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30 * \brief Linked list implementation.
31 * \details Also provides several low-level functions for custom linked list implementations.
33 * \author Olaf Wintermann
35 * \copyright 2-Clause BSD License
38 #ifndef UCX_LINKED_LIST_H
39 #define UCX_LINKED_LIST_H
49 * Set this flag to true, if you want to disable the use of SBO for
50 * linked list swap operations.
52 extern bool CX_DISABLE_LINKED_LIST_SWAP_SBO;
55 * Allocates a linked list for storing elements with \p item_size bytes each.
57 * If \p item_size is CX_STORE_POINTERS, the created list will be created as if
58 * cxListStorePointers() was called immediately after creation.
60 * @param allocator the allocator for allocating the list nodes
61 * (if \c NULL the cxDefaultAllocator will be used)
62 * @param comparator the comparator for the elements
63 * (if \c NULL sort and find functions will not work)
64 * @param item_size the size of each element in bytes
65 * @return the created list
67 CxList *cxLinkedListCreate(
68 CxAllocator const *allocator,
69 CxListComparator comparator,
74 * Allocates a linked list for storing elements with \p item_size bytes each.
76 * The list will use cxDefaultAllocator and no comparator function. If you want
77 * to call functions that need a comparator, you must either set one immediately
78 * after list creation or use cxLinkedListCreate().
80 * If \p item_size is CX_STORE_POINTERS, the created list will be created as if
81 * cxListStorePointers() was called immediately after creation.
83 * @param item_size the size of each element in bytes
84 * @return the created list
86 #define cxLinkedListCreateSimple(item_size) \
87 cxLinkedListCreate(NULL, NULL, item_size)
90 * Finds the node at a certain index.
92 * This function can be used to start at an arbitrary position within the list.
93 * If the search index is large than the start index, \p loc_advance must denote
94 * the location of some sort of \c next pointer (i.e. a pointer to the next node).
95 * But it is also possible that the search index is smaller than the start index
96 * (e.g. in cases where traversing a list backwards is faster) in which case
97 * \p loc_advance must denote the location of some sort of \c prev pointer
98 * (i.e. a pointer to the previous node).
100 * @param start a pointer to the start node
101 * @param start_index the start index
102 * @param loc_advance the location of the pointer to advance
103 * @param index the search index
104 * @return the node found at the specified index
106 void *cx_linked_list_at(
109 ptrdiff_t loc_advance,
111 ) __attribute__((__nonnull__));
114 * Finds the index of an element within a linked list.
116 * @param start a pointer to the start node
117 * @param loc_advance the location of the pointer to advance
118 * @param loc_data the location of the \c data pointer within your node struct
119 * @param cmp_func a compare function to compare \p elem against the node data
120 * @param elem a pointer to the element to find
121 * @return the index of the element or a past-one index if the element could not be found
123 size_t cx_linked_list_find(
125 ptrdiff_t loc_advance,
127 CxListComparator cmp_func,
129 ) __attribute__((__nonnull__));
132 * Finds the first node in a linked list.
134 * The function starts with the pointer denoted by \p node and traverses the list
135 * along a prev pointer whose location within the node struct is
136 * denoted by \p loc_prev.
138 * @param node a pointer to a node in the list
139 * @param loc_prev the location of the \c prev pointer
140 * @return a pointer to the first node
142 void *cx_linked_list_first(
145 ) __attribute__((__nonnull__));
148 * Finds the last node in a linked list.
150 * The function starts with the pointer denoted by \p node and traverses the list
151 * along a next pointer whose location within the node struct is
152 * denoted by \p loc_next.
154 * @param node a pointer to a node in the list
155 * @param loc_next the location of the \c next pointer
156 * @return a pointer to the last node
158 void *cx_linked_list_last(
161 ) __attribute__((__nonnull__));
164 * Finds the predecessor of a node in case it is not linked.
166 * \remark If \p node is not contained in the list starting with \p begin, the behavior is undefined.
168 * @param begin the node where to start the search
169 * @param loc_next the location of the \c next pointer
170 * @param node the successor of the node to find
171 * @return the node or \c NULL if \p node has no predecessor
173 void *cx_linked_list_prev(
177 ) __attribute__((__nonnull__));
180 * Adds a new node to a linked list.
181 * The node must not be part of any list already.
183 * \remark One of the pointers \p begin or \p end may be \c NULL, but not both.
185 * @param begin a pointer to the begin node pointer (if your list has one)
186 * @param end a pointer to the end node pointer (if your list has one)
187 * @param loc_prev the location of a \c prev pointer within your node struct (negative if your struct does not have one)
188 * @param loc_next the location of a \c next pointer within your node struct (required)
189 * @param new_node a pointer to the node that shall be appended
191 void cx_linked_list_add(
197 ) __attribute__((__nonnull__(5)));
200 * Prepends a new node to a linked list.
201 * The node must not be part of any list already.
203 * \remark One of the pointers \p begin or \p end may be \c NULL, but not both.
205 * @param begin a pointer to the begin node pointer (if your list has one)
206 * @param end a pointer to the end node pointer (if your list has one)
207 * @param loc_prev the location of a \c prev pointer within your node struct (negative if your struct does not have one)
208 * @param loc_next the location of a \c next pointer within your node struct (required)
209 * @param new_node a pointer to the node that shall be prepended
211 void cx_linked_list_prepend(
217 ) __attribute__((__nonnull__(5)));
222 * @param left the new predecessor of \p right
223 * @param right the new successor of \p left
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)
227 void cx_linked_list_link(
232 ) __attribute__((__nonnull__));
237 * If right is not the successor of left, the behavior is undefined.
