src/cx/iterator.h

Sun, 01 May 2022 16:48:26 +0200

author
Mike Becker <universe@uap-core.de>
date
Sun, 01 May 2022 16:48:26 +0200
changeset 546
900795d59d03
parent 516
7bcea73303ce
child 551
2946e13c89a4
permissions
-rw-r--r--

#184 #170 flush at threshold test

494
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
1 /*
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
3 *
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
4 * Copyright 2021 Mike Becker, Olaf Wintermann All rights reserved.
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
5 *
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
6 * Redistribution and use in source and binary forms, with or without
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
7 * modification, are permitted provided that the following conditions are met:
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
8 *
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
9 * 1. Redistributions of source code must retain the above copyright
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
10 * notice, this list of conditions and the following disclaimer.
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
11 *
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
12 * 2. Redistributions in binary form must reproduce the above copyright
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
13 * notice, this list of conditions and the following disclaimer in the
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
14 * documentation and/or other materials provided with the distribution.
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
15 *
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
20 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
26 * POSSIBILITY OF SUCH DAMAGE.
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
27 */
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
28 /**
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
29 * \file iterator.h
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
30 * \brief Interface for iterator implementations.
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
31 * \author Mike Becker
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
32 * \author Olaf Wintermann
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
33 * \version 3.0
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
34 * \copyright 2-Clause BSD License
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
35 */
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
36
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
37 #ifndef UCX_ITERATOR_H
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
38 #define UCX_ITERATOR_H
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
39
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
40 #include "common.h"
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
41
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
42 /**
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
43 * Internal iterator struct - use CxIterator.
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
44 */
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
45 struct cx_iterator_s {
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
46 /**
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
47 * True iff the iterator points to valid data.
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
48 */
500
eb9e7bd40a8e do not hide pointers behind typedefs
Mike Becker <universe@uap-core.de>
parents: 497
diff changeset
49 bool (*valid)(struct cx_iterator_s const *) __attribute__ ((__nonnull__));
494
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
50
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
51 /**
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
52 * Returns a pointer to the current element.
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
53 */
500
eb9e7bd40a8e do not hide pointers behind typedefs
Mike Becker <universe@uap-core.de>
parents: 497
diff changeset
54 void *(*current)(struct cx_iterator_s const *) __attribute__ ((__nonnull__));
494
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
55
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
56 /**
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
57 * Advances the iterator.
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
58 */
500
eb9e7bd40a8e do not hide pointers behind typedefs
Mike Becker <universe@uap-core.de>
parents: 497
diff changeset
59 void (*next)(struct cx_iterator_s *) __attribute__ ((__nonnull__));
495
2856c74e18ba add the feature to remove items during iteration
Mike Becker <universe@uap-core.de>
parents: 494
diff changeset
60
2856c74e18ba add the feature to remove items during iteration
Mike Becker <universe@uap-core.de>
parents: 494
diff changeset
61 /**
2856c74e18ba add the feature to remove items during iteration
Mike Becker <universe@uap-core.de>
parents: 494
diff changeset
62 * Handle for the current element, if required.
