to the next node).
universe@438 93 * But it is also possible that the search index is smaller than the start index
universe@438 94 * (e.g. in cases where traversing a list backwards is faster) in which case
universe@438 95 * \p loc_advance must denote the location of some sort of \c prev pointer
universe@438 96 * (i.e. a pointer to the previous node).
universe@438 97 *
universe@438 98 * @param start a pointer to the start node
universe@438 99 * @param start_index the start index
universe@438 100 * @param loc_advance the location of the pointer to advance
universe@438 101 * @param index the search index
universe@438 102 * @return the node found at the specified index
universe@438 103 */
universe@481 104 void *cx_linked_list_at(
universe@481 105 void *start,
universe@481 106 size_t start_index,
universe@481 107 ptrdiff_t loc_advance,
universe@481 108 size_t index
universe@481 109 ) __attribute__((__nonnull__));
universe@438 110
universe@453 111 /**
universe@480 112 * Finds the index of an element within a linked list.
universe@480 113 *
universe@480 114 * @param start a pointer to the start node
universe@480 115 * @param loc_advance the location of the pointer to advance
universe@480 116 * @param loc_data the location of the \c data pointer within your node struct
universe@480 117 * @param follow_ptr \c false if the pointer denoted by \p loc_data shall be passed to the \p cmp_func.
universe@480 118 * If \c true, the data at \p loc_data is assumed to be a pointer, dereferenced, and then passed to \p cmp_func.
universe@480 119 * @param cmp_func a compare function to compare \p elem against the node data
universe@480 120 * @param elem a pointer to the element to find
universe@480 121 * @return the index of the element or a past-one index if the element could not be found
universe@480 122 */
universe@481 123 size_t cx_linked_list_find(
universe@481 124 void *start,
universe@481 125 ptrdiff_t loc_advance,
universe@481 126 ptrdiff_t loc_data,
universe@481 127 int follow_ptr,
universe@481 128 CxListComparator cmp_func,
universe@481 129 void *elem
universe@481 130 ) __attribute__((__nonnull__));
universe@480 131
universe@480 132 /**
universe@475 133 * Finds the first node in a linked list.
universe@475 134 *
universe@475 135 * The function starts with the pointer denoted by \p node and traverses the list
universe@475 136 * along a prev pointer whose location within the node struct is
universe@475 137 * denoted by \p loc_prev.
universe@475 138 *
universe@475 139 * @param node a pointer to a node in the list
universe@475 140 * @param loc_prev the location of the \c prev pointer
universe@475 141 */
universe@481 142 void *cx_linked_list_first(
universe@481 143 void *node,
universe@481 144 ptrdiff_t loc_prev
universe@481 145 ) __attribute__((__nonnull__));
universe@475 146
universe@475 147 /**
universe@453 148 * Finds the last node in a linked list.
universe@453 149 *
universe@475 150 * The function starts with the pointer denoted by \p node and traverses the list
universe@456 151 * along a next pointer whose location within the node struct is
universe@453 152 * denoted by \p loc_next.
universe@453 153 *
universe@475 154 * @param node a pointer to a node in the list
universe@456 155 * @param loc_next the location of the \c next pointer
universe@478 156 * @return a pointer to the last node
universe@453 157 */
universe@481 158 void *cx_linked_list_last(
universe@481 159 void *node,
universe@481 160 ptrdiff_t loc_next
universe@481 161 ) __attribute__((__nonnull__));
universe@398 162
universe@453 163 /**
universe@473 164 * Finds the predecessor of a node in case it is not linked.
universe@473 165 *
universe@473 166 * \remark If \p node is not contained in the list starting with \p begin, the behavior is undefined.
universe@473 167 *
universe@473 168 * @param begin the node where to start the search
universe@473 169 * @param loc_next the location of the \c next pointer
universe@473 170 * @param node the successor of the node to find
universe@473 171 * @return the node or \c NULL if \p node has no predecessor
universe@473 172 */
universe@481 173 void *cx_linked_list_prev(
universe@481 174 void *begin,
universe@481 175 ptrdiff_t loc_next,
universe@481 176 void *node
universe@481 177 ) __attribute__((__nonnull__));
universe@473 178
universe@473 179 /**
universe@453 180 * Adds a new node to a linked list.