239 * @param left the predecessor of \p right
240 * @param right the 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)
244 void cx_linked_list_unlink(
249 ) __attribute__((__nonnull__));
252 * Inserts a new node after a given node of a linked list.
253 * The new node must not be part of any list already.
255 * \note If you specify \c NULL as the \p node to insert after, this function needs either the \p begin or
256 * the \p end pointer to determine the start of the list. Then the new node will be prepended to the list.
258 * @param begin a pointer to the begin node pointer (if your list has one)
259 * @param end a pointer to the end node pointer (if your list has one)
260 * @param loc_prev the location of a \c prev pointer within your node struct (negative if your struct does not have one)
261 * @param loc_next the location of a \c next pointer within your node struct (required)
262 * @param node the node after which to insert (\c NULL if you want to prepend the node to the list)
263 * @param new_node a pointer to the node that shall be prepended
265 void cx_linked_list_insert(
272 ) __attribute__((__nonnull__(6)));
275 * Inserts a chain of nodes after a given node of a linked list.
276 * The chain must not be part of any list already.
278 * If you do not explicitly specify the end of the chain, it will be determined by traversing
279 * the \c next pointer.
281 * \note If you specify \c NULL as the \p node to insert after, this function needs either the \p begin or
282 * the \p end pointer to determine the start of the list. If only the \p end pointer is specified, you also need
283 * to provide a valid \p loc_prev location.
284 * Then the chain will be prepended to the list.
286 * @param begin a pointer to the begin node pointer (if your list has one)
287 * @param end a pointer to the end node pointer (if your list has one)
288 * @param loc_prev the location of a \c prev pointer within your node struct (negative if your struct does not have one)
289 * @param loc_next the location of a \c next pointer within your node struct (required)
290 * @param node the node after which to insert (\c NULL to prepend the chain to the list)
291 * @param insert_begin a pointer to the first node of the chain that shall be inserted
292 * @param insert_end a pointer to the last node of the chain (or NULL if the last node shall be determined)
294 void cx_linked_list_insert_chain(
302 ) __attribute__((__nonnull__(6)));
305 * Removes a node from the linked list.
307 * If the node to remove is the begin (resp. end) node of the list and if \p begin (resp. \p end)
308 * addresses are provided, the pointers are adjusted accordingly.
310 * The following combinations of arguments are valid (more arguments are optional):
311 * \li \p loc_next and \p loc_prev (ancestor node is determined by using the prev pointer, overall O(1) performance)
312 * \li \p loc_next and \p begin (ancestor node is determined by list traversal, overall O(n) performance)
314 * \remark The \c next and \c prev pointers of the removed node are not cleared by this function and may still be used
315 * to traverse to a former adjacent node in the list.
317 * @param begin a pointer to the begin node pointer (optional)
318 * @param end a pointer to the end node pointer (optional)
319 * @param loc_prev the location of a \c prev pointer within your node struct (negative if your struct does not have one)
320 * @param loc_next the location of a \c next pointer within your node struct (required)
321 * @param node the node to remove
323 void cx_linked_list_remove(
329 ) __attribute__((__nonnull__(5)));
333 * Determines the size of a linked list starting with \p node.
334 * @param node the first node
335 * @param loc_next the location of the \c next pointer within the node struct
336 * @return the size of the list or zero if \p node is \c NULL
338 size_t cx_linked_list_size(
344 * Sorts a linked list based on a comparison function.
346 * This function can work with linked lists of the following structure:
348 * typedef struct node node;
356 * @note This is a recursive function with at most logarithmic recursion depth.
358 * @param begin a pointer to the begin node pointer (required)
359 * @param end a pointer to the end node pointer (optional)
360 * @param loc_prev the location of a \c prev pointer within your node struct (negative if not present)
361 * @param loc_next the location of a \c next pointer within your node struct (required)
362 * @param loc_data the location of the \c data pointer within your node struct
363 * @param cmp_func the compare function defining the sort order
365 void cx_linked_list_sort(
371 CxListComparator cmp_func
372 ) __attribute__((__nonnull__(1, 6)));
376 * Compares two lists element wise.
378 * \note Both list must have the same structure.
380 * @param begin_left the begin of the left list (\c NULL denotes an empty list)
381 * @param begin_right the begin of the right list (\c NULL denotes an empty list)
382 * @param loc_advance the location of the pointer to advance
383 * @param loc_data the location of the \c data pointer within your node struct
384 * @param cmp_func the function to compare the elements
385 * @return the first non-zero result of invoking \p cmp_func or: negative if the left list is smaller than the
386 * right list, positive if the left list is larger than the right list, zero if both lists are equal.
388 int cx_linked_list_compare(
389 void const *begin_left,
390 void const *begin_right,
391 ptrdiff_t loc_advance,
393 CxListComparator cmp_func
394 ) __attribute__((__nonnull__(5)));
397 * Reverses the order of the nodes in a linked list.
399 * @param begin a pointer to the begin node pointer (required)
400 * @param end a pointer to the end node pointer (optional)
401 * @param loc_prev the location of a \c prev pointer within your node struct (negative if your struct does not have one)
402 * @param loc_next the location of a \c next pointer within your node struct (required)
404 void cx_linked_list_reverse(
409 ) __attribute__((__nonnull__(1)));
415 #endif // UCX_LINKED_LIST_H