2856c74e18ba add the feature to remove items during iteration
Mike Becker <universe@uap-core.de>
parents: 494
diff changeset
63 */
2856c74e18ba add the feature to remove items during iteration
Mike Becker <universe@uap-core.de>
parents: 494
diff changeset
64 void *elem_handle;
2856c74e18ba add the feature to remove items during iteration
Mike Becker <universe@uap-core.de>
parents: 494
diff changeset
65
2856c74e18ba add the feature to remove items during iteration
Mike Becker <universe@uap-core.de>
parents: 494
diff changeset
66 /**
2856c74e18ba add the feature to remove items during iteration
Mike Becker <universe@uap-core.de>
parents: 494
diff changeset
67 * Handle for the source collection, if any.
2856c74e18ba add the feature to remove items during iteration
Mike Becker <universe@uap-core.de>
parents: 494
diff changeset
68 */
2856c74e18ba add the feature to remove items during iteration
Mike Becker <universe@uap-core.de>
parents: 494
diff changeset
69 void *src_handle;
2856c74e18ba add the feature to remove items during iteration
Mike Becker <universe@uap-core.de>
parents: 494
diff changeset
70
2856c74e18ba add the feature to remove items during iteration
Mike Becker <universe@uap-core.de>
parents: 494
diff changeset
71 /**
2856c74e18ba add the feature to remove items during iteration
Mike Becker <universe@uap-core.de>
parents: 494
diff changeset
72 * If the iterator is position-aware, contains the index of the element in the underlying collection.
2856c74e18ba add the feature to remove items during iteration
Mike Becker <universe@uap-core.de>
parents: 494
diff changeset
73 * Otherwise, this field is usually uninitialized.
2856c74e18ba add the feature to remove items during iteration
Mike Becker <universe@uap-core.de>
parents: 494
diff changeset
74 */
2856c74e18ba add the feature to remove items during iteration
Mike Becker <universe@uap-core.de>
parents: 494
diff changeset
75 size_t index;
2856c74e18ba add the feature to remove items during iteration
Mike Becker <universe@uap-core.de>
parents: 494
diff changeset
76
2856c74e18ba add the feature to remove items during iteration
Mike Becker <universe@uap-core.de>
parents: 494
diff changeset
77 /**
2856c74e18ba add the feature to remove items during iteration
Mike Becker <universe@uap-core.de>
parents: 494
diff changeset
78 * Users may set this to true, if the current element shall be removed from the underlying collection
2856c74e18ba add the feature to remove items during iteration
Mike Becker <universe@uap-core.de>
parents: 494
diff changeset
79 * when the iterator advances.
2856c74e18ba add the feature to remove items during iteration
Mike Becker <universe@uap-core.de>
parents: 494
diff changeset
80 * Has no effect on iterators that are not based on a collection.
2856c74e18ba add the feature to remove items during iteration
Mike Becker <universe@uap-core.de>
parents: 494
diff changeset
81 */
2856c74e18ba add the feature to remove items during iteration
Mike Becker <universe@uap-core.de>
parents: 494
diff changeset
82 bool remove;
494
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
83 };
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
84
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
85 /**
500
eb9e7bd40a8e do not hide pointers behind typedefs
Mike Becker <universe@uap-core.de>
parents: 497
diff changeset
86 * Iterator value type.
eb9e7bd40a8e do not hide pointers behind typedefs
Mike Becker <universe@uap-core.de>
parents: 497
diff changeset
87 * An iterator points to a certain element in an (possibly unbounded) chain of elements.
eb9e7bd40a8e do not hide pointers behind typedefs
Mike Becker <universe@uap-core.de>
parents: 497
diff changeset
88 * Iterators that are based on collections (which have a defined "first" element), are supposed
eb9e7bd40a8e do not hide pointers behind typedefs
Mike Becker <universe@uap-core.de>
parents: 497
diff changeset
89 * to be "position-aware", which means that they keep track of the current index within the collection.
eb9e7bd40a8e do not hide pointers behind typedefs
Mike Becker <universe@uap-core.de>
parents: 497
diff changeset
90 *
eb9e7bd40a8e do not hide pointers behind typedefs
Mike Becker <universe@uap-core.de>
parents: 497
diff changeset
91 * @note Objects that are pointed to by an iterator are mutable through that iterator. However, if the
eb9e7bd40a8e do not hide pointers behind typedefs
Mike Becker <universe@uap-core.de>
parents: 497
diff changeset
92 * iterator is based on a collection and the underlying collection is mutated (elements added or removed),
eb9e7bd40a8e do not hide pointers behind typedefs
Mike Becker <universe@uap-core.de>
parents: 497
diff changeset
93 * the iterator becomes invalid (regardless of what cxIteratorValid() returns) and MUST be re-obtained
eb9e7bd40a8e do not hide pointers behind typedefs
Mike Becker <universe@uap-core.de>
parents: 497
diff changeset
94 * from the collection.
eb9e7bd40a8e do not hide pointers behind typedefs
