src/cx/linked_list.h@1bd4b8c28722
src/cx/linked_list.h
Fri, 08 Oct 2021 19:47:31 +0200
- author
- Mike Becker <universe@uap-core.de>
- date
- Fri, 08 Oct 2021 19:47:31 +0200
- changeset 473
- 1bd4b8c28722
- parent 468
- 75ae1dccd101
- child 475
- 31bf97fdbf71
- permissions
- -rw-r--r--
add cx_linked_list_{prev, remove, reverse}
changes assertions for some low level methods (loc_next is now always mandatory)
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 */
38 #ifndef UCX_LINKED_LIST_H
39 #define UCX_LINKED_LIST_H
41 #include <stddef.h>
42 #include "list.h"
44 #ifdef __cplusplus
45 extern "C" {
46 #endif
48 /**
49 * Allocates a linked list for storing elements with \p item_size bytes each.
50 *
51 * Elements added to the list are copied.
52 *
53 * @param allocator the allocator for allocating the list nodes
54 * @param comparator the comparator for the elements
55 * @param item_size the size of each element in bytes
56 * @return the created list
57 */
58 CxList cxLinkedListCreate(CxAllocator allocator, CxListComparator comparator, size_t item_size);
60 /**
61 * Allocates a linked list for storing pointers.
62 *
63 * If you want to store the elements directly in this list, use cxLinkedListCreate().
64 *
65 * @param allocator the allocator for allocating the list nodes
66 * @param comparator the comparator for the elements
67 * @return the created list
68 */
69 CxList cxPointerLinkedListCreate(CxAllocator allocator, CxListComparator comparator);
71 /**
72 * Deallocates the memory of the entire list.
73 *
74 * \attention If this is a pointer list, the memory the pointers are referring to is \em not freed.
75 *
76 * @param list the list
77 */
78 void cxLinkedListDestroy(CxList list);
80 /**
81 * Finds the node at a certain index.
82 *
83 * This function can be used to start at an arbitrary position within the list.
84 * If the search index is large than the start index, \p loc_advance must denote
85 * the location of some sort of \c next pointer (i.e. a pointer to the next node).
86 * But it is also possible that the search index is smaller than the start index
87 * (e.g. in cases where traversing a list backwards is faster) in which case
88 * \p loc_advance must denote the location of some sort of \c prev pointer
89 * (i.e. a pointer to the previous node).
90 *
91 * @param start a pointer to the start node
92 * @param start_index the start index
93 * @param loc_advance the location of the pointer to advance
94 * @param index the search index
95 * @return the node found at the specified index
96 */
97 void *cx_linked_list_at(void *start, size_t start_index, ptrdiff_t loc_advance, size_t index);
99 /**
100 * Finds the last node in a linked list.
101 *
102 * The function starts with the pointer denoted by \p begin and traverses the list
103 * along a next pointer whose location within the node struct is
104 * denoted by \p loc_next.
105 *
106 * @param begin a pointer to the begin node
107 * @param loc_next the location of the \c next pointer
108 * @return a pointer to the last node or \c NULL if \p begin is \c NULL
109 */
110 void *cx_linked_list_last(void *begin, ptrdiff_t loc_next);
112 /**
113 * Finds the predecessor of a node in case it is not linked.
114 *
115 * \remark If \p node is not contained in the list starting with \p begin, the behavior is undefined.
116 *
117 * @param begin the node where to start the search
118 * @param loc_next the location of the \c next pointer
119 * @param node the successor of the node to find
120 * @return the node or \c NULL if \p node has no predecessor
121 */
122 void *cx_linked_list_prev(void *begin, ptrdiff_t loc_next, void *node);
124 /**
125 * Adds a new node to a linked list.
126 *
127 * \remark One of the pointers \p begin and \p end may be \c NULL, but not both.
