toaruos/kernel/ds/bitset.c

66 lines
1.3 KiB
C

/* vim: tabstop=4 shiftwidth=4 noexpandtab
* This file is part of ToaruOS and is released under the terms
* of the NCSA / University of Illinois License - see LICENSE.md
* Copyright (C) 2015-2018 K. Lange
* 2015 Dale Weiler
*/
#include <kernel/bitset.h>
#define CEIL(NUMBER, BASE) \
(((NUMBER) + (BASE) - 1) & ~((BASE) - 1))
#define iom \
size_t index = bit >> 3; \
bit = bit - index * 8; \
size_t offset = bit & 7; \
size_t mask = 1 << offset;
void bitset_init(bitset_t *set, size_t size) {
set->size = CEIL(size, 8);
set->data = malloc(set->size);
memset(set->data, 0, set->size);
}
void bitset_free(bitset_t *set) {
free(set->data);
}
static void bitset_resize(bitset_t *set, size_t size) {
if (set->size >= size) {
return;
}
set->data = realloc(set->data, size);
memset(set->data + set->size, 0, size - set->size);
set->size = size;
}
void bitset_set(bitset_t *set, size_t bit) {
iom;
if (set->size <= index) {
bitset_resize(set, set->size << 1);
}
set->data[index] |= mask;
}
int bitset_ffub(bitset_t *set) {
for (size_t i = 0; i < set->size * 8; i++) {
if (bitset_test(set, i)) {
continue;
}
return (int)i;
}
return -1;
}
void bitset_clear(bitset_t *set, size_t bit) {
iom;
set->data[index] &= ~mask;
}
int bitset_test(bitset_t *set, size_t bit) {
iom;
return !!(mask & set->data[index]);
}