Tue, 05 Oct 2021 13:03:45 +0200
add special linked list implementation for storing pointers
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
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25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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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 size_t cxLinkedListRecalculateSize(CxList list);
83 /**
84 * Finds the node at a certain index.
85 *
86 * This function can be used to start at an arbitrary position within the list.
87 * If the search index is large than the start index, \p loc_advance must denote
88 * the location of some sort of \c next pointer (i.e. a pointer to the next node).
89 * But it is also possible that the search index is smaller than the start index
90 * (e.g. in cases where traversing a list backwards is faster) in which case
91 * \p loc_advance must denote the location of some sort of \c prev pointer
92 * (i.e. a pointer to the previous node).
93 *
94 * @param start a pointer to the start node
95 * @param start_index the start index
96 * @param loc_advance the location of the pointer to advance
97 * @param index the search index
98 * @return the node found at the specified index
99 */
100 void *cx_linked_list_at(void *start, size_t start_index, ptrdiff_t loc_advance, size_t index);
102 /**
103 * Finds the last node in a linked list.
104 *
105 * The function starts with the pointer denoted by \p begin and traverses the list
106 * along a next pointer whose location within the node struct is
107 * denoted by \p loc_next.
108 *
109 * @param begin a pointer to the begin node
110 * @param loc_next the location of the \c next pointer
111 * @return a pointer to the last node or \c NULL if \p begin is \c NULL
112 */
113 void *cx_linked_list_last(void *begin, ptrdiff_t loc_next);
115 /**
116 * Adds a new node to a linked list.
117 *
118 * \remark One of the pointers \p begin and \p end may be \c NULL, but not both.
119 *
120 * @param begin a pointer to the begin node pointer (if your list has one)
121 * @param end a pointer to the end node pointer (if your list has one)
122 * @param loc_prev the location of a \c prev pointer within your node struct (negative if your struct does not have one)
123 * @param loc_next the location of a \c next pointer within your node struct (negative if your struct does not have one)
124 * @param new_node a pointer to the node that shall be appended
125 */
126 void cx_linked_list_add(void **begin, void **end, ptrdiff_t loc_prev, ptrdiff_t loc_next, void *new_node);
128 #ifdef __cplusplus
129 } /* extern "C" */
130 #endif
132 #endif /* UCX_LINKED_LIST_H */