universe@475 181 * The node must not be part of any list already.
universe@453 182 *
universe@478 183 * \remark One of the pointers \p begin or \p end may be \c NULL, but not both.
universe@453 184 *
universe@453 185 * @param begin a pointer to the begin node pointer (if your list has one)
universe@453 186 * @param end a pointer to the end node pointer (if your list has one)
universe@453 187 * @param loc_prev the location of a \c prev pointer within your node struct (negative if your struct does not have one)
universe@473 188 * @param loc_next the location of a \c next pointer within your node struct (required)
universe@453 189 * @param new_node a pointer to the node that shall be appended
universe@453 190 */
universe@481 191 void cx_linked_list_add(
universe@481 192 void **begin,
universe@481 193 void **end,
universe@481 194 ptrdiff_t loc_prev,
universe@481 195 ptrdiff_t loc_next,
universe@481 196 void *new_node
universe@481 197 ) __attribute__((__nonnull__(5)));
universe@406 198
universe@468 199 /**
universe@475 200 * Prepends a new node to a linked list.
universe@475 201 * The node must not be part of any list already.
universe@475 202 *
universe@478 203 * \remark One of the pointers \p begin or \p end may be \c NULL, but not both.
universe@475 204 *
universe@475 205 * @param begin a pointer to the begin node pointer (if your list has one)
universe@475 206 * @param end a pointer to the end node pointer (if your list has one)
universe@475 207 * @param loc_prev the location of a \c prev pointer within your node struct (negative if your struct does not have one)
universe@475 208 * @param loc_next the location of a \c next pointer within your node struct (required)
universe@475 209 * @param new_node a pointer to the node that shall be prepended
universe@475 210 */
universe@481 211 void cx_linked_list_prepend(
universe@481 212 void **begin,
universe@481 213 void **end,
universe@481 214 ptrdiff_t loc_prev,
universe@481 215 ptrdiff_t loc_next,
universe@481 216 void *new_node
universe@481 217 ) __attribute__((__nonnull__(5)));
universe@481 218
universe@481 219 /**
universe@481 220 * Links two nodes.
universe@481 221 *
universe@481 222 * @param left the new predecessor of \p right
universe@481 223 * @param right the new successor of \p left
universe@481 224 * @param loc_prev the location of a \c prev pointer within your node struct (negative if your struct does not have one)
universe@481 225 * @param loc_next the location of a \c next pointer within your node struct (required)
universe@481 226 */
universe@481 227 void cx_linked_list_link(
universe@481 228 void *left,
universe@481 229 void *right,
universe@481 230 ptrdiff_t loc_prev,
universe@481 231 ptrdiff_t loc_next
universe@481 232 ) __attribute__((__nonnull__));
universe@481 233
universe@481 234 /**
universe@481 235 * Unlinks two nodes.
universe@481 236 *
universe@481 237 * If right is not the successor of left, the behavior is undefined.
universe@481 238 *
universe@481 239 * @param left the predecessor of \p right
universe@481 240 * @param right the successor of \p left
universe@481 241 * @param loc_prev the location of a \c prev pointer within your node struct (negative if your struct does not have one)
universe@481 242 * @param loc_next the location of a \c next pointer within your node struct (required)
universe@481 243 */
universe@481 244 void cx_linked_list_unlink(
universe@481 245 void *left,
universe@481 246 void *right,
universe@481 247 ptrdiff_t loc_prev,
universe@481 248 ptrdiff_t loc_next
universe@481 249 ) __attribute__((__nonnull__));
universe@481 250
universe@481 251 /**
universe@481 252 * Inserts a new node after a given node of a linked list.
universe@481 253 * The new node must not be part of any list already.