128 *
129 * @param begin a pointer to the begin node pointer (if your list has one)
130 * @param end a pointer to the end node pointer (if your list has one)
131 * @param loc_prev the location of a \c prev pointer within your node struct (negative if your struct does not have one)
132 * @param loc_next the location of a \c next pointer within your node struct (required)
133 * @param new_node a pointer to the node that shall be appended
134 */
135 void cx_linked_list_add(void **begin, void **end, ptrdiff_t loc_prev, ptrdiff_t loc_next, void *new_node);
137 /**
138 * Removes a node from the linked list.
139 *
140 * If the node to remove is the begin (resp. end) node of the list and if \p begin (resp. \p end)
141 * addresses are provided, the pointers are adjusted accordingly.
142 *
143 * The following combinations of arguments are valid (more arguments are optional):
144 * \li \p loc_next and \p loc_prev
145 * \li \p loc_next and \p begin
146 *
147 * This function returns an adjacent node according to the following rules:
148 * \li if the node has only one adjacent node, that one is returned
149 * \li otherwise, the former \c prev node is returned
150 *
151 * \remark The \c next and \c prev pointers of the removed node are cleared by this function.
152 *
153 * @param begin a pointer to the begin node pointer (optional)
154 * @param end a pointer to the end node pointer (optional)
155 * @param loc_prev the location of a \c prev pointer within your node struct (negative if your struct does not have one)
156 * @param loc_next the location of a \c next pointer within your node struct (required)
157 * @param node the node to remove
158 * @return an adjacent node or \c NULL, if this was the last node
159 */
160 void *cx_linked_list_remove(void **begin, void **end, ptrdiff_t loc_prev, ptrdiff_t loc_next, void *node);
163 /**
164 * Determines the size of a linked list starting with \p node.
165 * @param node the first node
166 * @param loc_next the location of the \c next pointer within the node struct
167 * @return the size of the list or zero if \p node is \c NULL
168 */
169 size_t cx_linked_list_size(void *node, ptrdiff_t loc_next);
171 /**
172 * Sorts a linked list based on a comparison function.
173 *
174 * This function can work with linked lists of the following structures:
175 * \code
176 * typedef struct node node;
177 * struct node {
178 * node* prev;
179 * node* next;
180 * my_payload data; // in this case set follow_ptr = 0
181 * }
182 *
183 * typedef struct ptr_node ptr_node;
184 * struct ptr_node {
185 * ptr_node* prev;
186 * ptr_node* next;
187 * my_payload* data; // in this case set follow_ptr = 1
188 * }
189 * \endcode
190 *
191 * @param begin a pointer to the begin node pointer (required)
192 * @param end a pointer to the end node pointer (optional)
193 * @param loc_prev the location of a \c prev pointer within your node struct (negative if not present)
194 * @param loc_next the location of a \c next pointer within your node struct (required)
195 * @param loc_data the location of the \c data pointer within your node struct
196 * @param follow_ptr \c false if the pointer denoted by \p loc_data shall be passed to the \p cmp_func.
197 * If \c true, the data at \p loc_data is dereferenced, assuming to be a pointer, and then passed to \p cmp_func.
198 * @param cmp_func the compare function defining the sort order
199 */
200 void cx_linked_list_sort(void **begin, void **end, ptrdiff_t loc_prev, ptrdiff_t loc_next,
201 ptrdiff_t loc_data, int follow_ptr, CxListComparator cmp_func);
204 /**
205 * Reverses the order of the nodes in a linked list.
206 *
207 * @param begin a pointer to the begin node pointer (required)
208 * @param end a pointer to the end node pointer (optional)
209 * @param loc_prev the location of a \c prev pointer within your node struct (negative if your struct does not have one)
210 * @param loc_next the location of a \c next pointer within your node struct (required)
211 */
212 void cx_linked_list_reverse(void **begin, void **end, ptrdiff_t loc_prev, ptrdiff_t loc_next);
214 #ifdef __cplusplus
215 } /* extern "C" */
216 #endif
218 #endif /* UCX_LINKED_LIST_H */
