1 /*
2  * Copyright (c) 2016-2017 Dmitry V. Levin <ldv@altlinux.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. The name of the author may not be used to endorse or promote products
14  *    derived from this software without specific prior written permission.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #ifdef HAVE_CONFIG_H
29 # include "config.h"
30 #endif
31 
32 #include <stdbool.h>
33 #include <stdlib.h>
34 #include <string.h>
35 #include "number_set.h"
36 #include "xmalloc.h"
37 
38 typedef unsigned int number_slot_t;
39 #define BITS_PER_SLOT (sizeof(number_slot_t) * 8)
40 
41 struct number_set {
42 	number_slot_t *vec;
43 	unsigned int nslots;
44 	bool not;
45 };
46 
47 static void
number_setbit(const unsigned int i,number_slot_t * const vec)48 number_setbit(const unsigned int i, number_slot_t *const vec)
49 {
50 	vec[i / BITS_PER_SLOT] |= (number_slot_t) 1 << (i % BITS_PER_SLOT);
51 }
52 
53 static bool
number_isset(const unsigned int i,const number_slot_t * const vec)54 number_isset(const unsigned int i, const number_slot_t *const vec)
55 {
56 	return vec[i / BITS_PER_SLOT] & ((number_slot_t) 1 << (i % BITS_PER_SLOT));
57 }
58 
59 static void
reallocate_number_set(struct number_set * const set,const unsigned int new_nslots)60 reallocate_number_set(struct number_set *const set, const unsigned int new_nslots)
61 {
62 	if (new_nslots <= set->nslots)
63 		return;
64 	set->vec = xreallocarray(set->vec, new_nslots, sizeof(*set->vec));
65 	memset(set->vec + set->nslots, 0,
66 	       sizeof(*set->vec) * (new_nslots - set->nslots));
67 	set->nslots = new_nslots;
68 }
69 
70 bool
number_set_array_is_empty(const struct number_set * const set,const unsigned int idx)71 number_set_array_is_empty(const struct number_set *const set,
72 			  const unsigned int idx)
73 {
74 	return !(set && (set[idx].nslots || set[idx].not));
75 }
76 
77 bool
is_number_in_set(const unsigned int number,const struct number_set * const set)78 is_number_in_set(const unsigned int number, const struct number_set *const set)
79 {
80 	return set && ((number / BITS_PER_SLOT < set->nslots)
81 		&& number_isset(number, set->vec)) ^ set->not;
82 }
83 
84 bool
is_number_in_set_array(const unsigned int number,const struct number_set * const set,const unsigned int idx)85 is_number_in_set_array(const unsigned int number, const struct number_set *const set,
86 		       const unsigned int idx)
87 {
88 	return set && ((number / BITS_PER_SLOT < set[idx].nslots)
89 		&& number_isset(number, set[idx].vec)) ^ set[idx].not;
90 }
91 
92 void
add_number_to_set(const unsigned int number,struct number_set * const set)93 add_number_to_set(const unsigned int number, struct number_set *const set)
94 {
95 	reallocate_number_set(set, number / BITS_PER_SLOT + 1);
96 	number_setbit(number, set->vec);
97 }
98 
99 void
add_number_to_set_array(const unsigned int number,struct number_set * const set,const unsigned int idx)100 add_number_to_set_array(const unsigned int number, struct number_set *const set,
101 			const unsigned int idx)
102 {
103 	add_number_to_set(number, &set[idx]);
104 }
105 
106 void
clear_number_set_array(struct number_set * const set,const unsigned int nmemb)107 clear_number_set_array(struct number_set *const set, const unsigned int nmemb)
108 {
109 	unsigned int i;
110 
111 	for (i = 0; i < nmemb; ++i) {
112 		if (set[i].nslots)
113 			memset(set[i].vec, 0,
114 			       sizeof(*set[i].vec) * set[i].nslots);
115 		set[i].not = false;
116 	}
117 }
118 
119 void
invert_number_set_array(struct number_set * const set,const unsigned int nmemb)120 invert_number_set_array(struct number_set *const set, const unsigned int nmemb)
121 {
122 	unsigned int i;
123 
124 	for (i = 0; i < nmemb; ++i)
125 		set[i].not = !set[i].not;
126 }
127 
128 struct number_set *
alloc_number_set_array(const unsigned int nmemb)129 alloc_number_set_array(const unsigned int nmemb)
130 {
131 	return xcalloc(nmemb, sizeof(struct number_set));
132 }
133 
134 void
free_number_set_array(struct number_set * const set,unsigned int nmemb)135 free_number_set_array(struct number_set *const set, unsigned int nmemb)
136 {
137 	while (nmemb) {
138 		--nmemb;
139 		free(set[nmemb].vec);
140 		set[nmemb].vec = NULL;
141 	}
142 	free(set);
143 }
144