universe@481 254 *
universe@481 255 * \note If you specify \c NULL as the \p node to insert after, this function needs either the \p begin or
universe@481 256 * the \p end pointer to determine the start of the list. Then the new node will be prepended to the list.
universe@481 257 *
universe@481 258 * @param begin a pointer to the begin node pointer (if your list has one)
universe@481 259 * @param end a pointer to the end node pointer (if your list has one)
universe@481 260 * @param loc_prev the location of a \c prev pointer within your node struct (negative if your struct does not have one)
universe@481 261 * @param loc_next the location of a \c next pointer within your node struct (required)
universe@481 262 * @param node the node after which to insert (\c NULL if you want to prepend the node to the list)
universe@481 263 * @param new_node a pointer to the node that shall be prepended
universe@481 264 */
universe@481 265 void cx_linked_list_insert(
universe@481 266 void **begin,
universe@481 267 void **end,
universe@481 268 ptrdiff_t loc_prev,
universe@481 269 ptrdiff_t loc_next,
universe@481 270 void *node,
universe@481 271 void *new_node
universe@481 272 ) __attribute__((__nonnull__(6)));
universe@481 273
universe@481 274 /**
universe@481 275 * Inserts a chain of nodes after a given node of a linked list.
universe@481 276 * The chain must not be part of any list already.
universe@481 277 *
universe@481 278 * If you do not explicitly specify the end of the chain, it will be determined by traversing
universe@481 279 * the \c next pointer.
universe@481 280 *
universe@481 281 * \note If you specify \c NULL as the \p node to insert after, this function needs either the \p begin or
universe@481 282 * the \p end pointer to determine the start of the list. If only the \p end pointer is specified, you also need
universe@481 283 * to provide a valid \p loc_prev location.
universe@481 284 * Then the chain will be prepended to the list.
universe@481 285 *
universe@481 286 * @param begin a pointer to the begin node pointer (if your list has one)
universe@481 287 * @param end a pointer to the end node pointer (if your list has one)
universe@481 288 * @param loc_prev the location of a \c prev pointer within your node struct (negative if your struct does not have one)
universe@481 289 * @param loc_next the location of a \c next pointer within your node struct (required)
universe@481 290 * @param node the node after which to insert (\c NULL to prepend the chain to the list)
universe@481 291 * @param insert_begin a pointer to the first node of the chain that shall be inserted
universe@481 292 * @param insert_end a pointer to the last node of the chain (or NULL if the last node shall be determined)
universe@481 293 */
universe@481 294 void cx_linked_list_insert_chain(
universe@481 295 void **begin,
universe@481 296 void **end,
universe@481 297 ptrdiff_t loc_prev,
universe@481 298 ptrdiff_t loc_next,
universe@481 299 void *node,
universe@481 300 void *insert_begin,
universe@481 301 void *insert_end
universe@481 302 ) __attribute__((__nonnull__(6)));
universe@475 303
universe@475 304 /**
universe@473 305 * Removes a node from the linked list.
universe@473 306 *
universe@473 307 * If the node to remove is the begin (resp. end) node of the list and if \p begin (resp. \p end)
universe@473 308 * addresses are provided, the pointers are adjusted accordingly.
universe@473 309 *
universe@473 310 * The following combinations of arguments are valid (more arguments are optional):
universe@477 311 * \li \p loc_next and \p loc_prev (ancestor node is determined by using the prev pointer, overall O(1) performance)
universe@477 312 * \li \p loc_next and \p begin (ancestor node is determined by list traversal, overall O(n) performance)
universe@473 313 *
universe@476 314 * \remark The \c next and \c prev pointers of the removed node are not cleared by this function and may still be used
universe@476 315 * to traverse to a former adjacent node in the list.