Mike Becker <universe@uap-core.de>
parents: 497
diff changeset
95 */
eb9e7bd40a8e do not hide pointers behind typedefs
Mike Becker <universe@uap-core.de>
parents: 497
diff changeset
96 typedef struct cx_iterator_s CxIterator;
eb9e7bd40a8e do not hide pointers behind typedefs
Mike Becker <universe@uap-core.de>
parents: 497
diff changeset
97
eb9e7bd40a8e do not hide pointers behind typedefs
Mike Becker <universe@uap-core.de>
parents: 497
diff changeset
98 /**
494
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
99 * Checks if the iterator points to valid data.
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
100 *
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
101 * This is especially false for past-the-end iterators.
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
102 *
496
1a07e24801a9 add cx_foreach macro
Mike Becker <universe@uap-core.de>
parents: 495
diff changeset
103 * @param iter a pointer to the iterator
494
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
104 * @return true iff the iterator points to valid data
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
105 */
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
106 __attribute__ ((__nonnull__))
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
107 static inline bool cxIteratorValid(CxIterator const *iter) {
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
108 return iter->valid(iter);
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
109 }
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
110
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
111 /**
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
112 * Returns a pointer to the current element.
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
113 *
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
114 * The behavior is undefined if this iterator is invalid.
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
115 *
496
1a07e24801a9 add cx_foreach macro
Mike Becker <universe@uap-core.de>
parents: 495
diff changeset
116 * @param iter a pointer to the iterator
494
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
117 * @return a pointer to the current element
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
118 */
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
119 __attribute__ ((__nonnull__))
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
120 static inline void *cxIteratorCurrent(CxIterator const *iter) {
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
121 return iter->current(iter);
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
122 }
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
123
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
124 /**
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
125 * Advances the iterator to the next element.
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
126 *
496
1a07e24801a9 add cx_foreach macro
Mike Becker <universe@uap-core.de>
parents: 495
diff changeset
127 * @param iter a pointer to the iterator
494
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
128 */
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
129 __attribute__ ((__nonnull__))
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
130 static inline void cxIteratorNext(CxIterator *iter) {
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
131 iter->next(iter);
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
132 }
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
133
496
1a07e24801a9 add cx_foreach macro
Mike Becker <universe@uap-core.de>
parents: 495
diff changeset
134 /**
1a07e24801a9 add cx_foreach macro
Mike Becker <universe@uap-core.de>
parents: 495
diff changeset
135 * Loops over an iterator.
1a07e24801a9 add cx_foreach macro
Mike Becker <universe@uap-core.de>
parents: 495
diff changeset
136 * @param type the type of the elements
1a07e24801a9 add cx_foreach macro
Mike Becker <universe@uap-core.de>
parents: 495
diff changeset
137 * @param elem the name of the iteration variable
1a07e24801a9 add cx_foreach macro
Mike Becker <universe@uap-core.de>
parents: 495
diff changeset
138 * @param iter the iterator
1a07e24801a9 add cx_foreach macro
Mike Becker <universe@uap-core.de>
parents: 495
diff changeset
139 */
1a07e24801a9 add cx_foreach macro
Mike Becker <universe@uap-core.de>
parents: 495
diff changeset
140 #define cx_foreach(type, elem, iter) \
516
7bcea73303ce fix required cast if compiled with C++
Mike Becker <universe@uap-core.de>
parents: 500
diff changeset
141 for (type elem; cxIteratorValid(&iter) && (elem = (type)cxIteratorCurrent(&iter)) != NULL ; cxIteratorNext(&iter)) // NOLINT(bugprone-macro-parentheses)
496
1a07e24801a9 add cx_foreach macro
Mike Becker <universe@uap-core.de>
parents: 495
diff changeset
142
494
6ce8cfa10a96 add iterator interface + linked list iterator
Mike Becker <universe@uap-core.de>
parents:
diff changeset
143 #endif /* UCX_ITERATOR_H */

mercurial