universe@473 316 *
universe@473 317 * @param begin a pointer to the begin node pointer (optional)
universe@473 318 * @param end a pointer to the end node pointer (optional)
universe@473 319 * @param loc_prev the location of a \c prev pointer within your node struct (negative if your struct does not have one)
universe@473 320 * @param loc_next the location of a \c next pointer within your node struct (required)
universe@473 321 * @param node the node to remove
universe@473 322 */
universe@481 323 void cx_linked_list_remove(
universe@481 324 void **begin,
universe@481 325 void **end,
universe@481 326 ptrdiff_t loc_prev,
universe@481 327 ptrdiff_t loc_next,
universe@481 328 void *node
universe@481 329 ) __attribute__((__nonnull__(5)));
universe@473 330
universe@473 331
universe@473 332 /**
universe@468 333 * Determines the size of a linked list starting with \p node.
universe@468 334 * @param node the first node
universe@468 335 * @param loc_next the location of the \c next pointer within the node struct
universe@468 336 * @return the size of the list or zero if \p node is \c NULL
universe@468 337 */
universe@481 338 size_t cx_linked_list_size(
universe@481 339 void *node,
universe@481 340 ptrdiff_t loc_next
universe@481 341 );
universe@468 342
universe@468 343 /**
universe@468 344 * Sorts a linked list based on a comparison function.
universe@468 345 *
universe@468 346 * This function can work with linked lists of the following structures:
universe@468 347 * \code
universe@468 348 * typedef struct node node;
universe@468 349 * struct node {
universe@468 350 * node* prev;
universe@468 351 * node* next;
universe@468 352 * my_payload data; // in this case set follow_ptr = 0
universe@468 353 * }
universe@468 354 *
universe@468 355 * typedef struct ptr_node ptr_node;
universe@468 356 * struct ptr_node {
universe@468 357 * ptr_node* prev;
universe@468 358 * ptr_node* next;
universe@468 359 * my_payload* data; // in this case set follow_ptr = 1
universe@468 360 * }
universe@468 361 * \endcode
universe@468 362 *
universe@476 363 * @note This is a recursive function with at most logarithmic recursion depth.
universe@476 364 *
universe@468 365 * @param begin a pointer to the begin node pointer (required)
universe@468 366 * @param end a pointer to the end node pointer (optional)
universe@468 367 * @param loc_prev the location of a \c prev pointer within your node struct (negative if not present)
universe@468 368 * @param loc_next the location of a \c next pointer within your node struct (required)
universe@468 369 * @param loc_data the location of the \c data pointer within your node struct
universe@468 370 * @param follow_ptr \c false if the pointer denoted by \p loc_data shall be passed to the \p cmp_func.
universe@480 371 * If \c true, the data at \p loc_data is assumed to be a pointer, dereferenced, and then passed to \p cmp_func.
universe@468 372 * @param cmp_func the compare function defining the sort order
universe@468 373 */
universe@481 374 void cx_linked_list_sort(
universe@481 375 void **begin,
universe@481 376 void **end,
universe@481 377 ptrdiff_t loc_prev,
universe@481 378 ptrdiff_t loc_next,
universe@481 379 ptrdiff_t loc_data,
universe@481 380 int follow_ptr,
universe@481 381 CxListComparator cmp_func
universe@481 382 ) __attribute__((__nonnull__(1, 7)));
universe@473 383
universe@473 384 /**
universe@473 385 * Reverses the order of the nodes in a linked list.
universe@473 386 *
universe@473 387 * @param begin a pointer to the begin node pointer (required)
universe@473 388 * @param end a pointer to the end node pointer (optional)
universe@473 389 * @param loc_prev the location of a \c prev pointer within your node struct (negative if your struct does not have one)
universe@473 390 * @param loc_next the location of a \c next pointer within your node struct (required)
universe@473 391 */
universe@481 392 void cx_linked_list_reverse(
universe@481 393 void **begin,
universe@481 394 void **end,
universe@481 395 ptrdiff_t loc_prev,
universe@481 396 ptrdiff_t loc_next
universe@481 397 ) __attribute__((__nonnull__(1)));
universe@473 398
universe@415 399 #ifdef __cplusplus
universe@415 400 } /* extern "C" */
universe@415 401 #endif
universe@415 402
universe@398 403 #endif /* UCX_LINKED_LIST_H */

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